#ifndef BLUR_FUNCTIONS_H #define BLUR_FUNCTIONS_H ///////////////////////////////// MIT LICENSE //////////////////////////////// // Copyright (C) 2014 TroggleMonkey // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to // deal in the Software without restriction, including without limitation the // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or // sell copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS // IN THE SOFTWARE. ///////////////////////////////// DESCRIPTION //////////////////////////////// // This file provides reusable one-pass and separable (two-pass) blurs. // Requires: All blurs share these requirements (dxdy requirement is split): // 1.) All requirements of gamma-management.h must be satisfied! // 2.) filter_linearN must == "true" in your .cgp preset unless // you're using tex2DblurNresize at 1x scale. // 3.) mipmap_inputN must == "true" in your .cgp preset if // IN.output_size < IN.video_size. // 4.) IN.output_size == IN.video_size / pow(2, M), where M is some // positive integer. tex2Dblur*resize can resize arbitrarily // (and the blur will be done after resizing), but arbitrary // resizes "fail" with other blurs due to the way they mix // static weights with bilinear sample exploitation. // 5.) In general, dxdy should contain the uv pixel spacing: // dxdy = (IN.video_size/IN.output_size)/IN.texture_size // 6.) For separable blurs (tex2DblurNresize and tex2DblurNfast), // zero out the dxdy component in the unblurred dimension: // dxdy = float2(dxdy.x, 0.0) or float2(0.0, dxdy.y) // Many blurs share these requirements: // 1.) One-pass blurs require scale_xN == scale_yN or scales > 1.0, // or they will blur more in the lower-scaled dimension. // 2.) One-pass shared sample blurs require ddx(), ddy(), and // tex2Dlod() to be supported by the current Cg profile, and // the drivers must support high-quality derivatives. // 3.) One-pass shared sample blurs require: // tex_uv.w == log2(IN.video_size/IN.output_size).y; // Non-wrapper blurs share this requirement: // 1.) sigma is the intended standard deviation of the blur // Wrapper blurs share this requirement, which is automatically // met (unless OVERRIDE_BLUR_STD_DEVS is #defined; see below): // 1.) blurN_std_dev must be global static const float values // specifying standard deviations for Nx blurs in units // of destination pixels // Optional: 1.) The including file (or an earlier included file) may // optionally #define USE_BINOMIAL_BLUR_STD_DEVS to replace // default standard deviations with those matching a binomial // distribution. (See below for details/properties.) // 2.) The including file (or an earlier included file) may // optionally #define OVERRIDE_BLUR_STD_DEVS and override: // static const float blur3_std_dev // static const float blur4_std_dev // static const float blur5_std_dev // static const float blur6_std_dev // static const float blur7_std_dev // static const float blur8_std_dev // static const float blur9_std_dev // static const float blur10_std_dev // static const float blur11_std_dev // static const float blur12_std_dev // static const float blur17_std_dev // static const float blur25_std_dev // static const float blur31_std_dev // static const float blur43_std_dev // 3.) The including file (or an earlier included file) may // optionally #define OVERRIDE_ERROR_BLURRING and override: // static const float error_blurring // This tuning value helps mitigate weighting errors from one- // pass shared-sample blurs sharing bilinear samples between // fragments. Values closer to 0.0 have "correct" blurriness // but allow more artifacts, and values closer to 1.0 blur away // artifacts by sampling closer to halfway between texels. // UPDATE 6/21/14: The above static constants may now be overridden // by non-static uniform constants. This permits exposing blur // standard deviations as runtime GUI shader parameters. However, // using them keeps weights from being statically computed, and the // speed hit depends on the blur: On my machine, uniforms kill over // 53% of the framerate with tex2Dblur12x12shared, but they only // drop the framerate by about 18% with tex2Dblur11fast. // Quality and Performance Comparisons: // For the purposes of the following discussion, "no sRGB" means // GAMMA_ENCODE_EVERY_FBO is #defined, and "sRGB" means it isn't. // 1.) tex2DblurNfast is always faster than tex2DblurNresize. // 2.) tex2DblurNresize functions are the only ones that can arbitrarily resize // well, because they're the only ones that don't exploit bilinear samples. // This also means they're the only functions which can be truly gamma- // correct without linear (or sRGB FBO) input, but only at 1x scale. // 3.) One-pass shared sample blurs only have a speed advantage without sRGB. // They also have some inaccuracies due to their shared-[bilinear-]sample // design, which grow increasingly bothersome for smaller blurs and higher- // frequency source images (relative to their resolution). I had high // hopes for them, but their most realistic use case is limited to quickly // reblurring an already blurred input at full resolution. Otherwise: // a.) If you're blurring a low-resolution source, you want a better blur. // b.) If you're blurring a lower mipmap, you want a better blur. // c.) If you're blurring a high-resolution, high-frequency source, you // want a better blur. // 4.) The one-pass blurs without shared samples grow slower for larger blurs, // but they're competitive with separable blurs at 5x5 and smaller, and // even tex2Dblur7x7 isn't bad if you're wanting to conserve passes. // Here are some framerates from a GeForce 8800GTS. The first pass resizes to // viewport size (4x in this test) and linearizes for sRGB codepaths, and the // remaining passes perform 6 full blurs. Mipmapped tests are performed at the // same scale, so they just measure the cost of mipmapping each FBO (only every // other FBO is mipmapped for separable blurs, to mimic realistic usage). // Mipmap Neither sRGB+Mipmap sRGB Function // 76.0 92.3 131.3 193.7 tex2Dblur3fast // 63.2 74.4 122.4 175.5 tex2Dblur3resize // 93.7 121.2 159.3 263.2 tex2Dblur3x3 // 59.7 68.7 115.4 162.1 tex2Dblur3x3resize // 63.2 74.4 122.4 175.5 tex2Dblur5fast // 49.3 54.8 100.0 132.7 tex2Dblur5resize // 59.7 68.7 115.4 162.1 tex2Dblur5x5 // 64.9 77.2 99.1 137.2 tex2Dblur6x6shared // 55.8 63.7 110.4 151.8 tex2Dblur7fast // 39.8 43.9 83.9 105.8 tex2Dblur7resize // 40.0 44.2 83.2 104.9 tex2Dblur7x7 // 56.4 65.5 71.9 87.9 tex2Dblur8x8shared // 49.3 55.1 99.9 132.5 tex2Dblur9fast // 33.3 36.2 72.4 88.0 tex2Dblur9resize // 27.8 29.7 61.3 72.2 tex2Dblur9x9 // 37.2 41.1 52.6 60.2 tex2Dblur10x10shared // 44.4 49.5 91.3 117.8 tex2Dblur11fast // 28.8 30.8 63.6 75.4 tex2Dblur11resize // 33.6 36.5 40.9 45.5 tex2Dblur12x12shared // TODO: Fill in benchmarks for new untested blurs. // tex2Dblur17fast // tex2Dblur25fast // tex2Dblur31fast // tex2Dblur43fast // tex2Dblur3x3resize ///////////////////////////// SETTINGS MANAGEMENT //////////////////////////// // Set static standard deviations, but allow users to override them with their // own constants (even non-static uniforms if they're okay with the speed hit): #ifndef OVERRIDE_BLUR_STD_DEVS // blurN_std_dev values are specified in terms of dxdy strides. #ifdef USE_BINOMIAL_BLUR_STD_DEVS // By request, we can define standard deviations corresponding to a // binomial distribution with p = 0.5 (related to Pascal's triangle). // This distribution works such that blurring multiple times should // have the same result as a single larger blur. These values are // larger than default for blurs up to 6x and smaller thereafter. static const float blur3_std_dev = 0.84931640625; static const float blur4_std_dev = 0.84931640625; static const float blur5_std_dev = 1.0595703125; static const float blur6_std_dev = 1.06591796875; static const float blur7_std_dev = 1.17041015625; static const float blur8_std_dev = 1.1720703125; static const float blur9_std_dev = 1.2259765625; static const float blur10_std_dev = 1.21982421875; static const float blur11_std_dev = 1.25361328125; static const float blur12_std_dev = 1.2423828125; static const float blur17_std_dev = 1.27783203125; static const float blur25_std_dev = 1.2810546875; static const float blur31_std_dev = 1.28125; static const float blur43_std_dev = 1.28125; #else // The defaults are the largest values that keep the largest unused // blur term on each side <= 1.0/256.0. (We could get away with more // or be more conservative, but this compromise is pretty reasonable.) static const float blur3_std_dev = 0.62666015625; static const float blur4_std_dev = 0.66171875; static const float blur5_std_dev = 0.9845703125; static const float blur6_std_dev = 1.02626953125; static const float blur7_std_dev = 1.36103515625; static const float blur8_std_dev = 1.4080078125; static const float blur9_std_dev = 1.7533203125; static const float blur10_std_dev = 1.80478515625; static const float blur11_std_dev = 2.15986328125; static const float blur12_std_dev = 2.215234375; static const float blur17_std_dev = 3.45535583496; static const float blur25_std_dev = 5.3409576416; static const float blur31_std_dev = 6.86488037109; static const float blur43_std_dev = 10.1852050781; #endif // USE_BINOMIAL_BLUR_STD_DEVS #endif // OVERRIDE_BLUR_STD_DEVS #ifndef OVERRIDE_ERROR_BLURRING // error_blurring should be in [0.0, 1.0]. Higher values reduce ringing // in shared-sample blurs but increase blurring and feature shifting. static const float error_blurring = 0.5; #endif ////////////////////////////////// INCLUDES ////////////////////////////////// // gamma-management.h relies on pass-specific settings to guide its behavior: // FIRST_PASS, LAST_PASS, GAMMA_ENCODE_EVERY_FBO, etc. See it for details. #include "gamma-management.fxh" #include "quad-pixel-communication.fxh" #include "special-functions.fxh" /////////////////////////////////// HELPERS ////////////////////////////////// float4 uv2_to_uv4(float2 tex_uv) { // Make a float2 uv offset safe for adding to float4 tex2Dlod coords: return float4(tex_uv, 0.0, 0.0); } // Make a length squared helper macro (for usage with static constants): #define LENGTH_SQ(vec) (dot(vec, vec)) float get_fast_gaussian_weight_sum_inv(const float sigma) { // We can use the Gaussian integral to calculate the asymptotic weight for // the center pixel. Since the unnormalized center pixel weight is 1.0, // the normalized weight is the same as the weight sum inverse. Given a // large enough blur (9+), the asymptotic weight sum is close and faster: // center_weight = 0.5 * // (erf(0.5/(sigma*sqrt(2.0))) - erf(-0.5/(sigma*sqrt(2.0)))) // erf(-x) == -erf(x), so we get 0.5 * (2.0 * erf(blah blah)): // However, we can get even faster results with curve-fitting. These are // also closer than the asymptotic results, because they were constructed // from 64 blurs sizes from [3, 131) and 255 equally-spaced sigmas from // (0, blurN_std_dev), so the results for smaller sigmas are biased toward // smaller blurs. The max error is 0.0031793913. // Relative FPS: 134.3 with erf, 135.8 with curve-fitting. //static const float temp = 0.5/sqrt(2.0); //return erf(temp/sigma); return min(exp(exp(0.348348412457428/ (sigma - 0.0860587260734721))), 0.399334576340352/sigma); } //////////////////// ARBITRARILY RESIZABLE SEPARABLE BLURS /////////////////// float3 tex2Dblur11resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 1D 11x Gaussian blurred texture lookup using a 11-tap blur. // It may be mipmapped depending on settings and dxdy. // Calculate Gaussian blur kernel weights and a normalization factor for // distances of 0-4, ignoring constant factors (since we're normalizing). const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3 + w4 + w5)); // Statically normalize weights, sum weighted samples, and return. Blurs are // currently optimized for dynamic weights. float3 sum = 0.0.xxx; sum += w5 * tex2D_linearize(tex, tex_uv - 5.0 * dxdy).rgb; sum += w4 * tex2D_linearize(tex, tex_uv - 4.0 * dxdy).rgb; sum += w3 * tex2D_linearize(tex, tex_uv - 3.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv - 2.0 * dxdy).rgb; sum += w1 * tex2D_linearize(tex, tex_uv - 1.0 * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1 * tex2D_linearize(tex, tex_uv + 1.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv + 2.0 * dxdy).rgb; sum += w3 * tex2D_linearize(tex, tex_uv + 3.0 * dxdy).rgb; sum += w4 * tex2D_linearize(tex, tex_uv + 4.0 * dxdy).rgb; sum += w5 * tex2D_linearize(tex, tex_uv + 5.0 * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur9resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 1D 9x Gaussian blurred texture lookup using a 9-tap blur. // It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3 + w4)); // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w4 * tex2D_linearize(tex, tex_uv - 4.0 * dxdy).rgb; sum += w3 * tex2D_linearize(tex, tex_uv - 3.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv - 2.0 * dxdy).rgb; sum += w1 * tex2D_linearize(tex, tex_uv - 1.0 * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1 * tex2D_linearize(tex, tex_uv + 1.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv + 2.0 * dxdy).rgb; sum += w3 * tex2D_linearize(tex, tex_uv + 3.0 * dxdy).rgb; sum += w4 * tex2D_linearize(tex, tex_uv + 4.0 * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur7resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 1D 7x Gaussian blurred texture lookup using a 7-tap blur. // It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3)); // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w3 * tex2D_linearize(tex, tex_uv - 3.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv - 2.0 * dxdy).rgb; sum += w1 * tex2D_linearize(tex, tex_uv - 1.0 * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1 * tex2D_linearize(tex, tex_uv + 1.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv + 2.0 * dxdy).rgb; sum += w3 * tex2D_linearize(tex, tex_uv + 3.0 * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur5resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 1D 5x Gaussian blurred texture lookup using a 5-tap blur. // It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2)); // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w2 * tex2D_linearize(tex, tex_uv - 2.0 * dxdy).rgb; sum += w1 * tex2D_linearize(tex, tex_uv - 1.0 * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1 * tex2D_linearize(tex, tex_uv + 1.0 * dxdy).rgb; sum += w2 * tex2D_linearize(tex, tex_uv + 2.0 * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur3resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 1D 3x Gaussian blurred texture lookup using a 3-tap blur. // It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * w1); // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w1 * tex2D_linearize(tex, tex_uv - 1.0 * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1 * tex2D_linearize(tex, tex_uv + 1.0 * dxdy).rgb; return sum * weight_sum_inv; } /////////////////////////// FAST SEPARABLE BLURS /////////////////////////// float3 tex2Dblur11fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: 1.) Global requirements must be met (see file description). // 2.) filter_linearN must = "true" in your .cgp file. // 3.) For gamma-correct bilinear filtering, global // gamma_aware_bilinear == true (from gamma-management.h) // Returns: A 1D 11x Gaussian blurred texture lookup using 6 linear // taps. It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3 + w4 + w5)); // Calculate combined weights and linear sample ratios between texel pairs. // The center texel (with weight w0) is used twice, so halve its weight. const float w01 = w0 * 0.5 + w1; const float w23 = w2 + w3; const float w45 = w4 + w5; const float w01_ratio = w1/w01; const float w23_ratio = w3/w23; const float w45_ratio = w5/w45; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w45 * tex2D_linearize(tex, tex_uv - (4.0 + w45_ratio) * dxdy).rgb; sum += w23 * tex2D_linearize(tex, tex_uv - (2.0 + w23_ratio) * dxdy).rgb; sum += w01 * tex2D_linearize(tex, tex_uv - w01_ratio * dxdy).rgb; sum += w01 * tex2D_linearize(tex, tex_uv + w01_ratio * dxdy).rgb; sum += w23 * tex2D_linearize(tex, tex_uv + (2.0 + w23_ratio) * dxdy).rgb; sum += w45 * tex2D_linearize(tex, tex_uv + (4.0 + w45_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur9fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 9x Gaussian blurred texture lookup using 1 nearest // neighbor and 4 linear taps. It may be mipmapped depending // on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3 + w4)); // Calculate combined weights and linear sample ratios between texel pairs. const float w12 = w1 + w2; const float w34 = w3 + w4; const float w12_ratio = w2/w12; const float w34_ratio = w4/w34; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w34 * tex2D_linearize(tex, tex_uv - (3.0 + w34_ratio) * dxdy).rgb; sum += w12 * tex2D_linearize(tex, tex_uv - (1.0 + w12_ratio) * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w12 * tex2D_linearize(tex, tex_uv + (1.0 + w12_ratio) * dxdy).rgb; sum += w34 * tex2D_linearize(tex, tex_uv + (3.0 + w34_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur7fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 7x Gaussian blurred texture lookup using 4 linear // taps. It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2 + w3)); // Calculate combined weights and linear sample ratios between texel pairs. // The center texel (with weight w0) is used twice, so halve its weight. const float w01 = w0 * 0.5 + w1; const float w23 = w2 + w3; const float w01_ratio = w1/w01; const float w23_ratio = w3/w23; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w23 * tex2D_linearize(tex, tex_uv - (2.0 + w23_ratio) * dxdy).rgb; sum += w01 * tex2D_linearize(tex, tex_uv - w01_ratio * dxdy).rgb; sum += w01 * tex2D_linearize(tex, tex_uv + w01_ratio * dxdy).rgb; sum += w23 * tex2D_linearize(tex, tex_uv + (2.0 + w23_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur5fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 5x Gaussian blurred texture lookup using 1 nearest // neighbor and 2 linear taps. It may be mipmapped depending // on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * (w1 + w2)); // Calculate combined weights and linear sample ratios between texel pairs. const float w12 = w1 + w2; const float w12_ratio = w2/w12; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w12 * tex2D_linearize(tex, tex_uv - (1.0 + w12_ratio) * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w12 * tex2D_linearize(tex, tex_uv + (1.0 + w12_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur3fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 3x Gaussian blurred texture lookup using 2 linear // taps. It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float weight_sum_inv = 1.0 / (w0 + 2.0 * w1); // Calculate combined weights and linear sample ratios between texel pairs. // The center texel (with weight w0) is used twice, so halve its weight. const float w01 = w0 * 0.5 + w1; const float w01_ratio = w1/w01; // Weights for all samples are the same, so just average them: return 0.5 * ( tex2D_linearize(tex, tex_uv - w01_ratio * dxdy).rgb + tex2D_linearize(tex, tex_uv + w01_ratio * dxdy).rgb); } //////////////////////////// HUGE SEPARABLE BLURS //////////////////////////// // Huge separable blurs come only in "fast" versions. float3 tex2Dblur43fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 43x Gaussian blurred texture lookup using 22 linear // taps. It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float w6 = exp(-36.0 * denom_inv); const float w7 = exp(-49.0 * denom_inv); const float w8 = exp(-64.0 * denom_inv); const float w9 = exp(-81.0 * denom_inv); const float w10 = exp(-100.0 * denom_inv); const float w11 = exp(-121.0 * denom_inv); const float w12 = exp(-144.0 * denom_inv); const float w13 = exp(-169.0 * denom_inv); const float w14 = exp(-196.0 * denom_inv); const float w15 = exp(-225.0 * denom_inv); const float w16 = exp(-256.0 * denom_inv); const float w17 = exp(-289.0 * denom_inv); const float w18 = exp(-324.0 * denom_inv); const float w19 = exp(-361.0 * denom_inv); const float w20 = exp(-400.0 * denom_inv); const float w21 = exp(-441.0 * denom_inv); //const float weight_sum_inv = 1.0 / // (w0 + 2.0 * (w1 + w2 + w3 + w4 + w5 + w6 + w7 + w8 + w9 + w10 + w11 + // w12 + w13 + w14 + w15 + w16 + w17 + w18 + w19 + w20 + w21)); const float weight_sum_inv = get_fast_gaussian_weight_sum_inv(sigma); // Calculate combined weights and linear sample ratios between texel pairs. // The center texel (with weight w0) is used twice, so halve its weight. const float w0_1 = w0 * 0.5 + w1; const float w2_3 = w2 + w3; const float w4_5 = w4 + w5; const float w6_7 = w6 + w7; const float w8_9 = w8 + w9; const float w10_11 = w10 + w11; const float w12_13 = w12 + w13; const float w14_15 = w14 + w15; const float w16_17 = w16 + w17; const float w18_19 = w18 + w19; const float w20_21 = w20 + w21; const float w0_1_ratio = w1/w0_1; const float w2_3_ratio = w3/w2_3; const float w4_5_ratio = w5/w4_5; const float w6_7_ratio = w7/w6_7; const float w8_9_ratio = w9/w8_9; const float w10_11_ratio = w11/w10_11; const float w12_13_ratio = w13/w12_13; const float w14_15_ratio = w15/w14_15; const float w16_17_ratio = w17/w16_17; const float w18_19_ratio = w19/w18_19; const float w20_21_ratio = w21/w20_21; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w20_21 * tex2D_linearize(tex, tex_uv - (20.0 + w20_21_ratio) * dxdy).rgb; sum += w18_19 * tex2D_linearize(tex, tex_uv - (18.0 + w18_19_ratio) * dxdy).rgb; sum += w16_17 * tex2D_linearize(tex, tex_uv - (16.0 + w16_17_ratio) * dxdy).rgb; sum += w14_15 * tex2D_linearize(tex, tex_uv - (14.0 + w14_15_ratio) * dxdy).rgb; sum += w12_13 * tex2D_linearize(tex, tex_uv - (12.0 + w12_13_ratio) * dxdy).rgb; sum += w10_11 * tex2D_linearize(tex, tex_uv - (10.0 + w10_11_ratio) * dxdy).rgb; sum += w8_9 * tex2D_linearize(tex, tex_uv - (8.0 + w8_9_ratio) * dxdy).rgb; sum += w6_7 * tex2D_linearize(tex, tex_uv - (6.0 + w6_7_ratio) * dxdy).rgb; sum += w4_5 * tex2D_linearize(tex, tex_uv - (4.0 + w4_5_ratio) * dxdy).rgb; sum += w2_3 * tex2D_linearize(tex, tex_uv - (2.0 + w2_3_ratio) * dxdy).rgb; sum += w0_1 * tex2D_linearize(tex, tex_uv - w0_1_ratio * dxdy).rgb; sum += w0_1 * tex2D_linearize(tex, tex_uv + w0_1_ratio * dxdy).rgb; sum += w2_3 * tex2D_linearize(tex, tex_uv + (2.0 + w2_3_ratio) * dxdy).rgb; sum += w4_5 * tex2D_linearize(tex, tex_uv + (4.0 + w4_5_ratio) * dxdy).rgb; sum += w6_7 * tex2D_linearize(tex, tex_uv + (6.0 + w6_7_ratio) * dxdy).rgb; sum += w8_9 * tex2D_linearize(tex, tex_uv + (8.0 + w8_9_ratio) * dxdy).rgb; sum += w10_11 * tex2D_linearize(tex, tex_uv + (10.0 + w10_11_ratio) * dxdy).rgb; sum += w12_13 * tex2D_linearize(tex, tex_uv + (12.0 + w12_13_ratio) * dxdy).rgb; sum += w14_15 * tex2D_linearize(tex, tex_uv + (14.0 + w14_15_ratio) * dxdy).rgb; sum += w16_17 * tex2D_linearize(tex, tex_uv + (16.0 + w16_17_ratio) * dxdy).rgb; sum += w18_19 * tex2D_linearize(tex, tex_uv + (18.0 + w18_19_ratio) * dxdy).rgb; sum += w20_21 * tex2D_linearize(tex, tex_uv + (20.0 + w20_21_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur31fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 31x Gaussian blurred texture lookup using 16 linear // taps. It may be mipmapped depending on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float w6 = exp(-36.0 * denom_inv); const float w7 = exp(-49.0 * denom_inv); const float w8 = exp(-64.0 * denom_inv); const float w9 = exp(-81.0 * denom_inv); const float w10 = exp(-100.0 * denom_inv); const float w11 = exp(-121.0 * denom_inv); const float w12 = exp(-144.0 * denom_inv); const float w13 = exp(-169.0 * denom_inv); const float w14 = exp(-196.0 * denom_inv); const float w15 = exp(-225.0 * denom_inv); //const float weight_sum_inv = 1.0 / // (w0 + 2.0 * (w1 + w2 + w3 + w4 + w5 + w6 + w7 + w8 + // w9 + w10 + w11 + w12 + w13 + w14 + w15)); const float weight_sum_inv = get_fast_gaussian_weight_sum_inv(sigma); // Calculate combined weights and linear sample ratios between texel pairs. // The center texel (with weight w0) is used twice, so halve its weight. const float w0_1 = w0 * 0.5 + w1; const float w2_3 = w2 + w3; const float w4_5 = w4 + w5; const float w6_7 = w6 + w7; const float w8_9 = w8 + w9; const float w10_11 = w10 + w11; const float w12_13 = w12 + w13; const float w14_15 = w14 + w15; const float w0_1_ratio = w1/w0_1; const float w2_3_ratio = w3/w2_3; const float w4_5_ratio = w5/w4_5; const float w6_7_ratio = w7/w6_7; const float w8_9_ratio = w9/w8_9; const float w10_11_ratio = w11/w10_11; const float w12_13_ratio = w13/w12_13; const float w14_15_ratio = w15/w14_15; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w14_15 * tex2D_linearize(tex, tex_uv - (14.0 + w14_15_ratio) * dxdy).rgb; sum += w12_13 * tex2D_linearize(tex, tex_uv - (12.0 + w12_13_ratio) * dxdy).rgb; sum += w10_11 * tex2D_linearize(tex, tex_uv - (10.0 + w10_11_ratio) * dxdy).rgb; sum += w8_9 * tex2D_linearize(tex, tex_uv - (8.0 + w8_9_ratio) * dxdy).rgb; sum += w6_7 * tex2D_linearize(tex, tex_uv - (6.0 + w6_7_ratio) * dxdy).rgb; sum += w4_5 * tex2D_linearize(tex, tex_uv - (4.0 + w4_5_ratio) * dxdy).rgb; sum += w2_3 * tex2D_linearize(tex, tex_uv - (2.0 + w2_3_ratio) * dxdy).rgb; sum += w0_1 * tex2D_linearize(tex, tex_uv - w0_1_ratio * dxdy).rgb; sum += w0_1 * tex2D_linearize(tex, tex_uv + w0_1_ratio * dxdy).rgb; sum += w2_3 * tex2D_linearize(tex, tex_uv + (2.0 + w2_3_ratio) * dxdy).rgb; sum += w4_5 * tex2D_linearize(tex, tex_uv + (4.0 + w4_5_ratio) * dxdy).rgb; sum += w6_7 * tex2D_linearize(tex, tex_uv + (6.0 + w6_7_ratio) * dxdy).rgb; sum += w8_9 * tex2D_linearize(tex, tex_uv + (8.0 + w8_9_ratio) * dxdy).rgb; sum += w10_11 * tex2D_linearize(tex, tex_uv + (10.0 + w10_11_ratio) * dxdy).rgb; sum += w12_13 * tex2D_linearize(tex, tex_uv + (12.0 + w12_13_ratio) * dxdy).rgb; sum += w14_15 * tex2D_linearize(tex, tex_uv + (14.0 + w14_15_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur25fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 25x Gaussian blurred texture lookup using 1 nearest // neighbor and 12 linear taps. It may be mipmapped depending // on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float w6 = exp(-36.0 * denom_inv); const float w7 = exp(-49.0 * denom_inv); const float w8 = exp(-64.0 * denom_inv); const float w9 = exp(-81.0 * denom_inv); const float w10 = exp(-100.0 * denom_inv); const float w11 = exp(-121.0 * denom_inv); const float w12 = exp(-144.0 * denom_inv); //const float weight_sum_inv = 1.0 / (w0 + 2.0 * ( // w1 + w2 + w3 + w4 + w5 + w6 + w7 + w8 + w9 + w10 + w11 + w12)); const float weight_sum_inv = get_fast_gaussian_weight_sum_inv(sigma); // Calculate combined weights and linear sample ratios between texel pairs. const float w1_2 = w1 + w2; const float w3_4 = w3 + w4; const float w5_6 = w5 + w6; const float w7_8 = w7 + w8; const float w9_10 = w9 + w10; const float w11_12 = w11 + w12; const float w1_2_ratio = w2/w1_2; const float w3_4_ratio = w4/w3_4; const float w5_6_ratio = w6/w5_6; const float w7_8_ratio = w8/w7_8; const float w9_10_ratio = w10/w9_10; const float w11_12_ratio = w12/w11_12; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w11_12 * tex2D_linearize(tex, tex_uv - (11.0 + w11_12_ratio) * dxdy).rgb; sum += w9_10 * tex2D_linearize(tex, tex_uv - (9.0 + w9_10_ratio) * dxdy).rgb; sum += w7_8 * tex2D_linearize(tex, tex_uv - (7.0 + w7_8_ratio) * dxdy).rgb; sum += w5_6 * tex2D_linearize(tex, tex_uv - (5.0 + w5_6_ratio) * dxdy).rgb; sum += w3_4 * tex2D_linearize(tex, tex_uv - (3.0 + w3_4_ratio) * dxdy).rgb; sum += w1_2 * tex2D_linearize(tex, tex_uv - (1.0 + w1_2_ratio) * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1_2 * tex2D_linearize(tex, tex_uv + (1.0 + w1_2_ratio) * dxdy).rgb; sum += w3_4 * tex2D_linearize(tex, tex_uv + (3.0 + w3_4_ratio) * dxdy).rgb; sum += w5_6 * tex2D_linearize(tex, tex_uv + (5.0 + w5_6_ratio) * dxdy).rgb; sum += w7_8 * tex2D_linearize(tex, tex_uv + (7.0 + w7_8_ratio) * dxdy).rgb; sum += w9_10 * tex2D_linearize(tex, tex_uv + (9.0 + w9_10_ratio) * dxdy).rgb; sum += w11_12 * tex2D_linearize(tex, tex_uv + (11.0 + w11_12_ratio) * dxdy).rgb; return sum * weight_sum_inv; } float3 tex2Dblur17fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Same as tex2Dblur11() // Returns: A 1D 17x Gaussian blurred texture lookup using 1 nearest // neighbor and 8 linear taps. It may be mipmapped depending // on settings and dxdy. // First get the texel weights and normalization factor as above. const float denom_inv = 0.5/(sigma*sigma); const float w0 = 1.0; const float w1 = exp(-1.0 * denom_inv); const float w2 = exp(-4.0 * denom_inv); const float w3 = exp(-9.0 * denom_inv); const float w4 = exp(-16.0 * denom_inv); const float w5 = exp(-25.0 * denom_inv); const float w6 = exp(-36.0 * denom_inv); const float w7 = exp(-49.0 * denom_inv); const float w8 = exp(-64.0 * denom_inv); //const float weight_sum_inv = 1.0 / (w0 + 2.0 * ( // w1 + w2 + w3 + w4 + w5 + w6 + w7 + w8)); const float weight_sum_inv = get_fast_gaussian_weight_sum_inv(sigma); // Calculate combined weights and linear sample ratios between texel pairs. const float w1_2 = w1 + w2; const float w3_4 = w3 + w4; const float w5_6 = w5 + w6; const float w7_8 = w7 + w8; const float w1_2_ratio = w2/w1_2; const float w3_4_ratio = w4/w3_4; const float w5_6_ratio = w6/w5_6; const float w7_8_ratio = w8/w7_8; // Statically normalize weights, sum weighted samples, and return: float3 sum = 0.0.xxx; sum += w7_8 * tex2D_linearize(tex, tex_uv - (7.0 + w7_8_ratio) * dxdy).rgb; sum += w5_6 * tex2D_linearize(tex, tex_uv - (5.0 + w5_6_ratio) * dxdy).rgb; sum += w3_4 * tex2D_linearize(tex, tex_uv - (3.0 + w3_4_ratio) * dxdy).rgb; sum += w1_2 * tex2D_linearize(tex, tex_uv - (1.0 + w1_2_ratio) * dxdy).rgb; sum += w0 * tex2D_linearize(tex, tex_uv).rgb; sum += w1_2 * tex2D_linearize(tex, tex_uv + (1.0 + w1_2_ratio) * dxdy).rgb; sum += w3_4 * tex2D_linearize(tex, tex_uv + (3.0 + w3_4_ratio) * dxdy).rgb; sum += w5_6 * tex2D_linearize(tex, tex_uv + (5.0 + w5_6_ratio) * dxdy).rgb; sum += w7_8 * tex2D_linearize(tex, tex_uv + (7.0 + w7_8_ratio) * dxdy).rgb; return sum * weight_sum_inv; } //////////////////// ARBITRARILY RESIZABLE ONE-PASS BLURS //////////////////// float3 tex2Dblur3x3resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Requires: Global requirements must be met (see file description). // Returns: A 3x3 Gaussian blurred mipmapped texture lookup of the // resized input. // Description: // This is the only arbitrarily resizable one-pass blur; tex2Dblur5x5resize // would perform like tex2Dblur9x9, MUCH slower than tex2Dblur5resize. const float denom_inv = 0.5/(sigma*sigma); // Load each sample. We need all 3x3 samples. Quad-pixel communication // won't help either: This should perform like tex2Dblur5x5, but sharing a // 4x4 sample field would perform more like tex2Dblur8x8shared (worse). const float2 sample4_uv = tex_uv; const float2 dx = float2(dxdy.x, 0.0); const float2 dy = float2(0.0, dxdy.y); const float2 sample1_uv = sample4_uv - dy; const float2 sample7_uv = sample4_uv + dy; const float3 sample0 = tex2D_linearize(tex, sample1_uv - dx).rgb; const float3 sample1 = tex2D_linearize(tex, sample1_uv).rgb; const float3 sample2 = tex2D_linearize(tex, sample1_uv + dx).rgb; const float3 sample3 = tex2D_linearize(tex, sample4_uv - dx).rgb; const float3 sample4 = tex2D_linearize(tex, sample4_uv).rgb; const float3 sample5 = tex2D_linearize(tex, sample4_uv + dx).rgb; const float3 sample6 = tex2D_linearize(tex, sample7_uv - dx).rgb; const float3 sample7 = tex2D_linearize(tex, sample7_uv).rgb; const float3 sample8 = tex2D_linearize(tex, sample7_uv + dx).rgb; // Statically compute Gaussian sample weights: const float w4 = 1.0; const float w1_3_5_7 = exp(-LENGTH_SQ(float2(1.0, 0.0)) * denom_inv); const float w0_2_6_8 = exp(-LENGTH_SQ(float2(1.0, 1.0)) * denom_inv); const float weight_sum_inv = 1.0/(w4 + 4.0 * (w1_3_5_7 + w0_2_6_8)); // Weight and sum the samples: const float3 sum = w4 * sample4 + w1_3_5_7 * (sample1 + sample3 + sample5 + sample7) + w0_2_6_8 * (sample0 + sample2 + sample6 + sample8); return sum * weight_sum_inv; } //////////////////////////// FASTER ONE-PASS BLURS /////////////////////////// float3 tex2Dblur9x9(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Perform a 1-pass 9x9 blur with 5x5 bilinear samples. // Requires: Same as tex2Dblur9() // Returns: A 9x9 Gaussian blurred mipmapped texture lookup composed of // 5x5 carefully selected bilinear samples. // Description: // Perform a 1-pass 9x9 blur with 5x5 bilinear samples. Adjust the // bilinear sample location to reflect the true Gaussian weights for each // underlying texel. The following diagram illustrates the relative // locations of bilinear samples. Each sample with the same number has the // same weight (notice the symmetry). The letters a, b, c, d distinguish // quadrants, and the letters U, D, L, R, C (up, down, left, right, center) // distinguish 1D directions along the line containing the pixel center: // 6a 5a 2U 5b 6b // 4a 3a 1U 3b 4b // 2L 1L 0C 1R 2R // 4c 3c 1D 3d 4d // 6c 5c 2D 5d 6d // The following diagram illustrates the underlying equally spaced texels, // named after the sample that accesses them and subnamed by their location // within their 2x2, 2x1, 1x2, or 1x1 texel block: // 6a4 6a3 5a4 5a3 2U2 5b3 5b4 6b3 6b4 // 6a2 6a1 5a2 5a1 2U1 5b1 5b2 6b1 6b2 // 4a4 4a3 3a4 3a3 1U2 3b3 3b4 4b3 4b4 // 4a2 4a1 3a2 3a1 1U1 3b1 3b2 4b1 4b2 // 2L2 2L1 1L2 1L1 0C1 1R1 1R2 2R1 2R2 // 4c2 4c1 3c2 3c1 1D1 3d1 3d2 4d1 4d2 // 4c4 4c3 3c4 3c3 1D2 3d3 3d4 4d3 4d4 // 6c2 6c1 5c2 5c1 2D1 5d1 5d2 6d1 6d2 // 6c4 6c3 5c4 5c3 2D2 5d3 5d4 6d3 6d4 // Note there is only one C texel and only two texels for each U, D, L, or // R sample. The center sample is effectively a nearest neighbor sample, // and the U/D/L/R samples use 1D linear filtering. All other texels are // read with bilinear samples somewhere within their 2x2 texel blocks. // COMPUTE TEXTURE COORDS: // Statically compute sampling offsets within each 2x2 texel block, based // on 1D sampling ratios between texels [1, 2] and [3, 4] texels away from // the center, and reuse them independently for both dimensions. Compute // these offsets based on the relative 1D Gaussian weights of the texels // in question. (w1off means "Gaussian weight for the texel 1.0 texels // away from the pixel center," etc.). const float denom_inv = 0.5/(sigma*sigma); const float w1off = exp(-1.0 * denom_inv); const float w2off = exp(-4.0 * denom_inv); const float w3off = exp(-9.0 * denom_inv); const float w4off = exp(-16.0 * denom_inv); const float texel1to2ratio = w2off/(w1off + w2off); const float texel3to4ratio = w4off/(w3off + w4off); // Statically compute texel offsets from the fragment center to each // bilinear sample in the bottom-right quadrant, including x-axis-aligned: const float2 sample1R_texel_offset = float2(1.0, 0.0) + float2(texel1to2ratio, 0.0); const float2 sample2R_texel_offset = float2(3.0, 0.0) + float2(texel3to4ratio, 0.0); const float2 sample3d_texel_offset = float2(1.0, 1.0) + float2(texel1to2ratio, texel1to2ratio); const float2 sample4d_texel_offset = float2(3.0, 1.0) + float2(texel3to4ratio, texel1to2ratio); const float2 sample5d_texel_offset = float2(1.0, 3.0) + float2(texel1to2ratio, texel3to4ratio); const float2 sample6d_texel_offset = float2(3.0, 3.0) + float2(texel3to4ratio, texel3to4ratio); // CALCULATE KERNEL WEIGHTS FOR ALL SAMPLES: // Statically compute Gaussian texel weights for the bottom-right quadrant. // Read underscores as "and." const float w1R1 = w1off; const float w1R2 = w2off; const float w2R1 = w3off; const float w2R2 = w4off; const float w3d1 = exp(-LENGTH_SQ(float2(1.0, 1.0)) * denom_inv); const float w3d2_3d3 = exp(-LENGTH_SQ(float2(2.0, 1.0)) * denom_inv); const float w3d4 = exp(-LENGTH_SQ(float2(2.0, 2.0)) * denom_inv); const float w4d1_5d1 = exp(-LENGTH_SQ(float2(3.0, 1.0)) * denom_inv); const float w4d2_5d3 = exp(-LENGTH_SQ(float2(4.0, 1.0)) * denom_inv); const float w4d3_5d2 = exp(-LENGTH_SQ(float2(3.0, 2.0)) * denom_inv); const float w4d4_5d4 = exp(-LENGTH_SQ(float2(4.0, 2.0)) * denom_inv); const float w6d1 = exp(-LENGTH_SQ(float2(3.0, 3.0)) * denom_inv); const float w6d2_6d3 = exp(-LENGTH_SQ(float2(4.0, 3.0)) * denom_inv); const float w6d4 = exp(-LENGTH_SQ(float2(4.0, 4.0)) * denom_inv); // Statically add texel weights in each sample to get sample weights: const float w0 = 1.0; const float w1 = w1R1 + w1R2; const float w2 = w2R1 + w2R2; const float w3 = w3d1 + 2.0 * w3d2_3d3 + w3d4; const float w4 = w4d1_5d1 + w4d2_5d3 + w4d3_5d2 + w4d4_5d4; const float w5 = w4; const float w6 = w6d1 + 2.0 * w6d2_6d3 + w6d4; // Get the weight sum inverse (normalization factor): const float weight_sum_inv = 1.0/(w0 + 4.0 * (w1 + w2 + w3 + w4 + w5 + w6)); // LOAD TEXTURE SAMPLES: // Load all 25 samples (1 nearest, 8 linear, 16 bilinear) using symmetry: const float2 mirror_x = float2(-1.0, 1.0); const float2 mirror_y = float2(1.0, -1.0); const float2 mirror_xy = float2(-1.0, -1.0); const float2 dxdy_mirror_x = dxdy * mirror_x; const float2 dxdy_mirror_y = dxdy * mirror_y; const float2 dxdy_mirror_xy = dxdy * mirror_xy; // Sampling order doesn't seem to affect performance, so just be clear: const float3 sample0C = tex2D_linearize(tex, tex_uv).rgb; const float3 sample1R = tex2D_linearize(tex, tex_uv + dxdy * sample1R_texel_offset).rgb; const float3 sample1D = tex2D_linearize(tex, tex_uv + dxdy * sample1R_texel_offset.yx).rgb; const float3 sample1L = tex2D_linearize(tex, tex_uv - dxdy * sample1R_texel_offset).rgb; const float3 sample1U = tex2D_linearize(tex, tex_uv - dxdy * sample1R_texel_offset.yx).rgb; const float3 sample2R = tex2D_linearize(tex, tex_uv + dxdy * sample2R_texel_offset).rgb; const float3 sample2D = tex2D_linearize(tex, tex_uv + dxdy * sample2R_texel_offset.yx).rgb; const float3 sample2L = tex2D_linearize(tex, tex_uv - dxdy * sample2R_texel_offset).rgb; const float3 sample2U = tex2D_linearize(tex, tex_uv - dxdy * sample2R_texel_offset.yx).rgb; const float3 sample3d = tex2D_linearize(tex, tex_uv + dxdy * sample3d_texel_offset).rgb; const float3 sample3c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample3d_texel_offset).rgb; const float3 sample3b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample3d_texel_offset).rgb; const float3 sample3a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample3d_texel_offset).rgb; const float3 sample4d = tex2D_linearize(tex, tex_uv + dxdy * sample4d_texel_offset).rgb; const float3 sample4c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample4d_texel_offset).rgb; const float3 sample4b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample4d_texel_offset).rgb; const float3 sample4a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample4d_texel_offset).rgb; const float3 sample5d = tex2D_linearize(tex, tex_uv + dxdy * sample5d_texel_offset).rgb; const float3 sample5c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample5d_texel_offset).rgb; const float3 sample5b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample5d_texel_offset).rgb; const float3 sample5a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample5d_texel_offset).rgb; const float3 sample6d = tex2D_linearize(tex, tex_uv + dxdy * sample6d_texel_offset).rgb; const float3 sample6c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample6d_texel_offset).rgb; const float3 sample6b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample6d_texel_offset).rgb; const float3 sample6a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample6d_texel_offset).rgb; // SUM WEIGHTED SAMPLES: // Statically normalize weights (so total = 1.0), and sum weighted samples. float3 sum = w0 * sample0C; sum += w1 * (sample1R + sample1D + sample1L + sample1U); sum += w2 * (sample2R + sample2D + sample2L + sample2U); sum += w3 * (sample3d + sample3c + sample3b + sample3a); sum += w4 * (sample4d + sample4c + sample4b + sample4a); sum += w5 * (sample5d + sample5c + sample5b + sample5a); sum += w6 * (sample6d + sample6c + sample6b + sample6a); return sum * weight_sum_inv; } float3 tex2Dblur7x7(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Perform a 1-pass 7x7 blur with 5x5 bilinear samples. // Requires: Same as tex2Dblur9() // Returns: A 7x7 Gaussian blurred mipmapped texture lookup composed of // 4x4 carefully selected bilinear samples. // Description: // First see the descriptions for tex2Dblur9x9() and tex2Dblur7(). This // blur mixes concepts from both. The sample layout is as follows: // 4a 3a 3b 4b // 2a 1a 1b 2b // 2c 1c 1d 2d // 4c 3c 3d 4d // The texel layout is as follows. Note that samples 3a/3b, 1a/1b, 1c/1d, // and 3c/3d share a vertical column of texels, and samples 2a/2c, 1a/1c, // 1b/1d, and 2b/2d share a horizontal row of texels (all sample1's share // the center texel): // 4a4 4a3 3a4 3ab3 3b4 4b3 4b4 // 4a2 4a1 3a2 3ab1 3b2 4b1 4b2 // 2a4 2a3 1a4 1ab3 1b4 2b3 2b4 // 2ac2 2ac1 1ac2 1* 1bd2 2bd1 2bd2 // 2c4 2c3 1c4 1cd3 1d4 2d3 2d4 // 4c2 4c1 3c2 3cd1 3d2 4d1 4d2 // 4c4 4c3 3c4 3cd3 3d4 4d3 4d4 // COMPUTE TEXTURE COORDS: // Statically compute bilinear sampling offsets (details in tex2Dblur9x9). const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w1off = exp(-1.0 * denom_inv); const float w2off = exp(-4.0 * denom_inv); const float w3off = exp(-9.0 * denom_inv); const float texel0to1ratio = w1off/(w0off * 0.5 + w1off); const float texel2to3ratio = w3off/(w2off + w3off); // Statically compute texel offsets from the fragment center to each // bilinear sample in the bottom-right quadrant, including axis-aligned: const float2 sample1d_texel_offset = float2(texel0to1ratio, texel0to1ratio); const float2 sample2d_texel_offset = float2(2.0, 0.0) + float2(texel2to3ratio, texel0to1ratio); const float2 sample3d_texel_offset = float2(0.0, 2.0) + float2(texel0to1ratio, texel2to3ratio); const float2 sample4d_texel_offset = float2(2.0, 2.0) + float2(texel2to3ratio, texel2to3ratio); // CALCULATE KERNEL WEIGHTS FOR ALL SAMPLES: // Statically compute Gaussian texel weights for the bottom-right quadrant. // Read underscores as "and." const float w1abcd = 1.0; const float w1bd2_1cd3 = exp(-LENGTH_SQ(float2(1.0, 0.0)) * denom_inv); const float w2bd1_3cd1 = exp(-LENGTH_SQ(float2(2.0, 0.0)) * denom_inv); const float w2bd2_3cd2 = exp(-LENGTH_SQ(float2(3.0, 0.0)) * denom_inv); const float w1d4 = exp(-LENGTH_SQ(float2(1.0, 1.0)) * denom_inv); const float w2d3_3d2 = exp(-LENGTH_SQ(float2(2.0, 1.0)) * denom_inv); const float w2d4_3d4 = exp(-LENGTH_SQ(float2(3.0, 1.0)) * denom_inv); const float w4d1 = exp(-LENGTH_SQ(float2(2.0, 2.0)) * denom_inv); const float w4d2_4d3 = exp(-LENGTH_SQ(float2(3.0, 2.0)) * denom_inv); const float w4d4 = exp(-LENGTH_SQ(float2(3.0, 3.0)) * denom_inv); // Statically add texel weights in each sample to get sample weights. // Split weights for shared texels between samples sharing them: const float w1 = w1abcd * 0.25 + w1bd2_1cd3 + w1d4; const float w2_3 = (w2bd1_3cd1 + w2bd2_3cd2) * 0.5 + w2d3_3d2 + w2d4_3d4; const float w4 = w4d1 + 2.0 * w4d2_4d3 + w4d4; // Get the weight sum inverse (normalization factor): const float weight_sum_inv = 1.0/(4.0 * (w1 + 2.0 * w2_3 + w4)); // LOAD TEXTURE SAMPLES: // Load all 16 samples using symmetry: const float2 mirror_x = float2(-1.0, 1.0); const float2 mirror_y = float2(1.0, -1.0); const float2 mirror_xy = float2(-1.0, -1.0); const float2 dxdy_mirror_x = dxdy * mirror_x; const float2 dxdy_mirror_y = dxdy * mirror_y; const float2 dxdy_mirror_xy = dxdy * mirror_xy; const float3 sample1a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample1d_texel_offset).rgb; const float3 sample2a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample2d_texel_offset).rgb; const float3 sample3a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample3d_texel_offset).rgb; const float3 sample4a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample4d_texel_offset).rgb; const float3 sample1b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample1d_texel_offset).rgb; const float3 sample2b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample2d_texel_offset).rgb; const float3 sample3b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample3d_texel_offset).rgb; const float3 sample4b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample4d_texel_offset).rgb; const float3 sample1c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample1d_texel_offset).rgb; const float3 sample2c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample2d_texel_offset).rgb; const float3 sample3c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample3d_texel_offset).rgb; const float3 sample4c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample4d_texel_offset).rgb; const float3 sample1d = tex2D_linearize(tex, tex_uv + dxdy * sample1d_texel_offset).rgb; const float3 sample2d = tex2D_linearize(tex, tex_uv + dxdy * sample2d_texel_offset).rgb; const float3 sample3d = tex2D_linearize(tex, tex_uv + dxdy * sample3d_texel_offset).rgb; const float3 sample4d = tex2D_linearize(tex, tex_uv + dxdy * sample4d_texel_offset).rgb; // SUM WEIGHTED SAMPLES: // Statically normalize weights (so total = 1.0), and sum weighted samples. float3 sum = 0.0.xxx; sum += w1 * (sample1a + sample1b + sample1c + sample1d); sum += w2_3 * (sample2a + sample2b + sample2c + sample2d); sum += w2_3 * (sample3a + sample3b + sample3c + sample3d); sum += w4 * (sample4a + sample4b + sample4c + sample4d); return sum * weight_sum_inv; } float3 tex2Dblur5x5(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Perform a 1-pass 5x5 blur with 3x3 bilinear samples. // Requires: Same as tex2Dblur9() // Returns: A 5x5 Gaussian blurred mipmapped texture lookup composed of // 3x3 carefully selected bilinear samples. // Description: // First see the description for tex2Dblur9x9(). This blur uses the same // concept and sample/texel locations except on a smaller scale. Samples: // 2a 1U 2b // 1L 0C 1R // 2c 1D 2d // Texels: // 2a4 2a3 1U2 2b3 2b4 // 2a2 2a1 1U1 2b1 2b2 // 1L2 1L1 0C1 1R1 1R2 // 2c2 2c1 1D1 2d1 2d2 // 2c4 2c3 1D2 2d3 2d4 // COMPUTE TEXTURE COORDS: // Statically compute bilinear sampling offsets (details in tex2Dblur9x9). const float denom_inv = 0.5/(sigma*sigma); const float w1off = exp(-1.0 * denom_inv); const float w2off = exp(-4.0 * denom_inv); const float texel1to2ratio = w2off/(w1off + w2off); // Statically compute texel offsets from the fragment center to each // bilinear sample in the bottom-right quadrant, including x-axis-aligned: const float2 sample1R_texel_offset = float2(1.0, 0.0) + float2(texel1to2ratio, 0.0); const float2 sample2d_texel_offset = float2(1.0, 1.0) + float2(texel1to2ratio, texel1to2ratio); // CALCULATE KERNEL WEIGHTS FOR ALL SAMPLES: // Statically compute Gaussian texel weights for the bottom-right quadrant. // Read underscores as "and." const float w1R1 = w1off; const float w1R2 = w2off; const float w2d1 = exp(-LENGTH_SQ(float2(1.0, 1.0)) * denom_inv); const float w2d2_3 = exp(-LENGTH_SQ(float2(2.0, 1.0)) * denom_inv); const float w2d4 = exp(-LENGTH_SQ(float2(2.0, 2.0)) * denom_inv); // Statically add texel weights in each sample to get sample weights: const float w0 = 1.0; const float w1 = w1R1 + w1R2; const float w2 = w2d1 + 2.0 * w2d2_3 + w2d4; // Get the weight sum inverse (normalization factor): const float weight_sum_inv = 1.0/(w0 + 4.0 * (w1 + w2)); // LOAD TEXTURE SAMPLES: // Load all 9 samples (1 nearest, 4 linear, 4 bilinear) using symmetry: const float2 mirror_x = float2(-1.0, 1.0); const float2 mirror_y = float2(1.0, -1.0); const float2 mirror_xy = float2(-1.0, -1.0); const float2 dxdy_mirror_x = dxdy * mirror_x; const float2 dxdy_mirror_y = dxdy * mirror_y; const float2 dxdy_mirror_xy = dxdy * mirror_xy; const float3 sample0C = tex2D_linearize(tex, tex_uv).rgb; const float3 sample1R = tex2D_linearize(tex, tex_uv + dxdy * sample1R_texel_offset).rgb; const float3 sample1D = tex2D_linearize(tex, tex_uv + dxdy * sample1R_texel_offset.yx).rgb; const float3 sample1L = tex2D_linearize(tex, tex_uv - dxdy * sample1R_texel_offset).rgb; const float3 sample1U = tex2D_linearize(tex, tex_uv - dxdy * sample1R_texel_offset.yx).rgb; const float3 sample2d = tex2D_linearize(tex, tex_uv + dxdy * sample2d_texel_offset).rgb; const float3 sample2c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample2d_texel_offset).rgb; const float3 sample2b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample2d_texel_offset).rgb; const float3 sample2a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample2d_texel_offset).rgb; // SUM WEIGHTED SAMPLES: // Statically normalize weights (so total = 1.0), and sum weighted samples. float3 sum = w0 * sample0C; sum += w1 * (sample1R + sample1D + sample1L + sample1U); sum += w2 * (sample2a + sample2b + sample2c + sample2d); return sum * weight_sum_inv; } float3 tex2Dblur3x3(const sampler2D tex, const float2 tex_uv, const float2 dxdy, const float sigma) { // Perform a 1-pass 3x3 blur with 5x5 bilinear samples. // Requires: Same as tex2Dblur9() // Returns: A 3x3 Gaussian blurred mipmapped texture lookup composed of // 2x2 carefully selected bilinear samples. // Description: // First see the descriptions for tex2Dblur9x9() and tex2Dblur7(). This // blur mixes concepts from both. The sample layout is as follows: // 0a 0b // 0c 0d // The texel layout is as follows. Note that samples 0a/0b and 0c/0d share // a vertical column of texels, and samples 0a/0c and 0b/0d share a // horizontal row of texels (all samples share the center texel): // 0a3 0ab2 0b3 // 0ac1 0*0 0bd1 // 0c3 0cd2 0d3 // COMPUTE TEXTURE COORDS: // Statically compute bilinear sampling offsets (details in tex2Dblur9x9). const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w1off = exp(-1.0 * denom_inv); const float texel0to1ratio = w1off/(w0off * 0.5 + w1off); // Statically compute texel offsets from the fragment center to each // bilinear sample in the bottom-right quadrant, including axis-aligned: const float2 sample0d_texel_offset = float2(texel0to1ratio, texel0to1ratio); // LOAD TEXTURE SAMPLES: // Load all 4 samples using symmetry: const float2 mirror_x = float2(-1.0, 1.0); const float2 mirror_y = float2(1.0, -1.0); const float2 mirror_xy = float2(-1.0, -1.0); const float2 dxdy_mirror_x = dxdy * mirror_x; const float2 dxdy_mirror_y = dxdy * mirror_y; const float2 dxdy_mirror_xy = dxdy * mirror_xy; const float3 sample0a = tex2D_linearize(tex, tex_uv + dxdy_mirror_xy * sample0d_texel_offset).rgb; const float3 sample0b = tex2D_linearize(tex, tex_uv + dxdy_mirror_y * sample0d_texel_offset).rgb; const float3 sample0c = tex2D_linearize(tex, tex_uv + dxdy_mirror_x * sample0d_texel_offset).rgb; const float3 sample0d = tex2D_linearize(tex, tex_uv + dxdy * sample0d_texel_offset).rgb; // SUM WEIGHTED SAMPLES: // Weights for all samples are the same, so just average them: return 0.25 * (sample0a + sample0b + sample0c + sample0d); } ////////////////// LINEAR ONE-PASS BLURS WITH SHARED SAMPLES ///////////////// float3 tex2Dblur12x12shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector, const float sigma) { // Perform a 1-pass mipmapped blur with shared samples across a pixel quad. // Requires: 1.) Same as tex2Dblur9() // 2.) ddx() and ddy() are present in the current Cg profile. // 3.) The GPU driver is using fine/high-quality derivatives. // 4.) quad_vector *correctly* describes the current fragment's // location in its pixel quad, by the conventions noted in // get_quad_vector[_naive]. // 5.) tex_uv.w = log2(IN.video_size/IN.output_size).y // 6.) tex2Dlod() is present in the current Cg profile. // Optional: Tune artifacts vs. excessive blurriness with the global // float error_blurring. // Returns: A blurred texture lookup using a "virtual" 12x12 Gaussian // blur (a 6x6 blur of carefully selected bilinear samples) // of the given mip level. There will be subtle inaccuracies, // especially for small or high-frequency detailed sources. // Description: // Perform a 1-pass blur with shared texture lookups across a pixel quad. // We'll get neighboring samples with high-quality ddx/ddy derivatives, as // in GPU Pro 2, Chapter VI.2, "Shader Amortization using Pixel Quad // Message Passing" by Eric Penner. // // Our "virtual" 12x12 blur will be comprised of ((6 - 1)^2)/4 + 3 = 12 // bilinear samples, where bilinear sampling positions are computed from // the relative Gaussian weights of the 4 surrounding texels. The catch is // that the appropriate texel weights and sample coords differ for each // fragment, but we're reusing most of the same samples across a quad of // destination fragments. (We do use unique coords for the four nearest // samples at each fragment.) Mixing bilinear filtering and sample-sharing // therefore introduces some error into the weights, and this can get nasty // when the source image is small or high-frequency. Computing bilinear // ratios based on weights at the sample field center results in sharpening // and ringing artifacts, but we can move samples closer to halfway between // texels to try blurring away the error (which can move features around by // a texel or so). Tune this with the global float "error_blurring". // // The pixel quad's sample field covers 12x12 texels, accessed through 6x6 // bilinear (2x2 texel) taps. Each fragment depends on a window of 10x10 // texels (5x5 bilinear taps), and each fragment is responsible for loading // a 6x6 texel quadrant as a 3x3 block of bilinear taps, plus 3 more taps // to use unique bilinear coords for sample0* for each fragment. This // diagram illustrates the relative locations of bilinear samples 1-9 for // each quadrant a, b, c, d (note samples will not be equally spaced): // 8a 7a 6a 6b 7b 8b // 5a 4a 3a 3b 4b 5b // 2a 1a 0a 0b 1b 2b // 2c 1c 0c 0d 1d 2d // 5c 4c 3c 3d 4d 5d // 8c 7c 6c 6d 7d 8d // The following diagram illustrates the underlying equally spaced texels, // named after the sample that accesses them and subnamed by their location // within their 2x2 texel block: // 8a3 8a2 7a3 7a2 6a3 6a2 6b2 6b3 7b2 7b3 8b2 8b3 // 8a1 8a0 7a1 7a0 6a1 6a0 6b0 6b1 7b0 7b1 8b0 8b1 // 5a3 5a2 4a3 4a2 3a3 3a2 3b2 3b3 4b2 4b3 5b2 5b3 // 5a1 5a0 4a1 4a0 3a1 3a0 3b0 3b1 4b0 4b1 5b0 5b1 // 2a3 2a2 1a3 1a2 0a3 0a2 0b2 0b3 1b2 1b3 2b2 2b3 // 2a1 2a0 1a1 1a0 0a1 0a0 0b0 0b1 1b0 1b1 2b0 2b1 // 2c1 2c0 1c1 1c0 0c1 0c0 0d0 0d1 1d0 1d1 2d0 2d1 // 2c3 2c2 1c3 1c2 0c3 0c2 0d2 0d3 1d2 1d3 2d2 2d3 // 5c1 5c0 4c1 4c0 3c1 3c0 3d0 3d1 4d0 4d1 5d0 5d1 // 5c3 5c2 4c3 4c2 3c3 3c2 3d2 3d3 4d2 4d3 5d2 5d3 // 8c1 8c0 7c1 7c0 6c1 6c0 6d0 6d1 7d0 7d1 8d0 8d1 // 8c3 8c2 7c3 7c2 6c3 6c2 6d2 6d3 7d2 7d3 8d2 8d3 // With this symmetric arrangement, we don't have to know which absolute // quadrant a sample lies in to assign kernel weights; it's enough to know // the sample number and the relative quadrant of the sample (relative to // the current quadrant): // {current, adjacent x, adjacent y, diagonal} // COMPUTE COORDS FOR TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Statically compute sampling offsets within each 2x2 texel block, based // on appropriate 1D Gaussian sampling ratio between texels [0, 1], [2, 3], // and [4, 5] away from the fragment, and reuse them independently for both // dimensions. Use the sample field center as the estimated destination, // but nudge the result closer to halfway between texels to blur error. const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w0_5off = exp(-(0.5*0.5) * denom_inv); const float w1off = exp(-(1.0*1.0) * denom_inv); const float w1_5off = exp(-(1.5*1.5) * denom_inv); const float w2off = exp(-(2.0*2.0) * denom_inv); const float w2_5off = exp(-(2.5*2.5) * denom_inv); const float w3_5off = exp(-(3.5*3.5) * denom_inv); const float w4_5off = exp(-(4.5*4.5) * denom_inv); const float w5_5off = exp(-(5.5*5.5) * denom_inv); const float texel0to1ratio = lerp(w1_5off/(w0_5off + w1_5off), 0.5, error_blurring); const float texel2to3ratio = lerp(w3_5off/(w2_5off + w3_5off), 0.5, error_blurring); const float texel4to5ratio = lerp(w5_5off/(w4_5off + w5_5off), 0.5, error_blurring); // We don't share sample0*, so use the nearest destination fragment: const float texel0to1ratio_nearest = w1off/(w0off + w1off); const float texel1to2ratio_nearest = w2off/(w1off + w2off); // Statically compute texel offsets from the bottom-right fragment to each // bilinear sample in the bottom-right quadrant: const float2 sample0curr_texel_offset = float2(0.0, 0.0) + float2(texel0to1ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjx_texel_offset = float2(-1.0, 0.0) + float2(-texel1to2ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjy_texel_offset = float2(0.0, -1.0) + float2(texel0to1ratio_nearest, -texel1to2ratio_nearest); const float2 sample0diag_texel_offset = float2(-1.0, -1.0) + float2(-texel1to2ratio_nearest, -texel1to2ratio_nearest); const float2 sample1_texel_offset = float2(2.0, 0.0) + float2(texel2to3ratio, texel0to1ratio); const float2 sample2_texel_offset = float2(4.0, 0.0) + float2(texel4to5ratio, texel0to1ratio); const float2 sample3_texel_offset = float2(0.0, 2.0) + float2(texel0to1ratio, texel2to3ratio); const float2 sample4_texel_offset = float2(2.0, 2.0) + float2(texel2to3ratio, texel2to3ratio); const float2 sample5_texel_offset = float2(4.0, 2.0) + float2(texel4to5ratio, texel2to3ratio); const float2 sample6_texel_offset = float2(0.0, 4.0) + float2(texel0to1ratio, texel4to5ratio); const float2 sample7_texel_offset = float2(2.0, 4.0) + float2(texel2to3ratio, texel4to5ratio); const float2 sample8_texel_offset = float2(4.0, 4.0) + float2(texel4to5ratio, texel4to5ratio); // CALCULATE KERNEL WEIGHTS: // Statically compute bilinear sample weights at each destination fragment // based on the sum of their 4 underlying texel weights. Assume a same- // resolution blur, so each symmetrically named sample weight will compute // the same at every fragment in the pixel quad: We can therefore compute // texel weights based only on the bottom-right quadrant (fragment at 0d0). // Too avoid too much boilerplate code, use a macro to get all 4 texel // weights for a bilinear sample based on the offset of its top-left texel: #define GET_TEXEL_QUAD_WEIGHTS(xoff, yoff) \ (exp(-LENGTH_SQ(float2(xoff, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff, yoff + 1.0)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff + 1.0)) * denom_inv)) const float w8diag = GET_TEXEL_QUAD_WEIGHTS(-6.0, -6.0); const float w7diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -6.0); const float w6diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -6.0); const float w6adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -6.0); const float w7adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -6.0); const float w8adjy = GET_TEXEL_QUAD_WEIGHTS(4.0, -6.0); const float w5diag = GET_TEXEL_QUAD_WEIGHTS(-6.0, -4.0); const float w4diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -4.0); const float w3diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -4.0); const float w3adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -4.0); const float w4adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -4.0); const float w5adjy = GET_TEXEL_QUAD_WEIGHTS(4.0, -4.0); const float w2diag = GET_TEXEL_QUAD_WEIGHTS(-6.0, -2.0); const float w1diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -2.0); const float w0diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -2.0); const float w0adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -2.0); const float w1adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -2.0); const float w2adjy = GET_TEXEL_QUAD_WEIGHTS(4.0, -2.0); const float w2adjx = GET_TEXEL_QUAD_WEIGHTS(-6.0, 0.0); const float w1adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 0.0); const float w0adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 0.0); const float w0curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 0.0); const float w1curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 0.0); const float w2curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 0.0); const float w5adjx = GET_TEXEL_QUAD_WEIGHTS(-6.0, 2.0); const float w4adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 2.0); const float w3adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 2.0); const float w3curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 2.0); const float w4curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 2.0); const float w5curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 2.0); const float w8adjx = GET_TEXEL_QUAD_WEIGHTS(-6.0, 4.0); const float w7adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 4.0); const float w6adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 4.0); const float w6curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 4.0); const float w7curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 4.0); const float w8curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 4.0); #undef GET_TEXEL_QUAD_WEIGHTS // Statically pack weights for runtime: const float4 w0 = float4(w0curr, w0adjx, w0adjy, w0diag); const float4 w1 = float4(w1curr, w1adjx, w1adjy, w1diag); const float4 w2 = float4(w2curr, w2adjx, w2adjy, w2diag); const float4 w3 = float4(w3curr, w3adjx, w3adjy, w3diag); const float4 w4 = float4(w4curr, w4adjx, w4adjy, w4diag); const float4 w5 = float4(w5curr, w5adjx, w5adjy, w5diag); const float4 w6 = float4(w6curr, w6adjx, w6adjy, w6diag); const float4 w7 = float4(w7curr, w7adjx, w7adjy, w7diag); const float4 w8 = float4(w8curr, w8adjx, w8adjy, w8diag); // Get the weight sum inverse (normalization factor): const float4 weight_sum4 = w0 + w1 + w2 + w3 + w4 + w5 + w6 + w7 + w8; const float2 weight_sum2 = weight_sum4.xy + weight_sum4.zw; const float weight_sum = weight_sum2.x + weight_sum2.y; const float weight_sum_inv = 1.0/(weight_sum); // LOAD TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Get a uv vector from texel 0q0 of this quadrant to texel 0q3: const float2 dxdy_curr = dxdy * quad_vector.xy; // Load bilinear samples for the current quadrant (for this fragment): const float3 sample0curr = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0curr_texel_offset).rgb; const float3 sample0adjx = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjx_texel_offset).rgb; const float3 sample0adjy = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjy_texel_offset).rgb; const float3 sample0diag = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0diag_texel_offset).rgb; const float3 sample1curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample1_texel_offset)).rgb; const float3 sample2curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample2_texel_offset)).rgb; const float3 sample3curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample3_texel_offset)).rgb; const float3 sample4curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample4_texel_offset)).rgb; const float3 sample5curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample5_texel_offset)).rgb; const float3 sample6curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample6_texel_offset)).rgb; const float3 sample7curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample7_texel_offset)).rgb; const float3 sample8curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample8_texel_offset)).rgb; // GATHER NEIGHBORING SAMPLES AND SUM WEIGHTED SAMPLES: // Fetch the samples from other fragments in the 2x2 quad: float3 sample1adjx, sample1adjy, sample1diag; float3 sample2adjx, sample2adjy, sample2diag; float3 sample3adjx, sample3adjy, sample3diag; float3 sample4adjx, sample4adjy, sample4diag; float3 sample5adjx, sample5adjy, sample5diag; float3 sample6adjx, sample6adjy, sample6diag; float3 sample7adjx, sample7adjy, sample7diag; float3 sample8adjx, sample8adjy, sample8diag; quad_gather(quad_vector, sample1curr, sample1adjx, sample1adjy, sample1diag); quad_gather(quad_vector, sample2curr, sample2adjx, sample2adjy, sample2diag); quad_gather(quad_vector, sample3curr, sample3adjx, sample3adjy, sample3diag); quad_gather(quad_vector, sample4curr, sample4adjx, sample4adjy, sample4diag); quad_gather(quad_vector, sample5curr, sample5adjx, sample5adjy, sample5diag); quad_gather(quad_vector, sample6curr, sample6adjx, sample6adjy, sample6diag); quad_gather(quad_vector, sample7curr, sample7adjx, sample7adjy, sample7diag); quad_gather(quad_vector, sample8curr, sample8adjx, sample8adjy, sample8diag); // Statically normalize weights (so total = 1.0), and sum weighted samples. // Fill each row of a matrix with an rgb sample and pre-multiply by the // weights to obtain a weighted result: float3 sum = 0.0.xxx; sum += mul(w0, float4x3(sample0curr, sample0adjx, sample0adjy, sample0diag)); sum += mul(w1, float4x3(sample1curr, sample1adjx, sample1adjy, sample1diag)); sum += mul(w2, float4x3(sample2curr, sample2adjx, sample2adjy, sample2diag)); sum += mul(w3, float4x3(sample3curr, sample3adjx, sample3adjy, sample3diag)); sum += mul(w4, float4x3(sample4curr, sample4adjx, sample4adjy, sample4diag)); sum += mul(w5, float4x3(sample5curr, sample5adjx, sample5adjy, sample5diag)); sum += mul(w6, float4x3(sample6curr, sample6adjx, sample6adjy, sample6diag)); sum += mul(w7, float4x3(sample7curr, sample7adjx, sample7adjy, sample7diag)); sum += mul(w8, float4x3(sample8curr, sample8adjx, sample8adjy, sample8diag)); return sum * weight_sum_inv; } float3 tex2Dblur10x10shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector, const float sigma) { // Perform a 1-pass mipmapped blur with shared samples across a pixel quad. // Requires: Same as tex2Dblur12x12shared() // Returns: A blurred texture lookup using a "virtual" 10x10 Gaussian // blur (a 5x5 blur of carefully selected bilinear samples) // of the given mip level. There will be subtle inaccuracies, // especially for small or high-frequency detailed sources. // Description: // First see the description for tex2Dblur12x12shared(). This // function shares the same concept and sample placement, but each fragment // only uses 25 of the 36 samples taken across the pixel quad (to cover a // 5x5 sample area, or 10x10 texel area), and it uses a lower standard // deviation to compensate. Thanks to symmetry, the 11 omitted samples // are always the "same:" // 8adjx, 2adjx, 5adjx, // 6adjy, 7adjy, 8adjy, // 2diag, 5diag, 6diag, 7diag, 8diag // COMPUTE COORDS FOR TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Statically compute bilinear sampling offsets (details in tex2Dblur12x12shared). const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w0_5off = exp(-(0.5*0.5) * denom_inv); const float w1off = exp(-(1.0*1.0) * denom_inv); const float w1_5off = exp(-(1.5*1.5) * denom_inv); const float w2off = exp(-(2.0*2.0) * denom_inv); const float w2_5off = exp(-(2.5*2.5) * denom_inv); const float w3_5off = exp(-(3.5*3.5) * denom_inv); const float w4_5off = exp(-(4.5*4.5) * denom_inv); const float w5_5off = exp(-(5.5*5.5) * denom_inv); const float texel0to1ratio = lerp(w1_5off/(w0_5off + w1_5off), 0.5, error_blurring); const float texel2to3ratio = lerp(w3_5off/(w2_5off + w3_5off), 0.5, error_blurring); const float texel4to5ratio = lerp(w5_5off/(w4_5off + w5_5off), 0.5, error_blurring); // We don't share sample0*, so use the nearest destination fragment: const float texel0to1ratio_nearest = w1off/(w0off + w1off); const float texel1to2ratio_nearest = w2off/(w1off + w2off); // Statically compute texel offsets from the bottom-right fragment to each // bilinear sample in the bottom-right quadrant: const float2 sample0curr_texel_offset = float2(0.0, 0.0) + float2(texel0to1ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjx_texel_offset = float2(-1.0, 0.0) + float2(-texel1to2ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjy_texel_offset = float2(0.0, -1.0) + float2(texel0to1ratio_nearest, -texel1to2ratio_nearest); const float2 sample0diag_texel_offset = float2(-1.0, -1.0) + float2(-texel1to2ratio_nearest, -texel1to2ratio_nearest); const float2 sample1_texel_offset = float2(2.0, 0.0) + float2(texel2to3ratio, texel0to1ratio); const float2 sample2_texel_offset = float2(4.0, 0.0) + float2(texel4to5ratio, texel0to1ratio); const float2 sample3_texel_offset = float2(0.0, 2.0) + float2(texel0to1ratio, texel2to3ratio); const float2 sample4_texel_offset = float2(2.0, 2.0) + float2(texel2to3ratio, texel2to3ratio); const float2 sample5_texel_offset = float2(4.0, 2.0) + float2(texel4to5ratio, texel2to3ratio); const float2 sample6_texel_offset = float2(0.0, 4.0) + float2(texel0to1ratio, texel4to5ratio); const float2 sample7_texel_offset = float2(2.0, 4.0) + float2(texel2to3ratio, texel4to5ratio); const float2 sample8_texel_offset = float2(4.0, 4.0) + float2(texel4to5ratio, texel4to5ratio); // CALCULATE KERNEL WEIGHTS: // Statically compute bilinear sample weights at each destination fragment // from the sum of their 4 texel weights (details in tex2Dblur12x12shared). #define GET_TEXEL_QUAD_WEIGHTS(xoff, yoff) \ (exp(-LENGTH_SQ(float2(xoff, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff, yoff + 1.0)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff + 1.0)) * denom_inv)) // We only need 25 of the 36 sample weights. Skip the following weights: // 8adjx, 2adjx, 5adjx, // 6adjy, 7adjy, 8adjy, // 2diag, 5diag, 6diag, 7diag, 8diag const float w4diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -4.0); const float w3diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -4.0); const float w3adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -4.0); const float w4adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -4.0); const float w5adjy = GET_TEXEL_QUAD_WEIGHTS(4.0, -4.0); const float w1diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -2.0); const float w0diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -2.0); const float w0adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -2.0); const float w1adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -2.0); const float w2adjy = GET_TEXEL_QUAD_WEIGHTS(4.0, -2.0); const float w1adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 0.0); const float w0adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 0.0); const float w0curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 0.0); const float w1curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 0.0); const float w2curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 0.0); const float w4adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 2.0); const float w3adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 2.0); const float w3curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 2.0); const float w4curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 2.0); const float w5curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 2.0); const float w7adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 4.0); const float w6adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 4.0); const float w6curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 4.0); const float w7curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 4.0); const float w8curr = GET_TEXEL_QUAD_WEIGHTS(4.0, 4.0); #undef GET_TEXEL_QUAD_WEIGHTS // Get the weight sum inverse (normalization factor): const float weight_sum_inv = 1.0/(w0curr + w1curr + w2curr + w3curr + w4curr + w5curr + w6curr + w7curr + w8curr + w0adjx + w1adjx + w3adjx + w4adjx + w6adjx + w7adjx + w0adjy + w1adjy + w2adjy + w3adjy + w4adjy + w5adjy + w0diag + w1diag + w3diag + w4diag); // Statically pack most weights for runtime. Note the mixed packing: const float4 w0 = float4(w0curr, w0adjx, w0adjy, w0diag); const float4 w1 = float4(w1curr, w1adjx, w1adjy, w1diag); const float4 w3 = float4(w3curr, w3adjx, w3adjy, w3diag); const float4 w4 = float4(w4curr, w4adjx, w4adjy, w4diag); const float4 w2and5 = float4(w2curr, w2adjy, w5curr, w5adjy); const float4 w6and7 = float4(w6curr, w6adjx, w7curr, w7adjx); // LOAD TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Get a uv vector from texel 0q0 of this quadrant to texel 0q3: const float2 dxdy_curr = dxdy * quad_vector.xy; // Load bilinear samples for the current quadrant (for this fragment): const float3 sample0curr = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0curr_texel_offset).rgb; const float3 sample0adjx = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjx_texel_offset).rgb; const float3 sample0adjy = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjy_texel_offset).rgb; const float3 sample0diag = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0diag_texel_offset).rgb; const float3 sample1curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample1_texel_offset)).rgb; const float3 sample2curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample2_texel_offset)).rgb; const float3 sample3curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample3_texel_offset)).rgb; const float3 sample4curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample4_texel_offset)).rgb; const float3 sample5curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample5_texel_offset)).rgb; const float3 sample6curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample6_texel_offset)).rgb; const float3 sample7curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample7_texel_offset)).rgb; const float3 sample8curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample8_texel_offset)).rgb; // GATHER NEIGHBORING SAMPLES AND SUM WEIGHTED SAMPLES: // Fetch the samples from other fragments in the 2x2 quad in order of need: float3 sample1adjx, sample1adjy, sample1diag; float3 sample2adjx, sample2adjy, sample2diag; float3 sample3adjx, sample3adjy, sample3diag; float3 sample4adjx, sample4adjy, sample4diag; float3 sample5adjx, sample5adjy, sample5diag; float3 sample6adjx, sample6adjy, sample6diag; float3 sample7adjx, sample7adjy, sample7diag; quad_gather(quad_vector, sample1curr, sample1adjx, sample1adjy, sample1diag); quad_gather(quad_vector, sample2curr, sample2adjx, sample2adjy, sample2diag); quad_gather(quad_vector, sample3curr, sample3adjx, sample3adjy, sample3diag); quad_gather(quad_vector, sample4curr, sample4adjx, sample4adjy, sample4diag); quad_gather(quad_vector, sample5curr, sample5adjx, sample5adjy, sample5diag); quad_gather(quad_vector, sample6curr, sample6adjx, sample6adjy, sample6diag); quad_gather(quad_vector, sample7curr, sample7adjx, sample7adjy, sample7diag); // Statically normalize weights (so total = 1.0), and sum weighted samples. // Fill each row of a matrix with an rgb sample and pre-multiply by the // weights to obtain a weighted result. First do the simple ones: float3 sum = 0.0.xxx; sum += mul(w0, float4x3(sample0curr, sample0adjx, sample0adjy, sample0diag)); sum += mul(w1, float4x3(sample1curr, sample1adjx, sample1adjy, sample1diag)); sum += mul(w3, float4x3(sample3curr, sample3adjx, sample3adjy, sample3diag)); sum += mul(w4, float4x3(sample4curr, sample4adjx, sample4adjy, sample4diag)); // Now do the mixed-sample ones: sum += mul(w2and5, float4x3(sample2curr, sample2adjy, sample5curr, sample5adjy)); sum += mul(w6and7, float4x3(sample6curr, sample6adjx, sample7curr, sample7adjx)); sum += w8curr * sample8curr; // Normalize the sum (so the weights add to 1.0) and return: return sum * weight_sum_inv; } float3 tex2Dblur8x8shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector, const float sigma) { // Perform a 1-pass mipmapped blur with shared samples across a pixel quad. // Requires: Same as tex2Dblur12x12shared() // Returns: A blurred texture lookup using a "virtual" 8x8 Gaussian // blur (a 4x4 blur of carefully selected bilinear samples) // of the given mip level. There will be subtle inaccuracies, // especially for small or high-frequency detailed sources. // Description: // First see the description for tex2Dblur12x12shared(). This function // shares the same concept and a similar sample placement, except each // quadrant contains 4x4 texels and 2x2 samples instead of 6x6 and 3x3 // respectively. There could be a total of 16 samples, 4 of which each // fragment is responsible for, but each fragment loads 0a/0b/0c/0d with // its own offset to reduce shared sample artifacts, bringing the sample // count for each fragment to 7. Sample placement: // 3a 2a 2b 3b // 1a 0a 0b 1b // 1c 0c 0d 1d // 3c 2c 2d 3d // Texel placement: // 3a3 3a2 2a3 2a2 2b2 2b3 3b2 3b3 // 3a1 3a0 2a1 2a0 2b0 2b1 3b0 3b1 // 1a3 1a2 0a3 0a2 0b2 0b3 1b2 1b3 // 1a1 1a0 0a1 0a0 0b0 0b1 1b0 1b1 // 1c1 1c0 0c1 0c0 0d0 0d1 1d0 1d1 // 1c3 1c2 0c3 0c2 0d2 0d3 1d2 1d3 // 3c1 3c0 2c1 2c0 2d0 2d1 3d0 4d1 // 3c3 3c2 2c3 2c2 2d2 2d3 3d2 4d3 // COMPUTE COORDS FOR TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Statically compute bilinear sampling offsets (details in tex2Dblur12x12shared). const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w0_5off = exp(-(0.5*0.5) * denom_inv); const float w1off = exp(-(1.0*1.0) * denom_inv); const float w1_5off = exp(-(1.5*1.5) * denom_inv); const float w2off = exp(-(2.0*2.0) * denom_inv); const float w2_5off = exp(-(2.5*2.5) * denom_inv); const float w3_5off = exp(-(3.5*3.5) * denom_inv); const float texel0to1ratio = lerp(w1_5off/(w0_5off + w1_5off), 0.5, error_blurring); const float texel2to3ratio = lerp(w3_5off/(w2_5off + w3_5off), 0.5, error_blurring); // We don't share sample0*, so use the nearest destination fragment: const float texel0to1ratio_nearest = w1off/(w0off + w1off); const float texel1to2ratio_nearest = w2off/(w1off + w2off); // Statically compute texel offsets from the bottom-right fragment to each // bilinear sample in the bottom-right quadrant: const float2 sample0curr_texel_offset = float2(0.0, 0.0) + float2(texel0to1ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjx_texel_offset = float2(-1.0, 0.0) + float2(-texel1to2ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjy_texel_offset = float2(0.0, -1.0) + float2(texel0to1ratio_nearest, -texel1to2ratio_nearest); const float2 sample0diag_texel_offset = float2(-1.0, -1.0) + float2(-texel1to2ratio_nearest, -texel1to2ratio_nearest); const float2 sample1_texel_offset = float2(2.0, 0.0) + float2(texel2to3ratio, texel0to1ratio); const float2 sample2_texel_offset = float2(0.0, 2.0) + float2(texel0to1ratio, texel2to3ratio); const float2 sample3_texel_offset = float2(2.0, 2.0) + float2(texel2to3ratio, texel2to3ratio); // CALCULATE KERNEL WEIGHTS: // Statically compute bilinear sample weights at each destination fragment // from the sum of their 4 texel weights (details in tex2Dblur12x12shared). #define GET_TEXEL_QUAD_WEIGHTS(xoff, yoff) \ (exp(-LENGTH_SQ(float2(xoff, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff, yoff + 1.0)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff + 1.0)) * denom_inv)) const float w3diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -4.0); const float w2diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -4.0); const float w2adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -4.0); const float w3adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -4.0); const float w1diag = GET_TEXEL_QUAD_WEIGHTS(-4.0, -2.0); const float w0diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -2.0); const float w0adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -2.0); const float w1adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -2.0); const float w1adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 0.0); const float w0adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 0.0); const float w0curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 0.0); const float w1curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 0.0); const float w3adjx = GET_TEXEL_QUAD_WEIGHTS(-4.0, 2.0); const float w2adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 2.0); const float w2curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 2.0); const float w3curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 2.0); #undef GET_TEXEL_QUAD_WEIGHTS // Statically pack weights for runtime: const float4 w0 = float4(w0curr, w0adjx, w0adjy, w0diag); const float4 w1 = float4(w1curr, w1adjx, w1adjy, w1diag); const float4 w2 = float4(w2curr, w2adjx, w2adjy, w2diag); const float4 w3 = float4(w3curr, w3adjx, w3adjy, w3diag); // Get the weight sum inverse (normalization factor): const float4 weight_sum4 = w0 + w1 + w2 + w3; const float2 weight_sum2 = weight_sum4.xy + weight_sum4.zw; const float weight_sum = weight_sum2.x + weight_sum2.y; const float weight_sum_inv = 1.0/(weight_sum); // LOAD TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Get a uv vector from texel 0q0 of this quadrant to texel 0q3: const float2 dxdy_curr = dxdy * quad_vector.xy; // Load bilinear samples for the current quadrant (for this fragment): const float3 sample0curr = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0curr_texel_offset).rgb; const float3 sample0adjx = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjx_texel_offset).rgb; const float3 sample0adjy = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjy_texel_offset).rgb; const float3 sample0diag = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0diag_texel_offset).rgb; const float3 sample1curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample1_texel_offset)).rgb; const float3 sample2curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample2_texel_offset)).rgb; const float3 sample3curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample3_texel_offset)).rgb; // GATHER NEIGHBORING SAMPLES AND SUM WEIGHTED SAMPLES: // Fetch the samples from other fragments in the 2x2 quad: float3 sample1adjx, sample1adjy, sample1diag; float3 sample2adjx, sample2adjy, sample2diag; float3 sample3adjx, sample3adjy, sample3diag; quad_gather(quad_vector, sample1curr, sample1adjx, sample1adjy, sample1diag); quad_gather(quad_vector, sample2curr, sample2adjx, sample2adjy, sample2diag); quad_gather(quad_vector, sample3curr, sample3adjx, sample3adjy, sample3diag); // Statically normalize weights (so total = 1.0), and sum weighted samples. // Fill each row of a matrix with an rgb sample and pre-multiply by the // weights to obtain a weighted result: float3 sum = 0.0.xxx; sum += mul(w0, float4x3(sample0curr, sample0adjx, sample0adjy, sample0diag)); sum += mul(w1, float4x3(sample1curr, sample1adjx, sample1adjy, sample1diag)); sum += mul(w2, float4x3(sample2curr, sample2adjx, sample2adjy, sample2diag)); sum += mul(w3, float4x3(sample3curr, sample3adjx, sample3adjy, sample3diag)); return sum * weight_sum_inv; } float3 tex2Dblur6x6shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector, const float sigma) { // Perform a 1-pass mipmapped blur with shared samples across a pixel quad. // Requires: Same as tex2Dblur12x12shared() // Returns: A blurred texture lookup using a "virtual" 6x6 Gaussian // blur (a 3x3 blur of carefully selected bilinear samples) // of the given mip level. There will be some inaccuracies,subtle inaccuracies, // especially for small or high-frequency detailed sources. // Description: // First see the description for tex2Dblur8x8shared(). This // function shares the same concept and sample placement, but each fragment // only uses 9 of the 16 samples taken across the pixel quad (to cover a // 3x3 sample area, or 6x6 texel area), and it uses a lower standard // deviation to compensate. Thanks to symmetry, the 7 omitted samples // are always the "same:" // 1adjx, 3adjx // 2adjy, 3adjy // 1diag, 2diag, 3diag // COMPUTE COORDS FOR TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Statically compute bilinear sampling offsets (details in tex2Dblur12x12shared). const float denom_inv = 0.5/(sigma*sigma); const float w0off = 1.0; const float w0_5off = exp(-(0.5*0.5) * denom_inv); const float w1off = exp(-(1.0*1.0) * denom_inv); const float w1_5off = exp(-(1.5*1.5) * denom_inv); const float w2off = exp(-(2.0*2.0) * denom_inv); const float w2_5off = exp(-(2.5*2.5) * denom_inv); const float w3_5off = exp(-(3.5*3.5) * denom_inv); const float texel0to1ratio = lerp(w1_5off/(w0_5off + w1_5off), 0.5, error_blurring); const float texel2to3ratio = lerp(w3_5off/(w2_5off + w3_5off), 0.5, error_blurring); // We don't share sample0*, so use the nearest destination fragment: const float texel0to1ratio_nearest = w1off/(w0off + w1off); const float texel1to2ratio_nearest = w2off/(w1off + w2off); // Statically compute texel offsets from the bottom-right fragment to each // bilinear sample in the bottom-right quadrant: const float2 sample0curr_texel_offset = float2(0.0, 0.0) + float2(texel0to1ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjx_texel_offset = float2(-1.0, 0.0) + float2(-texel1to2ratio_nearest, texel0to1ratio_nearest); const float2 sample0adjy_texel_offset = float2(0.0, -1.0) + float2(texel0to1ratio_nearest, -texel1to2ratio_nearest); const float2 sample0diag_texel_offset = float2(-1.0, -1.0) + float2(-texel1to2ratio_nearest, -texel1to2ratio_nearest); const float2 sample1_texel_offset = float2(2.0, 0.0) + float2(texel2to3ratio, texel0to1ratio); const float2 sample2_texel_offset = float2(0.0, 2.0) + float2(texel0to1ratio, texel2to3ratio); const float2 sample3_texel_offset = float2(2.0, 2.0) + float2(texel2to3ratio, texel2to3ratio); // CALCULATE KERNEL WEIGHTS: // Statically compute bilinear sample weights at each destination fragment // from the sum of their 4 texel weights (details in tex2Dblur12x12shared). #define GET_TEXEL_QUAD_WEIGHTS(xoff, yoff) \ (exp(-LENGTH_SQ(float2(xoff, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff, yoff + 1.0)) * denom_inv) + \ exp(-LENGTH_SQ(float2(xoff + 1.0, yoff + 1.0)) * denom_inv)) // We only need 9 of the 16 sample weights. Skip the following weights: // 1adjx, 3adjx // 2adjy, 3adjy // 1diag, 2diag, 3diag const float w0diag = GET_TEXEL_QUAD_WEIGHTS(-2.0, -2.0); const float w0adjy = GET_TEXEL_QUAD_WEIGHTS(0.0, -2.0); const float w1adjy = GET_TEXEL_QUAD_WEIGHTS(2.0, -2.0); const float w0adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 0.0); const float w0curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 0.0); const float w1curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 0.0); const float w2adjx = GET_TEXEL_QUAD_WEIGHTS(-2.0, 2.0); const float w2curr = GET_TEXEL_QUAD_WEIGHTS(0.0, 2.0); const float w3curr = GET_TEXEL_QUAD_WEIGHTS(2.0, 2.0); #undef GET_TEXEL_QUAD_WEIGHTS // Get the weight sum inverse (normalization factor): const float weight_sum_inv = 1.0/(w0curr + w1curr + w2curr + w3curr + w0adjx + w2adjx + w0adjy + w1adjy + w0diag); // Statically pack some weights for runtime: const float4 w0 = float4(w0curr, w0adjx, w0adjy, w0diag); // LOAD TEXTURE SAMPLES THIS FRAGMENT IS RESPONSIBLE FOR: // Get a uv vector from texel 0q0 of this quadrant to texel 0q3: const float2 dxdy_curr = dxdy * quad_vector.xy; // Load bilinear samples for the current quadrant (for this fragment): const float3 sample0curr = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0curr_texel_offset).rgb; const float3 sample0adjx = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjx_texel_offset).rgb; const float3 sample0adjy = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0adjy_texel_offset).rgb; const float3 sample0diag = tex2D_linearize(tex, tex_uv.xy + dxdy_curr * sample0diag_texel_offset).rgb; const float3 sample1curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample1_texel_offset)).rgb; const float3 sample2curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample2_texel_offset)).rgb; const float3 sample3curr = tex2Dlod_linearize(tex, tex_uv + uv2_to_uv4(dxdy_curr * sample3_texel_offset)).rgb; // GATHER NEIGHBORING SAMPLES AND SUM WEIGHTED SAMPLES: // Fetch the samples from other fragments in the 2x2 quad: float3 sample1adjx, sample1adjy, sample1diag; float3 sample2adjx, sample2adjy, sample2diag; quad_gather(quad_vector, sample1curr, sample1adjx, sample1adjy, sample1diag); quad_gather(quad_vector, sample2curr, sample2adjx, sample2adjy, sample2diag); // Statically normalize weights (so total = 1.0), and sum weighted samples. // Fill each row of a matrix with an rgb sample and pre-multiply by the // weights to obtain a weighted result for sample1*, and handle the rest // of the weights more directly/verbosely: float3 sum = 0.0.xxx; sum += mul(w0, float4x3(sample0curr, sample0adjx, sample0adjy, sample0diag)); sum += w1curr * sample1curr + w1adjy * sample1adjy + w2curr * sample2curr + w2adjx * sample2adjx + w3curr * sample3curr; return sum * weight_sum_inv; } /////////////////////// MAX OPTIMAL SIGMA BLUR WRAPPERS ////////////////////// // The following blurs are static wrappers around the dynamic blurs above. // HOPEFULLY, the compiler will be smart enough to do constant-folding. // Resizable separable blurs: float3 tex2Dblur11resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur11resize(tex, tex_uv, dxdy, blur11_std_dev); } float3 tex2Dblur9resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur9resize(tex, tex_uv, dxdy, blur9_std_dev); } float3 tex2Dblur7resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur7resize(tex, tex_uv, dxdy, blur7_std_dev); } float3 tex2Dblur5resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur5resize(tex, tex_uv, dxdy, blur5_std_dev); } float3 tex2Dblur3resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur3resize(tex, tex_uv, dxdy, blur3_std_dev); } // Fast separable blurs: float3 tex2Dblur11fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur11fast(tex, tex_uv, dxdy, blur11_std_dev); } float3 tex2Dblur9fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur9fast(tex, tex_uv, dxdy, blur9_std_dev); } float3 tex2Dblur7fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur7fast(tex, tex_uv, dxdy, blur7_std_dev); } float3 tex2Dblur5fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur5fast(tex, tex_uv, dxdy, blur5_std_dev); } float3 tex2Dblur3fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur3fast(tex, tex_uv, dxdy, blur3_std_dev); } // Huge, "fast" separable blurs: float3 tex2Dblur43fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur43fast(tex, tex_uv, dxdy, blur43_std_dev); } float3 tex2Dblur31fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur31fast(tex, tex_uv, dxdy, blur31_std_dev); } float3 tex2Dblur25fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur25fast(tex, tex_uv, dxdy, blur25_std_dev); } float3 tex2Dblur17fast(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur17fast(tex, tex_uv, dxdy, blur17_std_dev); } // Resizable one-pass blurs: float3 tex2Dblur3x3resize(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur3x3resize(tex, tex_uv, dxdy, blur3_std_dev); } // "Fast" one-pass blurs: float3 tex2Dblur9x9(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur9x9(tex, tex_uv, dxdy, blur9_std_dev); } float3 tex2Dblur7x7(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur7x7(tex, tex_uv, dxdy, blur7_std_dev); } float3 tex2Dblur5x5(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur5x5(tex, tex_uv, dxdy, blur5_std_dev); } float3 tex2Dblur3x3(const sampler2D tex, const float2 tex_uv, const float2 dxdy) { return tex2Dblur3x3(tex, tex_uv, dxdy, blur3_std_dev); } // "Fast" shared-sample one-pass blurs: float3 tex2Dblur12x12shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector) { return tex2Dblur12x12shared(tex, tex_uv, dxdy, quad_vector, blur12_std_dev); } float3 tex2Dblur10x10shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector) { return tex2Dblur10x10shared(tex, tex_uv, dxdy, quad_vector, blur10_std_dev); } float3 tex2Dblur8x8shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector) { return tex2Dblur8x8shared(tex, tex_uv, dxdy, quad_vector, blur8_std_dev); } float3 tex2Dblur6x6shared(const sampler2D tex, const float4 tex_uv, const float2 dxdy, const float4 quad_vector) { return tex2Dblur6x6shared(tex, tex_uv, dxdy, quad_vector, blur6_std_dev); } #endif // BLUR_FUNCTIONS_H