/** ** Supermodel ** A Sega Model 3 Arcade Emulator. ** Copyright 2011-2012 Bart Trzynadlowski, Nik Henson ** ** This file is part of Supermodel. ** ** Supermodel is free software: you can redistribute it and/or modify it under ** the terms of the GNU General Public License as published by the Free ** Software Foundation, either version 3 of the License, or (at your option) ** any later version. ** ** Supermodel is distributed in the hope that it will be useful, but WITHOUT ** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for ** more details. ** ** You should have received a copy of the GNU General Public License along ** with Supermodel. If not, see . **/ /* * Fragment_MultiSheet.glsl * * Fragment shader for 3D rendering. Uses 8 texture sheets to decode the * different possible formats. */ #version 120 // Global uniforms uniform sampler2D textureMap0; // complete texture map (fmt 0), 2048x2048 texels uniform sampler2D textureMap1; // complete texture map (fmt 1), 2048x2048 texels uniform sampler2D textureMap2; // complete texture map (fmt 2), 2048x2048 texels uniform sampler2D textureMap3; // complete texture map (fmt 3), 2048x2048 texels uniform sampler2D textureMap4; // complete texture map (fmt 4), 2048x2048 texels uniform sampler2D textureMap5; // complete texture map (fmt 5), 2048x2048 texels uniform sampler2D textureMap6; // complete texture map (fmt 6), 2048x2048 texels uniform sampler2D textureMap7; // complete texture map (fmt 7), 2048x2048 texels uniform vec4 spotEllipse; // spotlight ellipse position: .x=X position (screen coordinates), .y=Y position, .z=half-width, .w=half-height) uniform vec2 spotRange; // spotlight Z range: .x=start (viewspace coordinates), .y=limit uniform vec3 spotColor; // spotlight RGB color uniform vec3 lighting[2]; // lighting state (lighting[0] = sun direction, lighting[1].x,y = diffuse, ambient intensities from 0-1.0) // Inputs from vertex shader varying vec4 fsSubTexture; // .x=texture X, .y=texture Y, .z=texture width, .w=texture height (all in texels) varying vec4 fsTexParams; // .x=texture enable (if 1, else 0), .y=use transparency (if > 0), .z=U wrap mode (1=mirror, 0=repeat), .w=V wrap mode varying float fsTexFormat; // T1RGB5 contour texture (if > 0) varying float fsTransLevel; // translucence level, 0.0 (transparent) to 1.0 (opaque) varying vec3 fsLightIntensity; // lighting intensity varying float fsSpecularTerm; // specular highlight varying float fsFogFactor; // fog factor varying float fsViewZ; // Z distance to fragment from viewpoint at origin /* * WrapTexelCoords(): * * Computes the normalized OpenGL S,T coordinates within the 2048x2048 texture * sheet, taking into account wrapping behavior. * * Computing normalized OpenGL texture coordinates (0 to 1) within the * Real3D texture sheet: * * If the texture is not mirrored, we simply have to clamp the * coordinates to fit within the texture dimensions, add the texture * X, Y position to select the appropriate one, and normalize by 2048 * (the dimensions of the Real3D texture sheet). * * = [(u,v)%(w,h)+(x,y)]/(2048,2048) * * If mirroring is enabled, textures are mirrored every odd multiple of * the original texture. To detect whether we are in an odd multiple, * simply divide the coordinate by the texture dimension and check * whether the result is odd. Then, clamp the coordinates as before but * subtract from the last texel to mirror them: * * = [M*((w-1,h-1)-(u,v)%(w,h)) + (1-M)*(u,v)%(w,h) + (x,y)]/(2048,2048) * where M is 1.0 if the texture must be mirrored. * * As an optimization, this function computes TWO texture coordinates * simultaneously. The first is texCoord.xy, the second is in .zw. The other * parameters must have .xy = .zw. */ vec4 WrapTexelCoords(vec4 texCoord, vec4 texOffset, vec4 texSize, vec4 mirrorEnable) { vec4 clampedCoord, mirror, glTexCoord; clampedCoord = mod(texCoord,texSize); // clamp coordinates to within texture size mirror = mirrorEnable * mod(floor(texCoord/texSize),2.0); // whether this texel needs to be mirrored glTexCoord = ( mirror*(texSize-clampedCoord) + (vec4(1.0,1.0,1.0,1.0)-mirror)*clampedCoord + texOffset ) / 2048.0; return glTexCoord; } /* * main(): * * Fragment shader entry point. */ void main(void) { vec4 uv_top, uv_bot, c[4]; vec2 r; vec4 fragColor; vec2 ellipse; vec3 lightIntensity; float insideSpot; int x; // Get polygon color for untextured polygons (textured polygons will overwrite) if (fsTexParams.x < 0.5) fragColor = gl_Color; else // Textured polygons: set fragment color to texel value { /* * Bilinear Filtering * * In order to get this working on ATI, the number of operations is * reduced by putting everything into vec4s. uv_top holds the UV * coordinates for the top two texels (.xy=left, .zw=right) and uv_bot * is for the lower two. */ // Compute fractional blending factor, r, and lower left corner of texel 0 uv_bot.xy = gl_TexCoord[0].st-vec2(0.5,0.5); // move into the lower left blending texel r = uv_bot.xy-floor(uv_bot.xy); // fractional part uv_bot.xy = floor(uv_bot.xy); // integral part // Compute texel coordinates uv_bot.xy += vec2(0.5,0.5); // offset to center of pixel (should not be needed but it fixes a lot of glitches, esp. on Nvidia) uv_bot.zw = uv_bot.xy + vec2(1.0,0.0); // compute coordinates of the other three neighbors uv_top = uv_bot + vec4(0.0,1.0,0.0,1.0); // Compute the properly wrapped texel coordinates uv_top = WrapTexelCoords(uv_top,vec4(fsSubTexture.xy,fsSubTexture.xy),vec4(fsSubTexture.zw,fsSubTexture.zw), vec4(fsTexParams.zw,fsTexParams.zw)); uv_bot = WrapTexelCoords(uv_bot,vec4(fsSubTexture.xy,fsSubTexture.xy),vec4(fsSubTexture.zw,fsSubTexture.zw), vec4(fsTexParams.zw,fsTexParams.zw)); // Fetch the texels from the texture map that corresponds to the current texture format if (fsTexFormat < 0.5f) { c[0]=texture2D(textureMap0, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap0, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap0, uv_top.xy); // top-left c[3]=texture2D(textureMap0, uv_top.zw); // top-right } else if (fsTexFormat < 1.5f) { c[0]=texture2D(textureMap1, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap1, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap1, uv_top.xy); // top-left c[3]=texture2D(textureMap1, uv_top.zw); // top-right } else if (fsTexFormat < 2.5f) { c[0]=texture2D(textureMap2, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap2, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap2, uv_top.xy); // top-left c[3]=texture2D(textureMap2, uv_top.zw); // top-right } else if (fsTexFormat < 3.5f) { c[0]=texture2D(textureMap3, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap3, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap3, uv_top.xy); // top-left c[3]=texture2D(textureMap3, uv_top.zw); // top-right } else if (fsTexFormat < 4.5f) { c[0]=texture2D(textureMap4, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap4, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap4, uv_top.xy); // top-left c[3]=texture2D(textureMap4, uv_top.zw); // top-right } else if (fsTexFormat < 5.5f) { c[0]=texture2D(textureMap5, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap5, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap5, uv_top.xy); // top-left c[3]=texture2D(textureMap5, uv_top.zw); // top-right } else if (fsTexFormat < 6.5f) { c[0]=texture2D(textureMap6, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap6, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap6, uv_top.xy); // top-left c[3]=texture2D(textureMap6, uv_top.zw); // top-right } else { c[0]=texture2D(textureMap7, uv_bot.xy); // bottom-left (base texel) c[1]=texture2D(textureMap7, uv_bot.zw); // bottom-right c[2]=texture2D(textureMap7, uv_top.xy); // top-left c[3]=texture2D(textureMap7, uv_top.zw); // top-right } // Interpolate texels and blend result with material color to determine final (unlit) fragment color // fragColor = (c[0]*(1.0-r.s)*(1.0-r.t) + c[1]*r.s*(1.0-r.t) + c[2]*(1.0-r.s)*r.t + c[3]*r.s*r.t); // Faster method: c[0] += (c[1]-c[0])*r.s; // 2 alu c[2] += (c[3]-c[2])*r.s; // 2 alu fragColor = c[0]+(c[2]-c[0])*r.t; // 2 alu /* * T1RGB5: * * The transparency bit determines whether to discard pixels (if set). * What is unknown is how this bit behaves when interpolated. OpenGL * processes it as an alpha value, so it might concievably be blended * with neighbors. Here, an arbitrary threshold is chosen. * * To-do: blending could probably enabled and this would work even * better with a hard threshold. * * Countour processing also seems to be enabled for RGBA4 textures. * When the alpha value is 0.0 (or close), pixels are discarded * entirely. */ if (fsTexParams.y > 0.5) // contour processing enabled { if (fragColor.a < 0.01) // discard anything with alpha == 0 discard; } // If contour texture and not discarded, force alpha to 1.0 because will later be modified by polygon translucency if (fsTexFormat < 0.5) // contour (T1RGB5) texture map fragColor.a = 1.0; } // Compute spotlight and apply lighting ellipse = (gl_FragCoord.xy-spotEllipse.xy)/spotEllipse.zw; insideSpot = dot(ellipse,ellipse); if ((insideSpot <= 1.0) && (fsViewZ>=spotRange.x) && (fsViewZ