/**
** Supermodel
** A Sega Model 3 Arcade Emulator.
** Copyright 2011 Bart Trzynadlowski
**
** 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 <http://www.gnu.org/licenses/>.
**/
/*
* Shaders3D.h
*
* Header file containing the 3D vertex and fragment shaders.
*/
#ifndef INCLUDED_SHADERS3D_H
#define INCLUDED_SHADERS3D_H
// Vertex shader
static const char vertexShaderSource[] =
{
"/** \n"
" ** Supermodel \n"
" ** A Sega Model 3 Arcade Emulator. \n"
" ** Copyright 2011 Bart Trzynadlowski \n"
" ** \n"
" ** This file is part of Supermodel. \n"
" ** \n"
" ** Supermodel is free software: you can redistribute it and/or modify it under \n"
" ** the terms of the GNU General Public License as published by the Free \n"
" ** Software Foundation, either version 3 of the License, or (at your option) \n"
" ** any later version. \n"
" ** \n"
" ** Supermodel is distributed in the hope that it will be useful, but WITHOUT \n"
" ** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or \n"
" ** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for \n"
" ** more details. \n"
" ** \n"
" ** You should have received a copy of the GNU General Public License along \n"
" ** with Supermodel. If not, see <http://www.gnu.org/licenses/>. \n"
" **/ \n"
"\n"
"/* \n"
" * Vertex.glsl \n"
" * \n"
" * Vertex shader for 3D rendering. \n"
" */ \n"
"\n"
"#version 120 \n"
"\n"
"// Global uniforms \n"
"uniform mat4 modelViewMatrix; // model -> view space matrix \n"
"uniform mat4 projectionMatrix; // view space -> screen space matrix \n"
"uniform vec3 lighting[2]; // lighting state (lighting[0] = sun direction, lighting[1].x,y = diffuse, ambient intensities from 0-1.0) \n"
"uniform vec4 spotEllipse; // spotlight ellipse position: .x=X position (normalized device coordinates), .y=Y position, .z=half-width, .w=half-height) \n"
"uniform vec2 spotRange; // spotlight Z range: .x=start (viewspace coordinates), .y=limit \n"
"uniform vec3 spotColor; // spotlight RGB color \n"
"\n"
"// Custom vertex attributes \n"
"attribute vec4 subTexture; // .x=texture X, .y=texture Y, .z=texture width, .w=texture height (all in texels) \n"
"attribute vec4 texParams; // .x=texture enable (if 1, else 0), .y=use transparency (if >=0), .z=U wrap mode (1=mirror, 0=repeat), .w=V wrap mode \n"
"attribute float texFormat; // .x=T1RGB5 contour texture (if > 0) \n"
"attribute float transLevel; // translucence level, 0.0 (transparent) to 1.0 (opaque). if less than 1.0, replace alpha value \n"
"attribute float lightEnable; // lighting enabled (1.0) or luminous (0.0), drawn at full intensity \n"
"attribute float fogIntensity; // fog intensity (1.0, full fog effect, 0.0, no fog) \n"
"\n"
"// Custom outputs to fragment shader \n"
"varying vec4 fsSubTexture; \n"
"varying vec4 fsTexParams; \n"
"varying float fsTexFormat; \n"
"varying float fsTransLevel; \n"
"varying vec3 fsLightIntensity; // total light intensity for this vertex \n"
"varying float fsFogFactor; // fog factor \n"
"varying float fsViewZ; \n"
"\n"
"// Gets the 3x3 matrix out of a 4x4 (because mat3(mat4matrix) does not work on ATI!) \n"
"mat3 GetLinearPart( mat4 m ) \n"
"{ \n"
" mat3 result; \n"
"\n"
" result[0][0] = m[0][0]; \n"
" result[0][1] = m[0][1]; \n"
" result[0][2] = m[0][2]; \n"
"\n"
" result[1][0] = m[1][0]; \n"
" result[1][1] = m[1][1]; \n"
" result[1][2] = m[1][2]; \n"
"\n"
" result[2][0] = m[2][0]; \n"
" result[2][1] = m[2][1]; \n"
" result[2][2] = m[2][2]; \n"
"\n"
" return result; \n"
"} \n"
"\n"
"void main(void) \n"
"{ \n"
" vec3 viewVertex; // vertex coordinates in view space \n"
" vec3 viewNormal; // vertex normal in view space \n"
" vec3 sunVector; // sun lighting vector (as reflecting away from vertex) \n"
" float sunFactor; // sun light projection along vertex normal (0.0 to 1.0) \n"
" vec3 halfway; \n"
" float specFactor; \n"
" \n"
" // Transform vertex \n"
" gl_Position = projectionMatrix * modelViewMatrix * gl_Vertex; \n"
" viewVertex = vec3(modelViewMatrix * gl_Vertex); \n"
" \n"
" /* \n"
" * Modulation \n"
" * \n"
" * Polygon color serves as material color (modulating the light intensity) \n"
" * for textured polygons. The fragment shader will ignore (overwrite) the \n"
" * the color passed to it if the fragment is textured. \n"
" * \n"
" * Untextured fragments must be set to the polygon color and the light \n"
" * intensity is initialized to 1.0 here. Alpha must be set to 1.0 because \n"
" * the fragment shader multiplies it by the polygon translucency setting. \n"
" * \n"
" * To-do: Does OpenGL set alpha to 1.0 by default if no alpha is specified \n"
" * for the vertex? If so, we can remove that line from here. \n"
" */ \n"
" \n"
" gl_FrontColor = gl_Color; // untextured polygons will use this \n"
" gl_FrontColor.a = 1.0; \n"
" fsLightIntensity = vec3(1.0,1.0,1.0); \n"
" if (texParams.x > 0.0) // textured \n"
" fsLightIntensity *= gl_Color.rgb; \n"
" \n"
" /* \n"
" * Sun Light \n"
" * \n"
" * Parallel light source and ambient lighting are only applied for non- \n"
" * luminous polygons. \n"
" */ \n"
" if (lightEnable > 0.5) // not luminous \n"
" { \n"
" // Normal -> view space \n"
" viewNormal = normalize(GetLinearPart(modelViewMatrix)*gl_Normal); \n"
" \n"
" // Real3D -> OpenGL view space convention (TO-DO: do this outside of shader) \n"
" sunVector = lighting[0]*vec3(1.0,-1.0,-1.0); \n"
" \n"
" // Compute diffuse factor for sunlight \n"
" sunFactor = max(dot(sunVector,viewNormal),0.0); \n"
" \n"
" // Total light intensity: sum of all components \n"
" fsLightIntensity *= (sunFactor*lighting[1].x+lighting[1].y); \n"
" fsLightIntensity = clamp(fsLightIntensity,0.0,1.0); \n"
" } \n"
" \n"
" // Fog \n"
" float z = length(viewVertex); \n"
" fsFogFactor = clamp(1.0-fogIntensity*(gl_Fog.start+z*gl_Fog.density), 0.0, 1.0); \n"
" \n"
" // Pass viewspace Z coordinate (for spotlight) \n"
" fsViewZ = -viewVertex.z; // convert Z from GL->Real3D convention (want +Z to be further into screen) \n"
" \n"
" // Pass remaining parameters to fragment shader \n"
" gl_TexCoord[0] = gl_MultiTexCoord0; \n"
" fsSubTexture = subTexture; \n"
" fsTexParams = texParams; \n"
" fsTransLevel = transLevel; \n"
" fsTexFormat = texFormat; \n"
"}\n"
};
// Fragment shader
static const char fragmentShaderSource[] =
{
"/** \n"
" ** Supermodel \n"
" ** A Sega Model 3 Arcade Emulator. \n"
" ** Copyright 2011 Bart Trzynadlowski \n"
" ** \n"
" ** This file is part of Supermodel. \n"
" ** \n"
" ** Supermodel is free software: you can redistribute it and/or modify it under \n"
" ** the terms of the GNU General Public License as published by the Free \n"
" ** Software Foundation, either version 3 of the License, or (at your option) \n"
" ** any later version. \n"
" ** \n"
" ** Supermodel is distributed in the hope that it will be useful, but WITHOUT \n"
" ** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or \n"
" ** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for \n"
" ** more details. \n"
" ** \n"
" ** You should have received a copy of the GNU General Public License along \n"
" ** with Supermodel. If not, see <http://www.gnu.org/licenses/>. \n"
" **/ \n"
" \n"
"/* \n"
" * Fragment.glsl \n"
" * \n"
" * Fragment shader for 3D rendering. \n"
" */ \n"
" \n"
"#version 120 \n"
" \n"
"// Global uniforms \n"
"uniform sampler2D textureMap; // complete texture map, 2048x2048 texels \n"
"uniform vec4 spotEllipse; // spotlight ellipse position: .x=X position (normalized device coordinates), .y=Y position, .z=half-width, .w=half-height) \n"
"uniform vec2 spotRange; // spotlight Z range: .x=start (viewspace coordinates), .y=limit \n"
"uniform vec3 spotColor; // spotlight RGB color \n"
"\n"
"// Inputs from vertex shader \n"
"varying vec4 fsSubTexture; // .x=texture X, .y=texture Y, .z=texture width, .w=texture height (all in texels) \n"
"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 \n"
"varying float fsTexFormat; // .x=T1RGB5 contour texture (if > 0) \n"
"varying float fsTransLevel; // translucence level, 0.0 (transparent) to 1.0 (opaque) \n"
"varying vec3 fsLightIntensity; // lighting intensity \n"
"varying float fsFogFactor; // fog factor \n"
"varying float fsViewZ; // Z distance to fragment from viewpoint at origin \n"
"\n"
"/* \n"
" * WrapTexelCoords(): \n"
" * \n"
" * Computes the normalized OpenGL S,T coordinates within the 2048x2048 texture \n"
" * sheet, taking into account wrapping behavior. \n"
" * \n"
" * Computing normalized OpenGL texture coordinates (0 to 1) within the \n"
" * Real3D texture sheet: \n"
" * \n"
" * If the texture is not mirrored, we simply have to clamp the \n"
" * coordinates to fit within the texture dimensions, add the texture \n"
" * X, Y position to select the appropriate one, and normalize by 2048 \n"
" * (the dimensions of the Real3D texture sheet). \n"
" * \n"
" * = [(u,v)%(w,h)+(x,y)]/(2048,2048) \n"
" * \n"
" * If mirroring is enabled, textures are mirrored every odd multiple of \n"
" * the original texture. To detect whether we are in an odd multiple, \n"
" * simply divide the coordinate by the texture dimension and check \n"
" * whether the result is odd. Then, clamp the coordinates as before but \n"
" * subtract from the last texel to mirror them: \n"
" * \n"
" * = [M*((w-1,h-1)-(u,v)%(w,h)) + (1-M)*(u,v)%(w,h) + (x,y)]/(2048,2048) \n"
" * where M is 1.0 if the texture must be mirrored. \n"
" * \n"
" * As an optimization, this function computes TWO texture coordinates \n"
" * simultaneously. The first is texCoord.xy, the second is in .zw. The other \n"
" * parameters must have .xy = .zw. \n"
" */ \n"
"vec4 WrapTexelCoords(vec4 texCoord, vec4 texOffset, vec4 texSize, vec4 mirrorEnable) \n"
"{ \n"
" vec4 clampedCoord, mirror, glTexCoord; \n"
" \n"
" clampedCoord = mod(texCoord,texSize); // clamp coordinates to within texture size \n"
" mirror = mirrorEnable * mod(floor(texCoord/texSize),2.0); // whether this texel needs to be mirrored \n"
" \n"
" glTexCoord = ( mirror*(texSize-clampedCoord) + \n"
" (vec4(1.0,1.0,1.0,1.0)-mirror)*clampedCoord + \n"
" texOffset \n"
" ) / 2048.0; \n"
" return glTexCoord; \n"
"} \n"
"\n"
"/* \n"
" * main(): \n"
" * \n"
" * Fragment shader entry point. \n"
" */ \n"
"\n"
"void main(void) \n"
"{ \n"
" vec4 uv_top, uv_bot, c[4]; \n"
" vec2 r; \n"
" vec4 fragColor; \n"
" vec2 ellipse; \n"
" vec3 lightIntensity; \n"
" float insideSpot; \n"
" \n"
" // Get polygon color for untextured polygons (textured polygons will overwrite) \n"
" if (fsTexParams.x==0.0) \n"
" fragColor = gl_Color; \n"
" else \n"
" // Textured polygons: set fragment color to texel value \n"
" { \n"
" /* \n"
" * Bilinear Filtering \n"
" * \n"
" * In order to get this working on ATI, the number of operations is \n"
" * reduced by putting everything into vec4s. uv_top holds the UV \n"
" * coordinates for the top two texels (.xy=left, .zw=right) and uv_bot \n"
" * is for the lower two. \n"
" */ \n"
" \n"
" // Compute fractional blending factor, r, and lower left corner of texel 0 \n"
" uv_bot.xy = gl_TexCoord[0].st-vec2(0.5,0.5); // move into the lower left blending texel \n"
" r = uv_bot.xy-floor(uv_bot.xy); // fractional part \n"
" uv_bot.xy = floor(uv_bot.xy); // integral part \n"
" \n"
" // Compute texel coordinates \n"
" 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) \n"
" uv_bot.zw = uv_bot.xy + vec2(1.0,0.0); // compute coordinates of the other three neighbors \n"
" uv_top = uv_bot + vec4(0.0,1.0,0.0,1.0); \n"
" \n"
" // Compute the properly wrapped texel coordinates \n"
" uv_top = WrapTexelCoords(uv_top,vec4(fsSubTexture.xy,fsSubTexture.xy),vec4(fsSubTexture.zw,fsSubTexture.zw), vec4(fsTexParams.zw,fsTexParams.zw)); \n"
" uv_bot = WrapTexelCoords(uv_bot,vec4(fsSubTexture.xy,fsSubTexture.xy),vec4(fsSubTexture.zw,fsSubTexture.zw), vec4(fsTexParams.zw,fsTexParams.zw)); \n"
" \n"
" // Fetch the texels \n"
" c[0]=texture2D(textureMap,uv_bot.xy); // bottom-left (base texel) \n"
" c[1]=texture2D(textureMap,uv_bot.zw); // bottom-right \n"
" c[2]=texture2D(textureMap,uv_top.xy); // top-left \n"
" c[3]=texture2D(textureMap,uv_top.zw); // top-right \n"
" \n"
" // Interpolate texels and blend result with material color to determine final (unlit) fragment color \n"
" // 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); \n"
" // Faster method: \n"
" c[0] += (c[1]-c[0])*r.s; // 2 alu \n"
" c[2] += (c[3]-c[2])*r.s; // 2 alu \n"
" fragColor = c[0]+(c[2]-c[0])*r.t; // 2 alu \n"
" \n"
" /* \n"
" * T1RGB5: \n"
" * \n"
" * The transparency bit determines whether to discard pixels (if set). \n"
" * What is unknown is how this bit behaves when interpolated. OpenGL \n"
" * processes it as an alpha value, so it might concievably be blended \n"
" * with neighbors. Here, an arbitrary threshold is chosen. \n"
" * \n"
" * To-do: blending could probably enabled and this would work even \n"
" * better with a hard threshold. \n"
" * \n"
" * Countour processing also seems to be enabled for RGBA4 textures. \n"
" * When the alpha value is 0.0 (or close), pixels are discarded \n"
" * entirely. \n"
" */ \n"
" if (fsTexParams.y > 0.0) // contour processing enabled \n"
" { \n"
" if (fragColor.a < 0.01) // discard anything with alpha == 0 \n"
" discard; \n"
" } \n"
" \n"
" // If contour texture and not discarded, force alpha to 1.0 because will later be modified by polygon translucency \n"
" if (fsTexFormat > 0.0) // contour (T1RGB5) texture map \n"
" fragColor.a = 1.0; \n"
" } \n"
" \n"
" // Compute spotlight and apply lighting \n"
" ellipse = (gl_FragCoord.xy-spotEllipse.xy)/spotEllipse.zw; \n"
" insideSpot = dot(ellipse,ellipse); \n"
" if ((insideSpot <= 1.0) && (fsViewZ>=spotRange.x) && (fsViewZ<spotRange.y)) \n"
" lightIntensity = min(fsLightIntensity+(1.0-insideSpot)*spotColor,1.0); \n"
" else \n"
" lightIntensity = fsLightIntensity; \n"
" fragColor.rgb *= lightIntensity; \n"
" \n"
" // Translucency (modulates existing alpha channel for RGBA4 texels) \n"
" fragColor.a *= fsTransLevel; \n"
" \n"
" // Apply fog under the control of fog factor setting from polygon header \n"
" fragColor.rgb = mix(gl_Fog.color.rgb, fragColor.rgb, fsFogFactor ); \n"
" \n"
" // Store final color \n"
" gl_FragColor = fragColor; \n"
"}\n"
};
#endif // INCLUDED_SHADERS3D_H