ppsspp/GPU/GLES/FragmentShaderGenerator.cpp
2013-09-10 09:20:50 +08:00

381 lines
12 KiB
C++

// Copyright (c) 2012- PPSSPP Project.
// This program 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, version 2.0 or later versions.
// This program 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 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
#if defined(USING_GLES2)
#define GLSL_ES_1_0
#else
#define GLSL_1_3
// SDL 1.2 on Apple does not have support for OpenGL 3 and hence needs
// special treatment in the shader generator.
#if defined(__APPLE__)
#define FORCE_OPENGL_2_0
#endif
#endif
#include "FragmentShaderGenerator.h"
#include "Framebuffer.h"
#include "../ge_constants.h"
#include "../GPUState.h"
#include "Core/Reporting.h"
#include <cstdio>
#define WRITE p+=sprintf
// #define DEBUG_SHADER
// GL_NV_shader_framebuffer_fetch looks interesting....
// Dest factors where it's safe to eliminate the alpha test under certain conditions
const bool safeDestFactors[16] = {
true, // GE_DSTBLEND_SRCCOLOR,
true, // GE_DSTBLEND_INVSRCCOLOR,
false, // GE_DSTBLEND_SRCALPHA,
true, // GE_DSTBLEND_INVSRCALPHA,
true, // GE_DSTBLEND_DSTALPHA,
true, // GE_DSTBLEND_INVDSTALPHA,
false, // GE_DSTBLEND_DOUBLESRCALPHA,
false, // GE_DSTBLEND_DOUBLEINVSRCALPHA,
true, // GE_DSTBLEND_DOUBLEDSTALPHA,
true, // GE_DSTBLEND_DOUBLEINVDSTALPHA,
true, //GE_DSTBLEND_FIXB,
};
static bool IsAlphaTestTriviallyTrue() {
GEComparison alphaTestFunc = gstate.getAlphaTestFunction();
int alphaTestRef = gstate.getAlphaTestRef();
int alphaTestMask = gstate.getAlphaTestMask();
switch (alphaTestFunc) {
case GE_COMP_NEVER:
return false;
case GE_COMP_ALWAYS:
return true;
case GE_COMP_GEQUAL:
return alphaTestRef == 0;
// Non-zero check. If we have no depth testing (and thus no depth writing), and an alpha func that will result in no change if zero alpha, get rid of the alpha test.
// Speeds up Lumines by a LOT on PowerVR.
case GE_COMP_NOTEQUAL:
case GE_COMP_GREATER:
{
bool depthTest = gstate.isDepthTestEnabled();
bool stencilTest = gstate.isStencilTestEnabled();
GEBlendSrcFactor src = gstate.getBlendFuncA();
GEBlendDstFactor dst = gstate.getBlendFuncB();
if (!stencilTest && !depthTest && alphaTestRef == 0 && gstate.isAlphaBlendEnabled() && src == GE_SRCBLEND_SRCALPHA && safeDestFactors[(int)dst])
return true;
return false;
}
case GE_COMP_LEQUAL:
return alphaTestRef == 255;
case GE_COMP_EQUAL:
case GE_COMP_LESS:
return false;
default:
return false;
}
}
static bool IsColorTestTriviallyTrue() {
GEComparison colorTestFunc = gstate.getColorTestFunction();
switch (colorTestFunc) {
case GE_COMP_NEVER:
return false;
case GE_COMP_ALWAYS:
return true;
case GE_COMP_EQUAL:
case GE_COMP_NOTEQUAL:
return false;
default:
return false;
}
}
static bool CanDoubleSrcBlendMode() {
if (!gstate.isAlphaBlendEnabled()) {
return false;
}
int funcA = gstate.getBlendFuncA();
int funcB = gstate.getBlendFuncB();
if (funcA != GE_SRCBLEND_DOUBLESRCALPHA) {
funcB = funcA;
funcA = gstate.getBlendFuncB();
}
if (funcA != GE_SRCBLEND_DOUBLESRCALPHA) {
return false;
}
// One side should be doubled. Let's check the other side.
// LittleBigPlanet, for example, uses 2.0 * src, 1.0 - src, which can't double.
switch (funcB) {
case GE_DSTBLEND_SRCALPHA:
case GE_DSTBLEND_INVSRCALPHA:
return false;
default:
return true;
}
}
// Here we must take all the bits of the gstate that determine what the fragment shader will
// look like, and concatenate them together into an ID.
void ComputeFragmentShaderID(FragmentShaderID *id) {
memset(&id->d[0], 0, sizeof(id->d));
if (gstate.isModeClear()) {
// We only need one clear shader, so let's ignore the rest of the bits.
id->d[0] = 1;
} else {
bool lmode = gstate.isUsingSecondaryColor() && gstate.isLightingEnabled();
bool enableFog = gstate.isFogEnabled() && !gstate.isModeThrough();
bool enableAlphaTest = gstate.isAlphaTestEnabled() && !IsAlphaTestTriviallyTrue();
bool enableColorTest = gstate.isColorTestEnabled() && !IsColorTestTriviallyTrue();
bool enableColorDoubling = gstate.isColorDoublingEnabled();
// This isn't really correct, but it's a hack to get doubled blend modes to work more correctly.
bool enableAlphaDoubling = CanDoubleSrcBlendMode();
bool doTextureProjection = gstate.getUVGenMode() == GE_TEXMAP_TEXTURE_MATRIX;
bool doTextureAlpha = gstate.isTextureAlphaUsed();
// All texfuncs except replace are the same for RGB as for RGBA with full alpha.
if (gstate_c.textureFullAlpha && gstate.getTextureFunction() != GE_TEXFUNC_REPLACE)
doTextureAlpha = false;
// id->d[0] |= (gstate.isModeClear() & 1);
if (gstate.isTextureMapEnabled()) {
id->d[0] |= 1 << 1;
id->d[0] |= gstate.getTextureFunction() << 2;
id->d[0] |= (doTextureAlpha & 1) << 5; // rgb or rgba
}
id->d[0] |= (lmode & 1) << 7;
id->d[0] |= gstate.isAlphaTestEnabled() << 8;
if (enableAlphaTest)
id->d[0] |= gstate.getAlphaTestFunction() << 9;
id->d[0] |= gstate.isColorTestEnabled() << 12;
if (enableColorTest)
id->d[0] |= gstate.getColorTestFunction() << 13; // color test func
id->d[0] |= (enableFog & 1) << 15;
id->d[0] |= (doTextureProjection & 1) << 16;
id->d[0] |= (enableColorDoubling & 1) << 17;
id->d[0] |= (enableAlphaDoubling & 1) << 18;
if (enableAlphaTest)
gpuStats.numAlphaTestedDraws++;
else
gpuStats.numNonAlphaTestedDraws++;
}
}
// Missing: Z depth range
// Also, logic ops etc, of course. Urgh.
void GenerateFragmentShader(char *buffer) {
char *p = buffer;
#if defined(GLSL_ES_1_0)
WRITE(p, "#version 100\n"); // GLSL ES 1.0
WRITE(p, "precision lowp float;\n");
#elif !defined(FORCE_OPENGL_2_0)
WRITE(p, "#version 110\n");
#endif
bool lmode = gstate.isUsingSecondaryColor() && gstate.isLightingEnabled();
bool doTexture = gstate.isTextureMapEnabled() && !gstate.isModeClear();
bool enableFog = gstate.isFogEnabled() && !gstate.isModeThrough() && !gstate.isModeClear();
bool enableAlphaTest = gstate.isAlphaTestEnabled() && !IsAlphaTestTriviallyTrue() && !gstate.isModeClear();
bool enableColorTest = gstate.isColorTestEnabled() && !IsColorTestTriviallyTrue() && !gstate.isModeClear();
bool enableColorDoubling = gstate.isColorDoublingEnabled();
// This isn't really correct, but it's a hack to get doubled blend modes to work more correctly.
bool enableAlphaDoubling = CanDoubleSrcBlendMode();
bool doTextureProjection = gstate.getUVGenMode() == GE_TEXMAP_TEXTURE_MATRIX;
bool doTextureAlpha = gstate.isTextureAlphaUsed();
if (gstate_c.textureFullAlpha && gstate.getTextureFunction() != GE_TEXFUNC_REPLACE)
doTextureAlpha = false;
if (doTexture)
WRITE(p, "uniform sampler2D tex;\n");
if (enableAlphaTest || enableColorTest) {
#if defined(GLSL_ES_1_0)
WRITE(p, "uniform mediump vec4 u_alphacolorref;\n");
#else
WRITE(p, "uniform vec4 u_alphacolorref;\n");
#endif
WRITE(p, "uniform vec4 u_colormask;\n");
}
if (gstate.isTextureMapEnabled())
WRITE(p, "uniform vec3 u_texenv;\n");
WRITE(p, "varying vec4 v_color0;\n");
if (lmode)
WRITE(p, "varying vec3 v_color1;\n");
if (enableFog) {
WRITE(p, "uniform vec3 u_fogcolor;\n");
#if defined(GLSL_ES_1_0)
WRITE(p, "varying mediump float v_fogdepth;\n");
#else
WRITE(p, "varying float v_fogdepth;\n");
#endif
}
if (doTexture)
{
if (doTextureProjection)
WRITE(p, "varying vec3 v_texcoord;\n");
else
WRITE(p, "varying vec2 v_texcoord;\n");
}
if (enableAlphaTest) {
if (gstate_c.gpuVendor == GPU_VENDOR_POWERVR)
WRITE(p, "float roundTo255th(in mediump float x) { mediump float y = x + (0.5/255.0); return y - fract(y * 255.0) * (1.0 / 255.0); }\n");
else
WRITE(p, "float roundAndScaleTo255f(in float x) { return floor(x * 255.0 + 0.5); }\n");
}
if (enableColorTest) {
if (gstate_c.gpuVendor == GPU_VENDOR_POWERVR)
WRITE(p, "vec3 roundTo255thv(in vec3 x) { vec3 y = x + (0.5/255.0); return y - fract(y * 255.0) * (1.0 / 255.0); }\n");
else
WRITE(p, "vec3 roundAndScaleTo255v(in vec3 x) { return floor(x * 255.0 + 0.5); }\n");
}
WRITE(p, "void main() {\n");
if (gstate.isModeClear()) {
// Clear mode does not allow any fancy shading.
WRITE(p, " gl_FragColor = v_color0;\n");
} else {
const char *secondary = "";
// Secondary color for specular on top of texture
if (lmode) {
WRITE(p, " vec4 s = vec4(v_color1, 0.0);\n");
secondary = " + s";
} else {
secondary = "";
}
if (gstate.isTextureMapEnabled()) {
if (doTextureProjection) {
WRITE(p, " vec4 t = texture2DProj(tex, v_texcoord);\n");
} else {
WRITE(p, " vec4 t = texture2D(tex, v_texcoord);\n");
}
WRITE(p, " vec4 p = v_color0;\n");
if (doTextureAlpha) { // texfmt == RGBA
switch (gstate.getTextureFunction()) {
case GE_TEXFUNC_MODULATE:
WRITE(p, " vec4 v = p * t%s;\n", secondary); break;
case GE_TEXFUNC_DECAL:
WRITE(p, " vec4 v = vec4(mix(p.rgb, t.rgb, t.a), p.a)%s;\n", secondary); break;
case GE_TEXFUNC_BLEND:
WRITE(p, " vec4 v = vec4(mix(p.rgb, u_texenv.rgb, t.rgb), p.a * t.a)%s;\n", secondary); break;
case GE_TEXFUNC_REPLACE:
WRITE(p, " vec4 v = t%s;\n", secondary); break;
case GE_TEXFUNC_ADD:
WRITE(p, " vec4 v = vec4(p.rgb + t.rgb, p.a * t.a)%s;\n", secondary); break;
default:
WRITE(p, " vec4 v = p;\n"); break;
}
} else { // texfmt == RGB
switch (gstate.getTextureFunction()) {
case GE_TEXFUNC_MODULATE:
WRITE(p, " vec4 v = vec4(t.rgb * p.rgb, p.a)%s;\n", secondary); break;
case GE_TEXFUNC_DECAL:
WRITE(p, " vec4 v = vec4(t.rgb, p.a)%s;\n", secondary); break;
case GE_TEXFUNC_BLEND:
WRITE(p, " vec4 v = vec4(mix(p.rgb, u_texenv.rgb, t.rgb), p.a)%s;\n", secondary); break;
case GE_TEXFUNC_REPLACE:
WRITE(p, " vec4 v = vec4(t.rgb, p.a)%s;\n", secondary); break;
case GE_TEXFUNC_ADD:
WRITE(p, " vec4 v = vec4(p.rgb + t.rgb, p.a)%s;\n", secondary); break;
default:
WRITE(p, " vec4 v = p;\n"); break;
}
}
} else {
// No texture mapping
WRITE(p, " vec4 v = v_color0 %s;\n", secondary);
}
if (enableAlphaTest) {
GEComparison alphaTestFunc = gstate.getAlphaTestFunction();
const char *alphaTestFuncs[] = { "#", "#", " != ", " == ", " >= ", " > ", " <= ", " < " }; // never/always don't make sense
if (alphaTestFuncs[alphaTestFunc][0] != '#') {
if (gstate_c.gpuVendor == GPU_VENDOR_POWERVR) {
// Work around bad PVR driver problem where equality check + discard just doesn't work.
if (alphaTestFunc != 3)
WRITE(p, " if (roundTo255th(v.a) %s u_alphacolorref.a) discard;\n", alphaTestFuncs[alphaTestFunc]);
} else {
WRITE(p, " if (roundAndScaleTo255f(v.a) %s u_alphacolorref.a) discard;\n", alphaTestFuncs[alphaTestFunc]);
}
}
}
// TODO: Before or after the color test?
if (enableColorDoubling && enableAlphaDoubling) {
WRITE(p, " v = v * 2.0;\n");
} else if (enableColorDoubling) {
WRITE(p, " v.rgb = v.rgb * 2.0;\n");
} else if (enableAlphaDoubling) {
WRITE(p, " v.a = v.a * 2.0;\n");
}
if (enableColorTest) {
GEComparison colorTestFunc = gstate.getColorTestFunction();
const char *colorTestFuncs[] = { "#", "#", " != ", " == " }; // never/always don't make sense
WARN_LOG_REPORT_ONCE(colortest, G3D, "Color test function : %s", colorTestFuncs[colorTestFunc]);
u32 colorTestMask = gstate.getColorTestMask();
if (colorTestFuncs[colorTestFunc][0] != '#') {
if (gstate_c.gpuVendor == GPU_VENDOR_POWERVR)
WRITE(p, "if (roundTo255thv(v.rgb) %s u_alphacolorref.rgb) discard;\n", colorTestFuncs[colorTestFunc]);
else
WRITE(p, "if (roundAndScaleTo255v(v.rgb) %s u_alphacolorref.rgb) discard;\n", colorTestFuncs[colorTestFunc]);
}
}
if (enableFog) {
WRITE(p, " float fogCoef = clamp(v_fogdepth, 0.0, 1.0);\n");
WRITE(p, " gl_FragColor = mix(vec4(u_fogcolor, v.a), v, fogCoef);\n");
// WRITE(p, " v.x = v_depth;\n");
} else {
WRITE(p, " gl_FragColor = v;\n");
}
}
#ifdef DEBUG_SHADER
if (doTexture) {
WRITE(p, " gl_FragColor = texture2D(tex, v_texcoord.xy);\n");
WRITE(p, " gl_FragColor += vec4(0.3,0,0.3,0.3);\n");
} else {
WRITE(p, " gl_FragColor = vec4(1,0,1,1);\n");
}
#endif
WRITE(p, "}\n");
}