Introduction of set of functions to manage generation of texture fetch shader code.
A new set of routines have been added to GrGLShaderBuilder to emit texture fetches, taking into consideration the format of the texture to be accessed, and the channel swizzle.
Review URL: https://codereview.appspot.com/6446072
git-svn-id: http://skia.googlecode.com/svn/trunk@4919 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLProgram.h b/src/gpu/gl/GrGLProgram.h
index 18d97d5..62c70e5 100644
--- a/src/gpu/gl/GrGLProgram.h
+++ b/src/gpu/gl/GrGLProgram.h
@@ -164,7 +164,7 @@
/** Non-zero if user-supplied code will write the stage's
contribution to the fragment shader. */
- uint16_t fCustomStageKey;
+ GrProgramStageFactory::StageKey fCustomStageKey;
GR_STATIC_ASSERT((InConfigFlags)(uint8_t)kInConfigBitMask ==
kInConfigBitMask);
diff --git a/src/gpu/gl/GrGLProgramStage.cpp b/src/gpu/gl/GrGLProgramStage.cpp
index 12c3894..b1a37fe 100644
--- a/src/gpu/gl/GrGLProgramStage.cpp
+++ b/src/gpu/gl/GrGLProgramStage.cpp
@@ -27,3 +27,14 @@
int stageNum) {
}
+GrGLProgramStage::StageKey GrGLProgramStage::GenTextureKey(const GrCustomStage& stage,
+ const GrGLCaps& caps) {
+ StageKey key = 0;
+ for (unsigned int index = 0; index < stage.numTextures(); ++index) {
+ if (stage.textureAccess(index)) {
+ key = (key << index) |
+ GrGLShaderBuilder::KeyForTextureAccess(*stage.textureAccess(index), caps);
+ }
+ }
+ return key;
+}
diff --git a/src/gpu/gl/GrGLProgramStage.h b/src/gpu/gl/GrGLProgramStage.h
index 12163f8..8e3a4b1 100644
--- a/src/gpu/gl/GrGLProgramStage.h
+++ b/src/gpu/gl/GrGLProgramStage.h
@@ -78,6 +78,8 @@
const char* name() const { return fFactory.name(); }
+ static StageKey GenTextureKey(const GrCustomStage&, const GrGLCaps&);
+
protected:
const GrProgramStageFactory& fFactory;
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 2844953..0d2a1ec 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -8,6 +8,7 @@
#include "gl/GrGLShaderBuilder.h"
#include "gl/GrGLProgram.h"
#include "gl/GrGLUniformHandle.h"
+#include "GrTexture.h"
// number of each input/output type in a single allocation block
static const int kVarsPerBlock = 8;
@@ -21,6 +22,50 @@
typedef GrGLUniformManager::UniformHandle UniformHandle;
///////////////////////////////////////////////////////////////////////////////
+static SkString build_sampler_string(GrGLShaderBuilder::SamplerMode samplerMode) {
+ SkString sampler("texture2D");
+ switch (samplerMode) {
+ case GrGLShaderBuilder::kDefault_SamplerMode:
+ break;
+ case GrGLShaderBuilder::kProj_SamplerMode:
+ sampler.append("Proj");
+ break;
+ case GrGLShaderBuilder::kExplicitDivide_SamplerMode:
+ GrAssert(false); // Not Implemented
+ break;
+ }
+
+ return sampler;
+}
+
+static bool texture_requires_alpha_to_red_swizzle(const GrGLCaps& caps,
+ const GrTextureAccess& access) {
+ return GrPixelConfigIsAlphaOnly(access.getTexture()->config()) && caps.textureRedSupport() &&
+ access.referencesAlpha();
+}
+
+static SkString build_swizzle_string(const GrTextureAccess& textureAccess,
+ const GrGLCaps& caps) {
+ const GrTextureAccess::Swizzle& swizzle = textureAccess.getSwizzle();
+ if (0 == swizzle[0]) {
+ return SkString("");
+ }
+
+ SkString swizzleOut(".");
+ bool alphaIsRed = texture_requires_alpha_to_red_swizzle(caps, textureAccess);
+ for (int offset = 0; offset < 4 && swizzle[offset]; ++offset) {
+ if (alphaIsRed && 'a' == swizzle[offset]) {
+ swizzleOut.appendf("r");
+ } else {
+ swizzleOut.appendf("%c", swizzle[offset]);
+ }
+ }
+
+ return swizzleOut;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
// Architectural assumption: always 2-d input coords.
// Likely to become non-constant and non-static, perhaps even
// varying by stage, if we use 1D textures for gradients!
@@ -120,6 +165,34 @@
fFSCode.appendf("%s%s;\n", fSwizzle.c_str(), fModulate.c_str());
}
+void GrGLShaderBuilder::emitCustomTextureLookup(SamplerMode samplerMode,
+ const GrTextureAccess& textureAccess,
+ const char* samplerName,
+ const char* coordName) {
+ GrAssert(samplerName && coordName);
+ SkString sampler = build_sampler_string(samplerMode);
+ SkString swizzle = build_swizzle_string(textureAccess, fContext.caps());
+
+ fFSCode.appendf("%s( %s, %s)%s;\n", sampler.c_str(), samplerName,
+ coordName, swizzle.c_str());
+}
+
+GrCustomStage::StageKey GrGLShaderBuilder::KeyForTextureAccess(const GrTextureAccess& access,
+ const GrGLCaps& caps) {
+ GrCustomStage::StageKey key = 0;
+ // Assume that swizzle support implies that we never have to modify a shader to adjust
+ // for texture format/swizzle settings.
+ if (caps.textureSwizzleSupport()) {
+ return key;
+ }
+
+ if (texture_requires_alpha_to_red_swizzle(caps, access)) {
+ key = 1;
+ }
+
+ return key;
+}
+
GrGLUniformManager::UniformHandle GrGLShaderBuilder::addUniformArray(uint32_t visibility,
GrSLType type,
const char* name,
diff --git a/src/gpu/gl/GrGLShaderBuilder.h b/src/gpu/gl/GrGLShaderBuilder.h
index f110628..16a11e2 100644
--- a/src/gpu/gl/GrGLShaderBuilder.h
+++ b/src/gpu/gl/GrGLShaderBuilder.h
@@ -9,6 +9,7 @@
#define GrGLShaderBuilder_DEFINED
#include "GrAllocator.h"
+#include "GrCustomStage.h"
#include "gl/GrGLShaderVar.h"
#include "gl/GrGLSL.h"
#include "gl/GrGLUniformManager.h"
@@ -55,6 +56,22 @@
void emitDefaultFetch(const char* outColor,
const char* samplerName);
+ /** Emits a texture lookup to the shader code with the form:
+ texture2D{Proj}(samplerName, coordName).swizzle
+ The routine selects the type of texturing based on samplerMode.
+ The generated swizzle state is built based on the format of the texture and the requested
+ swizzle access pattern. */
+ void emitCustomTextureLookup(SamplerMode samplerMode,
+ const GrTextureAccess& textureAccess,
+ const char* samplerName,
+ const char* coordName);
+
+ /** Generates a StageKey for the shader code based on the texture access parameters and the
+ capabilities of the GL context. This is useful for keying the shader programs that may
+ have multiple representations, based on the type/format of textures used. */
+ static GrCustomStage::StageKey KeyForTextureAccess(const GrTextureAccess& access,
+ const GrGLCaps& caps);
+
/** Add a uniform variable to the current program, that has visibilty in one or more shaders.
visibility is a bitfield of ShaderType values indicating from which shaders the uniform
should be accessible. At least one bit must be set. Geometry shader uniforms are not
diff --git a/src/gpu/gl/GrGpuGL_program.cpp b/src/gpu/gl/GrGpuGL_program.cpp
index 6d6d916..c959f66 100644
--- a/src/gpu/gl/GrGpuGL_program.cpp
+++ b/src/gpu/gl/GrGpuGL_program.cpp
@@ -596,12 +596,13 @@
void setup_custom_stage(GrGLProgram::Desc::StageDesc* stage,
const GrSamplerState& sampler,
+ const GrGLCaps& caps,
const GrCustomStage** customStages,
GrGLProgram* program, int index) {
const GrCustomStage* customStage = sampler.getCustomStage();
if (customStage) {
const GrProgramStageFactory& factory = customStage->getFactory();
- stage->fCustomStageKey = factory.glStageKey(*customStage);
+ stage->fCustomStageKey = factory.glStageKey(*customStage, caps);
customStages[index] = customStage;
} else {
stage->fCustomStageKey = 0;
@@ -746,7 +747,8 @@
}
}
- setup_custom_stage(&stage, sampler, customStages, fCurrentProgram.get(), s);
+ setup_custom_stage(&stage, sampler, this->glCaps(), customStages,
+ fCurrentProgram.get(), s);
} else {
stage.fOptFlags = 0;
diff --git a/src/gpu/gl/GrGpuGL_unittest.cpp b/src/gpu/gl/GrGpuGL_unittest.cpp
index 1a28b98..7fd61d9 100644
--- a/src/gpu/gl/GrGpuGL_unittest.cpp
+++ b/src/gpu/gl/GrGpuGL_unittest.cpp
@@ -413,7 +413,7 @@
customStages[s].reset(create_random_effect(&stage, &random, getContext()));
if (NULL != customStages[s]) {
stage.fCustomStageKey =
- customStages[s]->getFactory().glStageKey(*customStages[s]);
+ customStages[s]->getFactory().glStageKey(*customStages[s], this->glCaps());
}
}
}