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-rw-r--r--src/gpu/glsl/GrGLSLColorSpaceXformHelper.h8
-rw-r--r--src/gpu/glsl/GrGLSLShaderBuilder.cpp77
-rw-r--r--src/gpu/glsl/GrGLSLShaderBuilder.h18
3 files changed, 92 insertions, 11 deletions
diff --git a/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h b/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
index 940be57126..cd516e8c89 100644
--- a/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
+++ b/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
@@ -8,12 +8,13 @@
#ifndef GrGLSLColorSpaceXformHelper_DEFINED
#define GrGLSLColorSpaceXformHelper_DEFINED
+#include "GrColorSpaceXform.h"
#include "GrGLSLUniformHandler.h"
-class GrColorSpaceXform;
-
/**
* Stack helper class to assist with using GrColorSpaceXform within an FP's emitCode function.
+ * This injects the uniform declaration, and stores the information needed to generate correct
+ * gamut-transformation shader code.
*/
class GrGLSLColorSpaceXformHelper : public SkNoncopyable {
public:
@@ -25,15 +26,18 @@ public:
*handle = uniformHandler->addUniform(kFragment_GrShaderFlag, kMat44f_GrSLType,
kDefault_GrSLPrecision, "ColorXform",
&fXformMatrix);
+ fAlphaType = colorSpaceXform->alphaType();
} else {
fXformMatrix = nullptr;
}
}
const char* getXformMatrix() const { return fXformMatrix; }
+ SkAlphaType alphaType() const { return fAlphaType; }
private:
const char* fXformMatrix;
+ SkAlphaType fAlphaType;
};
#endif
diff --git a/src/gpu/glsl/GrGLSLShaderBuilder.cpp b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
index 1e52a11013..8b004b265f 100644
--- a/src/gpu/glsl/GrGLSLShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
@@ -8,6 +8,7 @@
#include "GrSwizzle.h"
#include "glsl/GrGLSLShaderBuilder.h"
#include "glsl/GrGLSLCaps.h"
+#include "glsl/GrGLSLColorSpaceXformHelper.h"
#include "glsl/GrGLSLShaderVar.h"
#include "glsl/GrGLSLSampler.h"
#include "glsl/GrGLSLProgramBuilder.h"
@@ -98,17 +99,79 @@ void GrGLSLShaderBuilder::appendTextureLookup(SkString* out,
void GrGLSLShaderBuilder::appendTextureLookup(SamplerHandle samplerHandle,
const char* coordName,
- GrSLType varyingType) {
- this->appendTextureLookup(&this->code(), samplerHandle, coordName, varyingType);
+ GrSLType varyingType,
+ GrGLSLColorSpaceXformHelper* colorXformHelper) {
+ if (colorXformHelper && colorXformHelper->getXformMatrix()) {
+ // With a color gamut transform, we need to wrap the lookup in another function call
+ SkString lookup;
+ this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
+ this->appendColorGamutXform(lookup.c_str(), colorXformHelper);
+ } else {
+ this->appendTextureLookup(&this->code(), samplerHandle, coordName, varyingType);
+ }
}
-void GrGLSLShaderBuilder::appendTextureLookupAndModulate(const char* modulation,
- SamplerHandle samplerHandle,
- const char* coordName,
- GrSLType varyingType) {
+void GrGLSLShaderBuilder::appendTextureLookupAndModulate(
+ const char* modulation,
+ SamplerHandle samplerHandle,
+ const char* coordName,
+ GrSLType varyingType,
+ GrGLSLColorSpaceXformHelper* colorXformHelper) {
SkString lookup;
this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
- this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(lookup)).c_str());
+ if (colorXformHelper && colorXformHelper->getXformMatrix()) {
+ SkString xform;
+ this->appendColorGamutXform(&xform, lookup.c_str(), colorXformHelper);
+ this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(xform)).c_str());
+ } else {
+ this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(lookup)).c_str());
+ }
+}
+
+void GrGLSLShaderBuilder::appendColorGamutXform(SkString* out,
+ const char* srcColor,
+ GrGLSLColorSpaceXformHelper* colorXformHelper) {
+ // Our color is (r, g, b, a), but we want to multiply (r, g, b, 1) by our matrix, then
+ // re-insert the original alpha. The supplied srcColor is likely to be of the form
+ // "texture(...)", and we don't want to evaluate that twice.
+ //
+ // Worse: We can't do the transformation on premultiplied colors, so if the source is premul,
+ // we need to unpremul, transform, then multiply again. Anyways, we wrap all of the work in a
+ // function.
+ static const GrGLSLShaderVar gColorGamutXformArgs[] = {
+ GrGLSLShaderVar("color", kVec4f_GrSLType),
+ GrGLSLShaderVar("xform", kMat44f_GrSLType),
+ };
+ SkString functionBody;
+ if (kPremul_SkAlphaType == colorXformHelper->alphaType()) {
+ // Unpremultiply
+ functionBody.append("\tfloat nonZeroAlpha = max(color.a, 0.00001);\n"
+ "\tcolor.rgb = color.rgb / nonZeroAlpha;\n");
+ }
+ // Gamut xform, clamp to destination gamut
+ functionBody.append("\tcolor.rgb = clamp((vec4(color.rgb, 1.0) * xform).rgb, 0.0, 1.0);\n");
+ if (kPremul_SkAlphaType == colorXformHelper->alphaType()) {
+ // Re-multiply by alpha
+ functionBody.append("\tcolor.rgb = color.rgb * nonZeroAlpha;\n");
+ }
+ functionBody.append("\treturn color;");
+ SkString colorGamutXformFuncName;
+ this->emitFunction(kVec4f_GrSLType,
+ "colorGamutXform",
+ SK_ARRAY_COUNT(gColorGamutXformArgs),
+ gColorGamutXformArgs,
+ functionBody.c_str(),
+ &colorGamutXformFuncName);
+
+ out->appendf("%s(%s, %s)", colorGamutXformFuncName.c_str(), srcColor,
+ colorXformHelper->getXformMatrix());
+}
+
+void GrGLSLShaderBuilder::appendColorGamutXform(const char* srcColor,
+ GrGLSLColorSpaceXformHelper* colorXformHelper) {
+ SkString xform;
+ this->appendColorGamutXform(&xform, srcColor, colorXformHelper);
+ this->codeAppend(xform.c_str());
}
void GrGLSLShaderBuilder::appendTexelFetch(SkString* out,
diff --git a/src/gpu/glsl/GrGLSLShaderBuilder.h b/src/gpu/glsl/GrGLSLShaderBuilder.h
index ea36a56a7a..a6ff96dd1b 100644
--- a/src/gpu/glsl/GrGLSLShaderBuilder.h
+++ b/src/gpu/glsl/GrGLSLShaderBuilder.h
@@ -15,6 +15,8 @@
#include <stdarg.h>
+class GrGLSLColorSpaceXformHelper;
+
/**
base class for all shaders builders
*/
@@ -37,7 +39,8 @@ public:
/** Version of above that appends the result to the shader code instead.*/
void appendTextureLookup(SamplerHandle,
const char* coordName,
- GrSLType coordType = kVec2f_GrSLType);
+ GrSLType coordType = kVec2f_GrSLType,
+ GrGLSLColorSpaceXformHelper* colorXformHelper = nullptr);
/** Does the work of appendTextureLookup and modulates the result by modulation. The result is
@@ -47,7 +50,18 @@ public:
void appendTextureLookupAndModulate(const char* modulation,
SamplerHandle,
const char* coordName,
- GrSLType coordType = kVec2f_GrSLType);
+ GrSLType coordType = kVec2f_GrSLType,
+ GrGLSLColorSpaceXformHelper* colorXformHelper = nullptr);
+
+ /** Adds a helper function to facilitate color gamut transformation, and produces code that
+ returns the srcColor transformed into a new gamut (via multiplication by the xform from
+ colorXformHelper). Premultiplied sources are also handled correctly (colorXformHelper
+ determines if the source is premultipled or not). */
+ void appendColorGamutXform(SkString* out, const char* srcColor,
+ GrGLSLColorSpaceXformHelper* colorXformHelper);
+
+ /** Version of above that appends the result to the shader code instead. */
+ void appendColorGamutXform(const char* srcColor, GrGLSLColorSpaceXformHelper* colorXformHelper);
/** Fetches an unfiltered texel from a sampler at integer coordinates. coordExpr must match the
dimensionality of the sampler and must be within the sampler's range. coordExpr is emitted
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-01 13:35:30 +0000