Allow gradient optimization with perspective
Before, gradients would only interpolate the linear portion of the
quadratic equation if there was no perspective. This updates them to
do so even in the case that there is perspective. The rearrangement
of math causes noise differences in the following gm tests:
gradients_no_texture_gpu
gradients_view_perspective_gpu
gradients_local_perspective_gpu
gradients_gpu
R=bsalomon@google.com
Author: cdalton@nvidia.com
Review URL: https://codereview.chromium.org/25645006
git-svn-id: http://skia.googlecode.com/svn/trunk@11595 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkTwoPointRadialGradient.cpp b/src/effects/gradients/SkTwoPointRadialGradient.cpp
index 53d980a..923ed1e 100644
--- a/src/effects/gradients/SkTwoPointRadialGradient.cpp
+++ b/src/effects/gradients/SkTwoPointRadialGradient.cpp
@@ -397,8 +397,7 @@
protected:
- UniformHandle fVSParamUni;
- UniformHandle fFSParamUni;
+ UniformHandle fParamUni;
const char* fVSVaryingName;
const char* fFSVaryingName;
@@ -463,7 +462,19 @@
: INHERITED(ctx, shader, matrix, tm)
, fCenterX1(shader.getCenterX1())
, fRadius0(shader.getStartRadius())
- , fPosRoot(shader.getDiffRadius() < 0) { }
+ , fPosRoot(shader.getDiffRadius() < 0) {
+ // We pass the linear part of the quadratic as a varying.
+ // float b = 2.0 * (fCenterX1 * x - fRadius0 * z)
+ fBTransform = this->getCoordTransform();
+ SkMatrix& bMatrix = *fBTransform.accessMatrix();
+ bMatrix[SkMatrix::kMScaleX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMScaleX]) -
+ SkScalarMul(fRadius0, bMatrix[SkMatrix::kMPersp0]));
+ bMatrix[SkMatrix::kMSkewX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMSkewX]) -
+ SkScalarMul(fRadius0, bMatrix[SkMatrix::kMPersp1]));
+ bMatrix[SkMatrix::kMTransX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMTransX]) -
+ SkScalarMul(fRadius0, bMatrix[SkMatrix::kMPersp2]));
+ this->addCoordTransform(&fBTransform);
+ }
GR_DECLARE_EFFECT_TEST;
@@ -471,9 +482,10 @@
// Cache of values - these can change arbitrarily, EXCEPT
// we shouldn't change between degenerate and non-degenerate?!
- SkScalar fCenterX1;
- SkScalar fRadius0;
- SkBool8 fPosRoot;
+ GrCoordTransform fBTransform;
+ SkScalar fCenterX1;
+ SkScalar fRadius0;
+ SkBool8 fPosRoot;
// @}
@@ -535,103 +547,68 @@
const TextureSamplerArray& samplers) {
this->emitUniforms(builder, key);
- // 2 copies of uniform array, 1 for each of vertex & fragment shader,
- // to work around Xoom bug. Doesn't seem to cause performance decrease
- // in test apps, but need to keep an eye on it.
- fVSParamUni = builder->addUniformArray(GrGLShaderBuilder::kVertex_Visibility,
- kFloat_GrSLType, "Radial2VSParams", 6);
- fFSParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
- kFloat_GrSLType, "Radial2FSParams", 6);
+ fParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
+ kFloat_GrSLType, "Radial2FSParams", 6);
- // For radial gradients without perspective we can pass the linear
- // part of the quadratic as a varying.
- GrGLShaderBuilder::VertexBuilder* vertexBuilder =
- (kVec2f_GrSLType == coords[0].type()) ? builder->getVertexBuilder() : NULL;
- if (NULL != vertexBuilder) {
- vertexBuilder->addVarying(kFloat_GrSLType, "Radial2BCoeff",
- &fVSVaryingName, &fFSVaryingName);
+ SkString cName("c");
+ SkString ac4Name("ac4");
+ SkString rootName("root");
+ SkString t;
+ SkString p0;
+ SkString p1;
+ SkString p2;
+ SkString p3;
+ SkString p4;
+ SkString p5;
+ builder->getUniformVariable(fParamUni).appendArrayAccess(0, &p0);
+ builder->getUniformVariable(fParamUni).appendArrayAccess(1, &p1);
+ builder->getUniformVariable(fParamUni).appendArrayAccess(2, &p2);
+ builder->getUniformVariable(fParamUni).appendArrayAccess(3, &p3);
+ builder->getUniformVariable(fParamUni).appendArrayAccess(4, &p4);
+ builder->getUniformVariable(fParamUni).appendArrayAccess(5, &p5);
+
+ // We interpolate the linear component in coords[1].
+ SkASSERT(coords[0].type() == coords[1].type());
+ const char* coords2D;
+ SkString bVar;
+ if (kVec3f_GrSLType == coords[0].type()) {
+ builder->fsCodeAppendf("\tvec3 interpolants = vec3(%s.xy, %s.x) / %s.z;\n",
+ coords[0].c_str(), coords[1].c_str(), coords[0].c_str());
+ coords2D = "interpolants.xy";
+ bVar = "interpolants.z";
+ } else {
+ coords2D = coords[0].c_str();
+ bVar.printf("%s.x", coords[1].c_str());
}
- // VS
- {
- SkString p2;
- SkString p3;
- builder->getUniformVariable(fVSParamUni).appendArrayAccess(2, &p2);
- builder->getUniformVariable(fVSParamUni).appendArrayAccess(3, &p3);
+ // c = (x^2)+(y^2) - params[4]
+ builder->fsCodeAppendf("\tfloat %s = dot(%s, %s) - %s;\n",
+ cName.c_str(), coords2D, coords2D, p4.c_str());
- // For radial gradients without perspective we can pass the linear
- // part of the quadratic as a varying.
- if (NULL != vertexBuilder) {
- // r2Var = 2 * (r2Parm[2] * varCoord.x - r2Param[3])
- vertexBuilder->vsCodeAppendf("\t%s = 2.0 *(%s * %s.x - %s);\n",
- fVSVaryingName, p2.c_str(),
- coords[0].getVSName().c_str(), p3.c_str());
- }
+ // If we aren't degenerate, emit some extra code, and accept a slightly
+ // more complex coord.
+ if (!fIsDegenerate) {
+
+ // ac4 = 4.0 * params[0] * c
+ builder->fsCodeAppendf("\tfloat %s = %s * 4.0 * %s;\n",
+ ac4Name.c_str(), p0.c_str(),
+ cName.c_str());
+
+ // root = sqrt(b^2-4ac)
+ // (abs to avoid exception due to fp precision)
+ builder->fsCodeAppendf("\tfloat %s = sqrt(abs(%s*%s - %s));\n",
+ rootName.c_str(), bVar.c_str(), bVar.c_str(),
+ ac4Name.c_str());
+
+ // t is: (-b + params[5] * sqrt(b^2-4ac)) * params[1]
+ t.printf("(-%s + %s * %s) * %s", bVar.c_str(), p5.c_str(),
+ rootName.c_str(), p1.c_str());
+ } else {
+ // t is: -c/b
+ t.printf("-%s / %s", cName.c_str(), bVar.c_str());
}
- // FS
- {
- SkString coords2D = builder->ensureFSCoords2D(coords, 0);
- SkString cName("c");
- SkString ac4Name("ac4");
- SkString rootName("root");
- SkString t;
- SkString p0;
- SkString p1;
- SkString p2;
- SkString p3;
- SkString p4;
- SkString p5;
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(0, &p0);
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(1, &p1);
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(2, &p2);
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(3, &p3);
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(4, &p4);
- builder->getUniformVariable(fFSParamUni).appendArrayAccess(5, &p5);
-
- // If we we're able to interpolate the linear component,
- // bVar is the varying; otherwise compute it
- SkString bVar;
- if (NULL != vertexBuilder) {
- bVar = fFSVaryingName;
- } else {
- bVar = "b";
- builder->fsCodeAppendf("\tfloat %s = 2.0 * (%s * %s.x - %s);\n",
- bVar.c_str(), p2.c_str(), coords2D.c_str(), p3.c_str());
- }
-
- // c = (x^2)+(y^2) - params[4]
- builder->fsCodeAppendf("\tfloat %s = dot(%s, %s) - %s;\n",
- cName.c_str(),
- coords2D.c_str(),
- coords2D.c_str(),
- p4.c_str());
-
- // If we aren't degenerate, emit some extra code, and accept a slightly
- // more complex coord.
- if (!fIsDegenerate) {
-
- // ac4 = 4.0 * params[0] * c
- builder->fsCodeAppendf("\tfloat %s = %s * 4.0 * %s;\n",
- ac4Name.c_str(), p0.c_str(),
- cName.c_str());
-
- // root = sqrt(b^2-4ac)
- // (abs to avoid exception due to fp precision)
- builder->fsCodeAppendf("\tfloat %s = sqrt(abs(%s*%s - %s));\n",
- rootName.c_str(), bVar.c_str(), bVar.c_str(),
- ac4Name.c_str());
-
- // t is: (-b + params[5] * sqrt(b^2-4ac)) * params[1]
- t.printf("(-%s + %s * %s) * %s", bVar.c_str(), p5.c_str(),
- rootName.c_str(), p1.c_str());
- } else {
- // t is: -c/b
- t.printf("-%s / %s", cName.c_str(), bVar.c_str());
- }
-
- this->emitColor(builder, t.c_str(), key, outputColor, inputColor, samplers);
- }
+ this->emitColor(builder, t.c_str(), key, outputColor, inputColor, samplers);
}
void GrGLRadial2Gradient::setData(const GrGLUniformManager& uman,
@@ -661,8 +638,7 @@
data.isPosRoot() ? 1.f : -1.f
};
- uman.set1fv(fVSParamUni, 0, 6, values);
- uman.set1fv(fFSParamUni, 0, 6, values);
+ uman.set1fv(fParamUni, 0, 6, values);
fCachedCenter = centerX1;
fCachedRadius = radius0;
fCachedPosRoot = data.isPosRoot();