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/SkTwoPointConicalGradient.cpp b/src/effects/gradients/SkTwoPointConicalGradient.cpp
index 0a5e29b..94eb72f 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient.cpp
@@ -355,8 +355,7 @@
protected:
- UniformHandle fVSParamUni;
- UniformHandle fFSParamUni;
+ UniformHandle fParamUni;
const char* fVSVaryingName;
const char* fFSVaryingName;
@@ -422,7 +421,20 @@
: INHERITED(ctx, shader, matrix, tm)
, fCenterX1(shader.getCenterX1())
, fRadius0(shader.getStartRadius())
- , fDiffRadius(shader.getDiffRadius()) { }
+ , fDiffRadius(shader.getDiffRadius()) {
+ // We pass the linear part of the quadratic as a varying.
+ // float b = -2.0 * (fCenterX1 * x + fRadius0 * fDiffRadius * z)
+ fBTransform = this->getCoordTransform();
+ SkMatrix& bMatrix = *fBTransform.accessMatrix();
+ SkScalar r0dr = SkScalarMul(fRadius0, fDiffRadius);
+ bMatrix[SkMatrix::kMScaleX] = -2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMScaleX]) +
+ SkScalarMul(r0dr, bMatrix[SkMatrix::kMPersp0]));
+ bMatrix[SkMatrix::kMSkewX] = -2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMSkewX]) +
+ SkScalarMul(r0dr, bMatrix[SkMatrix::kMPersp1]));
+ bMatrix[SkMatrix::kMTransX] = -2 * (SkScalarMul(fCenterX1, bMatrix[SkMatrix::kMTransX]) +
+ SkScalarMul(r0dr, bMatrix[SkMatrix::kMPersp2]));
+ this->addCoordTransform(&fBTransform);
+ }
GR_DECLARE_EFFECT_TEST;
@@ -430,9 +442,10 @@
// Cache of values - these can change arbitrarily, EXCEPT
// we shouldn't change between degenerate and non-degenerate?!
- SkScalar fCenterX1;
- SkScalar fRadius0;
- SkScalar fDiffRadius;
+ GrCoordTransform fBTransform;
+ SkScalar fCenterX1;
+ SkScalar fRadius0;
+ SkScalar fDiffRadius;
// @}
@@ -492,160 +505,124 @@
const TransformedCoordsArray& coords,
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, "Conical2VSParams", 6);
- fFSParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
- kFloat_GrSLType, "Conical2FSParams", 6);
+ fParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
+ kFloat_GrSLType, "Conical2FSParams", 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, "Conical2BCoeff",
- &fVSVaryingName, &fFSVaryingName);
+ SkString cName("c");
+ SkString ac4Name("ac4");
+ SkString dName("d");
+ SkString qName("q");
+ SkString r0Name("r0");
+ SkString r1Name("r1");
+ SkString tName("t");
+ SkString p0; // 4a
+ SkString p1; // 1/a
+ SkString p2; // distance between centers
+ SkString p3; // start radius
+ SkString p4; // start radius squared
+ SkString p5; // difference in radii (r1 - r0)
+
+ 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; // distance between centers
- SkString p3; // start radius
- SkString p5; // difference in radii (r1 - r0)
- builder->getUniformVariable(fVSParamUni).appendArrayAccess(2, &p2);
- builder->getUniformVariable(fVSParamUni).appendArrayAccess(3, &p3);
- builder->getUniformVariable(fVSParamUni).appendArrayAccess(5, &p5);
+ // output will default to transparent black (we simply won't write anything
+ // else to it if invalid, instead of discarding or returning prematurely)
+ builder->fsCodeAppendf("\t%s = vec4(0.0,0.0,0.0,0.0);\n", outputColor);
- // 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] * r2Param[5])
- vertexBuilder->vsCodeAppendf("\t%s = -2.0 * (%s * %s.x + %s * %s);\n",
- fVSVaryingName, p2.c_str(),
- coords[0].getVSName().c_str(), p3.c_str(), p5.c_str());
- }
- }
+ // c = (x^2)+(y^2) - params[4]
+ builder->fsCodeAppendf("\tfloat %s = dot(%s, %s) - %s;\n",
+ cName.c_str(), coords2D, coords2D, p4.c_str());
- // FS
- {
- SkString coords2D = builder->ensureFSCoords2D(coords, 0);
- SkString cName("c");
- SkString ac4Name("ac4");
- SkString dName("d");
- SkString qName("q");
- SkString r0Name("r0");
- SkString r1Name("r1");
- SkString tName("t");
- SkString p0; // 4a
- SkString p1; // 1/a
- SkString p2; // distance between centers
- SkString p3; // start radius
- SkString p4; // start radius squared
- SkString p5; // difference in radii (r1 - r0)
+ // Non-degenerate case (quadratic)
+ if (!fIsDegenerate) {
- 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);
+ // ac4 = params[0] * c
+ builder->fsCodeAppendf("\tfloat %s = %s * %s;\n", ac4Name.c_str(), p0.c_str(),
+ cName.c_str());
- // 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 * %s);\n",
- bVar.c_str(), p2.c_str(), coords2D.c_str(),
- p3.c_str(), p5.c_str());
- }
+ // d = b^2 - ac4
+ builder->fsCodeAppendf("\tfloat %s = %s * %s - %s;\n", dName.c_str(),
+ bVar.c_str(), bVar.c_str(), ac4Name.c_str());
- // output will default to transparent black (we simply won't write anything
- // else to it if invalid, instead of discarding or returning prematurely)
- builder->fsCodeAppendf("\t%s = vec4(0.0,0.0,0.0,0.0);\n", outputColor);
+ // only proceed if discriminant is >= 0
+ builder->fsCodeAppendf("\tif (%s >= 0.0) {\n", dName.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());
+ // intermediate value we'll use to compute the roots
+ // q = -0.5 * (b +/- sqrt(d))
+ builder->fsCodeAppendf("\t\tfloat %s = -0.5 * (%s + (%s < 0.0 ? -1.0 : 1.0)"
+ " * sqrt(%s));\n", qName.c_str(), bVar.c_str(),
+ bVar.c_str(), dName.c_str());
- // Non-degenerate case (quadratic)
- if (!fIsDegenerate) {
+ // compute both roots
+ // r0 = q * params[1]
+ builder->fsCodeAppendf("\t\tfloat %s = %s * %s;\n", r0Name.c_str(),
+ qName.c_str(), p1.c_str());
+ // r1 = c / q
+ builder->fsCodeAppendf("\t\tfloat %s = %s / %s;\n", r1Name.c_str(),
+ cName.c_str(), qName.c_str());
- // ac4 = params[0] * c
- builder->fsCodeAppendf("\tfloat %s = %s * %s;\n", ac4Name.c_str(), p0.c_str(),
- cName.c_str());
+ // Note: If there are two roots that both generate radius(t) > 0, the
+ // Canvas spec says to choose the larger t.
- // d = b^2 - ac4
- builder->fsCodeAppendf("\tfloat %s = %s * %s - %s;\n", dName.c_str(),
- bVar.c_str(), bVar.c_str(), ac4Name.c_str());
+ // so we'll look at the larger one first:
+ builder->fsCodeAppendf("\t\tfloat %s = max(%s, %s);\n", tName.c_str(),
+ r0Name.c_str(), r1Name.c_str());
- // only proceed if discriminant is >= 0
- builder->fsCodeAppendf("\tif (%s >= 0.0) {\n", dName.c_str());
+ // if r(t) > 0, then we're done; t will be our x coordinate
+ builder->fsCodeAppendf("\t\tif (%s * %s + %s > 0.0) {\n", tName.c_str(),
+ p5.c_str(), p3.c_str());
- // intermediate value we'll use to compute the roots
- // q = -0.5 * (b +/- sqrt(d))
- builder->fsCodeAppendf("\t\tfloat %s = -0.5 * (%s + (%s < 0.0 ? -1.0 : 1.0)"
- " * sqrt(%s));\n", qName.c_str(), bVar.c_str(),
- bVar.c_str(), dName.c_str());
+ builder->fsCodeAppend("\t\t");
+ this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
- // compute both roots
- // r0 = q * params[1]
- builder->fsCodeAppendf("\t\tfloat %s = %s * %s;\n", r0Name.c_str(),
- qName.c_str(), p1.c_str());
- // r1 = c / q
- builder->fsCodeAppendf("\t\tfloat %s = %s / %s;\n", r1Name.c_str(),
- cName.c_str(), qName.c_str());
+ // otherwise, if r(t) for the larger root was <= 0, try the other root
+ builder->fsCodeAppend("\t\t} else {\n");
+ builder->fsCodeAppendf("\t\t\t%s = min(%s, %s);\n", tName.c_str(),
+ r0Name.c_str(), r1Name.c_str());
- // Note: If there are two roots that both generate radius(t) > 0, the
- // Canvas spec says to choose the larger t.
+ // if r(t) > 0 for the smaller root, then t will be our x coordinate
+ builder->fsCodeAppendf("\t\t\tif (%s * %s + %s > 0.0) {\n",
+ tName.c_str(), p5.c_str(), p3.c_str());
- // so we'll look at the larger one first:
- builder->fsCodeAppendf("\t\tfloat %s = max(%s, %s);\n", tName.c_str(),
- r0Name.c_str(), r1Name.c_str());
+ builder->fsCodeAppend("\t\t\t");
+ this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
- // if r(t) > 0, then we're done; t will be our x coordinate
- builder->fsCodeAppendf("\t\tif (%s * %s + %s > 0.0) {\n", tName.c_str(),
- p5.c_str(), p3.c_str());
+ // end if (r(t) > 0) for smaller root
+ builder->fsCodeAppend("\t\t\t}\n");
+ // end if (r(t) > 0), else, for larger root
+ builder->fsCodeAppend("\t\t}\n");
+ // end if (discriminant >= 0)
+ builder->fsCodeAppend("\t}\n");
+ } else {
- builder->fsCodeAppend("\t\t");
- this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
+ // linear case: t = -c/b
+ builder->fsCodeAppendf("\tfloat %s = -(%s / %s);\n", tName.c_str(),
+ cName.c_str(), bVar.c_str());
- // otherwise, if r(t) for the larger root was <= 0, try the other root
- builder->fsCodeAppend("\t\t} else {\n");
- builder->fsCodeAppendf("\t\t\t%s = min(%s, %s);\n", tName.c_str(),
- r0Name.c_str(), r1Name.c_str());
-
- // if r(t) > 0 for the smaller root, then t will be our x coordinate
- builder->fsCodeAppendf("\t\t\tif (%s * %s + %s > 0.0) {\n",
- tName.c_str(), p5.c_str(), p3.c_str());
-
- builder->fsCodeAppend("\t\t\t");
- this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
-
- // end if (r(t) > 0) for smaller root
- builder->fsCodeAppend("\t\t\t}\n");
- // end if (r(t) > 0), else, for larger root
- builder->fsCodeAppend("\t\t}\n");
- // end if (discriminant >= 0)
- builder->fsCodeAppend("\t}\n");
- } else {
-
- // linear case: t = -c/b
- builder->fsCodeAppendf("\tfloat %s = -(%s / %s);\n", tName.c_str(),
- cName.c_str(), bVar.c_str());
-
- // if r(t) > 0, then t will be the x coordinate
- builder->fsCodeAppendf("\tif (%s * %s + %s > 0.0) {\n", tName.c_str(),
- p5.c_str(), p3.c_str());
- builder->fsCodeAppend("\t");
- this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
- builder->fsCodeAppend("\t}\n");
- }
+ // if r(t) > 0, then t will be the x coordinate
+ builder->fsCodeAppendf("\tif (%s * %s + %s > 0.0) {\n", tName.c_str(),
+ p5.c_str(), p3.c_str());
+ builder->fsCodeAppend("\t");
+ this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
+ builder->fsCodeAppend("\t}\n");
}
}
@@ -678,8 +655,7 @@
SkScalarToFloat(diffRadius)
};
- uman.set1fv(fVSParamUni, 0, 6, values);
- uman.set1fv(fFSParamUni, 0, 6, values);
+ uman.set1fv(fParamUni, 0, 6, values);
fCachedCenter = centerX1;
fCachedRadius = radius0;
fCachedDiffRadius = diffRadius;