Pull Gpu shader out of SkTwoPointConicalGradient into own file
BUG=skia:
R=bsalomon@google.com
Author: egdaniel@google.com
Review URL: https://codereview.chromium.org/222943002
git-svn-id: http://skia.googlecode.com/svn/trunk@14044 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp b/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp
new file mode 100644
index 0000000..e98d3ba
--- /dev/null
+++ b/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp
@@ -0,0 +1,306 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#if SK_SUPPORT_GPU
+#include "SkTwoPointConicalGradient_gpu.h"
+#include "GrTBackendEffectFactory.h"
+
+#include "SkTwoPointConicalGradient.h"
+
+// For brevity
+typedef GrGLUniformManager::UniformHandle UniformHandle;
+
+class GrGL2PtConicalGradientEffect : public GrGLGradientEffect {
+public:
+
+ GrGL2PtConicalGradientEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&);
+ virtual ~GrGL2PtConicalGradientEffect() { }
+
+ virtual void emitCode(GrGLShaderBuilder*,
+ const GrDrawEffect&,
+ EffectKey,
+ const char* outputColor,
+ const char* inputColor,
+ const TransformedCoordsArray&,
+ const TextureSamplerArray&) SK_OVERRIDE;
+ virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
+
+ static EffectKey GenKey(const GrDrawEffect&, const GrGLCaps& caps);
+
+protected:
+
+ UniformHandle fParamUni;
+
+ const char* fVSVaryingName;
+ const char* fFSVaryingName;
+
+ bool fIsDegenerate;
+
+ // @{
+ /// Values last uploaded as uniforms
+
+ SkScalar fCachedCenter;
+ SkScalar fCachedRadius;
+ SkScalar fCachedDiffRadius;
+
+ // @}
+
+private:
+
+ typedef GrGLGradientEffect INHERITED;
+
+};
+
+const GrBackendEffectFactory& Gr2PtConicalGradientEffect::getFactory() const {
+ return GrTBackendEffectFactory<Gr2PtConicalGradientEffect>::getInstance();
+}
+
+Gr2PtConicalGradientEffect::Gr2PtConicalGradientEffect(GrContext* ctx,
+ const SkTwoPointConicalGradient& shader,
+ const SkMatrix& matrix,
+ SkShader::TileMode tm) :
+ INHERITED(ctx, shader, matrix, tm),
+ fCenterX1(shader.getCenterX1()),
+ fRadius0(shader.getStartRadius()),
+ 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_DEFINE_EFFECT_TEST(Gr2PtConicalGradientEffect);
+
+GrEffectRef* Gr2PtConicalGradientEffect::TestCreate(SkRandom* random,
+ GrContext* context,
+ const GrDrawTargetCaps&,
+ GrTexture**) {
+ SkPoint center1 = {random->nextUScalar1(), random->nextUScalar1()};
+ SkScalar radius1 = random->nextUScalar1();
+ SkPoint center2;
+ SkScalar radius2;
+ do {
+ center2.set(random->nextUScalar1(), random->nextUScalar1());
+ radius2 = random->nextUScalar1 ();
+ // If the circles are identical the factory will give us an empty shader.
+ } while (radius1 == radius2 && center1 == center2);
+
+ SkColor colors[kMaxRandomGradientColors];
+ SkScalar stopsArray[kMaxRandomGradientColors];
+ SkScalar* stops = stopsArray;
+ SkShader::TileMode tm;
+ int colorCount = RandomGradientParams(random, colors, &stops, &tm);
+ SkAutoTUnref<SkShader> shader(SkGradientShader::CreateTwoPointConical(center1, radius1,
+ center2, radius2,
+ colors, stops, colorCount,
+ tm));
+ SkPaint paint;
+ return shader->asNewEffect(context, paint);
+}
+
+
+/////////////////////////////////////////////////////////////////////
+
+GrGL2PtConicalGradientEffect::GrGL2PtConicalGradientEffect(const GrBackendEffectFactory& factory,
+ const GrDrawEffect& drawEffect)
+ : INHERITED(factory)
+ , fVSVaryingName(NULL)
+ , fFSVaryingName(NULL)
+ , fCachedCenter(SK_ScalarMax)
+ , fCachedRadius(-SK_ScalarMax)
+ , fCachedDiffRadius(-SK_ScalarMax) {
+
+ const Gr2PtConicalGradientEffect& data = drawEffect.castEffect<Gr2PtConicalGradientEffect>();
+ fIsDegenerate = data.isDegenerate();
+}
+
+void GrGL2PtConicalGradientEffect::emitCode(GrGLShaderBuilder* builder,
+ const GrDrawEffect&,
+ EffectKey key,
+ const char* outputColor,
+ const char* inputColor,
+ const TransformedCoordsArray& coords,
+ const TextureSamplerArray& samplers) {
+ this->emitUniforms(builder, key);
+ fParamUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
+ kFloat_GrSLType, "Conical2FSParams", 6);
+
+ 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());
+ }
+
+ // 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);
+
+ // c = (x^2)+(y^2) - params[4]
+ builder->fsCodeAppendf("\tfloat %s = dot(%s, %s) - %s;\n",
+ cName.c_str(), coords2D, coords2D, p4.c_str());
+
+ // Non-degenerate case (quadratic)
+ if (!fIsDegenerate) {
+
+ // ac4 = params[0] * c
+ builder->fsCodeAppendf("\tfloat %s = %s * %s;\n", ac4Name.c_str(), p0.c_str(),
+ cName.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());
+
+ // only proceed if discriminant is >= 0
+ builder->fsCodeAppendf("\tif (%s >= 0.0) {\n", dName.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());
+
+ // 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());
+
+ // Note: If there are two roots that both generate radius(t) > 0, the
+ // Canvas spec says to choose the larger t.
+
+ // 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());
+
+ // 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());
+
+ builder->fsCodeAppend("\t\t");
+ this->emitColor(builder, tName.c_str(), key, outputColor, inputColor, samplers);
+
+ // 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");
+ }
+}
+
+void GrGL2PtConicalGradientEffect::setData(const GrGLUniformManager& uman,
+ const GrDrawEffect& drawEffect) {
+ INHERITED::setData(uman, drawEffect);
+ const Gr2PtConicalGradientEffect& data = drawEffect.castEffect<Gr2PtConicalGradientEffect>();
+ SkASSERT(data.isDegenerate() == fIsDegenerate);
+ SkScalar centerX1 = data.center();
+ SkScalar radius0 = data.radius();
+ SkScalar diffRadius = data.diffRadius();
+
+ if (fCachedCenter != centerX1 ||
+ fCachedRadius != radius0 ||
+ fCachedDiffRadius != diffRadius) {
+
+ SkScalar a = SkScalarMul(centerX1, centerX1) - diffRadius * diffRadius;
+
+ // When we're in the degenerate (linear) case, the second
+ // value will be INF but the program doesn't read it. (We
+ // use the same 6 uniforms even though we don't need them
+ // all in the linear case just to keep the code complexity
+ // down).
+ float values[6] = {
+ SkScalarToFloat(a * 4),
+ 1.f / (SkScalarToFloat(a)),
+ SkScalarToFloat(centerX1),
+ SkScalarToFloat(radius0),
+ SkScalarToFloat(SkScalarMul(radius0, radius0)),
+ SkScalarToFloat(diffRadius)
+ };
+
+ uman.set1fv(fParamUni, 6, values);
+ fCachedCenter = centerX1;
+ fCachedRadius = radius0;
+ fCachedDiffRadius = diffRadius;
+ }
+}
+
+GrGLEffect::EffectKey GrGL2PtConicalGradientEffect::GenKey(const GrDrawEffect& drawEffect,
+ const GrGLCaps&) {
+ enum {
+ kIsDegenerate = 1 << kBaseKeyBitCnt,
+ };
+
+ EffectKey key = GenBaseGradientKey(drawEffect);
+ if (drawEffect.castEffect<Gr2PtConicalGradientEffect>().isDegenerate()) {
+ key |= kIsDegenerate;
+ }
+ return key;
+}
+#endif
+