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- /*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- #ifndef GrGaussianConvolutionFragmentProcessor_DEFINED
- #define GrGaussianConvolutionFragmentProcessor_DEFINED
- #include "src/gpu/GrCoordTransform.h"
- #include "src/gpu/GrFragmentProcessor.h"
- #include "src/gpu/effects/GrTextureDomain.h"
- /**
- * A 1D Gaussian convolution effect. The kernel is computed as an array of 2 * half-width weights.
- * Each texel is multiplied by it's weight and summed to determine the filtered color. The output
- * color is set to a modulation of the filtered and input colors.
- */
- class GrGaussianConvolutionFragmentProcessor : public GrFragmentProcessor {
- public:
- enum class Direction { kX, kY };
- /// Convolve with a Gaussian kernel
- static std::unique_ptr<GrFragmentProcessor> Make(sk_sp<GrTextureProxy> proxy,
- Direction dir,
- int halfWidth,
- float gaussianSigma,
- GrTextureDomain::Mode mode,
- int* bounds) {
- return std::unique_ptr<GrFragmentProcessor>(new GrGaussianConvolutionFragmentProcessor(
- std::move(proxy), dir, halfWidth, gaussianSigma, mode, bounds));
- }
- const float* kernel() const { return fKernel; }
- const int* bounds() const { return fBounds; }
- bool useBounds() const { return fMode != GrTextureDomain::kIgnore_Mode; }
- int radius() const { return fRadius; }
- int width() const { return 2 * fRadius + 1; }
- Direction direction() const { return fDirection; }
- GrTextureDomain::Mode mode() const { return fMode; }
- const char* name() const override { return "GaussianConvolution"; }
- #ifdef SK_DEBUG
- SkString dumpInfo() const override {
- SkString str;
- str.appendf("dir: %s radius: %d bounds: [%d %d]",
- Direction::kX == fDirection ? "X" : "Y",
- fRadius,
- fBounds[0], fBounds[1]);
- return str;
- }
- #endif
- std::unique_ptr<GrFragmentProcessor> clone() const override {
- return std::unique_ptr<GrFragmentProcessor>(
- new GrGaussianConvolutionFragmentProcessor(*this));
- }
- // This was decided based on the min allowed value for the max texture
- // samples per fragment program run in DX9SM2 (32). A sigma param of 4.0
- // on a blur filter gives a kernel width of 25 while a sigma of 5.0
- // would exceed a 32 wide kernel.
- static const int kMaxKernelRadius = 12;
- // With a C++11 we could have a constexpr version of WidthFromRadius()
- // and not have to duplicate this calculation.
- static const int kMaxKernelWidth = 2 * kMaxKernelRadius + 1;
- private:
- /// Convolve with a Gaussian kernel
- GrGaussianConvolutionFragmentProcessor(sk_sp<GrTextureProxy>, Direction,
- int halfWidth, float gaussianSigma,
- GrTextureDomain::Mode mode, int bounds[2]);
- explicit GrGaussianConvolutionFragmentProcessor(const GrGaussianConvolutionFragmentProcessor&);
- GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
- void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override;
- bool onIsEqual(const GrFragmentProcessor&) const override;
- const TextureSampler& onTextureSampler(int) const override { return fTextureSampler; }
- GR_DECLARE_FRAGMENT_PROCESSOR_TEST
- GrCoordTransform fCoordTransform;
- TextureSampler fTextureSampler;
- // TODO: Inline the kernel constants into the generated shader code. This may involve pulling
- // some of the logic from SkGpuBlurUtils into this class related to radius/sigma calculations.
- float fKernel[kMaxKernelWidth];
- int fBounds[2];
- int fRadius;
- Direction fDirection;
- GrTextureDomain::Mode fMode;
- typedef GrFragmentProcessor INHERITED;
- };
- #endif
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