1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/gpu/effects/GrConvolutionEffect.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,113 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef GrConvolutionEffect_DEFINED
1.12 +#define GrConvolutionEffect_DEFINED
1.13 +
1.14 +#include "Gr1DKernelEffect.h"
1.15 +
1.16 +class GrGLConvolutionEffect;
1.17 +
1.18 +/**
1.19 + * A convolution effect. The kernel is specified as an array of 2 * half-width
1.20 + * + 1 weights. Each texel is multiplied by it's weight and summed to determine
1.21 + * the output color. The output color is modulated by the input color.
1.22 + */
1.23 +class GrConvolutionEffect : public Gr1DKernelEffect {
1.24 +
1.25 +public:
1.26 +
1.27 + /// Convolve with an arbitrary user-specified kernel
1.28 + static GrEffectRef* Create(GrTexture* tex,
1.29 + Direction dir,
1.30 + int halfWidth,
1.31 + const float* kernel,
1.32 + bool useBounds,
1.33 + float bounds[2]) {
1.34 + AutoEffectUnref effect(SkNEW_ARGS(GrConvolutionEffect, (tex,
1.35 + dir,
1.36 + halfWidth,
1.37 + kernel,
1.38 + useBounds,
1.39 + bounds)));
1.40 + return CreateEffectRef(effect);
1.41 + }
1.42 +
1.43 + /// Convolve with a Gaussian kernel
1.44 + static GrEffectRef* CreateGaussian(GrTexture* tex,
1.45 + Direction dir,
1.46 + int halfWidth,
1.47 + float gaussianSigma,
1.48 + bool useBounds,
1.49 + float bounds[2]) {
1.50 + AutoEffectUnref effect(SkNEW_ARGS(GrConvolutionEffect, (tex,
1.51 + dir,
1.52 + halfWidth,
1.53 + gaussianSigma,
1.54 + useBounds,
1.55 + bounds)));
1.56 + return CreateEffectRef(effect);
1.57 + }
1.58 +
1.59 + virtual ~GrConvolutionEffect();
1.60 +
1.61 + const float* kernel() const { return fKernel; }
1.62 +
1.63 + const float* bounds() const { return fBounds; }
1.64 + bool useBounds() const { return fUseBounds; }
1.65 +
1.66 + static const char* Name() { return "Convolution"; }
1.67 +
1.68 + typedef GrGLConvolutionEffect GLEffect;
1.69 +
1.70 + virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
1.71 +
1.72 + virtual void getConstantColorComponents(GrColor*, uint32_t* validFlags) const {
1.73 + // If the texture was opaque we could know that the output color if we knew the sum of the
1.74 + // kernel values.
1.75 + *validFlags = 0;
1.76 + }
1.77 +
1.78 + enum {
1.79 + // This was decided based on the min allowed value for the max texture
1.80 + // samples per fragment program run in DX9SM2 (32). A sigma param of 4.0
1.81 + // on a blur filter gives a kernel width of 25 while a sigma of 5.0
1.82 + // would exceed a 32 wide kernel.
1.83 + kMaxKernelRadius = 12,
1.84 + // With a C++11 we could have a constexpr version of WidthFromRadius()
1.85 + // and not have to duplicate this calculation.
1.86 + kMaxKernelWidth = 2 * kMaxKernelRadius + 1,
1.87 + };
1.88 +
1.89 +protected:
1.90 +
1.91 + float fKernel[kMaxKernelWidth];
1.92 + bool fUseBounds;
1.93 + float fBounds[2];
1.94 +
1.95 +private:
1.96 + GrConvolutionEffect(GrTexture*, Direction,
1.97 + int halfWidth,
1.98 + const float* kernel,
1.99 + bool useBounds,
1.100 + float bounds[2]);
1.101 +
1.102 + /// Convolve with a Gaussian kernel
1.103 + GrConvolutionEffect(GrTexture*, Direction,
1.104 + int halfWidth,
1.105 + float gaussianSigma,
1.106 + bool useBounds,
1.107 + float bounds[2]);
1.108 +
1.109 + virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
1.110 +
1.111 + GR_DECLARE_EFFECT_TEST;
1.112 +
1.113 + typedef Gr1DKernelEffect INHERITED;
1.114 +};
1.115 +
1.116 +#endif
