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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrBicubicTextureEffect_DEFINED
#define GrBicubicTextureEffect_DEFINED
#include "src/gpu/GrFragmentProcessor.h"
class GrInvariantOutput;
class GrBicubicEffect : public GrFragmentProcessor {
public:
enum {
kFilterTexelPad = 2, // Given a src rect in texels to be filtered, this number of
// surrounding texels are needed by the kernel in x and y.
};
inline static constexpr SkImage::CubicResampler gMitchell = { 1.0f/3, 1.0f/3 };
inline static constexpr SkImage::CubicResampler gCatmullRom = { 0, 1.0f/2 };
enum class Direction {
/** Apply bicubic kernel in local coord x, nearest neighbor in y. */
kX,
/** Apply bicubic kernel in local coord y, nearest neighbor in x. */
kY,
/** Apply bicubic in both x and y. */
kXY
};
const char* name() const override { return "Bicubic"; }
std::unique_ptr<GrFragmentProcessor> clone() const override {
return std::unique_ptr<GrFragmentProcessor>(new GrBicubicEffect(*this));
}
/**
* Create a bicubic filter effect with specified texture matrix with clamp wrap mode.
*/
static std::unique_ptr<GrFragmentProcessor> Make(GrSurfaceProxyView view,
SkAlphaType,
const SkMatrix&,
SkImage::CubicResampler,
Direction);
/**
* Create a bicubic filter effect for a texture with arbitrary wrap modes.
*/
static std::unique_ptr<GrFragmentProcessor> Make(GrSurfaceProxyView view,
SkAlphaType,
const SkMatrix&,
const GrSamplerState::WrapMode wrapX,
const GrSamplerState::WrapMode wrapY,
SkImage::CubicResampler,
Direction,
const GrCaps&);
/**
* Create a bicubic filter effect for a subset of a texture, specified by a texture coordinate
* rectangle subset. The WrapModes apply to the subset.
*/
static std::unique_ptr<GrFragmentProcessor> MakeSubset(GrSurfaceProxyView view,
SkAlphaType,
const SkMatrix&,
const GrSamplerState::WrapMode wrapX,
const GrSamplerState::WrapMode wrapY,
const SkRect& subset,
SkImage::CubicResampler,
Direction,
const GrCaps&);
/**
* Same as above but provides a known 'domain' that bounds the coords at which bicubic sampling
* occurs. Note that this is a bound on the coords after transformed by the matrix parameter.
*/
static std::unique_ptr<GrFragmentProcessor> MakeSubset(GrSurfaceProxyView view,
SkAlphaType,
const SkMatrix&,
const GrSamplerState::WrapMode wrapX,
const GrSamplerState::WrapMode wrapY,
const SkRect& subset,
const SkRect& domain,
SkImage::CubicResampler,
Direction,
const GrCaps&);
/**
* Make a bicubic filter of a another fragment processor. The bicubic filter assumes that the
* discrete samples of the provided processor are at half-integer coords.
*/
static std::unique_ptr<GrFragmentProcessor> Make(std::unique_ptr<GrFragmentProcessor>,
SkAlphaType,
const SkMatrix&,
SkImage::CubicResampler,
Direction);
private:
class Impl;
enum class Clamp {
kUnpremul, // clamps rgba to 0..1
kPremul, // clamps a to 0..1 and rgb to 0..a
};
GrBicubicEffect(std::unique_ptr<GrFragmentProcessor>,
SkImage::CubicResampler,
Direction,
Clamp);
explicit GrBicubicEffect(const GrBicubicEffect&);
std::unique_ptr<ProgramImpl> onMakeProgramImpl() const override;
void onAddToKey(const GrShaderCaps&, skgpu::KeyBuilder*) const override;
bool onIsEqual(const GrFragmentProcessor&) const override;
SkPMColor4f constantOutputForConstantInput(const SkPMColor4f&) const override;
SkImage::CubicResampler fKernel;
Direction fDirection;
Clamp fClamp;
GR_DECLARE_FRAGMENT_PROCESSOR_TEST
using INHERITED = GrFragmentProcessor;
};
#endif