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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 "GrSingleTextureEffect.h"
#include "GrTextureDomain.h"
#include "GrDrawEffect.h"
#include "gl/GrGLEffect.h"
#include "GrTBackendEffectFactory.h"
class GrGLBicubicEffect;
class GrBicubicEffect : public GrSingleTextureEffect {
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.
};
virtual ~GrBicubicEffect();
static const char* Name() { return "Bicubic"; }
const float* coefficients() const { return fCoefficients; }
typedef GrGLBicubicEffect GLEffect;
virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
const GrTextureDomain& domain() const { return fDomain; }
/**
* Create a simple filter effect with custom bicubic coefficients and optional domain.
*/
static GrEffect* Create(GrTexture* tex, const SkScalar coefficients[16],
const SkRect* domain = NULL) {
if (NULL == domain) {
static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode,
SkShader::kClamp_TileMode };
return Create(tex, coefficients, MakeDivByTextureWHMatrix(tex), kTileModes);
} else {
return SkNEW_ARGS(GrBicubicEffect, (tex, coefficients,
MakeDivByTextureWHMatrix(tex), *domain));
}
}
/**
* Create a Mitchell filter effect with specified texture matrix and x/y tile modes.
*/
static GrEffect* Create(GrTexture* tex, const SkMatrix& matrix,
SkShader::TileMode tileModes[2]) {
return Create(tex, gMitchellCoefficients, matrix, tileModes);
}
/**
* Create a filter effect with custom bicubic coefficients, the texture matrix, and the x/y
* tilemodes.
*/
static GrEffect* Create(GrTexture* tex, const SkScalar coefficients[16],
const SkMatrix& matrix, const SkShader::TileMode tileModes[2]) {
return SkNEW_ARGS(GrBicubicEffect, (tex, coefficients, matrix, tileModes));
}
/**
* Create a Mitchell filter effect with a texture matrix and a domain.
*/
static GrEffect* Create(GrTexture* tex, const SkMatrix& matrix, const SkRect& domain) {
return SkNEW_ARGS(GrBicubicEffect, (tex, gMitchellCoefficients, matrix, domain));
}
/**
* Determines whether the bicubic effect should be used based on the transformation from the
* local coords to the device. Returns true if the bicubic effect should be used. filterMode
* is set to appropriate filtering mode to use regardless of the return result (e.g. when this
* returns false it may indicate that the best fallback is to use kMipMap, kBilerp, or
* kNearest).
*/
static bool ShouldUseBicubic(const SkMatrix& localCoordsToDevice,
GrTextureParams::FilterMode* filterMode);
private:
GrBicubicEffect(GrTexture*, const SkScalar coefficients[16],
const SkMatrix &matrix, const SkShader::TileMode tileModes[2]);
GrBicubicEffect(GrTexture*, const SkScalar coefficients[16],
const SkMatrix &matrix, const SkRect& domain);
virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
float fCoefficients[16];
GrTextureDomain fDomain;
GR_DECLARE_EFFECT_TEST;
static const SkScalar gMitchellCoefficients[16];
typedef GrSingleTextureEffect INHERITED;
};
#endif