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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.
*/
#include "SkArithmeticMode.h"
#include "SkColorPriv.h"
#include "SkFlattenableBuffers.h"
#include "SkString.h"
#include "SkUnPreMultiply.h"
#if SK_SUPPORT_GPU
#include "GrContext.h"
#include "gl/GrGLEffect.h"
#include "gl/GrGLEffectMatrix.h"
#include "GrTBackendEffectFactory.h"
#include "SkImageFilterUtils.h"
#endif
static const bool gUseUnpremul = false;
class SkArithmeticMode_scalar : public SkXfermode {
public:
SkArithmeticMode_scalar(SkScalar k1, SkScalar k2, SkScalar k3, SkScalar k4) {
fK[0] = k1;
fK[1] = k2;
fK[2] = k3;
fK[3] = k4;
}
virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const SK_OVERRIDE;
SK_DEVELOPER_TO_STRING()
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkArithmeticMode_scalar)
#if SK_SUPPORT_GPU
virtual bool asNewEffectOrCoeff(GrContext*, GrEffectRef** effect, Coeff*, Coeff*, GrTexture* background) const SK_OVERRIDE;
#endif
private:
SkArithmeticMode_scalar(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
fK[0] = buffer.readScalar();
fK[1] = buffer.readScalar();
fK[2] = buffer.readScalar();
fK[3] = buffer.readScalar();
}
virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
INHERITED::flatten(buffer);
buffer.writeScalar(fK[0]);
buffer.writeScalar(fK[1]);
buffer.writeScalar(fK[2]);
buffer.writeScalar(fK[3]);
}
SkScalar fK[4];
typedef SkXfermode INHERITED;
};
static int pinToByte(int value) {
if (value < 0) {
value = 0;
} else if (value > 255) {
value = 255;
}
return value;
}
static int arith(SkScalar k1, SkScalar k2, SkScalar k3, SkScalar k4,
int src, int dst) {
SkScalar result = SkScalarMul(k1, src * dst) +
SkScalarMul(k2, src) +
SkScalarMul(k3, dst) +
k4;
int res = SkScalarRoundToInt(result);
return pinToByte(res);
}
static int blend(int src, int dst, int scale) {
return dst + ((src - dst) * scale >> 8);
}
static bool needsUnpremul(int alpha) {
return 0 != alpha && 0xFF != alpha;
}
void SkArithmeticMode_scalar::xfer32(SkPMColor dst[], const SkPMColor src[],
int count, const SkAlpha aaCoverage[]) const {
SkScalar k1 = fK[0] / 255;
SkScalar k2 = fK[1];
SkScalar k3 = fK[2];
SkScalar k4 = fK[3] * 255;
for (int i = 0; i < count; ++i) {
if ((NULL == aaCoverage) || aaCoverage[i]) {
SkPMColor sc = src[i];
SkPMColor dc = dst[i];
int a, r, g, b;
if (gUseUnpremul) {
int sa = SkGetPackedA32(sc);
int da = SkGetPackedA32(dc);
int srcNeedsUnpremul = needsUnpremul(sa);
int dstNeedsUnpremul = needsUnpremul(da);
if (!srcNeedsUnpremul && !dstNeedsUnpremul) {
a = arith(k1, k2, k3, k4, sa, da);
r = arith(k1, k2, k3, k4, SkGetPackedR32(sc), SkGetPackedR32(dc));
g = arith(k1, k2, k3, k4, SkGetPackedG32(sc), SkGetPackedG32(dc));
b = arith(k1, k2, k3, k4, SkGetPackedB32(sc), SkGetPackedB32(dc));
} else {
int sr = SkGetPackedR32(sc);
int sg = SkGetPackedG32(sc);
int sb = SkGetPackedB32(sc);
if (srcNeedsUnpremul) {
SkUnPreMultiply::Scale scale = SkUnPreMultiply::GetScale(sa);
sr = SkUnPreMultiply::ApplyScale(scale, sr);
sg = SkUnPreMultiply::ApplyScale(scale, sg);
sb = SkUnPreMultiply::ApplyScale(scale, sb);
}
int dr = SkGetPackedR32(dc);
int dg = SkGetPackedG32(dc);
int db = SkGetPackedB32(dc);
if (dstNeedsUnpremul) {
SkUnPreMultiply::Scale scale = SkUnPreMultiply::GetScale(da);
dr = SkUnPreMultiply::ApplyScale(scale, dr);
dg = SkUnPreMultiply::ApplyScale(scale, dg);
db = SkUnPreMultiply::ApplyScale(scale, db);
}
a = arith(k1, k2, k3, k4, sa, da);
r = arith(k1, k2, k3, k4, sr, dr);
g = arith(k1, k2, k3, k4, sg, dg);
b = arith(k1, k2, k3, k4, sb, db);
}
} else {
a = arith(k1, k2, k3, k4, SkGetPackedA32(sc), SkGetPackedA32(dc));
r = arith(k1, k2, k3, k4, SkGetPackedR32(sc), SkGetPackedR32(dc));
r = SkMin32(r, a);
g = arith(k1, k2, k3, k4, SkGetPackedG32(sc), SkGetPackedG32(dc));
g = SkMin32(g, a);
b = arith(k1, k2, k3, k4, SkGetPackedB32(sc), SkGetPackedB32(dc));
b = SkMin32(b, a);
}
// apply antialias coverage if necessary
if (aaCoverage && 0xFF != aaCoverage[i]) {
int scale = aaCoverage[i] + (aaCoverage[i] >> 7);
a = blend(a, SkGetPackedA32(sc), scale);
r = blend(r, SkGetPackedR32(sc), scale);
g = blend(g, SkGetPackedG32(sc), scale);
b = blend(b, SkGetPackedB32(sc), scale);
}
// turn the result back into premul
if (gUseUnpremul && (0xFF != a)) {
int scale = a + (a >> 7);
r = SkAlphaMul(r, scale);
g = SkAlphaMul(g, scale);
b = SkAlphaMul(b, scale);
}
dst[i] = SkPackARGB32(a, r, g, b);
}
}
}
#ifdef SK_DEVELOPER
void SkArithmeticMode_scalar::toString(SkString* str) const {
str->append("SkArithmeticMode_scalar: ");
for (int i = 0; i < 4; ++i) {
str->appendScalar(fK[i]);
if (i < 3) {
str->append(" ");
}
}
}
#endif
///////////////////////////////////////////////////////////////////////////////
static bool fitsInBits(SkScalar x, int bits) {
#ifdef SK_SCALAR_IS_FIXED
x = SkAbs32(x);
x += 1 << 7;
x >>= 8;
return x < (1 << (bits - 1));
#else
return SkScalarAbs(x) < (1 << (bits - 1));
#endif
}
#if 0 // UNUSED
static int32_t toDot8(SkScalar x) {
#ifdef SK_SCALAR_IS_FIXED
x += 1 << 7;
x >>= 8;
return x;
#else
return (int32_t)(x * 256);
#endif
}
#endif
SkXfermode* SkArithmeticMode::Create(SkScalar k1, SkScalar k2,
SkScalar k3, SkScalar k4) {
if (fitsInBits(k1, 8) && fitsInBits(k2, 16) &&
fitsInBits(k2, 16) && fitsInBits(k2, 24)) {
#if 0 // UNUSED
int32_t i1 = toDot8(k1);
int32_t i2 = toDot8(k2);
int32_t i3 = toDot8(k3);
int32_t i4 = toDot8(k4);
if (i1) {
return SkNEW_ARGS(SkArithmeticMode_quad, (i1, i2, i3, i4));
}
if (0 == i2) {
return SkNEW_ARGS(SkArithmeticMode_dst, (i3, i4));
}
if (0 == i3) {
return SkNEW_ARGS(SkArithmeticMode_src, (i2, i4));
}
return SkNEW_ARGS(SkArithmeticMode_linear, (i2, i3, i4));
#endif
}
return SkNEW_ARGS(SkArithmeticMode_scalar, (k1, k2, k3, k4));
}
//////////////////////////////////////////////////////////////////////////////
#if SK_SUPPORT_GPU
class GrGLArithmeticEffect : public GrGLEffect {
public:
GrGLArithmeticEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
virtual ~GrGLArithmeticEffect();
virtual void emitCode(GrGLShaderBuilder*,
const GrDrawEffect&,
EffectKey,
const char* outputColor,
const char* inputColor,
const TextureSamplerArray&) SK_OVERRIDE;
static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
private:
static const GrEffect::CoordsType kCoordsType = GrEffect::kLocal_CoordsType;
GrGLEffectMatrix fBackgroundEffectMatrix;
GrGLUniformManager::UniformHandle fKUni;
typedef GrGLEffect INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
class GrArithmeticEffect : public GrEffect {
public:
static GrEffectRef* Create(float k1, float k2, float k3, float k4, GrTexture* background) {
AutoEffectUnref effect(SkNEW_ARGS(GrArithmeticEffect, (k1, k2, k3, k4, background)));
return CreateEffectRef(effect);
}
virtual ~GrArithmeticEffect();
virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
typedef GrGLArithmeticEffect GLEffect;
static const char* Name() { return "Arithmetic"; }
GrTexture* backgroundTexture() const { return fBackgroundAccess.getTexture(); }
virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
float k1() const { return fK1; }
float k2() const { return fK2; }
float k3() const { return fK3; }
float k4() const { return fK4; }
private:
virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
GrArithmeticEffect(float k1, float k2, float k3, float k4, GrTexture* background);
float fK1, fK2, fK3, fK4;
GrTextureAccess fBackgroundAccess;
GR_DECLARE_EFFECT_TEST;
typedef GrEffect INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrArithmeticEffect::GrArithmeticEffect(float k1, float k2, float k3, float k4,
GrTexture* background)
: fK1(k1), fK2(k2), fK3(k3), fK4(k4) {
if (background) {
fBackgroundAccess.reset(background);
this->addTextureAccess(&fBackgroundAccess);
} else {
this->setWillReadDstColor();
}
}
GrArithmeticEffect::~GrArithmeticEffect() {
}
bool GrArithmeticEffect::onIsEqual(const GrEffect& sBase) const {
const GrArithmeticEffect& s = CastEffect<GrArithmeticEffect>(sBase);
return fK1 == s.fK1 &&
fK2 == s.fK2 &&
fK3 == s.fK3 &&
fK4 == s.fK4 &&
backgroundTexture() == s.backgroundTexture();
}
const GrBackendEffectFactory& GrArithmeticEffect::getFactory() const {
return GrTBackendEffectFactory<GrArithmeticEffect>::getInstance();
}
void GrArithmeticEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
// TODO: optimize this
*validFlags = 0;
}
///////////////////////////////////////////////////////////////////////////////
GrGLArithmeticEffect::GrGLArithmeticEffect(const GrBackendEffectFactory& factory,
const GrDrawEffect& drawEffect)
: INHERITED(factory)
, fBackgroundEffectMatrix(kCoordsType) {
}
GrGLArithmeticEffect::~GrGLArithmeticEffect() {
}
void GrGLArithmeticEffect::emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect& drawEffect,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TextureSamplerArray& samplers) {
GrTexture* backgroundTex = drawEffect.castEffect<GrArithmeticEffect>().backgroundTexture();
const char* dstColor;
if (backgroundTex) {
SkString bgCoords;
GrSLType bgCoordsType = fBackgroundEffectMatrix.emitCode(builder, key, &bgCoords, NULL, "BG");
builder->fsCodeAppend("\t\tvec4 bgColor = ");
builder->appendTextureLookup(GrGLShaderBuilder::kFragment_ShaderType,
samplers[0],
bgCoords.c_str(),
bgCoordsType);
builder->fsCodeAppendf(";\n");
dstColor = "bgColor";
} else {
dstColor = builder->dstColor();
}
SkASSERT(NULL != dstColor);
fKUni = builder->addUniform(GrGLShaderBuilder::kFragment_ShaderType,
kVec4f_GrSLType, "k");
const char* kUni = builder->getUniformCStr(fKUni);
// We don't try to optimize for this case at all
if (NULL == inputColor) {
builder->fsCodeAppendf("\t\tconst vec4 src = %s;\n", GrGLSLOnesVecf(4));
} else {
builder->fsCodeAppendf("\t\tvec4 src = %s;\n", inputColor);
if (gUseUnpremul) {
builder->fsCodeAppendf("\t\tsrc.rgb = clamp(src.rgb / src.a, 0.0, 1.0);\n");
}
}
builder->fsCodeAppendf("\t\tvec4 dst = %s;\n", dstColor);
if (gUseUnpremul) {
builder->fsCodeAppendf("\t\tdst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);\n");
}
builder->fsCodeAppendf("\t\t%s = %s.x * src * dst + %s.y * src + %s.z * dst + %s.w;\n", outputColor, kUni, kUni, kUni, kUni);
builder->fsCodeAppendf("\t\t%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
if (gUseUnpremul) {
builder->fsCodeAppendf("\t\t%s.rgb *= %s.a;\n", outputColor, outputColor);
} else {
builder->fsCodeAppendf("\t\t%s.rgb = min(%s.rgb, %s.a);\n", outputColor, outputColor, outputColor);
}
}
void GrGLArithmeticEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
const GrArithmeticEffect& arith = drawEffect.castEffect<GrArithmeticEffect>();
uman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
GrTexture* bgTex = arith.backgroundTexture();
if (bgTex) {
fBackgroundEffectMatrix.setData(uman,
GrEffect::MakeDivByTextureWHMatrix(bgTex),
drawEffect,
bgTex);
}
}
GrGLEffect::EffectKey GrGLArithmeticEffect::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
const GrArithmeticEffect& effect = drawEffect.castEffect<GrArithmeticEffect>();
GrTexture* bgTex = effect.backgroundTexture();
EffectKey bgKey = 0;
if (bgTex) {
bgKey = GrGLEffectMatrix::GenKey(GrEffect::MakeDivByTextureWHMatrix(bgTex),
drawEffect,
GrGLArithmeticEffect::kCoordsType,
bgTex);
}
return bgKey;
}
GrEffectRef* GrArithmeticEffect::TestCreate(SkMWCRandom* rand,
GrContext*,
const GrDrawTargetCaps&,
GrTexture*[]) {
float k1 = rand->nextF();
float k2 = rand->nextF();
float k3 = rand->nextF();
float k4 = rand->nextF();
static AutoEffectUnref gEffect(SkNEW_ARGS(GrArithmeticEffect, (k1, k2, k3, k4, NULL)));
return CreateEffectRef(gEffect);
}
GR_DEFINE_EFFECT_TEST(GrArithmeticEffect);
bool SkArithmeticMode_scalar::asNewEffectOrCoeff(GrContext*,
GrEffectRef** effect,
Coeff*,
Coeff*,
GrTexture* background) const {
if (effect) {
*effect = GrArithmeticEffect::Create(SkScalarToFloat(fK[0]),
SkScalarToFloat(fK[1]),
SkScalarToFloat(fK[2]),
SkScalarToFloat(fK[3]),
background);
}
return true;
}
#endif
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkArithmeticMode)
SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkArithmeticMode_scalar)
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END