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/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkCanvas.h"
#include "SkReadBuffer.h"
#include "SkShadowShader.h"
////////////////////////////////////////////////////////////////////////////
#ifdef SK_EXPERIMENTAL_SHADOWING
/** \class SkShadowShaderImpl
This subclass of shader applies shadowing
*/
class SkShadowShaderImpl : public SkShader {
public:
/** Create a new shadowing shader that shadows
@param to do to do
*/
SkShadowShaderImpl(sk_sp<SkShader> povDepthShader,
sk_sp<SkShader> diffuseShader,
sk_sp<SkLights> lights,
int diffuseWidth, int diffuseHeight,
const SkShadowParams& params)
: fPovDepthShader(std::move(povDepthShader))
, fDiffuseShader(std::move(diffuseShader))
, fLights(std::move(lights))
, fDiffuseWidth(diffuseWidth)
, fDiffuseHeight(diffuseHeight)
, fShadowParams(params) { }
bool isOpaque() const override;
#if SK_SUPPORT_GPU
sk_sp<GrFragmentProcessor> asFragmentProcessor(const AsFPArgs&) const override;
#endif
class ShadowShaderContext : public SkShader::Context {
public:
// The context takes ownership of the states. It will call their destructors
// but will NOT free the memory.
ShadowShaderContext(const SkShadowShaderImpl&, const ContextRec&,
SkShader::Context* povDepthContext,
SkShader::Context* diffuseContext,
void* heapAllocated);
~ShadowShaderContext() override;
void shadeSpan(int x, int y, SkPMColor[], int count) override;
uint32_t getFlags() const override { return fFlags; }
private:
SkShader::Context* fPovDepthContext;
SkShader::Context* fDiffuseContext;
uint32_t fFlags;
void* fHeapAllocated;
int fNonAmbLightCnt;
SkPixmap* fShadowMapPixels;
typedef SkShader::Context INHERITED;
};
SK_TO_STRING_OVERRIDE()
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkShadowShaderImpl)
protected:
void flatten(SkWriteBuffer&) const override;
size_t onContextSize(const ContextRec&) const override;
Context* onCreateContext(const ContextRec&, void*) const override;
private:
sk_sp<SkShader> fPovDepthShader;
sk_sp<SkShader> fDiffuseShader;
sk_sp<SkLights> fLights;
int fDiffuseWidth;
int fDiffuseHeight;
SkShadowParams fShadowParams;
friend class SkShadowShader;
typedef SkShader INHERITED;
};
////////////////////////////////////////////////////////////////////////////
#if SK_SUPPORT_GPU
#include "GrCoordTransform.h"
#include "GrFragmentProcessor.h"
#include "GrInvariantOutput.h"
#include "glsl/GrGLSLFragmentProcessor.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "SkGr.h"
#include "SkGrPriv.h"
#include "SkSpecialImage.h"
#include "SkImage_Base.h"
#include "GrContext.h"
class ShadowFP : public GrFragmentProcessor {
public:
ShadowFP(sk_sp<GrFragmentProcessor> povDepth,
sk_sp<GrFragmentProcessor> diffuse,
sk_sp<SkLights> lights,
int diffuseWidth, int diffuseHeight,
const SkShadowParams& params,
GrContext* context) {
fAmbientColor = lights->ambientLightColor();
fNumNonAmbLights = 0; // count of non-ambient lights
for (int i = 0; i < lights->numLights(); ++i) {
if (fNumNonAmbLights < SkShadowShader::kMaxNonAmbientLights) {
fLightColor[fNumNonAmbLights] = lights->light(i).color();
if (SkLights::Light::kDirectional_LightType == lights->light(i).type()) {
fLightDirOrPos[fNumNonAmbLights] = lights->light(i).dir();
fLightIntensity[fNumNonAmbLights] = 0.0f;
} else if (SkLights::Light::kPoint_LightType == lights->light(i).type()) {
fLightDirOrPos[fNumNonAmbLights] = lights->light(i).pos();
fLightIntensity[fNumNonAmbLights] = lights->light(i).intensity();
}
fIsPointLight[fNumNonAmbLights] =
SkLights::Light::kPoint_LightType == lights->light(i).type();
SkImage_Base* shadowMap = ((SkImage_Base*)lights->light(i).getShadowMap());
// gets deleted when the ShadowFP is destroyed, and frees the GrTexture*
fTexture[fNumNonAmbLights] = sk_sp<GrTexture>(shadowMap->asTextureRef(context,
GrTextureParams::ClampNoFilter(),
SkSourceGammaTreatment::kIgnore));
fDepthMapAccess[fNumNonAmbLights].reset(fTexture[fNumNonAmbLights].get());
this->addTextureAccess(&fDepthMapAccess[fNumNonAmbLights]);
fDepthMapHeight[fNumNonAmbLights] = shadowMap->height();
fDepthMapWidth[fNumNonAmbLights] = shadowMap->width();
fNumNonAmbLights++;
}
}
fWidth = diffuseWidth;
fHeight = diffuseHeight;
fShadowParams = params;
this->registerChildProcessor(std::move(povDepth));
this->registerChildProcessor(std::move(diffuse));
this->initClassID<ShadowFP>();
}
class GLSLShadowFP : public GrGLSLFragmentProcessor {
public:
GLSLShadowFP() { }
void emitCode(EmitArgs& args) override {
GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
const ShadowFP& shadowFP = args.fFp.cast<ShadowFP>();
SkASSERT(shadowFP.fNumNonAmbLights <= SkShadowShader::kMaxNonAmbientLights);
// add uniforms
int32_t numLights = shadowFP.fNumNonAmbLights;
SkASSERT(numLights <= SkShadowShader::kMaxNonAmbientLights);
int blurAlgorithm = shadowFP.fShadowParams.fType;
const char* lightDirOrPosUniName[SkShadowShader::kMaxNonAmbientLights] = {nullptr};
const char* lightColorUniName[SkShadowShader::kMaxNonAmbientLights] = {nullptr};
const char* lightIntensityUniName[SkShadowShader::kMaxNonAmbientLights] = {nullptr};
const char* depthMapWidthUniName[SkShadowShader::kMaxNonAmbientLights] = {nullptr};
const char* depthMapHeightUniName[SkShadowShader::kMaxNonAmbientLights] = {nullptr};
for (int i = 0; i < shadowFP.fNumNonAmbLights; i++) {
SkString lightDirOrPosUniNameStr("lightDir");
lightDirOrPosUniNameStr.appendf("%d", i);
SkString lightColorUniNameStr("lightColor");
lightColorUniNameStr.appendf("%d", i);
SkString lightIntensityUniNameStr("lightIntensity");
lightIntensityUniNameStr.appendf("%d", i);
SkString depthMapWidthUniNameStr("dmapWidth");
depthMapWidthUniNameStr.appendf("%d", i);
SkString depthMapHeightUniNameStr("dmapHeight");
depthMapHeightUniNameStr.appendf("%d", i);
fLightDirOrPosUni[i] = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec3f_GrSLType,
kDefault_GrSLPrecision,
lightDirOrPosUniNameStr.c_str(),
&lightDirOrPosUniName[i]);
fLightColorUni[i] = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec3f_GrSLType,
kDefault_GrSLPrecision,
lightColorUniNameStr.c_str(),
&lightColorUniName[i]);
fLightIntensityUni[i] =
uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
lightIntensityUniNameStr.c_str(),
&lightIntensityUniName[i]);
fDepthMapWidthUni[i] = uniformHandler->addUniform(kFragment_GrShaderFlag,
kInt_GrSLType,
kDefault_GrSLPrecision,
depthMapWidthUniNameStr.c_str(),
&depthMapWidthUniName[i]);
fDepthMapHeightUni[i] = uniformHandler->addUniform(kFragment_GrShaderFlag,
kInt_GrSLType,
kDefault_GrSLPrecision,
depthMapHeightUniNameStr.c_str(),
&depthMapHeightUniName[i]);
}
const char* shBiasUniName = nullptr;
const char* minVarianceUniName = nullptr;
fBiasingConstantUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
"shadowBias", &shBiasUniName);
fMinVarianceUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
"minVariance", &minVarianceUniName);
const char* widthUniName = nullptr;
const char* heightUniName = nullptr;
fWidthUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kInt_GrSLType,
kDefault_GrSLPrecision,
"width", &widthUniName);
fHeightUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kInt_GrSLType,
kDefault_GrSLPrecision,
"height", &heightUniName);
SkString povDepth("povDepth");
this->emitChild(0, nullptr, &povDepth, args);
SkString diffuseColor("inDiffuseColor");
this->emitChild(1, nullptr, &diffuseColor, args);
SkString depthMaps[SkShadowShader::kMaxNonAmbientLights];
// Multiply by 255 to transform from sampler coordinates to world
// coordinates (since 1 channel is 0xFF)
fragBuilder->codeAppendf("vec3 worldCor = vec3(vMatrixCoord_0_1_Stage0 * "
"vec2(%s, %s), %s.b * 255);",
widthUniName, heightUniName, povDepth.c_str());
// Applies the offset indexing that goes from our view space into the light's space.
for (int i = 0; i < shadowFP.fNumNonAmbLights; i++) {
SkString povCoord("povCoord");
povCoord.appendf("%d", i);
// vMatrixCoord_0_1_Stage0 is the texture sampler coordinates.
// povDepth.b * 255 scales it to 0 - 255, bringing it to world space,
// and the / vec2(width, height) brings it back to a sampler coordinate
SkString offset("offset");
offset.appendf("%d", i);
SkString scaleVec("scaleVec");
scaleVec.appendf("%d", i);
SkString scaleOffsetVec("scaleOffsetVec");
scaleOffsetVec.appendf("%d", i);
fragBuilder->codeAppendf("vec2 %s;", offset.c_str());
if (shadowFP.fIsPointLight[i]) {
fragBuilder->codeAppendf("vec3 fragToLight%d = %s - worldCor;",
i, lightDirOrPosUniName[i]);
fragBuilder->codeAppendf("float distsq%d = dot(fragToLight%d, fragToLight%d);"
"fragToLight%d = normalize(fragToLight%d);",
i, i, i, i, i);
fragBuilder->codeAppendf("%s = -vec2(%s.x - worldCor.x, worldCor.y - %s.y)*"
"(povDepth.b) / vec2(%s, %s);",
offset.c_str(), lightDirOrPosUniName[i],
lightDirOrPosUniName[i],
widthUniName, heightUniName);
} else {
fragBuilder->codeAppendf("%s = vec2(%s) * povDepth.b * 255 / vec2(%s, %s);",
offset.c_str(), lightDirOrPosUniName[i],
widthUniName, heightUniName);
}
fragBuilder->codeAppendf("vec2 %s = (vec2(%s, %s) / vec2(%s, %s));",
scaleVec.c_str(),
widthUniName, heightUniName,
depthMapWidthUniName[i], depthMapHeightUniName[i]);
fragBuilder->codeAppendf("vec2 %s = 1 - %s;\n",
scaleOffsetVec.c_str(),
scaleVec.c_str());
fragBuilder->codeAppendf("vec2 %s = (vMatrixCoord_0_1_Stage0 + "
"vec2(%s.x, 0 - %s.y)) "
" * %s + vec2(0,1) * %s;",
povCoord.c_str(), offset.c_str(), offset.c_str(),
scaleVec.c_str(), scaleOffsetVec.c_str());
fragBuilder->appendTextureLookup(&depthMaps[i], args.fTexSamplers[i],
povCoord.c_str(),
kVec2f_GrSLType);
}
const char* ambientColorUniName = nullptr;
fAmbientColorUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec3f_GrSLType, kDefault_GrSLPrecision,
"AmbientColor", &ambientColorUniName);
fragBuilder->codeAppendf("vec4 resultDiffuseColor = %s;", diffuseColor.c_str());
SkString totalLightColor("totalLightColor");
fragBuilder->codeAppendf("vec3 %s = vec3(0,0,0);", totalLightColor.c_str());
fragBuilder->codeAppendf("float lightProbability;");
fragBuilder->codeAppendf("float variance;");
fragBuilder->codeAppendf("float d;");
for (int i = 0; i < numLights; i++) {
if (!shadowFP.isPointLight(i)) {
fragBuilder->codeAppendf("lightProbability = 1;");
// 1/512 is less than half a pixel; imperceptible
fragBuilder->codeAppendf("if (%s.b <= %s.b + 1/512) {",
povDepth.c_str(), depthMaps[i].c_str());
if (blurAlgorithm == SkShadowParams::kVariance_ShadowType) {
fragBuilder->codeAppendf("vec2 moments%d = vec2(%s.b * 255,"
"%s.g * 255 * 256 );",
i, depthMaps[i].c_str(), depthMaps[i].c_str());
// variance biasing lessens light bleeding
fragBuilder->codeAppendf("variance = max(moments%d.y - "
"(moments%d.x * moments%d.x),"
"%s);", i, i, i,
minVarianceUniName);
fragBuilder->codeAppendf("d = (%s.b * 255) - moments%d.x;",
povDepth.c_str(), i);
fragBuilder->codeAppendf("lightProbability = "
"(variance / (variance + d * d));");
SkString clamp("clamp");
clamp.appendf("%d", i);
// choosing between light artifacts or correct shape shadows
// linstep
fragBuilder->codeAppendf("float %s = clamp((lightProbability - %s) /"
"(1 - %s), 0, 1);",
clamp.c_str(), shBiasUniName, shBiasUniName);
fragBuilder->codeAppendf("lightProbability = %s;", clamp.c_str());
} else {
fragBuilder->codeAppendf("if (%s.b >= %s.b) {",
povDepth.c_str(), depthMaps[i].c_str());
fragBuilder->codeAppendf("lightProbability = 1;");
fragBuilder->codeAppendf("} else { lightProbability = 0; }");
}
// VSM: The curved shadows near plane edges are artifacts from blurring
fragBuilder->codeAppendf("}");
fragBuilder->codeAppendf("%s += dot(vec3(0,0,1), %s) * %s * "
"lightProbability;",
totalLightColor.c_str(),
lightDirOrPosUniName[i],
lightColorUniName[i]);
} else {
// fragToLight%d.z is equal to the fragToLight dot the surface normal.
fragBuilder->codeAppendf("%s += max(fragToLight%d.z, 0) * %s /"
"(1 + distsq%d / (%s * %s));",
totalLightColor.c_str(), i,
lightColorUniName[i], i,
lightIntensityUniName[i],
lightIntensityUniName[i]);
}
}
fragBuilder->codeAppendf("%s += %s;", totalLightColor.c_str(), ambientColorUniName);
fragBuilder->codeAppendf("resultDiffuseColor *= vec4(%s, 1);",
totalLightColor.c_str());
fragBuilder->codeAppendf("%s = resultDiffuseColor;", args.fOutputColor);
}
static void GenKey(const GrProcessor& proc, const GrGLSLCaps&,
GrProcessorKeyBuilder* b) {
const ShadowFP& shadowFP = proc.cast<ShadowFP>();
b->add32(shadowFP.fNumNonAmbLights);
int isPL = 0;
for (int i = 0; i < SkShadowShader::kMaxNonAmbientLights; i++) {
isPL = isPL | ((shadowFP.fIsPointLight[i] ? 1 : 0) << i);
}
b->add32(isPL);
b->add32(shadowFP.fShadowParams.fType);
}
protected:
void onSetData(const GrGLSLProgramDataManager& pdman, const GrProcessor& proc) override {
const ShadowFP &shadowFP = proc.cast<ShadowFP>();
for (int i = 0; i < shadowFP.numLights(); i++) {
const SkVector3& lightDirOrPos = shadowFP.lightDirOrPos(i);
if (lightDirOrPos != fLightDirOrPos[i]) {
pdman.set3fv(fLightDirOrPosUni[i], 1, &lightDirOrPos.fX);
fLightDirOrPos[i] = lightDirOrPos;
}
const SkColor3f& lightColor = shadowFP.lightColor(i);
if (lightColor != fLightColor[i]) {
pdman.set3fv(fLightColorUni[i], 1, &lightColor.fX);
fLightColor[i] = lightColor;
}
SkScalar lightIntensity = shadowFP.lightIntensity(i);
if (lightIntensity != fLightIntensity[i]) {
pdman.set1f(fLightIntensityUni[i], lightIntensity);
fLightIntensity[i] = lightIntensity;
}
int depthMapWidth = shadowFP.depthMapWidth(i);
if (depthMapWidth != fDepthMapWidth[i]) {
pdman.set1i(fDepthMapWidthUni[i], depthMapWidth);
fDepthMapWidth[i] = depthMapWidth;
}
int depthMapHeight = shadowFP.depthMapHeight(i);
if (depthMapHeight != fDepthMapHeight[i]) {
pdman.set1i(fDepthMapHeightUni[i], depthMapHeight);
fDepthMapHeight[i] = depthMapHeight;
}
}
SkScalar biasingConstant = shadowFP.shadowParams().fBiasingConstant;
if (biasingConstant != fBiasingConstant) {
pdman.set1f(fBiasingConstantUni, biasingConstant);
fBiasingConstant = biasingConstant;
}
SkScalar minVariance = shadowFP.shadowParams().fMinVariance;
if (minVariance != fMinVariance) {
pdman.set1f(fMinVarianceUni, minVariance);
fMinVariance = minVariance;
}
int width = shadowFP.width();
if (width != fWidth) {
pdman.set1i(fWidthUni, width);
fWidth = width;
}
int height = shadowFP.height();
if (height != fHeight) {
pdman.set1i(fHeightUni, height);
fHeight = height;
}
const SkColor3f& ambientColor = shadowFP.ambientColor();
if (ambientColor != fAmbientColor) {
pdman.set3fv(fAmbientColorUni, 1, &ambientColor.fX);
fAmbientColor = ambientColor;
}
}
private:
SkVector3 fLightDirOrPos[SkShadowShader::kMaxNonAmbientLights];
GrGLSLProgramDataManager::UniformHandle
fLightDirOrPosUni[SkShadowShader::kMaxNonAmbientLights];
SkColor3f fLightColor[SkShadowShader::kMaxNonAmbientLights];
GrGLSLProgramDataManager::UniformHandle
fLightColorUni[SkShadowShader::kMaxNonAmbientLights];
SkScalar fLightIntensity[SkShadowShader::kMaxNonAmbientLights];
GrGLSLProgramDataManager::UniformHandle
fLightIntensityUni[SkShadowShader::kMaxNonAmbientLights];
int fDepthMapWidth[SkShadowShader::kMaxNonAmbientLights];
GrGLSLProgramDataManager::UniformHandle
fDepthMapWidthUni[SkShadowShader::kMaxNonAmbientLights];
int fDepthMapHeight[SkShadowShader::kMaxNonAmbientLights];
GrGLSLProgramDataManager::UniformHandle
fDepthMapHeightUni[SkShadowShader::kMaxNonAmbientLights];
int fWidth;
GrGLSLProgramDataManager::UniformHandle fWidthUni;
int fHeight;
GrGLSLProgramDataManager::UniformHandle fHeightUni;
SkScalar fBiasingConstant;
GrGLSLProgramDataManager::UniformHandle fBiasingConstantUni;
SkScalar fMinVariance;
GrGLSLProgramDataManager::UniformHandle fMinVarianceUni;
SkColor3f fAmbientColor;
GrGLSLProgramDataManager::UniformHandle fAmbientColorUni;
};
void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
GLSLShadowFP::GenKey(*this, caps, b);
}
const char* name() const override { return "shadowFP"; }
void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
inout->mulByUnknownFourComponents();
}
int32_t numLights() const { return fNumNonAmbLights; }
const SkColor3f& ambientColor() const { return fAmbientColor; }
bool isPointLight(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fIsPointLight[i];
}
const SkVector3& lightDirOrPos(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fLightDirOrPos[i];
}
const SkVector3& lightColor(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fLightColor[i];
}
SkScalar lightIntensity(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fLightIntensity[i];
}
int depthMapWidth(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fDepthMapWidth[i];
}
int depthMapHeight(int i) const {
SkASSERT(i < fNumNonAmbLights);
return fDepthMapHeight[i];
}
int width() const {return fWidth; }
int height() const {return fHeight; }
const SkShadowParams& shadowParams() const {return fShadowParams; }
private:
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new GLSLShadowFP; }
bool onIsEqual(const GrFragmentProcessor& proc) const override {
const ShadowFP& shadowFP = proc.cast<ShadowFP>();
if (fAmbientColor != shadowFP.fAmbientColor ||
fNumNonAmbLights != shadowFP.fNumNonAmbLights) {
return false;
}
if (fWidth != shadowFP.fWidth || fHeight != shadowFP.fHeight) {
return false;
}
for (int i = 0; i < fNumNonAmbLights; i++) {
if (fLightDirOrPos[i] != shadowFP.fLightDirOrPos[i] ||
fLightColor[i] != shadowFP.fLightColor[i] ||
fLightIntensity[i] != shadowFP.fLightIntensity[i] ||
fIsPointLight[i] != shadowFP.fIsPointLight[i]) {
return false;
}
if (fDepthMapWidth[i] != shadowFP.fDepthMapWidth[i] ||
fDepthMapHeight[i] != shadowFP.fDepthMapHeight[i]) {
return false;
}
}
return true;
}
int fNumNonAmbLights;
bool fIsPointLight[SkShadowShader::kMaxNonAmbientLights];
SkVector3 fLightDirOrPos[SkShadowShader::kMaxNonAmbientLights];
SkColor3f fLightColor[SkShadowShader::kMaxNonAmbientLights];
SkScalar fLightIntensity[SkShadowShader::kMaxNonAmbientLights];
GrTextureAccess fDepthMapAccess[SkShadowShader::kMaxNonAmbientLights];
sk_sp<GrTexture> fTexture[SkShadowShader::kMaxNonAmbientLights];
int fDepthMapWidth[SkShadowShader::kMaxNonAmbientLights];
int fDepthMapHeight[SkShadowShader::kMaxNonAmbientLights];
int fHeight;
int fWidth;
SkShadowParams fShadowParams;
SkColor3f fAmbientColor;
};
////////////////////////////////////////////////////////////////////////////
sk_sp<GrFragmentProcessor> SkShadowShaderImpl::asFragmentProcessor(const AsFPArgs& fpargs) const {
sk_sp<GrFragmentProcessor> povDepthFP = fPovDepthShader->asFragmentProcessor(fpargs);
sk_sp<GrFragmentProcessor> diffuseFP = fDiffuseShader->asFragmentProcessor(fpargs);
sk_sp<GrFragmentProcessor> shadowfp = sk_make_sp<ShadowFP>(std::move(povDepthFP),
std::move(diffuseFP),
std::move(fLights),
fDiffuseWidth, fDiffuseHeight,
fShadowParams, fpargs.fContext);
return shadowfp;
}
#endif
////////////////////////////////////////////////////////////////////////////
bool SkShadowShaderImpl::isOpaque() const {
return fDiffuseShader->isOpaque();
}
SkShadowShaderImpl::ShadowShaderContext::ShadowShaderContext(
const SkShadowShaderImpl& shader, const ContextRec& rec,
SkShader::Context* povDepthContext,
SkShader::Context* diffuseContext,
void* heapAllocated)
: INHERITED(shader, rec)
, fPovDepthContext(povDepthContext)
, fDiffuseContext(diffuseContext)
, fHeapAllocated(heapAllocated) {
bool isOpaque = shader.isOpaque();
// update fFlags
uint32_t flags = 0;
if (isOpaque && (255 == this->getPaintAlpha())) {
flags |= kOpaqueAlpha_Flag;
}
fFlags = flags;
const SkShadowShaderImpl& lightShader = static_cast<const SkShadowShaderImpl&>(fShader);
fNonAmbLightCnt = lightShader.fLights->numLights();
fShadowMapPixels = new SkPixmap[fNonAmbLightCnt];
for (int i = 0; i < fNonAmbLightCnt; i++) {
if (lightShader.fLights->light(i).type() == SkLights::Light::kDirectional_LightType) {
lightShader.fLights->light(i).getShadowMap()->
peekPixels(&fShadowMapPixels[i]);
}
}
}
SkShadowShaderImpl::ShadowShaderContext::~ShadowShaderContext() {
delete[] fShadowMapPixels;
// The dependencies have been created outside of the context on memory that was allocated by
// the onCreateContext() method. Call the destructors and free the memory.
fPovDepthContext->~Context();
fDiffuseContext->~Context();
sk_free(fHeapAllocated);
}
static inline SkPMColor convert(SkColor3f color, U8CPU a) {
if (color.fX <= 0.0f) {
color.fX = 0.0f;
} else if (color.fX >= 255.0f) {
color.fX = 255.0f;
}
if (color.fY <= 0.0f) {
color.fY = 0.0f;
} else if (color.fY >= 255.0f) {
color.fY = 255.0f;
}
if (color.fZ <= 0.0f) {
color.fZ = 0.0f;
} else if (color.fZ >= 255.0f) {
color.fZ = 255.0f;
}
return SkPreMultiplyARGB(a, (int) color.fX, (int) color.fY, (int) color.fZ);
}
// larger is better (fewer times we have to loop), but we shouldn't
// take up too much stack-space (each one here costs 16 bytes)
#define BUFFER_MAX 16
void SkShadowShaderImpl::ShadowShaderContext::shadeSpan(int x, int y,
SkPMColor result[], int count) {
const SkShadowShaderImpl& lightShader = static_cast<const SkShadowShaderImpl&>(fShader);
SkPMColor diffuse[BUFFER_MAX];
SkPMColor povDepth[BUFFER_MAX];
do {
int n = SkTMin(count, BUFFER_MAX);
fDiffuseContext->shadeSpan(x, y, diffuse, n);
fPovDepthContext->shadeSpan(x, y, povDepth, n);
for (int i = 0; i < n; ++i) {
SkColor diffColor = SkUnPreMultiply::PMColorToColor(diffuse[i]);
SkColor povDepthColor = povDepth[i];
SkColor3f totalLight = lightShader.fLights->ambientLightColor();
// This is all done in linear unpremul color space (each component 0..255.0f though)
for (int l = 0; l < lightShader.fLights->numLights(); ++l) {
const SkLights::Light& light = lightShader.fLights->light(l);
if (light.type() == SkLights::Light::kDirectional_LightType) {
int pvDepth = SkColorGetB(povDepthColor); // depth stored in blue channel
int xOffset = SkScalarRoundToInt(light.dir().fX * pvDepth);
int yOffset = SkScalarRoundToInt(light.dir().fY * pvDepth);
int shX = SkClampMax(x + i + xOffset, light.getShadowMap()->width() - 1);
int shY = SkClampMax(y + yOffset, light.getShadowMap()->height() - 1);
int shDepth = 0;
// pixmaps that point to things have nonzero heights
if (fShadowMapPixels[l].height() > 0) {
uint32_t pix = *fShadowMapPixels[l].addr32(shX, shY);
SkColor shColor(pix);
shDepth = SkColorGetB(shColor);
} else {
// Make lights w/o a shadow map receive the full light contribution
shDepth = pvDepth;
}
if (pvDepth >= shDepth) {
// assume object normals are pointing straight up
totalLight.fX += light.dir().fZ * light.color().fX;
totalLight.fY += light.dir().fZ * light.color().fY;
totalLight.fZ += light.dir().fZ * light.color().fZ;
}
} else {
totalLight += light.color();
}
}
SkColor3f totalColor = SkColor3f::Make(SkColorGetR(diffColor) * totalLight.fX,
SkColorGetG(diffColor) * totalLight.fY,
SkColorGetB(diffColor) * totalLight.fZ);
result[i] = convert(totalColor, SkColorGetA(diffColor));
}
result += n;
x += n;
count -= n;
} while (count > 0);
}
////////////////////////////////////////////////////////////////////////////
#ifndef SK_IGNORE_TO_STRING
void SkShadowShaderImpl::toString(SkString* str) const {
str->appendf("ShadowShader: ()");
}
#endif
sk_sp<SkFlattenable> SkShadowShaderImpl::CreateProc(SkReadBuffer& buf) {
// Discarding SkShader flattenable params
bool hasLocalMatrix = buf.readBool();
SkAssertResult(!hasLocalMatrix);
sk_sp<SkLights> lights = SkLights::MakeFromBuffer(buf);
SkShadowParams params;
params.fMinVariance = buf.readScalar();
params.fBiasingConstant = buf.readScalar();
params.fType = (SkShadowParams::ShadowType) buf.readInt();
params.fShadowRadius = buf.readScalar();
int diffuseWidth = buf.readInt();
int diffuseHeight = buf.readInt();
sk_sp<SkShader> povDepthShader(buf.readFlattenable<SkShader>());
sk_sp<SkShader> diffuseShader(buf.readFlattenable<SkShader>());
return sk_make_sp<SkShadowShaderImpl>(std::move(povDepthShader),
std::move(diffuseShader),
std::move(lights),
diffuseWidth, diffuseHeight,
params);
}
void SkShadowShaderImpl::flatten(SkWriteBuffer& buf) const {
this->INHERITED::flatten(buf);
fLights->flatten(buf);
buf.writeScalar(fShadowParams.fMinVariance);
buf.writeScalar(fShadowParams.fBiasingConstant);
buf.writeInt(fShadowParams.fType);
buf.writeScalar(fShadowParams.fShadowRadius);
buf.writeInt(fDiffuseWidth);
buf.writeInt(fDiffuseHeight);
buf.writeFlattenable(fPovDepthShader.get());
buf.writeFlattenable(fDiffuseShader.get());
}
size_t SkShadowShaderImpl::onContextSize(const ContextRec& rec) const {
return sizeof(ShadowShaderContext);
}
SkShader::Context* SkShadowShaderImpl::onCreateContext(const ContextRec& rec,
void* storage) const {
size_t heapRequired = fPovDepthShader->contextSize(rec) +
fDiffuseShader->contextSize(rec);
void* heapAllocated = sk_malloc_throw(heapRequired);
void* povDepthContextStorage = heapAllocated;
SkShader::Context* povDepthContext =
fPovDepthShader->createContext(rec, povDepthContextStorage);
if (!povDepthContext) {
sk_free(heapAllocated);
return nullptr;
}
void* diffuseContextStorage = (char*)heapAllocated + fPovDepthShader->contextSize(rec);
SkShader::Context* diffuseContext = fDiffuseShader->createContext(rec, diffuseContextStorage);
if (!diffuseContext) {
sk_free(heapAllocated);
return nullptr;
}
return new (storage) ShadowShaderContext(*this, rec, povDepthContext, diffuseContext,
heapAllocated);
}
///////////////////////////////////////////////////////////////////////////////
sk_sp<SkShader> SkShadowShader::Make(sk_sp<SkShader> povDepthShader,
sk_sp<SkShader> diffuseShader,
sk_sp<SkLights> lights,
int diffuseWidth, int diffuseHeight,
const SkShadowParams& params) {
if (!povDepthShader || !diffuseShader) {
// TODO: Use paint's color in absence of a diffuseShader
// TODO: Use a default implementation of normalSource instead
return nullptr;
}
return sk_make_sp<SkShadowShaderImpl>(std::move(povDepthShader),
std::move(diffuseShader),
std::move(lights),
diffuseWidth, diffuseHeight,
params);
}
///////////////////////////////////////////////////////////////////////////////
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkShadowShader)
SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkShadowShaderImpl)
SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
///////////////////////////////////////////////////////////////////////////////
#endif