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Diffstat (limited to 'src/effects/SkLightingShader.cpp')
| -rw-r--r-- | src/effects/SkLightingShader.cpp | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/src/effects/SkLightingShader.cpp b/src/effects/SkLightingShader.cpp new file mode 100644 index 0000000000..d441d9ba9f --- /dev/null +++ b/src/effects/SkLightingShader.cpp @@ -0,0 +1,588 @@ + +/* + * Copyright 2015 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "SkBitmapProcState.h" +#include "SkColor.h" +#include "SkEmptyShader.h" +#include "SkErrorInternals.h" +#include "SkLightingShader.h" +#include "SkMathPriv.h" +#include "SkReadBuffer.h" +#include "SkWriteBuffer.h" + +//////////////////////////////////////////////////////////////////////////// + +/* + SkLightingShader TODOs: + support other than clamp mode + allow 'diffuse' & 'normal' to be of different dimensions? + support different light types + support multiple lights + enforce normal map is 4 channel + use SkImages instead if SkBitmaps + + To Test: + non-opaque diffuse textures + A8 diffuse textures + down & upsampled draws +*/ + + + +/** \class SkLightingShaderImpl + This subclass of shader applies lighting. +*/ +class SK_API SkLightingShaderImpl : public SkShader { +public: + + /** Create a new lighting shader that use the provided normal map, light + and ambient color to light the diffuse bitmap. + @param diffuse the diffuse bitmap + @param normal the normal map + @param light the light applied to the normal map + @param ambient the linear (unpremul) ambient light color + */ + SkLightingShaderImpl(const SkBitmap& diffuse, const SkBitmap& normal, + const SkLightingShader::Light& light, + const SkColor3f& ambient, const SkMatrix* localMatrix) + : INHERITED(localMatrix) + , fDiffuseMap(diffuse) + , fNormalMap(normal) + , fLight(light) + , fAmbientColor(ambient) { + if (!fLight.fDirection.normalize()) { + fLight.fDirection = SkPoint3::Make(0.0f, 0.0f, 1.0f); + } + } + + bool isOpaque() const override; + + bool asFragmentProcessor(GrContext*, const SkPaint& paint, const SkMatrix& viewM, + const SkMatrix* localMatrix, GrColor* color, + GrProcessorDataManager*, GrFragmentProcessor** fp) const override; + + size_t contextSize() const override; + + class LightingShaderContext : public SkShader::Context { + public: + // The context takes ownership of the states. It will call their destructors + // but will NOT free the memory. + LightingShaderContext(const SkLightingShaderImpl&, const ContextRec&, + SkBitmapProcState* diffuseState, SkBitmapProcState* normalState); + ~LightingShaderContext() override; + + void shadeSpan(int x, int y, SkPMColor[], int count) override; + + uint32_t getFlags() const override { return fFlags; } + + private: + SkBitmapProcState* fDiffuseState; + SkBitmapProcState* fNormalState; + uint32_t fFlags; + + typedef SkShader::Context INHERITED; + }; + + SK_TO_STRING_OVERRIDE() + SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLightingShaderImpl) + +protected: + void flatten(SkWriteBuffer&) const override; + Context* onCreateContext(const ContextRec&, void*) const override; + +private: + SkBitmap fDiffuseMap; + SkBitmap fNormalMap; + SkLightingShader::Light fLight; + SkColor3f fAmbientColor; // linear (unpremul) color. Range is 0..1/channel. + + friend class SkLightingShader; + + typedef SkShader INHERITED; +}; + +//////////////////////////////////////////////////////////////////////////// + +#if SK_SUPPORT_GPU + +#include "GrCoordTransform.h" +#include "GrFragmentProcessor.h" +#include "GrTextureAccess.h" +#include "gl/GrGLProcessor.h" +#include "gl/builders/GrGLProgramBuilder.h" +#include "SkGr.h" + +class LightingFP : public GrFragmentProcessor { +public: + LightingFP(GrTexture* diffuse, GrTexture* normal, const SkMatrix& matrix, + const SkVector3& lightDir, const SkColor3f& lightColor, + const SkColor3f& ambientColor) + : fDeviceTransform(kDevice_GrCoordSet, matrix) + , fDiffuseTextureAccess(diffuse) + , fNormalTextureAccess(normal) + , fLightDir(lightDir) + , fLightColor(lightColor) + , fAmbientColor(ambientColor) { + this->addCoordTransform(&fDeviceTransform); + this->addTextureAccess(&fDiffuseTextureAccess); + this->addTextureAccess(&fNormalTextureAccess); + + this->initClassID<LightingFP>(); + } + + class LightingGLFP : public GrGLFragmentProcessor { + public: + LightingGLFP() { + fLightDir.fX = 10000.0f; + fLightColor.fX = 0.0f; + fAmbientColor.fX = 0.0f; + } + + void emitCode(EmitArgs& args) override { + + GrGLFragmentBuilder* fpb = args.fBuilder->getFragmentShaderBuilder(); + + // add uniforms + const char* lightDirUniName = NULL; + fLightDirUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, + kVec3f_GrSLType, kDefault_GrSLPrecision, + "LightDir", &lightDirUniName); + + const char* lightColorUniName = NULL; + fLightColorUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, + kVec3f_GrSLType, kDefault_GrSLPrecision, + "LightColor", &lightColorUniName); + + const char* ambientColorUniName = NULL; + fAmbientColorUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, + kVec3f_GrSLType, kDefault_GrSLPrecision, + "AmbientColor", &ambientColorUniName); + + fpb->codeAppend("vec4 diffuseColor = "); + fpb->appendTextureLookupAndModulate(args.fInputColor, args.fSamplers[0], + args.fCoords[0].c_str(), + args.fCoords[0].getType()); + fpb->codeAppend(";"); + + fpb->codeAppend("vec4 normalColor = "); + fpb->appendTextureLookup(args.fSamplers[1], + args.fCoords[0].c_str(), + args.fCoords[0].getType()); + fpb->codeAppend(";"); + + fpb->codeAppend("vec3 normal = normalize(normalColor.rgb - vec3(0.5));"); + fpb->codeAppendf("vec3 lightDir = normalize(%s);", lightDirUniName); + fpb->codeAppend("float NdotL = dot(normal, lightDir);"); + // diffuse light + fpb->codeAppendf("vec3 result = %s*diffuseColor.rgb*NdotL;", lightColorUniName); + // ambient light + fpb->codeAppendf("result += %s;", ambientColorUniName); + fpb->codeAppendf("%s = vec4(result.rgb, diffuseColor.a);", args.fOutputColor); + } + + static void GenKey(const GrProcessor& proc, const GrGLSLCaps&, + GrProcessorKeyBuilder* b) { +// const LightingFP& lightingFP = proc.cast<LightingFP>(); + // only one shader generated currently + b->add32(0x0); + } + + protected: + void onSetData(const GrGLProgramDataManager& pdman, const GrProcessor& proc) override { + const LightingFP& lightingFP = proc.cast<LightingFP>(); + + const SkVector3& lightDir = lightingFP.lightDir(); + if (lightDir != fLightDir) { + pdman.set3fv(fLightDirUni, 1, &lightDir.fX); + fLightDir = lightDir; + } + + const SkColor3f& lightColor = lightingFP.lightColor(); + if (lightColor != fLightColor) { + pdman.set3fv(fLightColorUni, 1, &lightColor.fX); + fLightColor = lightColor; + } + + const SkColor3f& ambientColor = lightingFP.ambientColor(); + if (ambientColor != fAmbientColor) { + pdman.set3fv(fAmbientColorUni, 1, &ambientColor.fX); + fAmbientColor = ambientColor; + } + } + + private: + SkVector3 fLightDir; + GrGLProgramDataManager::UniformHandle fLightDirUni; + + SkColor3f fLightColor; + GrGLProgramDataManager::UniformHandle fLightColorUni; + + SkColor3f fAmbientColor; + GrGLProgramDataManager::UniformHandle fAmbientColorUni; + }; + + void onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override { + LightingGLFP::GenKey(*this, caps, b); + } + + const char* name() const override { return "LightingFP"; } + + void onComputeInvariantOutput(GrInvariantOutput* inout) const override { + inout->mulByUnknownFourComponents(); + } + + const SkVector3& lightDir() const { return fLightDir; } + const SkColor3f& lightColor() const { return fLightColor; } + const SkColor3f& ambientColor() const { return fAmbientColor; } + +private: + GrGLFragmentProcessor* onCreateGLInstance() const override { return SkNEW(LightingGLFP); } + + bool onIsEqual(const GrFragmentProcessor& proc) const override { + const LightingFP& lightingFP = proc.cast<LightingFP>(); + return fDeviceTransform == lightingFP.fDeviceTransform && + fDiffuseTextureAccess == lightingFP.fDiffuseTextureAccess && + fNormalTextureAccess == lightingFP.fNormalTextureAccess && + fLightDir == lightingFP.fLightDir && + fLightColor == lightingFP.fLightColor && + fAmbientColor == lightingFP.fAmbientColor; + } + + GrCoordTransform fDeviceTransform; + GrTextureAccess fDiffuseTextureAccess; + GrTextureAccess fNormalTextureAccess; + SkVector3 fLightDir; + SkColor3f fLightColor; + SkColor3f fAmbientColor; +}; + +//////////////////////////////////////////////////////////////////////////// + +bool SkLightingShaderImpl::asFragmentProcessor(GrContext* context, const SkPaint& paint, + const SkMatrix& viewM, const SkMatrix* localMatrix, + GrColor* color, GrProcessorDataManager*, + GrFragmentProcessor** fp) const { + // we assume diffuse and normal maps have same width and height + // TODO: support different sizes + SkASSERT(fDiffuseMap.width() == fNormalMap.width() && + fDiffuseMap.height() == fNormalMap.height()); + SkMatrix matrix; + matrix.setIDiv(fDiffuseMap.width(), fDiffuseMap.height()); + + SkMatrix lmInverse; + if (!this->getLocalMatrix().invert(&lmInverse)) { + return false; + } + if (localMatrix) { + SkMatrix inv; + if (!localMatrix->invert(&inv)) { + return false; + } + lmInverse.postConcat(inv); + } + matrix.preConcat(lmInverse); + + // Must set wrap and filter on the sampler before requesting a texture. In two places below + // we check the matrix scale factors to determine how to interpret the filter quality setting. + // This completely ignores the complexity of the drawVertices case where explicit local coords + // are provided by the caller. + GrTextureParams::FilterMode textureFilterMode = GrTextureParams::kBilerp_FilterMode; + switch (paint.getFilterQuality()) { + case kNone_SkFilterQuality: + textureFilterMode = GrTextureParams::kNone_FilterMode; + break; + case kLow_SkFilterQuality: + textureFilterMode = GrTextureParams::kBilerp_FilterMode; + break; + case kMedium_SkFilterQuality:{ + SkMatrix matrix; + matrix.setConcat(viewM, this->getLocalMatrix()); + if (matrix.getMinScale() < SK_Scalar1) { + textureFilterMode = GrTextureParams::kMipMap_FilterMode; + } else { + // Don't trigger MIP level generation unnecessarily. + textureFilterMode = GrTextureParams::kBilerp_FilterMode; + } + break; + } + case kHigh_SkFilterQuality: + default: + SkErrorInternals::SetError(kInvalidPaint_SkError, + "Sorry, I don't understand the filtering " + "mode you asked for. Falling back to " + "MIPMaps."); + textureFilterMode = GrTextureParams::kMipMap_FilterMode; + break; + + } + + // TODO: support other tile modes + GrTextureParams params(kClamp_TileMode, textureFilterMode); + SkAutoTUnref<GrTexture> diffuseTexture(GrRefCachedBitmapTexture(context, fDiffuseMap, ¶ms)); + if (!diffuseTexture) { + SkErrorInternals::SetError(kInternalError_SkError, + "Couldn't convert bitmap to texture."); + return false; + } + + SkAutoTUnref<GrTexture> normalTexture(GrRefCachedBitmapTexture(context, fNormalMap, ¶ms)); + if (!normalTexture) { + SkErrorInternals::SetError(kInternalError_SkError, + "Couldn't convert bitmap to texture."); + return false; + } + + *fp = SkNEW_ARGS(LightingFP, (diffuseTexture, normalTexture, matrix, + fLight.fDirection, fLight.fColor, fAmbientColor)); + *color = GrColorPackA4(paint.getAlpha()); + return true; +} +#else + +bool SkLightingShaderImpl::asFragmentProcessor(GrContext* context, const SkPaint& paint, + const SkMatrix& viewM, const SkMatrix* localMatrix, + GrColor* color, GrProcessorDataManager*, + GrFragmentProcessor** fp) const { + SkDEBUGFAIL("Should not call in GPU-less build"); + return false; +} + +#endif + +//////////////////////////////////////////////////////////////////////////// + +bool SkLightingShaderImpl::isOpaque() const { + return fDiffuseMap.isOpaque(); +} + +size_t SkLightingShaderImpl::contextSize() const { + return 2 * sizeof(SkBitmapProcState) + sizeof(LightingShaderContext); +} + +SkLightingShaderImpl::LightingShaderContext::LightingShaderContext(const SkLightingShaderImpl& shader, + const ContextRec& rec, + SkBitmapProcState* diffuseState, + SkBitmapProcState* normalState) + : INHERITED(shader, rec) + , fDiffuseState(diffuseState) + , fNormalState(normalState) +{ + const SkPixmap& pixmap = fDiffuseState->fPixmap; + bool isOpaque = pixmap.isOpaque(); + + // update fFlags + uint32_t flags = 0; + if (isOpaque && (255 == this->getPaintAlpha())) { + flags |= kOpaqueAlpha_Flag; + } + + fFlags = flags; +} + +SkLightingShaderImpl::LightingShaderContext::~LightingShaderContext() { + // The bitmap proc states have been created outside of the context on memory that will be freed + // elsewhere. Call the destructors but leave the freeing of the memory to the caller. + fDiffuseState->~SkBitmapProcState(); + fNormalState->~SkBitmapProcState(); +} + +static inline int light(SkScalar light, int diff, SkScalar NdotL, SkScalar ambient) { + SkScalar color = light * diff * NdotL + 255 * ambient; + if (color <= 0.0f) { + return 0; + } else if (color >= 255.0f) { + return 255; + } else { + return (int) color; + } +} + +// larger is better (fewer times we have to loop), but we shouldn't +// take up too much stack-space (each could here costs 16 bytes) +#define TMP_COUNT 16 + +void SkLightingShaderImpl::LightingShaderContext::shadeSpan(int x, int y, + SkPMColor result[], int count) { + const SkLightingShaderImpl& lightShader = static_cast<const SkLightingShaderImpl&>(fShader); + + SkPMColor tmpColor[TMP_COUNT], tmpColor2[TMP_COUNT]; + SkPMColor tmpNormal[TMP_COUNT], tmpNormal2[TMP_COUNT]; + + SkBitmapProcState::MatrixProc diffMProc = fDiffuseState->getMatrixProc(); + SkBitmapProcState::SampleProc32 diffSProc = fDiffuseState->getSampleProc32(); + + SkBitmapProcState::MatrixProc normalMProc = fNormalState->getMatrixProc(); + SkBitmapProcState::SampleProc32 normalSProc = fNormalState->getSampleProc32(); + + SkASSERT(fDiffuseState->fPixmap.addr()); + SkASSERT(fNormalState->fPixmap.addr()); + + SkPoint3 norm; + SkScalar NdotL; + int r, g, b; + + do { + int n = count; + if (n > TMP_COUNT) { + n = TMP_COUNT; + } + + diffMProc(*fDiffuseState, tmpColor, n, x, y); + diffSProc(*fDiffuseState, tmpColor, n, tmpColor2); + + normalMProc(*fNormalState, tmpNormal, n, x, y); + normalSProc(*fNormalState, tmpNormal, n, tmpNormal2); + + for (int i = 0; i < n; ++i) { + SkASSERT(0xFF == SkColorGetA(tmpNormal2[i])); // opaque -> unpremul + norm.set(SkIntToScalar(SkGetPackedR32(tmpNormal2[i]))-127.0f, + SkIntToScalar(SkGetPackedG32(tmpNormal2[i]))-127.0f, + SkIntToScalar(SkGetPackedB32(tmpNormal2[i]))-127.0f); + norm.normalize(); + + SkColor diffColor = SkUnPreMultiply::PMColorToColor(tmpColor2[i]); + NdotL = norm.dot(lightShader.fLight.fDirection); + + // This is all done in linear unpremul color space + r = light(lightShader.fLight.fColor.fX, SkColorGetR(diffColor), NdotL, + lightShader.fAmbientColor.fX); + g = light(lightShader.fLight.fColor.fY, SkColorGetG(diffColor), NdotL, + lightShader.fAmbientColor.fY); + b = light(lightShader.fLight.fColor.fZ, SkColorGetB(diffColor), NdotL, + lightShader.fAmbientColor.fZ); + + result[i] = SkPreMultiplyARGB(SkColorGetA(diffColor), r, g, b); + } + + result += n; + x += n; + count -= n; + } while (count > 0); +} + +//////////////////////////////////////////////////////////////////////////// + +#ifndef SK_IGNORE_TO_STRING +void SkLightingShaderImpl::toString(SkString* str) const { + str->appendf("LightingShader: ()"); +} +#endif + +SkFlattenable* SkLightingShaderImpl::CreateProc(SkReadBuffer& buf) { + SkMatrix localMatrix; + buf.readMatrix(&localMatrix); + + SkBitmap diffuse; + if (!buf.readBitmap(&diffuse)) { + return NULL; + } + diffuse.setImmutable(); + + SkBitmap normal; + if (!buf.readBitmap(&normal)) { + return NULL; + } + normal.setImmutable(); + + SkLightingShader::Light light; + if (!buf.readScalarArray(&light.fDirection.fX, 3)) { + return NULL; + } + if (!buf.readScalarArray(&light.fColor.fX, 3)) { + return NULL; + } + + SkColor3f ambient; + if (!buf.readScalarArray(&ambient.fX, 3)) { + return NULL; + } + + return SkNEW_ARGS(SkLightingShaderImpl, (diffuse, normal, light, ambient, &localMatrix)); +} + +void SkLightingShaderImpl::flatten(SkWriteBuffer& buf) const { + buf.writeMatrix(this->getLocalMatrix()); + + buf.writeBitmap(fDiffuseMap); + buf.writeBitmap(fNormalMap); + buf.writeScalarArray(&fLight.fDirection.fX, 3); + buf.writeScalarArray(&fLight.fColor.fX, 3); + buf.writeScalarArray(&fAmbientColor.fX, 3); +} + +SkShader::Context* SkLightingShaderImpl::onCreateContext(const ContextRec& rec, + void* storage) const { + + SkMatrix totalInverse; + // Do this first, so we know the matrix can be inverted. + if (!this->computeTotalInverse(rec, &totalInverse)) { + return NULL; + } + + void* diffuseStateStorage = (char*)storage + sizeof(LightingShaderContext); + SkBitmapProcState* diffuseState = SkNEW_PLACEMENT(diffuseStateStorage, SkBitmapProcState); + SkASSERT(diffuseState); + + diffuseState->fTileModeX = SkShader::kClamp_TileMode; + diffuseState->fTileModeY = SkShader::kClamp_TileMode; + diffuseState->fOrigBitmap = fDiffuseMap; + if (!diffuseState->chooseProcs(totalInverse, *rec.fPaint)) { + diffuseState->~SkBitmapProcState(); + return NULL; + } + + void* normalStateStorage = (char*)storage + sizeof(LightingShaderContext) + sizeof(SkBitmapProcState); + SkBitmapProcState* normalState = SkNEW_PLACEMENT(normalStateStorage, SkBitmapProcState); + SkASSERT(normalState); + + normalState->fTileModeX = SkShader::kClamp_TileMode; + normalState->fTileModeY = SkShader::kClamp_TileMode; + normalState->fOrigBitmap = fNormalMap; + if (!normalState->chooseProcs(totalInverse, *rec.fPaint)) { + diffuseState->~SkBitmapProcState(); + normalState->~SkBitmapProcState(); + return NULL; + } + + return SkNEW_PLACEMENT_ARGS(storage, LightingShaderContext, (*this, rec, + diffuseState, normalState)); +} + +/////////////////////////////////////////////////////////////////////////////// + +static bool bitmap_is_too_big(const SkBitmap& bm) { + // SkBitmapProcShader stores bitmap coordinates in a 16bit buffer, as it + // communicates between its matrix-proc and its sampler-proc. Until we can + // widen that, we have to reject bitmaps that are larger. + // + static const int kMaxSize = 65535; + + return bm.width() > kMaxSize || bm.height() > kMaxSize; +} + +SkShader* SkLightingShader::Create(const SkBitmap& diffuse, const SkBitmap& normal, + const SkLightingShader::Light& light, + const SkColor3f& ambient, + const SkMatrix* localMatrix) { + if (diffuse.isNull() || bitmap_is_too_big(diffuse) || + normal.isNull() || bitmap_is_too_big(normal) || + diffuse.width() != normal.width() || + diffuse.height() != normal.height()) { + return nullptr; + } + + return SkNEW_ARGS(SkLightingShaderImpl, (diffuse, normal, light, ambient, localMatrix)); +} + +/////////////////////////////////////////////////////////////////////////////// + +SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingShader) + SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkLightingShaderImpl) +SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END + +/////////////////////////////////////////////////////////////////////////////// |