/* * Copyright 2012 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SkRadialGradient.h" #include "SkRadialGradient_Table.h" #define kSQRT_TABLE_BITS 11 #define kSQRT_TABLE_SIZE (1 << kSQRT_TABLE_BITS) #if 0 #include void SkRadialGradient_BuildTable() { // build it 0..127 x 0..127, so we use 2^15 - 1 in the numerator for our "fixed" table FILE* file = ::fopen("SkRadialGradient_Table.h", "w"); SkASSERT(file); ::fprintf(file, "static const uint8_t gSqrt8Table[] = {\n"); for (int i = 0; i < kSQRT_TABLE_SIZE; i++) { if ((i & 15) == 0) { ::fprintf(file, "\t"); } uint8_t value = SkToU8(SkFixedSqrt(i * SK_Fixed1 / kSQRT_TABLE_SIZE) >> 8); ::fprintf(file, "0x%02X", value); if (i < kSQRT_TABLE_SIZE-1) { ::fprintf(file, ", "); } if ((i & 15) == 15) { ::fprintf(file, "\n"); } } ::fprintf(file, "};\n"); ::fclose(file); } #endif namespace { // GCC doesn't like using static functions as template arguments. So force these to be non-static. inline SkFixed mirror_tileproc_nonstatic(SkFixed x) { return mirror_tileproc(x); } inline SkFixed repeat_tileproc_nonstatic(SkFixed x) { return repeat_tileproc(x); } void rad_to_unit_matrix(const SkPoint& center, SkScalar radius, SkMatrix* matrix) { SkScalar inv = SkScalarInvert(radius); matrix->setTranslate(-center.fX, -center.fY); matrix->postScale(inv, inv); } typedef void (* RadialShade16Proc)(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy, uint16_t* dstC, const uint16_t* cache, int toggle, int count); void shadeSpan16_radial_clamp(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy, uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache, int toggle, int count) { const uint8_t* SK_RESTRICT sqrt_table = gSqrt8Table; /* knock these down so we can pin against +- 0x7FFF, which is an immediate load, rather than 0xFFFF which is slower. This is a compromise, since it reduces our precision, but that appears to be visually OK. If we decide this is OK for all of our cases, we could (it seems) put this scale-down into fDstToIndex, to avoid having to do these extra shifts each time. */ SkFixed fx = SkScalarToFixed(sfx) >> 1; SkFixed dx = SkScalarToFixed(sdx) >> 1; SkFixed fy = SkScalarToFixed(sfy) >> 1; SkFixed dy = SkScalarToFixed(sdy) >> 1; // might perform this check for the other modes, // but the win will be a smaller % of the total if (dy == 0) { fy = SkPin32(fy, -0xFFFF >> 1, 0xFFFF >> 1); fy *= fy; do { unsigned xx = SkPin32(fx, -0xFFFF >> 1, 0xFFFF >> 1); unsigned fi = (xx * xx + fy) >> (14 + 16 - kSQRT_TABLE_BITS); fi = SkFastMin32(fi, 0xFFFF >> (16 - kSQRT_TABLE_BITS)); fx += dx; *dstC++ = cache[toggle + (sqrt_table[fi] >> SkGradientShaderBase::kSqrt16Shift)]; toggle = next_dither_toggle16(toggle); } while (--count != 0); } else { do { unsigned xx = SkPin32(fx, -0xFFFF >> 1, 0xFFFF >> 1); unsigned fi = SkPin32(fy, -0xFFFF >> 1, 0xFFFF >> 1); fi = (xx * xx + fi * fi) >> (14 + 16 - kSQRT_TABLE_BITS); fi = SkFastMin32(fi, 0xFFFF >> (16 - kSQRT_TABLE_BITS)); fx += dx; fy += dy; *dstC++ = cache[toggle + (sqrt_table[fi] >> SkGradientShaderBase::kSqrt16Shift)]; toggle = next_dither_toggle16(toggle); } while (--count != 0); } } template void shadeSpan16_radial(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache, int toggle, int count) { do { const SkFixed dist = SkFloatToFixed(sk_float_sqrt(fx*fx + fy*fy)); const unsigned fi = TileProc(dist); SkASSERT(fi <= 0xFFFF); *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache16Shift)]; toggle = next_dither_toggle16(toggle); fx += dx; fy += dy; } while (--count != 0); } void shadeSpan16_radial_mirror(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache, int toggle, int count) { shadeSpan16_radial(fx, dx, fy, dy, dstC, cache, toggle, count); } void shadeSpan16_radial_repeat(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache, int toggle, int count) { shadeSpan16_radial(fx, dx, fy, dy, dstC, cache, toggle, count); } } // namespace ///////////////////////////////////////////////////////////////////// SkRadialGradient::SkRadialGradient(const SkPoint& center, SkScalar radius, const Descriptor& desc) : SkGradientShaderBase(desc) , fCenter(center) , fRadius(radius) { // make sure our table is insync with our current #define for kSQRT_TABLE_SIZE SkASSERT(sizeof(gSqrt8Table) == kSQRT_TABLE_SIZE); rad_to_unit_matrix(center, radius, &fPtsToUnit); } size_t SkRadialGradient::contextSize() const { return sizeof(RadialGradientContext); } SkShader::Context* SkRadialGradient::onCreateContext(const ContextRec& rec, void* storage) const { return SkNEW_PLACEMENT_ARGS(storage, RadialGradientContext, (*this, rec)); } SkRadialGradient::RadialGradientContext::RadialGradientContext( const SkRadialGradient& shader, const ContextRec& rec) : INHERITED(shader, rec) {} void SkRadialGradient::RadialGradientContext::shadeSpan16(int x, int y, uint16_t* dstCParam, int count) { SkASSERT(count > 0); const SkRadialGradient& radialGradient = static_cast(fShader); uint16_t* SK_RESTRICT dstC = dstCParam; SkPoint srcPt; SkMatrix::MapXYProc dstProc = fDstToIndexProc; TileProc proc = radialGradient.fTileProc; const uint16_t* SK_RESTRICT cache = fCache->getCache16(); int toggle = init_dither_toggle16(x, y); if (fDstToIndexClass != kPerspective_MatrixClass) { dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf, SkIntToScalar(y) + SK_ScalarHalf, &srcPt); SkScalar sdx = fDstToIndex.getScaleX(); SkScalar sdy = fDstToIndex.getSkewY(); if (fDstToIndexClass == kFixedStepInX_MatrixClass) { SkFixed storage[2]; (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), &storage[0], &storage[1]); sdx = SkFixedToScalar(storage[0]); sdy = SkFixedToScalar(storage[1]); } else { SkASSERT(fDstToIndexClass == kLinear_MatrixClass); } RadialShade16Proc shadeProc = shadeSpan16_radial_repeat; if (SkShader::kClamp_TileMode == radialGradient.fTileMode) { shadeProc = shadeSpan16_radial_clamp; } else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) { shadeProc = shadeSpan16_radial_mirror; } else { SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode); } (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC, cache, toggle, count); } else { // perspective case SkScalar dstX = SkIntToScalar(x); SkScalar dstY = SkIntToScalar(y); do { dstProc(fDstToIndex, dstX, dstY, &srcPt); unsigned fi = proc(SkScalarToFixed(srcPt.length())); SkASSERT(fi <= 0xFFFF); int index = fi >> (16 - kCache16Bits); *dstC++ = cache[toggle + index]; toggle = next_dither_toggle16(toggle); dstX += SK_Scalar1; } while (--count != 0); } } SkShader::BitmapType SkRadialGradient::asABitmap(SkBitmap* bitmap, SkMatrix* matrix, SkShader::TileMode* xy) const { if (bitmap) { this->getGradientTableBitmap(bitmap); } if (matrix) { matrix->setScale(SkIntToScalar(kCache32Count), SkIntToScalar(kCache32Count)); matrix->preConcat(fPtsToUnit); } if (xy) { xy[0] = fTileMode; xy[1] = kClamp_TileMode; } return kRadial_BitmapType; } SkShader::GradientType SkRadialGradient::asAGradient(GradientInfo* info) const { if (info) { commonAsAGradient(info); info->fPoint[0] = fCenter; info->fRadius[0] = fRadius; } return kRadial_GradientType; } #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING SkRadialGradient::SkRadialGradient(SkReadBuffer& buffer) : INHERITED(buffer), fCenter(buffer.readPoint()), fRadius(buffer.readScalar()) { } #endif SkFlattenable* SkRadialGradient::CreateProc(SkReadBuffer& buffer) { DescriptorScope desc; if (!desc.unflatten(buffer)) { return NULL; } const SkPoint center = buffer.readPoint(); const SkScalar radius = buffer.readScalar(); return SkGradientShader::CreateRadial(center, radius, desc.fColors, desc.fPos, desc.fCount, desc.fTileMode, desc.fGradFlags, desc.fLocalMatrix); } void SkRadialGradient::flatten(SkWriteBuffer& buffer) const { this->INHERITED::flatten(buffer); buffer.writePoint(fCenter); buffer.writeScalar(fRadius); } namespace { inline bool radial_completely_pinned(int fx, int dx, int fy, int dy) { // fast, overly-conservative test: checks unit square instead // of unit circle bool xClamped = (fx >= SK_FixedHalf && dx >= 0) || (fx <= -SK_FixedHalf && dx <= 0); bool yClamped = (fy >= SK_FixedHalf && dy >= 0) || (fy <= -SK_FixedHalf && dy <= 0); return xClamped || yClamped; } // Return true if (fx * fy) is always inside the unit circle // SkPin32 is expensive, but so are all the SkFixedMul in this test, // so it shouldn't be run if count is small. inline bool no_need_for_radial_pin(int fx, int dx, int fy, int dy, int count) { SkASSERT(count > 0); if (SkAbs32(fx) > 0x7FFF || SkAbs32(fy) > 0x7FFF) { return false; } if (fx*fx + fy*fy > 0x7FFF*0x7FFF) { return false; } fx += (count - 1) * dx; fy += (count - 1) * dy; if (SkAbs32(fx) > 0x7FFF || SkAbs32(fy) > 0x7FFF) { return false; } return fx*fx + fy*fy <= 0x7FFF*0x7FFF; } #define UNPINNED_RADIAL_STEP \ fi = (fx * fx + fy * fy) >> (14 + 16 - kSQRT_TABLE_BITS); \ *dstC++ = cache[toggle + \ (sqrt_table[fi] >> SkGradientShaderBase::kSqrt32Shift)]; \ toggle = next_dither_toggle(toggle); \ fx += dx; \ fy += dy; typedef void (* RadialShadeProc)(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy, SkPMColor* dstC, const SkPMColor* cache, int count, int toggle); // On Linux, this is faster with SkPMColor[] params than SkPMColor* SK_RESTRICT void shadeSpan_radial_clamp(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int count, int toggle) { // Floating point seems to be slower than fixed point, // even when we have float hardware. const uint8_t* SK_RESTRICT sqrt_table = gSqrt8Table; SkFixed fx = SkScalarToFixed(sfx) >> 1; SkFixed dx = SkScalarToFixed(sdx) >> 1; SkFixed fy = SkScalarToFixed(sfy) >> 1; SkFixed dy = SkScalarToFixed(sdy) >> 1; if ((count > 4) && radial_completely_pinned(fx, dx, fy, dy)) { unsigned fi = SkGradientShaderBase::kCache32Count - 1; sk_memset32_dither(dstC, cache[toggle + fi], cache[next_dither_toggle(toggle) + fi], count); } else if ((count > 4) && no_need_for_radial_pin(fx, dx, fy, dy, count)) { unsigned fi; // 4x unroll appears to be no faster than 2x unroll on Linux while (count > 1) { UNPINNED_RADIAL_STEP; UNPINNED_RADIAL_STEP; count -= 2; } if (count) { UNPINNED_RADIAL_STEP; } } else { // Specializing for dy == 0 gains us 25% on Skia benchmarks if (dy == 0) { unsigned yy = SkPin32(fy, -0xFFFF >> 1, 0xFFFF >> 1); yy *= yy; do { unsigned xx = SkPin32(fx, -0xFFFF >> 1, 0xFFFF >> 1); unsigned fi = (xx * xx + yy) >> (14 + 16 - kSQRT_TABLE_BITS); fi = SkFastMin32(fi, 0xFFFF >> (16 - kSQRT_TABLE_BITS)); *dstC++ = cache[toggle + (sqrt_table[fi] >> SkGradientShaderBase::kSqrt32Shift)]; toggle = next_dither_toggle(toggle); fx += dx; } while (--count != 0); } else { do { unsigned xx = SkPin32(fx, -0xFFFF >> 1, 0xFFFF >> 1); unsigned fi = SkPin32(fy, -0xFFFF >> 1, 0xFFFF >> 1); fi = (xx * xx + fi * fi) >> (14 + 16 - kSQRT_TABLE_BITS); fi = SkFastMin32(fi, 0xFFFF >> (16 - kSQRT_TABLE_BITS)); *dstC++ = cache[toggle + (sqrt_table[fi] >> SkGradientShaderBase::kSqrt32Shift)]; toggle = next_dither_toggle(toggle); fx += dx; fy += dy; } while (--count != 0); } } } // Unrolling this loop doesn't seem to help (when float); we're stalling to // get the results of the sqrt (?), and don't have enough extra registers to // have many in flight. template void shadeSpan_radial(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int count, int toggle) { do { const SkFixed dist = SkFloatToFixed(sk_float_sqrt(fx*fx + fy*fy)); const unsigned fi = TileProc(dist); SkASSERT(fi <= 0xFFFF); *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache32Shift)]; toggle = next_dither_toggle(toggle); fx += dx; fy += dy; } while (--count != 0); } void shadeSpan_radial_mirror(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int count, int toggle) { shadeSpan_radial(fx, dx, fy, dy, dstC, cache, count, toggle); } void shadeSpan_radial_repeat(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int count, int toggle) { shadeSpan_radial(fx, dx, fy, dy, dstC, cache, count, toggle); } } // namespace void SkRadialGradient::RadialGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC, int count) { SkASSERT(count > 0); const SkRadialGradient& radialGradient = static_cast(fShader); SkPoint srcPt; SkMatrix::MapXYProc dstProc = fDstToIndexProc; TileProc proc = radialGradient.fTileProc; const SkPMColor* SK_RESTRICT cache = fCache->getCache32(); int toggle = init_dither_toggle(x, y); if (fDstToIndexClass != kPerspective_MatrixClass) { dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf, SkIntToScalar(y) + SK_ScalarHalf, &srcPt); SkScalar sdx = fDstToIndex.getScaleX(); SkScalar sdy = fDstToIndex.getSkewY(); if (fDstToIndexClass == kFixedStepInX_MatrixClass) { SkFixed storage[2]; (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), &storage[0], &storage[1]); sdx = SkFixedToScalar(storage[0]); sdy = SkFixedToScalar(storage[1]); } else { SkASSERT(fDstToIndexClass == kLinear_MatrixClass); } RadialShadeProc shadeProc = shadeSpan_radial_repeat; if (SkShader::kClamp_TileMode == radialGradient.fTileMode) { shadeProc = shadeSpan_radial_clamp; } else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) { shadeProc = shadeSpan_radial_mirror; } else { SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode); } (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC, cache, count, toggle); } else { // perspective case SkScalar dstX = SkIntToScalar(x); SkScalar dstY = SkIntToScalar(y); do { dstProc(fDstToIndex, dstX, dstY, &srcPt); unsigned fi = proc(SkScalarToFixed(srcPt.length())); SkASSERT(fi <= 0xFFFF); *dstC++ = cache[fi >> SkGradientShaderBase::kCache32Shift]; dstX += SK_Scalar1; } while (--count != 0); } } ///////////////////////////////////////////////////////////////////// #if SK_SUPPORT_GPU #include "GrTBackendProcessorFactory.h" #include "gl/builders/GrGLProgramBuilder.h" #include "SkGr.h" class GrGLRadialGradient : public GrGLGradientEffect { public: GrGLRadialGradient(const GrBackendProcessorFactory& factory, const GrProcessor&) : INHERITED (factory) { } virtual ~GrGLRadialGradient() { } virtual void emitCode(GrGLFPBuilder*, const GrFragmentProcessor&, const char* outputColor, const char* inputColor, const TransformedCoordsArray&, const TextureSamplerArray&) SK_OVERRIDE; static void GenKey(const GrProcessor& processor, const GrGLCaps&, GrProcessorKeyBuilder* b) { b->add32(GenBaseGradientKey(processor)); } private: typedef GrGLGradientEffect INHERITED; }; ///////////////////////////////////////////////////////////////////// class GrRadialGradient : public GrGradientEffect { public: static GrFragmentProcessor* Create(GrContext* ctx, const SkRadialGradient& shader, const SkMatrix& matrix, SkShader::TileMode tm) { return SkNEW_ARGS(GrRadialGradient, (ctx, shader, matrix, tm)); } virtual ~GrRadialGradient() { } static const char* Name() { return "Radial Gradient"; } virtual const GrBackendFragmentProcessorFactory& getFactory() const SK_OVERRIDE { return GrTBackendFragmentProcessorFactory::getInstance(); } typedef GrGLRadialGradient GLProcessor; private: GrRadialGradient(GrContext* ctx, const SkRadialGradient& shader, const SkMatrix& matrix, SkShader::TileMode tm) : INHERITED(ctx, shader, matrix, tm) { } GR_DECLARE_FRAGMENT_PROCESSOR_TEST; typedef GrGradientEffect INHERITED; }; ///////////////////////////////////////////////////////////////////// GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrRadialGradient); GrFragmentProcessor* GrRadialGradient::TestCreate(SkRandom* random, GrContext* context, const GrDrawTargetCaps&, GrTexture**) { SkPoint center = {random->nextUScalar1(), random->nextUScalar1()}; SkScalar radius = random->nextUScalar1(); SkColor colors[kMaxRandomGradientColors]; SkScalar stopsArray[kMaxRandomGradientColors]; SkScalar* stops = stopsArray; SkShader::TileMode tm; int colorCount = RandomGradientParams(random, colors, &stops, &tm); SkAutoTUnref shader(SkGradientShader::CreateRadial(center, radius, colors, stops, colorCount, tm)); SkPaint paint; GrColor paintColor; GrFragmentProcessor* fp; SkAssertResult(shader->asFragmentProcessor(context, paint, NULL, &paintColor, &fp)); return fp; } ///////////////////////////////////////////////////////////////////// void GrGLRadialGradient::emitCode(GrGLFPBuilder* builder, const GrFragmentProcessor& fp, const char* outputColor, const char* inputColor, const TransformedCoordsArray& coords, const TextureSamplerArray& samplers) { const GrGradientEffect& ge = fp.cast(); this->emitUniforms(builder, ge); SkString t("length("); t.append(builder->getFragmentShaderBuilder()->ensureFSCoords2D(coords, 0)); t.append(")"); this->emitColor(builder, ge, t.c_str(), outputColor, inputColor, samplers); } ///////////////////////////////////////////////////////////////////// bool SkRadialGradient::asFragmentProcessor(GrContext* context, const SkPaint& paint, const SkMatrix* localMatrix, GrColor* paintColor, GrFragmentProcessor** fp) const { SkASSERT(context); SkMatrix matrix; if (!this->getLocalMatrix().invert(&matrix)) { return false; } if (localMatrix) { SkMatrix inv; if (!localMatrix->invert(&inv)) { return false; } matrix.postConcat(inv); } matrix.postConcat(fPtsToUnit); *paintColor = SkColor2GrColorJustAlpha(paint.getColor()); *fp = GrRadialGradient::Create(context, *this, matrix, fTileMode); return true; } #else bool SkRadialGradient::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix*, GrColor*, GrFragmentProcessor**) const { SkDEBUGFAIL("Should not call in GPU-less build"); return false; } #endif #ifndef SK_IGNORE_TO_STRING void SkRadialGradient::toString(SkString* str) const { str->append("SkRadialGradient: ("); str->append("center: ("); str->appendScalar(fCenter.fX); str->append(", "); str->appendScalar(fCenter.fY); str->append(") radius: "); str->appendScalar(fRadius); str->append(" "); this->INHERITED::toString(str); str->append(")"); } #endif