Split SkGradientShader into separate files for each gradient subclass.
Review URL: https://codereview.appspot.com/6447049
git-svn-id: http://skia.googlecode.com/svn/trunk@4792 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
new file mode 100644
index 0000000..4ac93d7
--- /dev/null
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -0,0 +1,479 @@
+
+/*
+ * 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 defined(SK_BUILD_FOR_WIN32) && defined(SK_DEBUG)
+
+#include <stdio.h>
+
+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 {
+
+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 ^= SkGradientShaderBase::kDitherStride16;
+ } 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 ^= SkGradientShaderBase::kDitherStride16;
+ } while (--count != 0);
+ }
+}
+
+void shadeSpan16_radial_mirror(SkScalar sfx, SkScalar sdx,
+ SkScalar sfy, SkScalar sdy,
+ uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache,
+ int toggle, int count) {
+ do {
+#ifdef SK_SCALAR_IS_FLOAT
+ float fdist = sk_float_sqrt(sfx*sfx + sfy*sfy);
+ SkFixed dist = SkFloatToFixed(fdist);
+#else
+ SkFixed magnitudeSquared = SkFixedSquare(sfx) +
+ SkFixedSquare(sfy);
+ if (magnitudeSquared < 0) // Overflow.
+ magnitudeSquared = SK_FixedMax;
+ SkFixed dist = SkFixedSqrt(magnitudeSquared);
+#endif
+ unsigned fi = mirror_tileproc(dist);
+ SkASSERT(fi <= 0xFFFF);
+ *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache16Shift)];
+ toggle ^= SkGradientShaderBase::kDitherStride16;
+ sfx += sdx;
+ sfy += sdy;
+ } while (--count != 0);
+}
+
+void shadeSpan16_radial_repeat(SkScalar sfx, SkScalar sdx,
+ SkScalar sfy, SkScalar sdy,
+ uint16_t* SK_RESTRICT dstC, const uint16_t* SK_RESTRICT cache,
+ int toggle, int count) {
+ SkFixed fx = SkScalarToFixed(sfx);
+ SkFixed dx = SkScalarToFixed(sdx);
+ SkFixed fy = SkScalarToFixed(sfy);
+ SkFixed dy = SkScalarToFixed(sdy);
+ do {
+ SkFixed dist = SkFixedSqrt(SkFixedSquare(fx) + SkFixedSquare(fy));
+ unsigned fi = repeat_tileproc(dist);
+ SkASSERT(fi <= 0xFFFF);
+ fx += dx;
+ fy += dy;
+ *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache16Shift)];
+ toggle ^= SkGradientShaderBase::kDitherStride16;
+ } while (--count != 0);
+}
+
+}
+
+SkRadialGradient::SkRadialGradient(const SkPoint& center, SkScalar radius,
+ const SkColor colors[], const SkScalar pos[], int colorCount,
+ SkShader::TileMode mode, SkUnitMapper* mapper)
+ : SkGradientShaderBase(colors, pos, colorCount, mode, mapper),
+ 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);
+}
+
+void SkRadialGradient::shadeSpan16(int x, int y, uint16_t* dstCParam,
+ int count) {
+ SkASSERT(count > 0);
+
+ uint16_t* SK_RESTRICT dstC = dstCParam;
+
+ SkPoint srcPt;
+ SkMatrix::MapXYProc dstProc = fDstToIndexProc;
+ TileProc proc = fTileProc;
+ const uint16_t* SK_RESTRICT cache = this->getCache16();
+ int toggle = ((x ^ y) & 1) * kDitherStride16;
+
+ 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 == fTileMode) {
+ shadeProc = shadeSpan16_radial_clamp;
+ } else if (SkShader::kMirror_TileMode == fTileMode) {
+ shadeProc = shadeSpan16_radial_mirror;
+ } else {
+ SkASSERT(SkShader::kRepeat_TileMode == 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 ^= kDitherStride16;
+
+ dstX += SK_Scalar1;
+ } while (--count != 0);
+ }
+}
+
+SkShader::BitmapType SkRadialGradient::asABitmap(SkBitmap* bitmap,
+ SkMatrix* matrix, SkShader::TileMode* xy) const {
+ if (bitmap) {
+ this->commonAsABitmap(bitmap);
+ }
+ if (matrix) {
+ matrix->setScale(SkIntToScalar(kGradient32Length),
+ SkIntToScalar(kGradient32Length));
+ 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;
+}
+
+GrCustomStage* SkRadialGradient::asNewCustomStage(GrContext* context,
+ GrSamplerState* sampler) const {
+ SkASSERT(NULL != context && NULL != sampler);
+ sampler->matrix()->preConcat(fPtsToUnit);
+ sampler->textureParams()->setTileModeX(fTileMode);
+ sampler->textureParams()->setTileModeY(kClamp_TileMode);
+ sampler->textureParams()->setBilerp(true);
+ return SkNEW_ARGS(GrRadialGradient, (context, *this, sampler));
+}
+
+SkRadialGradient::SkRadialGradient(SkFlattenableReadBuffer& buffer)
+ : INHERITED(buffer),
+ fCenter(buffer.readPoint()),
+ fRadius(buffer.readScalar()) {
+}
+
+void SkRadialGradient::flatten(SkFlattenableWriteBuffer& 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 ^= SkGradientShaderBase::kDitherStride32; \
+ 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::kGradient32Length;
+ sk_memset32_dither(dstC,
+ cache[toggle + fi],
+ cache[(toggle ^ SkGradientShaderBase::kDitherStride32) + 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 ^= SkGradientShaderBase::kDitherStride32;
+ 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 ^= SkGradientShaderBase::kDitherStride32;
+ 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.
+void shadeSpan_radial_mirror(SkScalar sfx, SkScalar sdx,
+ SkScalar sfy, SkScalar sdy,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
+ int count, int toggle) {
+ do {
+#ifdef SK_SCALAR_IS_FLOAT
+ float fdist = sk_float_sqrt(sfx*sfx + sfy*sfy);
+ SkFixed dist = SkFloatToFixed(fdist);
+#else
+ SkFixed magnitudeSquared = SkFixedSquare(sfx) +
+ SkFixedSquare(sfy);
+ if (magnitudeSquared < 0) // Overflow.
+ magnitudeSquared = SK_FixedMax;
+ SkFixed dist = SkFixedSqrt(magnitudeSquared);
+#endif
+ unsigned fi = mirror_tileproc(dist);
+ SkASSERT(fi <= 0xFFFF);
+ *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache32Shift)];
+ toggle ^= SkGradientShaderBase::kDitherStride32;
+ sfx += sdx;
+ sfy += sdy;
+ } while (--count != 0);
+}
+
+void shadeSpan_radial_repeat(SkScalar sfx, SkScalar sdx,
+ SkScalar sfy, SkScalar sdy,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
+ int count, int toggle) {
+ SkFixed fx = SkScalarToFixed(sfx);
+ SkFixed dx = SkScalarToFixed(sdx);
+ SkFixed fy = SkScalarToFixed(sfy);
+ SkFixed dy = SkScalarToFixed(sdy);
+ do {
+ SkFixed magnitudeSquared = SkFixedSquare(fx) +
+ SkFixedSquare(fy);
+ if (magnitudeSquared < 0) // Overflow.
+ magnitudeSquared = SK_FixedMax;
+ SkFixed dist = SkFixedSqrt(magnitudeSquared);
+ unsigned fi = repeat_tileproc(dist);
+ SkASSERT(fi <= 0xFFFF);
+ *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache32Shift)];
+ toggle ^= SkGradientShaderBase::kDitherStride32;
+ fx += dx;
+ fy += dy;
+ } while (--count != 0);
+}
+}
+
+void SkRadialGradient::shadeSpan(int x, int y,
+ SkPMColor* SK_RESTRICT dstC, int count) {
+ SkASSERT(count > 0);
+
+ SkPoint srcPt;
+ SkMatrix::MapXYProc dstProc = fDstToIndexProc;
+ TileProc proc = fTileProc;
+ const SkPMColor* SK_RESTRICT cache = this->getCache32();
+#ifdef USE_DITHER_32BIT_GRADIENT
+ int toggle = ((x ^ y) & 1) * SkGradientShaderBase::kDitherStride32;
+#else
+ int toggle = 0;
+#endif
+
+ 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 == fTileMode) {
+ shadeProc = shadeSpan_radial_clamp;
+ } else if (SkShader::kMirror_TileMode == fTileMode) {
+ shadeProc = shadeSpan_radial_mirror;
+ } else {
+ SkASSERT(SkShader::kRepeat_TileMode == 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);
+ }
+}
+