Create floating-point square root path for 16b mirrored radial gradients
(6x-16x speedup). Create specialized dy=0 path for clamped radial gradients
(25% speedup). Make 16b radial gradient proc signature similar to 32b,
passing in SkScalar instead of SkFixed and/or SkFloat.
git-svn-id: http://skia.googlecode.com/svn/trunk@3030 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/SkGradientShader.cpp b/src/effects/SkGradientShader.cpp
index 797dc5b..729d39b 100644
--- a/src/effects/SkGradientShader.cpp
+++ b/src/effects/SkGradientShader.cpp
@@ -130,6 +130,11 @@
kCache32Mask = kCache32Count - 1,
kCache32Shift = 16 - kCache32Bits,
kSqrt32Shift = 8 - kCache32Bits,
+
+ /** ToggleMasks are used in dithering to switch between the two
+ halves of the gradient cache; they should be equal to the size
+ of a half-cache.
+ */
#ifdef USE_DITHER_32BIT_GRADIENT
kToggleMask32 = kCache32Count,
#else
@@ -852,8 +857,7 @@
namespace {
typedef void (*LinearShadeProc)(TileProc proc, SkFixed dx, SkFixed fx,
- SkPMColor* SK_RESTRICT dstC,
- const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* dstC, const SkPMColor* cache,
int toggle, int count);
void shadeSpan_linear_vertical(TileProc proc, SkFixed dx, SkFixed fx,
@@ -1040,8 +1044,7 @@
namespace {
typedef void (*LinearShade16Proc)(TileProc proc, SkFixed dx, SkFixed fx,
- uint16_t* SK_RESTRICT dstC,
- const uint16_t* SK_RESTRICT cache,
+ uint16_t* dstC, const uint16_t* cache,
int toggle, int count);
void shadeSpan16_linear_vertical(TileProc proc, SkFixed dx, SkFixed fx,
@@ -1226,14 +1229,14 @@
namespace {
-typedef void (* RadialShade16Proc)(SkFixed fx, SkFixed dx,
- SkFixed fy, SkFixed dy,
- uint16_t* dstC, const uint16_t* SK_RESTRICT cache,
+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(SkFixed fx, SkFixed dx,
- SkFixed fy, SkFixed dy,
- uint16_t* dstC, const uint16_t* SK_RESTRICT cache,
+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;
@@ -1244,10 +1247,10 @@
we could (it seems) put this scale-down into fDstToIndex,
to avoid having to do these extra shifts each time.
*/
- fx >>= 1;
- dx >>= 1;
- fy >>= 1;
- dy >>= 1;
+ 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) {
@@ -1277,23 +1280,38 @@
}
}
-void shadeSpan16_radial_mirror(SkFixed fx, SkFixed dx, SkFixed fy, SkFixed dy,
- uint16_t* dstC, const uint16_t* SK_RESTRICT cache,
+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 {
- SkFixed dist = SkFixedSqrt(SkFixedSquare(fx) + SkFixedSquare(fy));
+#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);
- fx += dx;
- fy += dy;
*dstC++ = cache[toggle + (fi >> Gradient_Shader::kCache16Shift)];
toggle ^= Gradient_Shader::kToggleMask16;
+ sfx += sdx;
+ sfy += sdy;
} while (--count != 0);
}
-void shadeSpan16_radial_repeat(SkFixed fx, SkFixed dx, SkFixed fy, SkFixed dy,
- uint16_t* dstC, const uint16_t* SK_RESTRICT cache,
+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);
@@ -1322,8 +1340,10 @@
rad_to_unit_matrix(center, radius, &fPtsToUnit);
}
- virtual void shadeSpan(int x, int y, SkPMColor* dstC, int count) SK_OVERRIDE;
- virtual void shadeSpan16(int x, int y, uint16_t* SK_RESTRICT dstC, int count) SK_OVERRIDE {
+ virtual void shadeSpan(int x, int y, SkPMColor* dstC, int count)
+ SK_OVERRIDE;
+ virtual void shadeSpan16(int x, int y, uint16_t* SK_RESTRICT dstC,
+ int count) SK_OVERRIDE {
SkASSERT(count > 0);
SkPoint srcPt;
@@ -1335,18 +1355,18 @@
if (fDstToIndexClass != kPerspective_MatrixClass) {
dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf,
SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
- SkFixed dx, fx = SkScalarToFixed(srcPt.fX);
- SkFixed dy, fy = SkScalarToFixed(srcPt.fY);
+
+ SkScalar sdx = fDstToIndex.getScaleX();
+ SkScalar sdy = fDstToIndex.getSkewY();
if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
SkFixed storage[2];
- (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), &storage[0], &storage[1]);
- dx = storage[0];
- dy = storage[1];
+ (void)fDstToIndex.fixedStepInX(SkIntToScalar(y),
+ &storage[0], &storage[1]);
+ sdx = SkFixedToScalar(storage[0]);
+ sdy = SkFixedToScalar(storage[1]);
} else {
SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
- dx = SkScalarToFixed(fDstToIndex.getScaleX());
- dy = SkScalarToFixed(fDstToIndex.getSkewY());
}
RadialShade16Proc shadeProc = shadeSpan16_radial_repeat;
@@ -1357,7 +1377,8 @@
} else {
SkASSERT(proc == repeat_tileproc);
}
- (*shadeProc)(fx, dx, fy, dy, dstC, cache, toggle, count);
+ (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC,
+ cache, toggle, count);
} else { // perspective case
SkScalar dstX = SkIntToScalar(x);
SkScalar dstY = SkIntToScalar(y);
@@ -1469,7 +1490,7 @@
typedef void (* RadialShadeProc)(SkScalar sfx, SkScalar sdx,
SkScalar sfy, SkScalar sdy,
- SkPMColor* dstC, const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* dstC, const SkPMColor* cache,
int count);
// On Linux, this is faster with SkPMColor[] params than SkPMColor* SK_RESTRICT
@@ -1500,18 +1521,36 @@
}
}
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[sqrt_table[fi] >> Gradient_Shader::kSqrt32Shift];
- fx += dx;
- fy += dy;
- } while (--count != 0);
+ // 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[sqrt_table[fi] >>
+ Gradient_Shader::kSqrt32Shift];
+ 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[sqrt_table[fi] >>
+ Gradient_Shader::kSqrt32Shift];
+ 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,
@@ -1705,14 +1744,14 @@
SkScalar fy, SkScalar dy,
SkScalar b, SkScalar db,
SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot,
- SkPMColor* dstC, const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
int count);
void shadeSpan_twopoint_clamp(SkScalar fx, SkScalar dx,
SkScalar fy, SkScalar dy,
SkScalar b, SkScalar db,
SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot,
- SkPMColor* dstC, const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
int count) {
for (; count > 0; --count) {
SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura,
@@ -1729,7 +1768,7 @@
SkScalar fy, SkScalar dy,
SkScalar b, SkScalar db,
SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot,
- SkPMColor* dstC, const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
int count) {
for (; count > 0; --count) {
SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura,
@@ -1747,7 +1786,7 @@
SkScalar fy, SkScalar dy,
SkScalar b, SkScalar db,
SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot,
- SkPMColor* dstC, const SkPMColor* SK_RESTRICT cache,
+ SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
int count) {
for (; count > 0; --count) {
SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura,
@@ -2255,7 +2294,8 @@
}
#endif
-void Sweep_Gradient::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC, int count) {
+void Sweep_Gradient::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC,
+ int count) {
SkMatrix::MapXYProc proc = fDstToIndexProc;
const SkMatrix& matrix = fDstToIndex;
const SkPMColor* SK_RESTRICT cache = this->getCache32();
@@ -2293,7 +2333,8 @@
}
}
-void Sweep_Gradient::shadeSpan16(int x, int y, uint16_t* SK_RESTRICT dstC, int count) {
+void Sweep_Gradient::shadeSpan16(int x, int y, uint16_t* SK_RESTRICT dstC,
+ int count) {
SkMatrix::MapXYProc proc = fDstToIndexProc;
const SkMatrix& matrix = fDstToIndex;
const uint16_t* SK_RESTRICT cache = this->getCache16();