2 * Copyright 2012 Google Inc.
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
8 #include "SkLinearGradient.h"
10 static inline int repeat_bits(int x, const int bits) {
11 return x & ((1 << bits) - 1);
14 static inline int repeat_8bits(int x) {
18 // Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly.
19 // See http://code.google.com/p/skia/issues/detail?id=472
20 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
21 #pragma optimize("", off)
24 static inline int mirror_bits(int x, const int bits) {
25 if (x & (1 << bits)) {
28 return x & ((1 << bits) - 1);
31 static inline int mirror_8bits(int x) {
38 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
39 #pragma optimize("", on)
42 static void pts_to_unit_matrix(const SkPoint pts[2], SkMatrix* matrix) {
43 SkVector vec = pts[1] - pts[0];
44 SkScalar mag = vec.length();
45 SkScalar inv = mag ? SkScalarInvert(mag) : 0;
48 matrix->setSinCos(-vec.fY, vec.fX, pts[0].fX, pts[0].fY);
49 matrix->postTranslate(-pts[0].fX, -pts[0].fY);
50 matrix->postScale(inv, inv);
53 ///////////////////////////////////////////////////////////////////////////////
55 SkLinearGradient::SkLinearGradient(const SkPoint pts[2], const Descriptor& desc)
56 : SkGradientShaderBase(desc)
60 pts_to_unit_matrix(pts, &fPtsToUnit);
63 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
64 SkLinearGradient::SkLinearGradient(SkReadBuffer& buffer)
66 , fStart(buffer.readPoint())
67 , fEnd(buffer.readPoint()) {
71 SkFlattenable* SkLinearGradient::CreateProc(SkReadBuffer& buffer) {
73 if (!desc.unflatten(buffer)) {
77 pts[0] = buffer.readPoint();
78 pts[1] = buffer.readPoint();
79 return SkGradientShader::CreateLinear(pts, desc.fColors, desc.fPos, desc.fCount,
80 desc.fTileMode, desc.fGradFlags, desc.fLocalMatrix);
83 void SkLinearGradient::flatten(SkWriteBuffer& buffer) const {
84 this->INHERITED::flatten(buffer);
85 buffer.writePoint(fStart);
86 buffer.writePoint(fEnd);
89 size_t SkLinearGradient::contextSize() const {
90 return sizeof(LinearGradientContext);
93 SkShader::Context* SkLinearGradient::onCreateContext(const ContextRec& rec, void* storage) const {
94 return SkNEW_PLACEMENT_ARGS(storage, LinearGradientContext, (*this, rec));
97 SkLinearGradient::LinearGradientContext::LinearGradientContext(
98 const SkLinearGradient& shader, const ContextRec& rec)
99 : INHERITED(shader, rec)
101 unsigned mask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask;
102 if ((fDstToIndex.getType() & ~mask) == 0) {
103 // when we dither, we are (usually) not const-in-Y
104 if ((fFlags & SkShader::kHasSpan16_Flag) && !rec.fPaint->isDither()) {
105 // only claim this if we do have a 16bit mode (i.e. none of our
106 // colors have alpha), and if we are not dithering (which obviously
107 // is not const in Y).
108 fFlags |= SkShader::kConstInY16_Flag;
113 #define NO_CHECK_ITER \
115 unsigned fi = fx >> SkGradientShaderBase::kCache32Shift; \
116 SkASSERT(fi <= 0xFF); \
118 *dstC++ = cache[toggle + fi]; \
119 toggle = next_dither_toggle(toggle); \
124 typedef void (*LinearShadeProc)(TileProc proc, SkFixed dx, SkFixed fx,
125 SkPMColor* dstC, const SkPMColor* cache,
126 int toggle, int count);
128 // Linear interpolation (lerp) is unnecessary if there are no sharp
129 // discontinuities in the gradient - which must be true if there are
130 // only 2 colors - but it's cheap.
131 void shadeSpan_linear_vertical_lerp(TileProc proc, SkFixed dx, SkFixed fx,
132 SkPMColor* SK_RESTRICT dstC,
133 const SkPMColor* SK_RESTRICT cache,
134 int toggle, int count) {
135 // We're a vertical gradient, so no change in a span.
136 // If colors change sharply across the gradient, dithering is
137 // insufficient (it subsamples the color space) and we need to lerp.
138 unsigned fullIndex = proc(fx);
139 unsigned fi = fullIndex >> SkGradientShaderBase::kCache32Shift;
140 unsigned remainder = fullIndex & ((1 << SkGradientShaderBase::kCache32Shift) - 1);
142 int index0 = fi + toggle;
144 if (fi < SkGradientShaderBase::kCache32Count - 1) {
147 SkPMColor lerp = SkFastFourByteInterp(cache[index1], cache[index0], remainder);
148 index0 ^= SkGradientShaderBase::kDitherStride32;
149 index1 ^= SkGradientShaderBase::kDitherStride32;
150 SkPMColor dlerp = SkFastFourByteInterp(cache[index1], cache[index0], remainder);
151 sk_memset32_dither(dstC, lerp, dlerp, count);
154 void shadeSpan_linear_clamp(TileProc proc, SkFixed dx, SkFixed fx,
155 SkPMColor* SK_RESTRICT dstC,
156 const SkPMColor* SK_RESTRICT cache,
157 int toggle, int count) {
159 range.init(fx, dx, count, 0, SkGradientShaderBase::kCache32Count - 1);
161 if ((count = range.fCount0) > 0) {
162 sk_memset32_dither(dstC,
163 cache[toggle + range.fV0],
164 cache[next_dither_toggle(toggle) + range.fV0],
168 if ((count = range.fCount1) > 0) {
169 int unroll = count >> 3;
171 for (int i = 0; i < unroll; i++) {
172 NO_CHECK_ITER; NO_CHECK_ITER;
173 NO_CHECK_ITER; NO_CHECK_ITER;
174 NO_CHECK_ITER; NO_CHECK_ITER;
175 NO_CHECK_ITER; NO_CHECK_ITER;
177 if ((count &= 7) > 0) {
180 } while (--count != 0);
183 if ((count = range.fCount2) > 0) {
184 sk_memset32_dither(dstC,
185 cache[toggle + range.fV1],
186 cache[next_dither_toggle(toggle) + range.fV1],
191 void shadeSpan_linear_mirror(TileProc proc, SkFixed dx, SkFixed fx,
192 SkPMColor* SK_RESTRICT dstC,
193 const SkPMColor* SK_RESTRICT cache,
194 int toggle, int count) {
196 unsigned fi = mirror_8bits(fx >> 8);
197 SkASSERT(fi <= 0xFF);
199 *dstC++ = cache[toggle + fi];
200 toggle = next_dither_toggle(toggle);
201 } while (--count != 0);
204 void shadeSpan_linear_repeat(TileProc proc, SkFixed dx, SkFixed fx,
205 SkPMColor* SK_RESTRICT dstC,
206 const SkPMColor* SK_RESTRICT cache,
207 int toggle, int count) {
209 unsigned fi = repeat_8bits(fx >> 8);
210 SkASSERT(fi <= 0xFF);
212 *dstC++ = cache[toggle + fi];
213 toggle = next_dither_toggle(toggle);
214 } while (--count != 0);
219 void SkLinearGradient::LinearGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC,
223 const SkLinearGradient& linearGradient = static_cast<const SkLinearGradient&>(fShader);
226 SkMatrix::MapXYProc dstProc = fDstToIndexProc;
227 TileProc proc = linearGradient.fTileProc;
228 const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
229 int toggle = init_dither_toggle(x, y);
231 if (fDstToIndexClass != kPerspective_MatrixClass) {
232 dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf,
233 SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
234 SkFixed dx, fx = SkScalarToFixed(srcPt.fX);
236 if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
237 SkFixed dxStorage[1];
238 (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), dxStorage, NULL);
241 SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
242 dx = SkScalarToFixed(fDstToIndex.getScaleX());
245 LinearShadeProc shadeProc = shadeSpan_linear_repeat;
247 shadeProc = shadeSpan_linear_vertical_lerp;
248 } else if (SkShader::kClamp_TileMode == linearGradient.fTileMode) {
249 shadeProc = shadeSpan_linear_clamp;
250 } else if (SkShader::kMirror_TileMode == linearGradient.fTileMode) {
251 shadeProc = shadeSpan_linear_mirror;
253 SkASSERT(SkShader::kRepeat_TileMode == linearGradient.fTileMode);
255 (*shadeProc)(proc, dx, fx, dstC, cache, toggle, count);
257 SkScalar dstX = SkIntToScalar(x);
258 SkScalar dstY = SkIntToScalar(y);
260 dstProc(fDstToIndex, dstX, dstY, &srcPt);
261 unsigned fi = proc(SkScalarToFixed(srcPt.fX));
262 SkASSERT(fi <= 0xFFFF);
263 *dstC++ = cache[toggle + (fi >> kCache32Shift)];
264 toggle = next_dither_toggle(toggle);
266 } while (--count != 0);
270 SkShader::BitmapType SkLinearGradient::asABitmap(SkBitmap* bitmap,
272 TileMode xy[]) const {
274 this->getGradientTableBitmap(bitmap);
277 matrix->preConcat(fPtsToUnit);
281 xy[1] = kClamp_TileMode;
283 return kLinear_BitmapType;
286 SkShader::GradientType SkLinearGradient::asAGradient(GradientInfo* info) const {
288 commonAsAGradient(info);
289 info->fPoint[0] = fStart;
290 info->fPoint[1] = fEnd;
292 return kLinear_GradientType;
295 static void dither_memset16(uint16_t dst[], uint16_t value, uint16_t other,
297 if (reinterpret_cast<uintptr_t>(dst) & 2) {
300 SkTSwap(value, other);
303 sk_memset32((uint32_t*)dst, (value << 16) | other, count >> 1);
306 dst[count - 1] = value;
310 #define NO_CHECK_ITER_16 \
312 unsigned fi = fx >> SkGradientShaderBase::kCache16Shift; \
313 SkASSERT(fi < SkGradientShaderBase::kCache16Count); \
315 *dstC++ = cache[toggle + fi]; \
316 toggle = next_dither_toggle16(toggle); \
321 typedef void (*LinearShade16Proc)(TileProc proc, SkFixed dx, SkFixed fx,
322 uint16_t* dstC, const uint16_t* cache,
323 int toggle, int count);
325 void shadeSpan16_linear_vertical(TileProc proc, SkFixed dx, SkFixed fx,
326 uint16_t* SK_RESTRICT dstC,
327 const uint16_t* SK_RESTRICT cache,
328 int toggle, int count) {
329 // we're a vertical gradient, so no change in a span
330 unsigned fi = proc(fx) >> SkGradientShaderBase::kCache16Shift;
331 SkASSERT(fi < SkGradientShaderBase::kCache16Count);
332 dither_memset16(dstC, cache[toggle + fi],
333 cache[next_dither_toggle16(toggle) + fi], count);
336 void shadeSpan16_linear_clamp(TileProc proc, SkFixed dx, SkFixed fx,
337 uint16_t* SK_RESTRICT dstC,
338 const uint16_t* SK_RESTRICT cache,
339 int toggle, int count) {
341 range.init(fx, dx, count, 0, SkGradientShaderBase::kCache32Count - 1);
343 if ((count = range.fCount0) > 0) {
344 dither_memset16(dstC,
345 cache[toggle + range.fV0],
346 cache[next_dither_toggle16(toggle) + range.fV0],
350 if ((count = range.fCount1) > 0) {
351 int unroll = count >> 3;
353 for (int i = 0; i < unroll; i++) {
354 NO_CHECK_ITER_16; NO_CHECK_ITER_16;
355 NO_CHECK_ITER_16; NO_CHECK_ITER_16;
356 NO_CHECK_ITER_16; NO_CHECK_ITER_16;
357 NO_CHECK_ITER_16; NO_CHECK_ITER_16;
359 if ((count &= 7) > 0) {
362 } while (--count != 0);
365 if ((count = range.fCount2) > 0) {
366 dither_memset16(dstC,
367 cache[toggle + range.fV1],
368 cache[next_dither_toggle16(toggle) + range.fV1],
373 void shadeSpan16_linear_mirror(TileProc proc, SkFixed dx, SkFixed fx,
374 uint16_t* SK_RESTRICT dstC,
375 const uint16_t* SK_RESTRICT cache,
376 int toggle, int count) {
378 unsigned fi = mirror_bits(fx >> SkGradientShaderBase::kCache16Shift,
379 SkGradientShaderBase::kCache16Bits);
380 SkASSERT(fi < SkGradientShaderBase::kCache16Count);
382 *dstC++ = cache[toggle + fi];
383 toggle = next_dither_toggle16(toggle);
384 } while (--count != 0);
387 void shadeSpan16_linear_repeat(TileProc proc, SkFixed dx, SkFixed fx,
388 uint16_t* SK_RESTRICT dstC,
389 const uint16_t* SK_RESTRICT cache,
390 int toggle, int count) {
392 unsigned fi = repeat_bits(fx >> SkGradientShaderBase::kCache16Shift,
393 SkGradientShaderBase::kCache16Bits);
394 SkASSERT(fi < SkGradientShaderBase::kCache16Count);
396 *dstC++ = cache[toggle + fi];
397 toggle = next_dither_toggle16(toggle);
398 } while (--count != 0);
402 static bool fixed_nearly_zero(SkFixed x) {
403 return SkAbs32(x) < (SK_Fixed1 >> 12);
406 void SkLinearGradient::LinearGradientContext::shadeSpan16(int x, int y,
407 uint16_t* SK_RESTRICT dstC, int count) {
410 const SkLinearGradient& linearGradient = static_cast<const SkLinearGradient&>(fShader);
413 SkMatrix::MapXYProc dstProc = fDstToIndexProc;
414 TileProc proc = linearGradient.fTileProc;
415 const uint16_t* SK_RESTRICT cache = fCache->getCache16();
416 int toggle = init_dither_toggle16(x, y);
418 if (fDstToIndexClass != kPerspective_MatrixClass) {
419 dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf,
420 SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
421 SkFixed dx, fx = SkScalarToFixed(srcPt.fX);
423 if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
424 SkFixed dxStorage[1];
425 (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), dxStorage, NULL);
428 SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
429 dx = SkScalarToFixed(fDstToIndex.getScaleX());
432 LinearShade16Proc shadeProc = shadeSpan16_linear_repeat;
433 if (fixed_nearly_zero(dx)) {
434 shadeProc = shadeSpan16_linear_vertical;
435 } else if (SkShader::kClamp_TileMode == linearGradient.fTileMode) {
436 shadeProc = shadeSpan16_linear_clamp;
437 } else if (SkShader::kMirror_TileMode == linearGradient.fTileMode) {
438 shadeProc = shadeSpan16_linear_mirror;
440 SkASSERT(SkShader::kRepeat_TileMode == linearGradient.fTileMode);
442 (*shadeProc)(proc, dx, fx, dstC, cache, toggle, count);
444 SkScalar dstX = SkIntToScalar(x);
445 SkScalar dstY = SkIntToScalar(y);
447 dstProc(fDstToIndex, dstX, dstY, &srcPt);
448 unsigned fi = proc(SkScalarToFixed(srcPt.fX));
449 SkASSERT(fi <= 0xFFFF);
451 int index = fi >> kCache16Shift;
452 *dstC++ = cache[toggle + index];
453 toggle = next_dither_toggle16(toggle);
456 } while (--count != 0);
462 #include "GrTBackendProcessorFactory.h"
463 #include "gl/builders/GrGLProgramBuilder.h"
466 /////////////////////////////////////////////////////////////////////
468 class GrGLLinearGradient : public GrGLGradientEffect {
471 GrGLLinearGradient(const GrBackendProcessorFactory& factory, const GrProcessor&)
472 : INHERITED (factory) { }
474 virtual ~GrGLLinearGradient() { }
476 virtual void emitCode(GrGLFPBuilder*,
477 const GrFragmentProcessor&,
478 const GrProcessorKey&,
479 const char* outputColor,
480 const char* inputColor,
481 const TransformedCoordsArray&,
482 const TextureSamplerArray&) SK_OVERRIDE;
484 static void GenKey(const GrProcessor& processor, const GrGLCaps&, GrProcessorKeyBuilder* b) {
485 b->add32(GenBaseGradientKey(processor));
490 typedef GrGLGradientEffect INHERITED;
493 /////////////////////////////////////////////////////////////////////
495 class GrLinearGradient : public GrGradientEffect {
498 static GrFragmentProcessor* Create(GrContext* ctx,
499 const SkLinearGradient& shader,
500 const SkMatrix& matrix,
501 SkShader::TileMode tm) {
502 return SkNEW_ARGS(GrLinearGradient, (ctx, shader, matrix, tm));
505 virtual ~GrLinearGradient() { }
507 static const char* Name() { return "Linear Gradient"; }
508 const GrBackendFragmentProcessorFactory& getFactory() const SK_OVERRIDE {
509 return GrTBackendFragmentProcessorFactory<GrLinearGradient>::getInstance();
512 typedef GrGLLinearGradient GLProcessor;
515 GrLinearGradient(GrContext* ctx,
516 const SkLinearGradient& shader,
517 const SkMatrix& matrix,
518 SkShader::TileMode tm)
519 : INHERITED(ctx, shader, matrix, tm) { }
520 GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
522 typedef GrGradientEffect INHERITED;
525 /////////////////////////////////////////////////////////////////////
527 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrLinearGradient);
529 GrFragmentProcessor* GrLinearGradient::TestCreate(SkRandom* random,
531 const GrDrawTargetCaps&,
533 SkPoint points[] = {{random->nextUScalar1(), random->nextUScalar1()},
534 {random->nextUScalar1(), random->nextUScalar1()}};
536 SkColor colors[kMaxRandomGradientColors];
537 SkScalar stopsArray[kMaxRandomGradientColors];
538 SkScalar* stops = stopsArray;
539 SkShader::TileMode tm;
540 int colorCount = RandomGradientParams(random, colors, &stops, &tm);
541 SkAutoTUnref<SkShader> shader(SkGradientShader::CreateLinear(points,
542 colors, stops, colorCount,
546 GrFragmentProcessor* fp;
547 SkAssertResult(shader->asFragmentProcessor(context, paint, NULL, &paintColor, &fp));
551 /////////////////////////////////////////////////////////////////////
553 void GrGLLinearGradient::emitCode(GrGLFPBuilder* builder,
554 const GrFragmentProcessor&,
555 const GrProcessorKey& key,
556 const char* outputColor,
557 const char* inputColor,
558 const TransformedCoordsArray& coords,
559 const TextureSamplerArray& samplers) {
560 uint32_t baseKey = key.get32(0);
561 this->emitUniforms(builder, baseKey);
562 SkString t = builder->getFragmentShaderBuilder()->ensureFSCoords2D(coords, 0);
564 this->emitColor(builder, t.c_str(), baseKey, outputColor, inputColor, samplers);
567 /////////////////////////////////////////////////////////////////////
569 bool SkLinearGradient::asFragmentProcessor(GrContext* context, const SkPaint& paint,
570 const SkMatrix* localMatrix, GrColor* paintColor,
571 GrFragmentProcessor** fp) const {
575 if (!this->getLocalMatrix().invert(&matrix)) {
580 if (!localMatrix->invert(&inv)) {
583 matrix.postConcat(inv);
585 matrix.postConcat(fPtsToUnit);
587 *paintColor = SkColor2GrColorJustAlpha(paint.getColor());
588 *fp = GrLinearGradient::Create(context, *this, matrix, fTileMode);
595 bool SkLinearGradient::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix*, GrColor*,
596 GrFragmentProcessor**) const {
597 SkDEBUGFAIL("Should not call in GPU-less build");
603 #ifndef SK_IGNORE_TO_STRING
604 void SkLinearGradient::toString(SkString* str) const {
605 str->append("SkLinearGradient (");
607 str->appendf("start: (%f, %f)", fStart.fX, fStart.fY);
608 str->appendf(" end: (%f, %f) ", fEnd.fX, fEnd.fY);
610 this->INHERITED::toString(str);