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 #ifndef SkGradientShaderPriv_DEFINED
9 #define SkGradientShaderPriv_DEFINED
11 #include "SkGradientShader.h"
12 #include "SkClampRange.h"
13 #include "SkColorPriv.h"
14 #include "SkReadBuffer.h"
15 #include "SkWriteBuffer.h"
16 #include "SkMallocPixelRef.h"
17 #include "SkUnitMapper.h"
19 #include "SkTemplates.h"
20 #include "SkBitmapCache.h"
24 static inline void sk_memset32_dither(uint32_t dst[], uint32_t v0, uint32_t v1,
28 sk_memset32(dst, v0, count);
30 int pairs = count >> 1;
31 for (int i = 0; i < pairs; i++) {
44 static inline SkFixed clamp_tileproc(SkFixed x) {
45 return SkClampMax(x, 0xFFFF);
50 static inline SkFixed repeat_tileproc(SkFixed x) {
56 // Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly.
57 // See http://code.google.com/p/skia/issues/detail?id=472
58 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
59 #pragma optimize("", off)
62 static inline SkFixed mirror_tileproc(SkFixed x) {
63 int s = x << 15 >> 31;
64 return (x ^ s) & 0xFFFF;
67 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
68 #pragma optimize("", on)
71 ///////////////////////////////////////////////////////////////////////////////
73 typedef SkFixed (*TileProc)(SkFixed);
75 ///////////////////////////////////////////////////////////////////////////////
77 static const TileProc gTileProcs[] = {
83 ///////////////////////////////////////////////////////////////////////////////
85 class SkGradientShaderBase : public SkShader {
89 sk_bzero(this, sizeof(*this));
90 fTileMode = SkShader::kClamp_TileMode;
93 const SkColor* fColors;
96 SkShader::TileMode fTileMode;
97 SkUnitMapper* fMapper;
102 SkGradientShaderBase(const Descriptor& desc, const SkMatrix* localMatrix);
103 virtual ~SkGradientShaderBase();
105 // The cache is initialized on-demand when getCache16/32 is called.
106 class GradientShaderCache : public SkRefCnt {
108 GradientShaderCache(U8CPU alpha, const SkGradientShaderBase& shader);
109 ~GradientShaderCache();
111 const uint16_t* getCache16();
112 const SkPMColor* getCache32();
114 SkMallocPixelRef* getCache32PixelRef() const { return fCache32PixelRef; }
116 unsigned getAlpha() const { return fCacheAlpha; }
119 // Working pointers. If either is NULL, we need to recompute the corresponding cache values.
123 uint16_t* fCache16Storage; // Storage for fCache16, allocated on demand.
124 SkMallocPixelRef* fCache32PixelRef;
125 const unsigned fCacheAlpha; // The alpha value we used when we computed the cache.
126 // Larger than 8bits so we can store uninitialized
129 const SkGradientShaderBase& fShader;
131 // Make sure we only initialize the caches once.
132 bool fCache16Inited, fCache32Inited;
133 SkMutex fCache16Mutex, fCache32Mutex;
135 static void initCache16(GradientShaderCache* cache);
136 static void initCache32(GradientShaderCache* cache);
138 static void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count);
139 static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count,
140 U8CPU alpha, uint32_t gradFlags);
143 class GradientShaderBaseContext : public SkShader::Context {
145 GradientShaderBaseContext(const SkGradientShaderBase& shader, const ContextRec&);
147 virtual uint32_t getFlags() const SK_OVERRIDE { return fFlags; }
150 SkMatrix fDstToIndex;
151 SkMatrix::MapXYProc fDstToIndexProc;
152 uint8_t fDstToIndexClass;
155 SkAutoTUnref<GradientShaderCache> fCache;
158 typedef SkShader::Context INHERITED;
161 virtual bool isOpaque() const SK_OVERRIDE;
163 void getGradientTableBitmap(SkBitmap*) const;
166 /// Seems like enough for visual accuracy. TODO: if pos[] deserves
167 /// it, use a larger cache.
169 kCache16Count = (1 << kCache16Bits),
170 kCache16Shift = 16 - kCache16Bits,
171 kSqrt16Shift = 8 - kCache16Bits,
173 /// Seems like enough for visual accuracy. TODO: if pos[] deserves
174 /// it, use a larger cache.
176 kCache32Count = (1 << kCache32Bits),
177 kCache32Shift = 16 - kCache32Bits,
178 kSqrt32Shift = 8 - kCache32Bits,
180 /// This value is used to *read* the dither cache; it may be 0
181 /// if dithering is disabled.
182 kDitherStride32 = kCache32Count,
183 kDitherStride16 = kCache16Count,
188 kThree_GpuColorType, // Symmetric three color
189 kTexture_GpuColorType
192 // Determines and returns the gradient is a two color gradient, symmetric three color gradient
193 // or other (texture gradient). If it is two or symmetric three color, the colors array will
194 // also be filled with the gradient colors
195 GpuColorType getGpuColorType(SkColor colors[3]) const;
197 uint32_t getGradFlags() const { return fGradFlags; }
200 SkGradientShaderBase(SkReadBuffer& );
201 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
202 SK_TO_STRING_OVERRIDE()
204 SkUnitMapper* fMapper;
205 SkMatrix fPtsToUnit; // set by subclass
212 SkFixed fPos; // 0...1
213 uint32_t fScale; // (1 << 24) / range
217 void commonAsAGradient(GradientInfo*, bool flipGrad = false) const;
220 * Takes in pointers to gradient color and Rec info as colorSrc and recSrc respectively.
221 * Count is the number of colors in the gradient
222 * It will then flip all the color and rec information and return in their respective Dst
223 * pointers. It is assumed that space has already been allocated for the Dst pointers.
224 * The rec src and dst are only assumed to be valid if count > 2
226 static void FlipGradientColors(SkColor* colorDst, Rec* recDst,
227 SkColor* colorSrc, Rec* recSrc,
230 // V23_COMPATIBILITY_CODE
231 // Used for 2-pt conical gradients since we sort start/end cirlces by radius
232 // Assumes space has already been allocated for fOrigColors
233 void flipGradientColors();
237 kColorStorageCount = 4, // more than this many colors, and we'll use sk_malloc for the space
239 kStorageSize = kColorStorageCount * (sizeof(SkColor) + sizeof(Rec))
241 SkColor fStorage[(kStorageSize + 3) >> 2];
242 SkColor* fOrigColors; // original colors, before modulation by paint in context.
243 bool fColorsAreOpaque;
245 GradientShaderCache* refCache(U8CPU alpha) const;
246 mutable SkMutex fCacheMutex;
247 mutable SkAutoTUnref<GradientShaderCache> fCache;
251 typedef SkShader INHERITED;
254 static inline int init_dither_toggle(int x, int y) {
257 return (x | y) * SkGradientShaderBase::kDitherStride32;
260 static inline int next_dither_toggle(int toggle) {
261 return toggle ^ SkGradientShaderBase::kDitherStride32;
264 static inline int init_dither_toggle16(int x, int y) {
265 return ((x ^ y) & 1) * SkGradientShaderBase::kDitherStride16;
268 static inline int next_dither_toggle16(int toggle) {
269 return toggle ^ SkGradientShaderBase::kDitherStride16;
272 ///////////////////////////////////////////////////////////////////////////////
276 #include "GrCoordTransform.h"
277 #include "gl/GrGLEffect.h"
280 class GrBackendEffectFactory;
283 * The interpretation of the texture matrix depends on the sample mode. The
284 * texture matrix is applied both when the texture coordinates are explicit
285 * and when vertex positions are used as texture coordinates. In the latter
286 * case the texture matrix is applied to the pre-view-matrix position
290 * The post-matrix texture coordinates are in normalize space with (0,0) at
291 * the top-left and (1,1) at the bottom right.
293 * The matrix specifies the radial gradient parameters.
294 * (0,0) in the post-matrix space is center of the radial gradient.
296 * Matrix transforms to space where first circle is centered at the
297 * origin. The second circle will be centered (x, 0) where x may be
298 * 0 and is provided by setRadial2Params. The post-matrix space is
299 * normalized such that 1 is the second radius - first radius.
301 * The angle from the origin of texture coordinates in post-matrix space
302 * determines the gradient value.
305 class GrTextureStripAtlas;
307 // Base class for Gr gradient effects
308 class GrGradientEffect : public GrEffect {
311 GrGradientEffect(GrContext* ctx,
312 const SkGradientShaderBase& shader,
313 const SkMatrix& matrix,
314 SkShader::TileMode tileMode);
316 virtual ~GrGradientEffect();
318 bool useAtlas() const { return SkToBool(-1 != fRow); }
319 SkScalar getYCoord() const { return fYCoord; };
321 virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
323 SkGradientShaderBase::GpuColorType getColorType() const { return fColorType; }
326 kBeforeInterp_PremulType,
327 kAfterInterp_PremulType,
330 PremulType getPremulType() const { return fPremulType; }
332 const SkColor* getColors(int pos) const {
333 SkASSERT(fColorType != SkGradientShaderBase::kTexture_GpuColorType);
334 SkASSERT((pos-1) <= fColorType);
335 return &fColors[pos];
340 /** Populates a pair of arrays with colors and stop info to construct a random gradient.
341 The function decides whether stop values should be used or not. The return value indicates
342 the number of colors, which will be capped by kMaxRandomGradientColors. colors should be
343 sized to be at least kMaxRandomGradientColors. stops is a pointer to an array of at least
344 size kMaxRandomGradientColors. It may be updated to NULL, indicating that NULL should be
345 passed to the gradient factory rather than the array.
347 static const int kMaxRandomGradientColors = 4;
348 static int RandomGradientParams(SkRandom* r,
349 SkColor colors[kMaxRandomGradientColors],
351 SkShader::TileMode* tm);
353 virtual bool onIsEqual(const GrEffect& effect) const SK_OVERRIDE;
355 const GrCoordTransform& getCoordTransform() const { return fCoordTransform; }
358 static const GrCoordSet kCoordSet = kLocal_GrCoordSet;
360 GrCoordTransform fCoordTransform;
361 GrTextureAccess fTextureAccess;
363 GrTextureStripAtlas* fAtlas;
366 SkGradientShaderBase::GpuColorType fColorType;
367 SkColor fColors[3]; // More than 3 colors we use texture
368 PremulType fPremulType; // This only changes behavior for two and three color special cases.
369 // It is already baked into to the table for texture gradients.
370 typedef GrEffect INHERITED;
374 ///////////////////////////////////////////////////////////////////////////////
376 // Base class for GL gradient effects
377 class GrGLGradientEffect : public GrGLEffect {
379 GrGLGradientEffect(const GrBackendEffectFactory& factory);
380 virtual ~GrGLGradientEffect();
382 virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
386 kPremulTypeKeyBitCnt = 1,
388 kPremulBeforeInterpKey = kPremulTypeMask,
390 kTwoColorKey = 2 << kPremulTypeKeyBitCnt,
391 kThreeColorKey = 3 << kPremulTypeKeyBitCnt,
392 kColorKeyMask = kTwoColorKey | kThreeColorKey,
395 // Subclasses must shift any key bits they produce up by this amount
396 // and combine with the result of GenBaseGradientKey.
397 kBaseKeyBitCnt = (kPremulTypeKeyBitCnt + kColorKeyBitCnt)
400 static SkGradientShaderBase::GpuColorType ColorTypeFromKey(EffectKey key){
401 if (kTwoColorKey == (key & kColorKeyMask)) {
402 return SkGradientShaderBase::kTwo_GpuColorType;
403 } else if (kThreeColorKey == (key & kColorKeyMask)) {
404 return SkGradientShaderBase::kThree_GpuColorType;
405 } else {return SkGradientShaderBase::kTexture_GpuColorType;}
408 static GrGradientEffect::PremulType PremulTypeFromKey(EffectKey key){
409 if (kPremulBeforeInterpKey == (key & kPremulTypeMask)) {
410 return GrGradientEffect::kBeforeInterp_PremulType;
412 return GrGradientEffect::kAfterInterp_PremulType;
417 * Subclasses must call this. It will return a value restricted to the lower kBaseKeyBitCnt
420 static EffectKey GenBaseGradientKey(const GrDrawEffect&);
422 // Emits the uniform used as the y-coord to texture samples in derived classes. Subclasses
423 // should call this method from their emitCode().
424 void emitUniforms(GrGLShaderBuilder* builder, EffectKey key);
427 // emit code that gets a fragment's color from an expression for t; Has branches for 3 separate
428 // control flows inside -- 2 color gradients, 3 color symmetric gradients (both using
429 // native GLSL mix), and 4+ color gradients that use the traditional texture lookup.
430 void emitColor(GrGLShaderBuilder* builder,
431 const char* gradientTValue,
433 const char* outputColor,
434 const char* inputColor,
435 const TextureSamplerArray& samplers);
438 SkScalar fCachedYCoord;
439 GrGLUniformManager::UniformHandle fFSYUni;
440 GrGLUniformManager::UniformHandle fColorStartUni;
441 GrGLUniformManager::UniformHandle fColorMidUni;
442 GrGLUniformManager::UniformHandle fColorEndUni;
444 typedef GrGLEffect INHERITED;