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      1 /*
      2  * Copyright 2006 The Android Open Source Project
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkBitmapProcShader.h"
      9 #include "SkColorShader.h"
     10 #include "SkEmptyShader.h"
     11 #include "SkReadBuffer.h"
     12 #include "SkMallocPixelRef.h"
     13 #include "SkPaint.h"
     14 #include "SkPicture.h"
     15 #include "SkPictureShader.h"
     16 #include "SkScalar.h"
     17 #include "SkShader.h"
     18 #include "SkThread.h"
     19 #include "SkWriteBuffer.h"
     20 
     21 //#define SK_TRACK_SHADER_LIFETIME
     22 
     23 #ifdef SK_TRACK_SHADER_LIFETIME
     24     static int32_t gShaderCounter;
     25 #endif
     26 
     27 static inline void inc_shader_counter() {
     28 #ifdef SK_TRACK_SHADER_LIFETIME
     29     int32_t prev = sk_atomic_inc(&gShaderCounter);
     30     SkDebugf("+++ shader counter %d\n", prev + 1);
     31 #endif
     32 }
     33 static inline void dec_shader_counter() {
     34 #ifdef SK_TRACK_SHADER_LIFETIME
     35     int32_t prev = sk_atomic_dec(&gShaderCounter);
     36     SkDebugf("--- shader counter %d\n", prev - 1);
     37 #endif
     38 }
     39 
     40 SkShader::SkShader(const SkMatrix* localMatrix) {
     41     inc_shader_counter();
     42     if (localMatrix) {
     43         fLocalMatrix = *localMatrix;
     44     } else {
     45         fLocalMatrix.reset();
     46     }
     47     // Pre-cache so future calls to fLocalMatrix.getType() are threadsafe.
     48     (void)fLocalMatrix.getType();
     49 }
     50 
     51 SkShader::~SkShader() {
     52     dec_shader_counter();
     53 }
     54 
     55 void SkShader::flatten(SkWriteBuffer& buffer) const {
     56     this->INHERITED::flatten(buffer);
     57     bool hasLocalM = !fLocalMatrix.isIdentity();
     58     buffer.writeBool(hasLocalM);
     59     if (hasLocalM) {
     60         buffer.writeMatrix(fLocalMatrix);
     61     }
     62 }
     63 
     64 bool SkShader::computeTotalInverse(const ContextRec& rec, SkMatrix* totalInverse) const {
     65     SkMatrix total;
     66     total.setConcat(*rec.fMatrix, fLocalMatrix);
     67 
     68     const SkMatrix* m = &total;
     69     if (rec.fLocalMatrix) {
     70         total.setConcat(*m, *rec.fLocalMatrix);
     71         m = &total;
     72     }
     73     return m->invert(totalInverse);
     74 }
     75 
     76 bool SkShader::asLuminanceColor(SkColor* colorPtr) const {
     77     SkColor storage;
     78     if (NULL == colorPtr) {
     79         colorPtr = &storage;
     80     }
     81     if (this->onAsLuminanceColor(colorPtr)) {
     82         *colorPtr = SkColorSetA(*colorPtr, 0xFF);   // we only return opaque
     83         return true;
     84     }
     85     return false;
     86 }
     87 
     88 SkShader::Context* SkShader::createContext(const ContextRec& rec, void* storage) const {
     89     if (!this->computeTotalInverse(rec, NULL)) {
     90         return NULL;
     91     }
     92     return this->onCreateContext(rec, storage);
     93 }
     94 
     95 SkShader::Context* SkShader::onCreateContext(const ContextRec& rec, void*) const {
     96     return NULL;
     97 }
     98 
     99 size_t SkShader::contextSize() const {
    100     return 0;
    101 }
    102 
    103 SkShader::Context::Context(const SkShader& shader, const ContextRec& rec)
    104     : fShader(shader), fCTM(*rec.fMatrix)
    105 {
    106     // Because the context parameters must be valid at this point, we know that the matrix is
    107     // invertible.
    108     SkAssertResult(fShader.computeTotalInverse(rec, &fTotalInverse));
    109     fTotalInverseClass = (uint8_t)ComputeMatrixClass(fTotalInverse);
    110 
    111     fPaintAlpha = rec.fPaint->getAlpha();
    112 }
    113 
    114 SkShader::Context::~Context() {}
    115 
    116 SkShader::Context::ShadeProc SkShader::Context::asAShadeProc(void** ctx) {
    117     return NULL;
    118 }
    119 
    120 #include "SkColorPriv.h"
    121 
    122 void SkShader::Context::shadeSpan16(int x, int y, uint16_t span16[], int count) {
    123     SkASSERT(span16);
    124     SkASSERT(count > 0);
    125     SkASSERT(this->canCallShadeSpan16());
    126 
    127     // basically, if we get here, the subclass screwed up
    128     SkDEBUGFAIL("kHasSpan16 flag is set, but shadeSpan16() not implemented");
    129 }
    130 
    131 #define kTempColorQuadCount 6   // balance between speed (larger) and saving stack-space
    132 #define kTempColorCount     (kTempColorQuadCount << 2)
    133 
    134 #ifdef SK_CPU_BENDIAN
    135     #define SkU32BitShiftToByteOffset(shift)    (3 - ((shift) >> 3))
    136 #else
    137     #define SkU32BitShiftToByteOffset(shift)    ((shift) >> 3)
    138 #endif
    139 
    140 void SkShader::Context::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
    141     SkASSERT(count > 0);
    142 
    143     SkPMColor   colors[kTempColorCount];
    144 
    145     while ((count -= kTempColorCount) >= 0) {
    146         this->shadeSpan(x, y, colors, kTempColorCount);
    147         x += kTempColorCount;
    148 
    149         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    150         int quads = kTempColorQuadCount;
    151         do {
    152             U8CPU a0 = srcA[0];
    153             U8CPU a1 = srcA[4];
    154             U8CPU a2 = srcA[8];
    155             U8CPU a3 = srcA[12];
    156             srcA += 4*4;
    157             *alpha++ = SkToU8(a0);
    158             *alpha++ = SkToU8(a1);
    159             *alpha++ = SkToU8(a2);
    160             *alpha++ = SkToU8(a3);
    161         } while (--quads != 0);
    162     }
    163     SkASSERT(count < 0);
    164     SkASSERT(count + kTempColorCount >= 0);
    165     if (count += kTempColorCount) {
    166         this->shadeSpan(x, y, colors, count);
    167 
    168         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    169         do {
    170             *alpha++ = *srcA;
    171             srcA += 4;
    172         } while (--count != 0);
    173     }
    174 #if 0
    175     do {
    176         int n = count;
    177         if (n > kTempColorCount)
    178             n = kTempColorCount;
    179         SkASSERT(n > 0);
    180 
    181         this->shadeSpan(x, y, colors, n);
    182         x += n;
    183         count -= n;
    184 
    185         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    186         do {
    187             *alpha++ = *srcA;
    188             srcA += 4;
    189         } while (--n != 0);
    190     } while (count > 0);
    191 #endif
    192 }
    193 
    194 SkShader::Context::MatrixClass SkShader::Context::ComputeMatrixClass(const SkMatrix& mat) {
    195     MatrixClass mc = kLinear_MatrixClass;
    196 
    197     if (mat.hasPerspective()) {
    198         if (mat.fixedStepInX(0, NULL, NULL)) {
    199             mc = kFixedStepInX_MatrixClass;
    200         } else {
    201             mc = kPerspective_MatrixClass;
    202         }
    203     }
    204     return mc;
    205 }
    206 
    207 //////////////////////////////////////////////////////////////////////////////
    208 
    209 SkShader::BitmapType SkShader::asABitmap(SkBitmap*, SkMatrix*, TileMode*) const {
    210     return kNone_BitmapType;
    211 }
    212 
    213 SkShader::GradientType SkShader::asAGradient(GradientInfo* info) const {
    214     return kNone_GradientType;
    215 }
    216 
    217 bool SkShader::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix&, const SkMatrix*,
    218                                    GrColor*, GrFragmentProcessor**)  const {
    219     return false;
    220 }
    221 
    222 SkShader* SkShader::refAsALocalMatrixShader(SkMatrix*) const {
    223     return NULL;
    224 }
    225 
    226 SkShader* SkShader::CreateEmptyShader() {
    227     return SkNEW(SkEmptyShader);
    228 }
    229 
    230 SkShader* SkShader::CreateColorShader(SkColor color) {
    231     return SkNEW_ARGS(SkColorShader, (color));
    232 }
    233 
    234 SkShader* SkShader::CreateBitmapShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
    235                                        const SkMatrix* localMatrix) {
    236     return SkCreateBitmapShader(src, tmx, tmy, localMatrix, NULL);
    237 }
    238 
    239 SkShader* SkShader::CreatePictureShader(const SkPicture* src, TileMode tmx, TileMode tmy,
    240                                         const SkMatrix* localMatrix, const SkRect* tile) {
    241     return SkPictureShader::Create(src, tmx, tmy, localMatrix, tile);
    242 }
    243 
    244 #ifndef SK_IGNORE_TO_STRING
    245 void SkShader::toString(SkString* str) const {
    246     if (!fLocalMatrix.isIdentity()) {
    247         str->append(" ");
    248         fLocalMatrix.toString(str);
    249     }
    250 }
    251 #endif
    252 
    253 //////////////////////////////////////////////////////////////////////////////
    254 
    255 #include "SkUtils.h"
    256 
    257 SkColorShader::SkColorShader(SkColor c)
    258     : fColor(c) {
    259 }
    260 
    261 bool SkColorShader::isOpaque() const {
    262     return SkColorGetA(fColor) == 255;
    263 }
    264 
    265 SkFlattenable* SkColorShader::CreateProc(SkReadBuffer& buffer) {
    266     return SkNEW_ARGS(SkColorShader, (buffer.readColor()));
    267 }
    268 
    269 void SkColorShader::flatten(SkWriteBuffer& buffer) const {
    270     buffer.writeColor(fColor);
    271 }
    272 
    273 uint32_t SkColorShader::ColorShaderContext::getFlags() const {
    274     return fFlags;
    275 }
    276 
    277 uint8_t SkColorShader::ColorShaderContext::getSpan16Alpha() const {
    278     return SkGetPackedA32(fPMColor);
    279 }
    280 
    281 SkShader::Context* SkColorShader::onCreateContext(const ContextRec& rec, void* storage) const {
    282     return SkNEW_PLACEMENT_ARGS(storage, ColorShaderContext, (*this, rec));
    283 }
    284 
    285 SkColorShader::ColorShaderContext::ColorShaderContext(const SkColorShader& shader,
    286                                                       const ContextRec& rec)
    287     : INHERITED(shader, rec)
    288 {
    289     SkColor color = shader.fColor;
    290     unsigned a = SkAlphaMul(SkColorGetA(color), SkAlpha255To256(rec.fPaint->getAlpha()));
    291 
    292     unsigned r = SkColorGetR(color);
    293     unsigned g = SkColorGetG(color);
    294     unsigned b = SkColorGetB(color);
    295 
    296     // we want this before we apply any alpha
    297     fColor16 = SkPack888ToRGB16(r, g, b);
    298 
    299     if (a != 255) {
    300         r = SkMulDiv255Round(r, a);
    301         g = SkMulDiv255Round(g, a);
    302         b = SkMulDiv255Round(b, a);
    303     }
    304     fPMColor = SkPackARGB32(a, r, g, b);
    305 
    306     fFlags = kConstInY32_Flag;
    307     if (255 == a) {
    308         fFlags |= kOpaqueAlpha_Flag;
    309         if (rec.fPaint->isDither() == false) {
    310             fFlags |= kHasSpan16_Flag;
    311         }
    312     }
    313 }
    314 
    315 void SkColorShader::ColorShaderContext::shadeSpan(int x, int y, SkPMColor span[], int count) {
    316     sk_memset32(span, fPMColor, count);
    317 }
    318 
    319 void SkColorShader::ColorShaderContext::shadeSpan16(int x, int y, uint16_t span[], int count) {
    320     sk_memset16(span, fColor16, count);
    321 }
    322 
    323 void SkColorShader::ColorShaderContext::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
    324     memset(alpha, SkGetPackedA32(fPMColor), count);
    325 }
    326 
    327 // if we had a asAColor method, that would be more efficient...
    328 SkShader::BitmapType SkColorShader::asABitmap(SkBitmap* bitmap, SkMatrix* matrix,
    329                                               TileMode modes[]) const {
    330     return kNone_BitmapType;
    331 }
    332 
    333 SkShader::GradientType SkColorShader::asAGradient(GradientInfo* info) const {
    334     if (info) {
    335         if (info->fColors && info->fColorCount >= 1) {
    336             info->fColors[0] = fColor;
    337         }
    338         info->fColorCount = 1;
    339         info->fTileMode = SkShader::kRepeat_TileMode;
    340     }
    341     return kColor_GradientType;
    342 }
    343 
    344 #if SK_SUPPORT_GPU
    345 
    346 #include "SkGr.h"
    347 
    348 bool SkColorShader::asFragmentProcessor(GrContext*, const SkPaint& paint, const SkMatrix&,
    349                                         const SkMatrix*, GrColor* paintColor,
    350                                         GrFragmentProcessor** fp) const {
    351     *fp = NULL;
    352     SkColor skColor = fColor;
    353     U8CPU newA = SkMulDiv255Round(SkColorGetA(fColor), paint.getAlpha());
    354     *paintColor = SkColor2GrColor(SkColorSetA(skColor, newA));
    355     return true;
    356 }
    357 
    358 #else
    359 
    360 bool SkColorShader::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix&,
    361                                         const SkMatrix*, GrColor*,
    362                                         GrFragmentProcessor**) const {
    363     SkDEBUGFAIL("Should not call in GPU-less build");
    364     return false;
    365 }
    366 
    367 #endif
    368 
    369 #ifndef SK_IGNORE_TO_STRING
    370 void SkColorShader::toString(SkString* str) const {
    371     str->append("SkColorShader: (");
    372 
    373     str->append("Color: ");
    374     str->appendHex(fColor);
    375 
    376     this->INHERITED::toString(str);
    377 
    378     str->append(")");
    379 }
    380 #endif
    381 
    382 ///////////////////////////////////////////////////////////////////////////////
    383 
    384 SkFlattenable* SkEmptyShader::CreateProc(SkReadBuffer&) {
    385     return SkShader::CreateEmptyShader();
    386 }
    387 
    388 #ifndef SK_IGNORE_TO_STRING
    389 #include "SkEmptyShader.h"
    390 
    391 void SkEmptyShader::toString(SkString* str) const {
    392     str->append("SkEmptyShader: (");
    393 
    394     this->INHERITED::toString(str);
    395 
    396     str->append(")");
    397 }
    398 #endif
    399