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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 }
     48 
     49 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     50 SkShader::SkShader(SkReadBuffer& buffer) : INHERITED(buffer) {
     51     inc_shader_counter();
     52     if (buffer.readBool()) {
     53         buffer.readMatrix(&fLocalMatrix);
     54     } else {
     55         fLocalMatrix.reset();
     56     }
     57 }
     58 #endif
     59 
     60 SkShader::~SkShader() {
     61     dec_shader_counter();
     62 }
     63 
     64 void SkShader::flatten(SkWriteBuffer& buffer) const {
     65     this->INHERITED::flatten(buffer);
     66     bool hasLocalM = !fLocalMatrix.isIdentity();
     67     buffer.writeBool(hasLocalM);
     68     if (hasLocalM) {
     69         buffer.writeMatrix(fLocalMatrix);
     70     }
     71 }
     72 
     73 bool SkShader::computeTotalInverse(const ContextRec& rec, SkMatrix* totalInverse) const {
     74     SkMatrix total;
     75     total.setConcat(*rec.fMatrix, fLocalMatrix);
     76 
     77     const SkMatrix* m = &total;
     78     if (rec.fLocalMatrix) {
     79         total.setConcat(*m, *rec.fLocalMatrix);
     80         m = &total;
     81     }
     82     return m->invert(totalInverse);
     83 }
     84 
     85 bool SkShader::asLuminanceColor(SkColor* colorPtr) const {
     86     SkColor storage;
     87     if (NULL == colorPtr) {
     88         colorPtr = &storage;
     89     }
     90     if (this->onAsLuminanceColor(colorPtr)) {
     91         *colorPtr = SkColorSetA(*colorPtr, 0xFF);   // we only return opaque
     92         return true;
     93     }
     94     return false;
     95 }
     96 
     97 SkShader::Context* SkShader::createContext(const ContextRec& rec, void* storage) const {
     98     if (!this->computeTotalInverse(rec, NULL)) {
     99         return NULL;
    100     }
    101     return this->onCreateContext(rec, storage);
    102 }
    103 
    104 SkShader::Context* SkShader::onCreateContext(const ContextRec& rec, void*) const {
    105     return NULL;
    106 }
    107 
    108 size_t SkShader::contextSize() const {
    109     return 0;
    110 }
    111 
    112 SkShader::Context::Context(const SkShader& shader, const ContextRec& rec)
    113     : fShader(shader), fCTM(*rec.fMatrix)
    114 {
    115     // Because the context parameters must be valid at this point, we know that the matrix is
    116     // invertible.
    117     SkAssertResult(fShader.computeTotalInverse(rec, &fTotalInverse));
    118     fTotalInverseClass = (uint8_t)ComputeMatrixClass(fTotalInverse);
    119 
    120     fPaintAlpha = rec.fPaint->getAlpha();
    121 }
    122 
    123 SkShader::Context::~Context() {}
    124 
    125 SkShader::Context::ShadeProc SkShader::Context::asAShadeProc(void** ctx) {
    126     return NULL;
    127 }
    128 
    129 #include "SkColorPriv.h"
    130 
    131 void SkShader::Context::shadeSpan16(int x, int y, uint16_t span16[], int count) {
    132     SkASSERT(span16);
    133     SkASSERT(count > 0);
    134     SkASSERT(this->canCallShadeSpan16());
    135 
    136     // basically, if we get here, the subclass screwed up
    137     SkDEBUGFAIL("kHasSpan16 flag is set, but shadeSpan16() not implemented");
    138 }
    139 
    140 #define kTempColorQuadCount 6   // balance between speed (larger) and saving stack-space
    141 #define kTempColorCount     (kTempColorQuadCount << 2)
    142 
    143 #ifdef SK_CPU_BENDIAN
    144     #define SkU32BitShiftToByteOffset(shift)    (3 - ((shift) >> 3))
    145 #else
    146     #define SkU32BitShiftToByteOffset(shift)    ((shift) >> 3)
    147 #endif
    148 
    149 void SkShader::Context::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
    150     SkASSERT(count > 0);
    151 
    152     SkPMColor   colors[kTempColorCount];
    153 
    154     while ((count -= kTempColorCount) >= 0) {
    155         this->shadeSpan(x, y, colors, kTempColorCount);
    156         x += kTempColorCount;
    157 
    158         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    159         int quads = kTempColorQuadCount;
    160         do {
    161             U8CPU a0 = srcA[0];
    162             U8CPU a1 = srcA[4];
    163             U8CPU a2 = srcA[8];
    164             U8CPU a3 = srcA[12];
    165             srcA += 4*4;
    166             *alpha++ = SkToU8(a0);
    167             *alpha++ = SkToU8(a1);
    168             *alpha++ = SkToU8(a2);
    169             *alpha++ = SkToU8(a3);
    170         } while (--quads != 0);
    171     }
    172     SkASSERT(count < 0);
    173     SkASSERT(count + kTempColorCount >= 0);
    174     if (count += kTempColorCount) {
    175         this->shadeSpan(x, y, colors, count);
    176 
    177         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    178         do {
    179             *alpha++ = *srcA;
    180             srcA += 4;
    181         } while (--count != 0);
    182     }
    183 #if 0
    184     do {
    185         int n = count;
    186         if (n > kTempColorCount)
    187             n = kTempColorCount;
    188         SkASSERT(n > 0);
    189 
    190         this->shadeSpan(x, y, colors, n);
    191         x += n;
    192         count -= n;
    193 
    194         const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
    195         do {
    196             *alpha++ = *srcA;
    197             srcA += 4;
    198         } while (--n != 0);
    199     } while (count > 0);
    200 #endif
    201 }
    202 
    203 SkShader::Context::MatrixClass SkShader::Context::ComputeMatrixClass(const SkMatrix& mat) {
    204     MatrixClass mc = kLinear_MatrixClass;
    205 
    206     if (mat.hasPerspective()) {
    207         if (mat.fixedStepInX(0, NULL, NULL)) {
    208             mc = kFixedStepInX_MatrixClass;
    209         } else {
    210             mc = kPerspective_MatrixClass;
    211         }
    212     }
    213     return mc;
    214 }
    215 
    216 //////////////////////////////////////////////////////////////////////////////
    217 
    218 SkShader::BitmapType SkShader::asABitmap(SkBitmap*, SkMatrix*, TileMode*) const {
    219     return kNone_BitmapType;
    220 }
    221 
    222 SkShader::GradientType SkShader::asAGradient(GradientInfo* info) const {
    223     return kNone_GradientType;
    224 }
    225 
    226 bool SkShader::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix*, GrColor*,
    227                                    GrFragmentProcessor**)  const {
    228     return false;
    229 }
    230 
    231 SkShader* SkShader::refAsALocalMatrixShader(SkMatrix*) const {
    232     return NULL;
    233 }
    234 
    235 SkShader* SkShader::CreateEmptyShader() {
    236     return SkNEW(SkEmptyShader);
    237 }
    238 
    239 SkShader* SkShader::CreateColorShader(SkColor color) {
    240     return SkNEW_ARGS(SkColorShader, (color));
    241 }
    242 
    243 SkShader* SkShader::CreateBitmapShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
    244                                        const SkMatrix* localMatrix) {
    245     return ::CreateBitmapShader(src, tmx, tmy, localMatrix, NULL);
    246 }
    247 
    248 SkShader* SkShader::CreatePictureShader(SkPicture* src, TileMode tmx, TileMode tmy,
    249                                         const SkMatrix* localMatrix, const SkRect* tile) {
    250     return SkPictureShader::Create(src, tmx, tmy, localMatrix, tile);
    251 }
    252 
    253 #ifndef SK_IGNORE_TO_STRING
    254 void SkShader::toString(SkString* str) const {
    255     if (!fLocalMatrix.isIdentity()) {
    256         str->append(" ");
    257         fLocalMatrix.toString(str);
    258     }
    259 }
    260 #endif
    261 
    262 //////////////////////////////////////////////////////////////////////////////
    263 
    264 #include "SkUtils.h"
    265 
    266 SkColorShader::SkColorShader(SkColor c)
    267     : fColor(c) {
    268 }
    269 
    270 bool SkColorShader::isOpaque() const {
    271     return SkColorGetA(fColor) == 255;
    272 }
    273 
    274 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
    275 SkColorShader::SkColorShader(SkReadBuffer& b) : INHERITED(b) {
    276     // V25_COMPATIBILITY_CODE We had a boolean to make the color shader inherit the paint's
    277     // color. We don't support that any more.
    278     if (b.isVersionLT(SkReadBuffer::kColorShaderNoBool_Version)) {
    279         if (b.readBool()) {
    280             SkDEBUGFAIL("We shouldn't have pictures that recorded the inherited case.");
    281             fColor = SK_ColorWHITE;
    282             return;
    283         }
    284     }
    285     fColor = b.readColor();
    286 }
    287 #endif
    288 
    289 SkFlattenable* SkColorShader::CreateProc(SkReadBuffer& buffer) {
    290     return SkNEW_ARGS(SkColorShader, (buffer.readColor()));
    291 }
    292 
    293 void SkColorShader::flatten(SkWriteBuffer& buffer) const {
    294     buffer.writeColor(fColor);
    295 }
    296 
    297 uint32_t SkColorShader::ColorShaderContext::getFlags() const {
    298     return fFlags;
    299 }
    300 
    301 uint8_t SkColorShader::ColorShaderContext::getSpan16Alpha() const {
    302     return SkGetPackedA32(fPMColor);
    303 }
    304 
    305 SkShader::Context* SkColorShader::onCreateContext(const ContextRec& rec, void* storage) const {
    306     return SkNEW_PLACEMENT_ARGS(storage, ColorShaderContext, (*this, rec));
    307 }
    308 
    309 SkColorShader::ColorShaderContext::ColorShaderContext(const SkColorShader& shader,
    310                                                       const ContextRec& rec)
    311     : INHERITED(shader, rec)
    312 {
    313     SkColor color = shader.fColor;
    314     unsigned a = SkAlphaMul(SkColorGetA(color), SkAlpha255To256(rec.fPaint->getAlpha()));
    315 
    316     unsigned r = SkColorGetR(color);
    317     unsigned g = SkColorGetG(color);
    318     unsigned b = SkColorGetB(color);
    319 
    320     // we want this before we apply any alpha
    321     fColor16 = SkPack888ToRGB16(r, g, b);
    322 
    323     if (a != 255) {
    324         r = SkMulDiv255Round(r, a);
    325         g = SkMulDiv255Round(g, a);
    326         b = SkMulDiv255Round(b, a);
    327     }
    328     fPMColor = SkPackARGB32(a, r, g, b);
    329 
    330     fFlags = kConstInY32_Flag;
    331     if (255 == a) {
    332         fFlags |= kOpaqueAlpha_Flag;
    333         if (rec.fPaint->isDither() == false) {
    334             fFlags |= kHasSpan16_Flag;
    335         }
    336     }
    337 }
    338 
    339 void SkColorShader::ColorShaderContext::shadeSpan(int x, int y, SkPMColor span[], int count) {
    340     sk_memset32(span, fPMColor, count);
    341 }
    342 
    343 void SkColorShader::ColorShaderContext::shadeSpan16(int x, int y, uint16_t span[], int count) {
    344     sk_memset16(span, fColor16, count);
    345 }
    346 
    347 void SkColorShader::ColorShaderContext::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
    348     memset(alpha, SkGetPackedA32(fPMColor), count);
    349 }
    350 
    351 // if we had a asAColor method, that would be more efficient...
    352 SkShader::BitmapType SkColorShader::asABitmap(SkBitmap* bitmap, SkMatrix* matrix,
    353                                               TileMode modes[]) const {
    354     return kNone_BitmapType;
    355 }
    356 
    357 SkShader::GradientType SkColorShader::asAGradient(GradientInfo* info) const {
    358     if (info) {
    359         if (info->fColors && info->fColorCount >= 1) {
    360             info->fColors[0] = fColor;
    361         }
    362         info->fColorCount = 1;
    363         info->fTileMode = SkShader::kRepeat_TileMode;
    364     }
    365     return kColor_GradientType;
    366 }
    367 
    368 #if SK_SUPPORT_GPU
    369 
    370 #include "SkGr.h"
    371 
    372 bool SkColorShader::asFragmentProcessor(GrContext*, const SkPaint& paint, const SkMatrix*,
    373                                         GrColor* paintColor, GrFragmentProcessor** fp) const {
    374     *fp = NULL;
    375     SkColor skColor = fColor;
    376     U8CPU newA = SkMulDiv255Round(SkColorGetA(fColor), paint.getAlpha());
    377     *paintColor = SkColor2GrColor(SkColorSetA(skColor, newA));
    378     return true;
    379 }
    380 
    381 #else
    382 
    383 bool SkColorShader::asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix*, GrColor*,
    384                                         GrFragmentProcessor**) const {
    385     SkDEBUGFAIL("Should not call in GPU-less build");
    386     return false;
    387 }
    388 
    389 #endif
    390 
    391 #ifndef SK_IGNORE_TO_STRING
    392 void SkColorShader::toString(SkString* str) const {
    393     str->append("SkColorShader: (");
    394 
    395     str->append("Color: ");
    396     str->appendHex(fColor);
    397 
    398     this->INHERITED::toString(str);
    399 
    400     str->append(")");
    401 }
    402 #endif
    403 
    404 ///////////////////////////////////////////////////////////////////////////////
    405 
    406 SkFlattenable* SkEmptyShader::CreateProc(SkReadBuffer&) {
    407     return SkShader::CreateEmptyShader();
    408 }
    409 
    410 #ifndef SK_IGNORE_TO_STRING
    411 #include "SkEmptyShader.h"
    412 
    413 void SkEmptyShader::toString(SkString* str) const {
    414     str->append("SkEmptyShader: (");
    415 
    416     this->INHERITED::toString(str);
    417 
    418     str->append(")");
    419 }
    420 #endif
    421