The Tor Browser: gfx/skia/trunk/src/effects/gradients/SkGradientShader.cpp@b8a032363ba2 (annotated)

gfx/skia/trunk/src/effects/gradients/SkGradientShader.cpp@b8a032363ba2 (annotated)

gfx/skia/trunk/src/effects/gradients/SkGradientShader.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkGradientShaderPriv.h"
 #include "SkLinearGradient.h"
 #include "SkRadialGradient.h"
 #include "SkTwoPointRadialGradient.h"
 #include "SkTwoPointConicalGradient.h"
 #include "SkSweepGradient.h"
 SkGradientShaderBase::SkGradientShaderBase(const Descriptor& desc) {
     SkASSERT(desc.fCount > 1);
     fCacheAlpha = 256;  // init to a value that paint.getAlpha() can't return
     fMapper = desc.fMapper;
     SkSafeRef(fMapper);
     fGradFlags = SkToU8(desc.fFlags);
     SkASSERT((unsigned)desc.fTileMode < SkShader::kTileModeCount);
     SkASSERT(SkShader::kTileModeCount == SK_ARRAY_COUNT(gTileProcs));
     fTileMode = desc.fTileMode;
     fTileProc = gTileProcs[desc.fTileMode];
     fCache16 = fCache16Storage = NULL;
     fCache32 = NULL;
     fCache32PixelRef = NULL;
     /*  Note: we let the caller skip the first and/or last position.
         i.e. pos[0] = 0.3, pos[1] = 0.7
         In these cases, we insert dummy entries to ensure that the final data
         will be bracketed by [0, 1].
         i.e. our_pos[0] = 0, our_pos[1] = 0.3, our_pos[2] = 0.7, our_pos[3] = 1
         Thus colorCount (the caller's value, and fColorCount (our value) may
         differ by up to 2. In the above example:
             colorCount = 2
             fColorCount = 4
      */
     fColorCount = desc.fCount;
     // check if we need to add in dummy start and/or end position/colors
     bool dummyFirst = false;
     bool dummyLast = false;
     if (desc.fPos) {
         dummyFirst = desc.fPos[0] != 0;
         dummyLast = desc.fPos[desc.fCount - 1] != SK_Scalar1;
         fColorCount += dummyFirst + dummyLast;
     }
     if (fColorCount > kColorStorageCount) {
         size_t size = sizeof(SkColor) + sizeof(Rec);
         fOrigColors = reinterpret_cast<SkColor*>(
                                         sk_malloc_throw(size * fColorCount));
     }
     else {
         fOrigColors = fStorage;
     }
     // Now copy over the colors, adding the dummies as needed
     {
         SkColor* origColors = fOrigColors;
         if (dummyFirst) {
             *origColors++ = desc.fColors[0];
         }
         memcpy(origColors, desc.fColors, desc.fCount * sizeof(SkColor));
         if (dummyLast) {
             origColors += desc.fCount;
             *origColors = desc.fColors[desc.fCount - 1];
         }
     }
     fRecs = (Rec*)(fOrigColors + fColorCount);
     if (fColorCount > 2) {
         Rec* recs = fRecs;
         recs->fPos = 0;
         //  recs->fScale = 0; // unused;
         recs += 1;
         if (desc.fPos) {
             /*  We need to convert the user's array of relative positions into
                 fixed-point positions and scale factors. We need these results
                 to be strictly monotonic (no two values equal or out of order).
                 Hence this complex loop that just jams a zero for the scale
                 value if it sees a segment out of order, and it assures that
                 we start at 0 and end at 1.0
             */
             SkFixed prev = 0;
             int startIndex = dummyFirst ? 0 : 1;
             int count = desc.fCount + dummyLast;
             for (int i = startIndex; i < count; i++) {
                 // force the last value to be 1.0
                 SkFixed curr;
                 if (i == desc.fCount) {  // we're really at the dummyLast
                     curr = SK_Fixed1;
                 } else {
                     curr = SkScalarToFixed(desc.fPos[i]);
                 }
                 // pin curr withing range
                 if (curr < 0) {
                     curr = 0;
                 } else if (curr > SK_Fixed1) {
                     curr = SK_Fixed1;
                 }
                 recs->fPos = curr;
                 if (curr > prev) {
                     recs->fScale = (1 << 24) / (curr - prev);
                 } else {
                     recs->fScale = 0; // ignore this segment
                 }
                 // get ready for the next value
                 prev = curr;
                 recs += 1;
             }
         } else {    // assume even distribution
             SkFixed dp = SK_Fixed1 / (desc.fCount - 1);
             SkFixed p = dp;
             SkFixed scale = (desc.fCount - 1) << 8;  // (1 << 24) / dp
             for (int i = 1; i < desc.fCount; i++) {
                 recs->fPos   = p;
                 recs->fScale = scale;
                 recs += 1;
                 p += dp;
             }
         }
     }
     this->initCommon();
 }
 static uint32_t pack_mode_flags(SkShader::TileMode mode, uint32_t flags) {
     SkASSERT(0 == (flags >> 28));
     SkASSERT(0 == ((uint32_t)mode >> 4));
     return (flags << 4) | mode;
 }
 static SkShader::TileMode unpack_mode(uint32_t packed) {
     return (SkShader::TileMode)(packed & 0xF);
 }
 static uint32_t unpack_flags(uint32_t packed) {
     return packed >> 4;
 }
 SkGradientShaderBase::SkGradientShaderBase(SkReadBuffer& buffer) : INHERITED(buffer) {
     fCacheAlpha = 256;
     fMapper = buffer.readUnitMapper();
     fCache16 = fCache16Storage = NULL;
     fCache32 = NULL;
     fCache32PixelRef = NULL;
     int colorCount = fColorCount = buffer.getArrayCount();
     if (colorCount > kColorStorageCount) {
         size_t allocSize = (sizeof(SkColor) + sizeof(SkPMColor) + sizeof(Rec)) * colorCount;
         if (buffer.validateAvailable(allocSize)) {
             fOrigColors = reinterpret_cast<SkColor*>(sk_malloc_throw(allocSize));
         } else {
             fOrigColors =  NULL;
             colorCount = fColorCount = 0;
         }
     } else {
         fOrigColors = fStorage;
     }
     buffer.readColorArray(fOrigColors, colorCount);
     {
         uint32_t packed = buffer.readUInt();
         fGradFlags = SkToU8(unpack_flags(packed));
         fTileMode = unpack_mode(packed);
     }
     fTileProc = gTileProcs[fTileMode];
     fRecs = (Rec*)(fOrigColors + colorCount);
     if (colorCount > 2) {
         Rec* recs = fRecs;
         recs[0].fPos = 0;
         for (int i = 1; i < colorCount; i++) {
             recs[i].fPos = buffer.readInt();
             recs[i].fScale = buffer.readUInt();
         }
     }
     buffer.readMatrix(&fPtsToUnit);
     this->initCommon();
 }
 SkGradientShaderBase::~SkGradientShaderBase() {
     if (fCache16Storage) {
         sk_free(fCache16Storage);
     }
     SkSafeUnref(fCache32PixelRef);
     if (fOrigColors != fStorage) {
         sk_free(fOrigColors);
     }
     SkSafeUnref(fMapper);
 }
 void SkGradientShaderBase::initCommon() {
     fFlags = 0;
     unsigned colorAlpha = 0xFF;
     for (int i = 0; i < fColorCount; i++) {
         colorAlpha &= SkColorGetA(fOrigColors[i]);
     }
     fColorsAreOpaque = colorAlpha == 0xFF;
 }
 void SkGradientShaderBase::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fMapper);
     buffer.writeColorArray(fOrigColors, fColorCount);
     buffer.writeUInt(pack_mode_flags(fTileMode, fGradFlags));
     if (fColorCount > 2) {
         Rec* recs = fRecs;
         for (int i = 1; i < fColorCount; i++) {
             buffer.writeInt(recs[i].fPos);
             buffer.writeUInt(recs[i].fScale);
         }
     }
     buffer.writeMatrix(fPtsToUnit);
 }
 bool SkGradientShaderBase::isOpaque() const {
     return fColorsAreOpaque;
 }
 bool SkGradientShaderBase::setContext(const SkBitmap& device,
                                  const SkPaint& paint,
                                  const SkMatrix& matrix) {
     if (!this->INHERITED::setContext(device, paint, matrix)) {
         return false;
     }
     const SkMatrix& inverse = this->getTotalInverse();
     if (!fDstToIndex.setConcat(fPtsToUnit, inverse)) {
         // need to keep our set/end context calls balanced.
         this->INHERITED::endContext();
         return false;
     }
     fDstToIndexProc = fDstToIndex.getMapXYProc();
     fDstToIndexClass = (uint8_t)SkShader::ComputeMatrixClass(fDstToIndex);
     // now convert our colors in to PMColors
     unsigned paintAlpha = this->getPaintAlpha();
     fFlags = this->INHERITED::getFlags();
     if (fColorsAreOpaque && paintAlpha == 0xFF) {
         fFlags |= kOpaqueAlpha_Flag;
     }
     // we can do span16 as long as our individual colors are opaque,
     // regardless of the paint's alpha
     if (fColorsAreOpaque) {
         fFlags |= kHasSpan16_Flag;
     }
     this->setCacheAlpha(paintAlpha);
     return true;
 }
 void SkGradientShaderBase::setCacheAlpha(U8CPU alpha) const {
     // if the new alpha differs from the previous time we were called, inval our cache
     // this will trigger the cache to be rebuilt.
     // we don't care about the first time, since the cache ptrs will already be NULL
     if (fCacheAlpha != alpha) {
         fCache16 = NULL;            // inval the cache
         fCache32 = NULL;            // inval the cache
         fCacheAlpha = alpha;        // record the new alpha
         // inform our subclasses
         if (fCache32PixelRef) {
             fCache32PixelRef->notifyPixelsChanged();
         }
     }
 }
 #define Fixed_To_Dot8(x)        (((x) + 0x80) >> 8)
 /** We take the original colors, not our premultiplied PMColors, since we can
     build a 16bit table as long as the original colors are opaque, even if the
     paint specifies a non-opaque alpha.
 */
 void SkGradientShaderBase::Build16bitCache(uint16_t cache[], SkColor c0, SkColor c1,
                                       int count) {
     SkASSERT(count > 1);
     SkASSERT(SkColorGetA(c0) == 0xFF);
     SkASSERT(SkColorGetA(c1) == 0xFF);
     SkFixed r = SkColorGetR(c0);
     SkFixed g = SkColorGetG(c0);
     SkFixed b = SkColorGetB(c0);
     SkFixed dr = SkIntToFixed(SkColorGetR(c1) - r) / (count - 1);
     SkFixed dg = SkIntToFixed(SkColorGetG(c1) - g) / (count - 1);
     SkFixed db = SkIntToFixed(SkColorGetB(c1) - b) / (count - 1);
     r = SkIntToFixed(r) + 0x8000;
     g = SkIntToFixed(g) + 0x8000;
     b = SkIntToFixed(b) + 0x8000;
     do {
         unsigned rr = r >> 16;
         unsigned gg = g >> 16;
         unsigned bb = b >> 16;
         cache[0] = SkPackRGB16(SkR32ToR16(rr), SkG32ToG16(gg), SkB32ToB16(bb));
         cache[kCache16Count] = SkDitherPack888ToRGB16(rr, gg, bb);
         cache += 1;
         r += dr;
         g += dg;
         b += db;
     } while (--count != 0);
 }
 /*
  *  r,g,b used to be SkFixed, but on gcc (4.2.1 mac and 4.6.3 goobuntu) in
  *  release builds, we saw a compiler error where the 0xFF parameter in
  *  SkPackARGB32() was being totally ignored whenever it was called with
  *  a non-zero add (e.g. 0x8000).
  *
  *  We found two work-arounds:
  *      1. change r,g,b to unsigned (or just one of them)
  *      2. change SkPackARGB32 to + its (a << SK_A32_SHIFT) value instead
  *         of using |
  *
  *  We chose #1 just because it was more localized.
  *  See http://code.google.com/p/skia/issues/detail?id=1113
  *
  *  The type SkUFixed encapsulate this need for unsigned, but logically Fixed.
  */
 typedef uint32_t SkUFixed;
 void SkGradientShaderBase::Build32bitCache(SkPMColor cache[], SkColor c0, SkColor c1,
                                       int count, U8CPU paintAlpha, uint32_t gradFlags) {
     SkASSERT(count > 1);
     // need to apply paintAlpha to our two endpoints
     uint32_t a0 = SkMulDiv255Round(SkColorGetA(c0), paintAlpha);
     uint32_t a1 = SkMulDiv255Round(SkColorGetA(c1), paintAlpha);
     const bool interpInPremul = SkToBool(gradFlags &
                            SkGradientShader::kInterpolateColorsInPremul_Flag);
     uint32_t r0 = SkColorGetR(c0);
     uint32_t g0 = SkColorGetG(c0);
     uint32_t b0 = SkColorGetB(c0);
     uint32_t r1 = SkColorGetR(c1);
     uint32_t g1 = SkColorGetG(c1);
     uint32_t b1 = SkColorGetB(c1);
     if (interpInPremul) {
         r0 = SkMulDiv255Round(r0, a0);
         g0 = SkMulDiv255Round(g0, a0);
         b0 = SkMulDiv255Round(b0, a0);
         r1 = SkMulDiv255Round(r1, a1);
         g1 = SkMulDiv255Round(g1, a1);
         b1 = SkMulDiv255Round(b1, a1);
     }
     SkFixed da = SkIntToFixed(a1 - a0) / (count - 1);
     SkFixed dr = SkIntToFixed(r1 - r0) / (count - 1);
     SkFixed dg = SkIntToFixed(g1 - g0) / (count - 1);
     SkFixed db = SkIntToFixed(b1 - b0) / (count - 1);
     /*  We pre-add 1/8 to avoid having to add this to our [0] value each time
         in the loop. Without this, the bias for each would be
 x2000  0xA000  0xE000  0x6000
         With this trick, we can add 0 for the first (no-op) and just adjust the
         others.
      */
     SkUFixed a = SkIntToFixed(a0) + 0x2000;
     SkUFixed r = SkIntToFixed(r0) + 0x2000;
     SkUFixed g = SkIntToFixed(g0) + 0x2000;
     SkUFixed b = SkIntToFixed(b0) + 0x2000;
     /*
      *  Our dither-cell (spatially) is
      *      0 2
      *      3 1
      *  Where
      *      [0] -> [-1/8 ... 1/8 ) values near 0
      *      [1] -> [ 1/8 ... 3/8 ) values near 1/4
      *      [2] -> [ 3/8 ... 5/8 ) values near 1/2
      *      [3] -> [ 5/8 ... 7/8 ) values near 3/4
      */
     if (0xFF == a0 && 0 == da) {
         do {
             cache[kCache32Count*0] = SkPackARGB32(0xFF, (r + 0     ) >> 16,
                                                         (g + 0     ) >> 16,
                                                         (b + 0     ) >> 16);
             cache[kCache32Count*1] = SkPackARGB32(0xFF, (r + 0x8000) >> 16,
                                                         (g + 0x8000) >> 16,
                                                         (b + 0x8000) >> 16);
             cache[kCache32Count*2] = SkPackARGB32(0xFF, (r + 0xC000) >> 16,
                                                         (g + 0xC000) >> 16,
                                                         (b + 0xC000) >> 16);
             cache[kCache32Count*3] = SkPackARGB32(0xFF, (r + 0x4000) >> 16,
                                                         (g + 0x4000) >> 16,
                                                         (b + 0x4000) >> 16);
             cache += 1;
             r += dr;
             g += dg;
             b += db;
         } while (--count != 0);
     } else if (interpInPremul) {
         do {
             cache[kCache32Count*0] = SkPackARGB32((a + 0     ) >> 16,
                                                   (r + 0     ) >> 16,
                                                   (g + 0     ) >> 16,
                                                   (b + 0     ) >> 16);
             cache[kCache32Count*1] = SkPackARGB32((a + 0x8000) >> 16,
                                                   (r + 0x8000) >> 16,
                                                   (g + 0x8000) >> 16,
                                                   (b + 0x8000) >> 16);
             cache[kCache32Count*2] = SkPackARGB32((a + 0xC000) >> 16,
                                                   (r + 0xC000) >> 16,
                                                   (g + 0xC000) >> 16,
                                                   (b + 0xC000) >> 16);
             cache[kCache32Count*3] = SkPackARGB32((a + 0x4000) >> 16,
                                                   (r + 0x4000) >> 16,
                                                   (g + 0x4000) >> 16,
                                                   (b + 0x4000) >> 16);
             cache += 1;
             a += da;
             r += dr;
             g += dg;
             b += db;
         } while (--count != 0);
     } else {    // interpolate in unpreml space
         do {
             cache[kCache32Count*0] = SkPremultiplyARGBInline((a + 0     ) >> 16,
                                                              (r + 0     ) >> 16,
                                                              (g + 0     ) >> 16,
                                                              (b + 0     ) >> 16);
             cache[kCache32Count*1] = SkPremultiplyARGBInline((a + 0x8000) >> 16,
                                                              (r + 0x8000) >> 16,
                                                              (g + 0x8000) >> 16,
                                                              (b + 0x8000) >> 16);
             cache[kCache32Count*2] = SkPremultiplyARGBInline((a + 0xC000) >> 16,
                                                              (r + 0xC000) >> 16,
                                                              (g + 0xC000) >> 16,
                                                              (b + 0xC000) >> 16);
             cache[kCache32Count*3] = SkPremultiplyARGBInline((a + 0x4000) >> 16,
                                                              (r + 0x4000) >> 16,
                                                              (g + 0x4000) >> 16,
                                                              (b + 0x4000) >> 16);
             cache += 1;
             a += da;
             r += dr;
             g += dg;
             b += db;
         } while (--count != 0);
     }
 }
 static inline int SkFixedToFFFF(SkFixed x) {
     SkASSERT((unsigned)x <= SK_Fixed1);
     return x - (x >> 16);
 }
 static inline U16CPU bitsTo16(unsigned x, const unsigned bits) {
     SkASSERT(x < (1U << bits));
     if (6 == bits) {
         return (x << 10) | (x << 4) | (x >> 2);
     }
     if (8 == bits) {
         return (x << 8) | x;
     }
     sk_throw();
     return 0;
 }
 const uint16_t* SkGradientShaderBase::getCache16() const {
     if (fCache16 == NULL) {
         // double the count for dither entries
         const int entryCount = kCache16Count * 2;
         const size_t allocSize = sizeof(uint16_t) * entryCount;
         if (fCache16Storage == NULL) { // set the storage and our working ptr
             fCache16Storage = (uint16_t*)sk_malloc_throw(allocSize);
         }
         fCache16 = fCache16Storage;
         if (fColorCount == 2) {
             Build16bitCache(fCache16, fOrigColors[0], fOrigColors[1],
                             kCache16Count);
         } else {
             Rec* rec = fRecs;
             int prevIndex = 0;
             for (int i = 1; i < fColorCount; i++) {
                 int nextIndex = SkFixedToFFFF(rec[i].fPos) >> kCache16Shift;
                 SkASSERT(nextIndex < kCache16Count);
                 if (nextIndex > prevIndex)
                     Build16bitCache(fCache16 + prevIndex, fOrigColors[i-1], fOrigColors[i], nextIndex - prevIndex + 1);
                 prevIndex = nextIndex;
             }
         }
         if (fMapper) {
             fCache16Storage = (uint16_t*)sk_malloc_throw(allocSize);
             uint16_t* linear = fCache16;         // just computed linear data
             uint16_t* mapped = fCache16Storage;  // storage for mapped data
             SkUnitMapper* map = fMapper;
             for (int i = 0; i < kCache16Count; i++) {
                 int index = map->mapUnit16(bitsTo16(i, kCache16Bits)) >> kCache16Shift;
                 mapped[i] = linear[index];
                 mapped[i + kCache16Count] = linear[index + kCache16Count];
             }
             sk_free(fCache16);
             fCache16 = fCache16Storage;
         }
     }
     return fCache16;
 }
 const SkPMColor* SkGradientShaderBase::getCache32() const {
     if (fCache32 == NULL) {
         SkImageInfo info;
         info.fWidth = kCache32Count;
         info.fHeight = 4;   // for our 4 dither rows
         info.fAlphaType = kPremul_SkAlphaType;
         info.fColorType = kPMColor_SkColorType;
         if (NULL == fCache32PixelRef) {
             fCache32PixelRef = SkMallocPixelRef::NewAllocate(info, 0, NULL);
         }
         fCache32 = (SkPMColor*)fCache32PixelRef->getAddr();
         if (fColorCount == 2) {
             Build32bitCache(fCache32, fOrigColors[0], fOrigColors[1],
                             kCache32Count, fCacheAlpha, fGradFlags);
         } else {
             Rec* rec = fRecs;
             int prevIndex = 0;
             for (int i = 1; i < fColorCount; i++) {
                 int nextIndex = SkFixedToFFFF(rec[i].fPos) >> kCache32Shift;
                 SkASSERT(nextIndex < kCache32Count);
                 if (nextIndex > prevIndex)
                     Build32bitCache(fCache32 + prevIndex, fOrigColors[i-1],
                                     fOrigColors[i], nextIndex - prevIndex + 1,
                                     fCacheAlpha, fGradFlags);
                 prevIndex = nextIndex;
             }
         }
         if (fMapper) {
             SkMallocPixelRef* newPR = SkMallocPixelRef::NewAllocate(info, 0, NULL);
             SkPMColor* linear = fCache32;           // just computed linear data
             SkPMColor* mapped = (SkPMColor*)newPR->getAddr();    // storage for mapped data
             SkUnitMapper* map = fMapper;
             for (int i = 0; i < kCache32Count; i++) {
                 int index = map->mapUnit16((i << 8) | i) >> 8;
                 mapped[i + kCache32Count*0] = linear[index + kCache32Count*0];
                 mapped[i + kCache32Count*1] = linear[index + kCache32Count*1];
                 mapped[i + kCache32Count*2] = linear[index + kCache32Count*2];
                 mapped[i + kCache32Count*3] = linear[index + kCache32Count*3];
             }
             fCache32PixelRef->unref();
             fCache32PixelRef = newPR;
             fCache32 = (SkPMColor*)newPR->getAddr();
         }
     }
     return fCache32;
 }
 /*
  *  Because our caller might rebuild the same (logically the same) gradient
  *  over and over, we'd like to return exactly the same "bitmap" if possible,
  *  allowing the client to utilize a cache of our bitmap (e.g. with a GPU).
  *  To do that, we maintain a private cache of built-bitmaps, based on our
  *  colors and positions. Note: we don't try to flatten the fMapper, so if one
  *  is present, we skip the cache for now.
  */
 void SkGradientShaderBase::getGradientTableBitmap(SkBitmap* bitmap) const {
     // our caller assumes no external alpha, so we ensure that our cache is
     // built with 0xFF
     this->setCacheAlpha(0xFF);
     // don't have a way to put the mapper into our cache-key yet
     if (fMapper) {
         // force our cahce32pixelref to be built
         (void)this->getCache32();
         bitmap->setConfig(SkImageInfo::MakeN32Premul(kCache32Count, 1));
         bitmap->setPixelRef(fCache32PixelRef);
         return;
     }
     // build our key: [numColors + colors[] + {positions[]} + flags ]
     int count = 1 + fColorCount + 1;
     if (fColorCount > 2) {
         count += fColorCount - 1;    // fRecs[].fPos
     }
     SkAutoSTMalloc<16, int32_t> storage(count);
     int32_t* buffer = storage.get();
     *buffer++ = fColorCount;
     memcpy(buffer, fOrigColors, fColorCount * sizeof(SkColor));
     buffer += fColorCount;
     if (fColorCount > 2) {
         for (int i = 1; i < fColorCount; i++) {
             *buffer++ = fRecs[i].fPos;
         }
     }
     *buffer++ = fGradFlags;
     SkASSERT(buffer - storage.get() == count);
     ///////////////////////////////////
     SK_DECLARE_STATIC_MUTEX(gMutex);
     static SkBitmapCache* gCache;
     // each cache cost 1K of RAM, since each bitmap will be 1x256 at 32bpp
     static const int MAX_NUM_CACHED_GRADIENT_BITMAPS = 32;
     SkAutoMutexAcquire ama(gMutex);
     if (NULL == gCache) {
         gCache = SkNEW_ARGS(SkBitmapCache, (MAX_NUM_CACHED_GRADIENT_BITMAPS));
     }
     size_t size = count * sizeof(int32_t);
     if (!gCache->find(storage.get(), size, bitmap)) {
         // force our cahce32pixelref to be built
         (void)this->getCache32();
         bitmap->setConfig(SkImageInfo::MakeN32Premul(kCache32Count, 1));
         bitmap->setPixelRef(fCache32PixelRef);
         gCache->add(storage.get(), size, *bitmap);
     }
 }
 void SkGradientShaderBase::commonAsAGradient(GradientInfo* info) const {
     if (info) {
         if (info->fColorCount >= fColorCount) {
             if (info->fColors) {
                 memcpy(info->fColors, fOrigColors, fColorCount * sizeof(SkColor));
             }
             if (info->fColorOffsets) {
                 if (fColorCount == 2) {
                     info->fColorOffsets[0] = 0;
                     info->fColorOffsets[1] = SK_Scalar1;
                 } else if (fColorCount > 2) {
                     for (int i = 0; i < fColorCount; ++i) {
                         info->fColorOffsets[i] = SkFixedToScalar(fRecs[i].fPos);
                     }
                 }
             }
         }
         info->fColorCount = fColorCount;
         info->fTileMode = fTileMode;
         info->fGradientFlags = fGradFlags;
     }
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkGradientShaderBase::toString(SkString* str) const {
     str->appendf("%d colors: ", fColorCount);
     for (int i = 0; i < fColorCount; ++i) {
         str->appendHex(fOrigColors[i]);
         if (i < fColorCount-1) {
             str->append(", ");
         }
     }
     if (fColorCount > 2) {
         str->append(" points: (");
         for (int i = 0; i < fColorCount; ++i) {
             str->appendScalar(SkFixedToScalar(fRecs[i].fPos));
             if (i < fColorCount-1) {
                 str->append(", ");
             }
         }
         str->append(")");
     }
     static const char* gTileModeName[SkShader::kTileModeCount] = {
         "clamp", "repeat", "mirror"
     };
     str->append(" ");
     str->append(gTileModeName[fTileMode]);
     // TODO: add "fMapper->toString(str);" when SkUnitMapper::toString is added
     this->INHERITED::toString(str);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 #include "SkEmptyShader.h"
 // assumes colors is SkColor* and pos is SkScalar*
 #define EXPAND_1_COLOR(count)               \
     SkColor tmp[2];                         \
     do {                                    \
         if (1 == count) {                   \
             tmp[0] = tmp[1] = colors[0];    \
             colors = tmp;                   \
             pos = NULL;                     \
             count = 2;                      \
         }                                   \
     } while (0)
 static void desc_init(SkGradientShaderBase::Descriptor* desc,
                       const SkColor colors[],
                       const SkScalar pos[], int colorCount,
                       SkShader::TileMode mode,
                       SkUnitMapper* mapper, uint32_t flags) {
     desc->fColors   = colors;
     desc->fPos      = pos;
     desc->fCount    = colorCount;
     desc->fTileMode = mode;
     desc->fMapper   = mapper;
     desc->fFlags    = flags;
 }
 SkShader* SkGradientShader::CreateLinear(const SkPoint pts[2],
                                          const SkColor colors[],
                                          const SkScalar pos[], int colorCount,
                                          SkShader::TileMode mode,
                                          SkUnitMapper* mapper,
                                          uint32_t flags) {
     if (NULL == pts || NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
     SkGradientShaderBase::Descriptor desc;
     desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkLinearGradient, (pts, desc));
 }
 SkShader* SkGradientShader::CreateRadial(const SkPoint& center, SkScalar radius,
                                          const SkColor colors[],
                                          const SkScalar pos[], int colorCount,
                                          SkShader::TileMode mode,
                                          SkUnitMapper* mapper,
                                          uint32_t flags) {
     if (radius <= 0 || NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
     SkGradientShaderBase::Descriptor desc;
     desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkRadialGradient, (center, radius, desc));
 }
 SkShader* SkGradientShader::CreateTwoPointRadial(const SkPoint& start,
                                                  SkScalar startRadius,
                                                  const SkPoint& end,
                                                  SkScalar endRadius,
                                                  const SkColor colors[],
                                                  const SkScalar pos[],
                                                  int colorCount,
                                                  SkShader::TileMode mode,
                                                  SkUnitMapper* mapper,
                                                  uint32_t flags) {
     if (startRadius < 0 || endRadius < 0 || NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
     SkGradientShaderBase::Descriptor desc;
     desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkTwoPointRadialGradient,
                       (start, startRadius, end, endRadius, desc));
 }
 SkShader* SkGradientShader::CreateTwoPointConical(const SkPoint& start,
                                                   SkScalar startRadius,
                                                   const SkPoint& end,
                                                   SkScalar endRadius,
                                                   const SkColor colors[],
                                                   const SkScalar pos[],
                                                   int colorCount,
                                                   SkShader::TileMode mode,
                                                   SkUnitMapper* mapper,
                                                   uint32_t flags) {
     if (startRadius < 0 || endRadius < 0 || NULL == colors || colorCount < 1) {
         return NULL;
     }
     if (start == end && startRadius == endRadius) {
         return SkNEW(SkEmptyShader);
     }
     EXPAND_1_COLOR(colorCount);
     SkGradientShaderBase::Descriptor desc;
     desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkTwoPointConicalGradient,
                       (start, startRadius, end, endRadius, desc));
 }
 SkShader* SkGradientShader::CreateSweep(SkScalar cx, SkScalar cy,
                                         const SkColor colors[],
                                         const SkScalar pos[],
                                         int colorCount, SkUnitMapper* mapper,
                                         uint32_t flags) {
     if (NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
     SkGradientShaderBase::Descriptor desc;
     desc_init(&desc, colors, pos, colorCount, SkShader::kClamp_TileMode, mapper, flags);
     return SkNEW_ARGS(SkSweepGradient, (cx, cy, desc));
 }
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkGradientShader)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkLinearGradient)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkRadialGradient)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSweepGradient)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkTwoPointRadialGradient)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkTwoPointConicalGradient)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
 ///////////////////////////////////////////////////////////////////////////////
 #if SK_SUPPORT_GPU
 #include "effects/GrTextureStripAtlas.h"
 #include "GrTBackendEffectFactory.h"
 #include "SkGr.h"
 GrGLGradientEffect::GrGLGradientEffect(const GrBackendEffectFactory& factory)
     : INHERITED(factory)
     , fCachedYCoord(SK_ScalarMax) {
 }
 GrGLGradientEffect::~GrGLGradientEffect() { }
 void GrGLGradientEffect::emitUniforms(GrGLShaderBuilder* builder, EffectKey key) {
     if (GrGradientEffect::kTwo_ColorType == ColorTypeFromKey(key)) { // 2 Color case
         fColorStartUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec4f_GrSLType, "GradientStartColor");
         fColorEndUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                            kVec4f_GrSLType, "GradientEndColor");
     } else if (GrGradientEffect::kThree_ColorType == ColorTypeFromKey(key)){ // 3 Color Case
         fColorStartUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec4f_GrSLType, "GradientStartColor");
         fColorMidUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                            kVec4f_GrSLType, "GradientMidColor");
         fColorEndUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec4f_GrSLType, "GradientEndColor");
     } else { // if not a fast case
         fFSYUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                       kFloat_GrSLType, "GradientYCoordFS");
     }
 }
 static inline void set_color_uni(const GrGLUniformManager& uman,
                                  const GrGLUniformManager::UniformHandle uni,
                                  const SkColor* color) {
        uman.set4f(uni,
                   SkColorGetR(*color) / 255.f,
                   SkColorGetG(*color) / 255.f,
                   SkColorGetB(*color) / 255.f,
                   SkColorGetA(*color) / 255.f);
 }
 static inline void set_mul_color_uni(const GrGLUniformManager& uman,
                                      const GrGLUniformManager::UniformHandle uni,
                                      const SkColor* color){
        float a = SkColorGetA(*color) / 255.f;
        float aDiv255 = a / 255.f;
        uman.set4f(uni,
                   SkColorGetR(*color) * aDiv255,
                   SkColorGetG(*color) * aDiv255,
                   SkColorGetB(*color) * aDiv255,
                   a);
 }
 void GrGLGradientEffect::setData(const GrGLUniformManager& uman,
                                  const GrDrawEffect& drawEffect) {
     const GrGradientEffect& e = drawEffect.castEffect<GrGradientEffect>();
     if (GrGradientEffect::kTwo_ColorType == e.getColorType()){
         if (GrGradientEffect::kBeforeInterp_PremulType == e.getPremulType()) {
             set_mul_color_uni(uman, fColorStartUni, e.getColors(0));
             set_mul_color_uni(uman, fColorEndUni,   e.getColors(1));
         } else {
             set_color_uni(uman, fColorStartUni, e.getColors(0));
             set_color_uni(uman, fColorEndUni,   e.getColors(1));
         }
     } else if (GrGradientEffect::kThree_ColorType == e.getColorType()){
         if (GrGradientEffect::kBeforeInterp_PremulType == e.getPremulType()) {
             set_mul_color_uni(uman, fColorStartUni, e.getColors(0));
             set_mul_color_uni(uman, fColorMidUni,   e.getColors(1));
             set_mul_color_uni(uman, fColorEndUni,   e.getColors(2));
         } else {
             set_color_uni(uman, fColorStartUni, e.getColors(0));
             set_color_uni(uman, fColorMidUni,   e.getColors(1));
             set_color_uni(uman, fColorEndUni,   e.getColors(2));
         }
     } else {
         SkScalar yCoord = e.getYCoord();
         if (yCoord != fCachedYCoord) {
             uman.set1f(fFSYUni, yCoord);
             fCachedYCoord = yCoord;
         }
     }
 }
 GrGLEffect::EffectKey GrGLGradientEffect::GenBaseGradientKey(const GrDrawEffect& drawEffect) {
     const GrGradientEffect& e = drawEffect.castEffect<GrGradientEffect>();
     EffectKey key = 0;
     if (GrGradientEffect::kTwo_ColorType == e.getColorType()) {
         key |= kTwoColorKey;
     } else if (GrGradientEffect::kThree_ColorType == e.getColorType()){
         key |= kThreeColorKey;
     }
     if (GrGradientEffect::kBeforeInterp_PremulType == e.getPremulType()) {
         key |= kPremulBeforeInterpKey;
     }
     return key;
 }
 void GrGLGradientEffect::emitColor(GrGLShaderBuilder* builder,
                                    const char* gradientTValue,
                                    EffectKey key,
                                    const char* outputColor,
                                    const char* inputColor,
                                    const TextureSamplerArray& samplers) {
     if (GrGradientEffect::kTwo_ColorType == ColorTypeFromKey(key)){
         builder->fsCodeAppendf("\tvec4 colorTemp = mix(%s, %s, clamp(%s, 0.0, 1.0));\n",
                                builder->getUniformVariable(fColorStartUni).c_str(),
                                builder->getUniformVariable(fColorEndUni).c_str(),
                                gradientTValue);
         // Note that we could skip this step if both colors are known to be opaque. Two
         // considerations:
         // The gradient SkShader reporting opaque is more restrictive than necessary in the two pt
         // case. Make sure the key reflects this optimization (and note that it can use the same
         // shader as thekBeforeIterp case). This same optimization applies to the 3 color case below.
         if (GrGradientEffect::kAfterInterp_PremulType == PremulTypeFromKey(key)) {
             builder->fsCodeAppend("\tcolorTemp.rgb *= colorTemp.a;\n");
         }
         builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
                                (GrGLSLExpr4(inputColor) * GrGLSLExpr4("colorTemp")).c_str());
     } else if (GrGradientEffect::kThree_ColorType == ColorTypeFromKey(key)){
         builder->fsCodeAppendf("\tfloat oneMinus2t = 1.0 - (2.0 * (%s));\n",
                                gradientTValue);
         builder->fsCodeAppendf("\tvec4 colorTemp = clamp(oneMinus2t, 0.0, 1.0) * %s;\n",
                                builder->getUniformVariable(fColorStartUni).c_str());
         if (kTegra3_GrGLRenderer == builder->ctxInfo().renderer()) {
             // The Tegra3 compiler will sometimes never return if we have
             // min(abs(oneMinus2t), 1.0), or do the abs first in a separate expression.
             builder->fsCodeAppend("\tfloat minAbs = abs(oneMinus2t);\n");
             builder->fsCodeAppend("\tminAbs = minAbs > 1.0 ? 1.0 : minAbs;\n");
             builder->fsCodeAppendf("\tcolorTemp += (1.0 - minAbs) * %s;\n",
                                    builder->getUniformVariable(fColorMidUni).c_str());
         } else {
             builder->fsCodeAppendf("\tcolorTemp += (1.0 - min(abs(oneMinus2t), 1.0)) * %s;\n",
                                    builder->getUniformVariable(fColorMidUni).c_str());
         }
         builder->fsCodeAppendf("\tcolorTemp += clamp(-oneMinus2t, 0.0, 1.0) * %s;\n",
                                builder->getUniformVariable(fColorEndUni).c_str());
         if (GrGradientEffect::kAfterInterp_PremulType == PremulTypeFromKey(key)) {
             builder->fsCodeAppend("\tcolorTemp.rgb *= colorTemp.a;\n");
         }
         builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
                                (GrGLSLExpr4(inputColor) * GrGLSLExpr4("colorTemp")).c_str());
     } else {
         builder->fsCodeAppendf("\tvec2 coord = vec2(%s, %s);\n",
                                gradientTValue,
                                builder->getUniformVariable(fFSYUni).c_str());
         builder->fsCodeAppendf("\t%s = ", outputColor);
         builder->fsAppendTextureLookupAndModulate(inputColor,
                                                   samplers[0],
                                                   "coord");
         builder->fsCodeAppend(";\n");
     }
 }
 /////////////////////////////////////////////////////////////////////
 GrGradientEffect::GrGradientEffect(GrContext* ctx,
                                    const SkGradientShaderBase& shader,
                                    const SkMatrix& matrix,
                                    SkShader::TileMode tileMode) {
     fIsOpaque = shader.isOpaque();
     SkShader::GradientInfo info;
     SkScalar pos[3] = {0};
     info.fColorCount = 3;
     info.fColors = &fColors[0];
     info.fColorOffsets = &pos[0];
     shader.asAGradient(&info);
     // The two and three color specializations do not currently support tiling.
     bool foundSpecialCase = false;
     if (SkShader::kClamp_TileMode == info.fTileMode) {
         if (2 == info.fColorCount) {
             fRow = -1; // flag for no atlas
             fColorType = kTwo_ColorType;
             foundSpecialCase = true;
         } else if (3 == info.fColorCount &&
                    (SkScalarAbs(pos[1] - SK_ScalarHalf) < SK_Scalar1 / 1000)) { // 3 color symmetric
             fRow = -1; // flag for no atlas
             fColorType = kThree_ColorType;
             foundSpecialCase = true;
         }
     }
     if (foundSpecialCase) {
         if (SkGradientShader::kInterpolateColorsInPremul_Flag & info.fGradientFlags) {
             fPremulType = kBeforeInterp_PremulType;
         } else {
             fPremulType = kAfterInterp_PremulType;
         }
         fCoordTransform.reset(kCoordSet, matrix);
     } else {
         // doesn't matter how this is set, just be consistent because it is part of the effect key.
         fPremulType = kBeforeInterp_PremulType;
         SkBitmap bitmap;
         shader.getGradientTableBitmap(&bitmap);
         fColorType = kTexture_ColorType;
         GrTextureStripAtlas::Desc desc;
         desc.fWidth  = bitmap.width();
         desc.fHeight = 32;
         desc.fRowHeight = bitmap.height();
         desc.fContext = ctx;
         desc.fConfig = SkImageInfo2GrPixelConfig(bitmap.colorType(), bitmap.alphaType());
         fAtlas = GrTextureStripAtlas::GetAtlas(desc);
         SkASSERT(NULL != fAtlas);
         // We always filter the gradient table. Each table is one row of a texture, always y-clamp.
         GrTextureParams params;
         params.setFilterMode(GrTextureParams::kBilerp_FilterMode);
         params.setTileModeX(tileMode);
         fRow = fAtlas->lockRow(bitmap);
         if (-1 != fRow) {
             fYCoord = fAtlas->getYOffset(fRow) + SK_ScalarHalf *
             fAtlas->getVerticalScaleFactor();
             fCoordTransform.reset(kCoordSet, matrix, fAtlas->getTexture());
             fTextureAccess.reset(fAtlas->getTexture(), params);
         } else {
             GrTexture* texture = GrLockAndRefCachedBitmapTexture(ctx, bitmap, &params);
             fCoordTransform.reset(kCoordSet, matrix, texture);
             fTextureAccess.reset(texture, params);
             fYCoord = SK_ScalarHalf;
             // Unlock immediately, this is not great, but we don't have a way of
             // knowing when else to unlock it currently, so it may get purged from
             // the cache, but it'll still be ref'd until it's no longer being used.
             GrUnlockAndUnrefCachedBitmapTexture(texture);
         }
         this->addTextureAccess(&fTextureAccess);
     }
     this->addCoordTransform(&fCoordTransform);
 }
 GrGradientEffect::~GrGradientEffect() {
     if (this->useAtlas()) {
         fAtlas->unlockRow(fRow);
     }
 }
 bool GrGradientEffect::onIsEqual(const GrEffect& effect) const {
     const GrGradientEffect& s = CastEffect<GrGradientEffect>(effect);
     if (this->fColorType == s.getColorType()){
         if (kTwo_ColorType == fColorType) {
             if (*this->getColors(0) != *s.getColors(0) ||
                 *this->getColors(1) != *s.getColors(1)) {
                 return false;
             }
         } else if (kThree_ColorType == fColorType) {
             if (*this->getColors(0) != *s.getColors(0) ||
                 *this->getColors(1) != *s.getColors(1) ||
                 *this->getColors(2) != *s.getColors(2)) {
                 return false;
             }
         } else {
             if (fYCoord != s.getYCoord()) {
                 return false;
             }
         }
         return fTextureAccess.getTexture() == s.fTextureAccess.getTexture()  &&
             fTextureAccess.getParams().getTileModeX() ==
                 s.fTextureAccess.getParams().getTileModeX() &&
             this->useAtlas() == s.useAtlas() &&
             fCoordTransform.getMatrix().cheapEqualTo(s.fCoordTransform.getMatrix());
     }
     return false;
 }
 void GrGradientEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
     if (fIsOpaque && (kA_GrColorComponentFlag & *validFlags) && 0xff == GrColorUnpackA(*color)) {
         *validFlags = kA_GrColorComponentFlag;
     } else {
         *validFlags = 0;
     }
 }
 int GrGradientEffect::RandomGradientParams(SkRandom* random,
                                            SkColor colors[],
                                            SkScalar** stops,
                                            SkShader::TileMode* tm) {
     int outColors = random->nextRangeU(1, kMaxRandomGradientColors);
     // if one color, omit stops, otherwise randomly decide whether or not to
     if (outColors == 1 || (outColors >= 2 && random->nextBool())) {
         *stops = NULL;
     }
     SkScalar stop = 0.f;
     for (int i = 0; i < outColors; ++i) {
         colors[i] = random->nextU();
         if (NULL != *stops) {
             (*stops)[i] = stop;
             stop = i < outColors - 1 ? stop + random->nextUScalar1() * (1.f - stop) : 1.f;
         }
     }
     *tm = static_cast<SkShader::TileMode>(random->nextULessThan(SkShader::kTileModeCount));
     return outColors;
 }
 #endif

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gfx/skia/trunk/src/effects/gradients/SkGradientShader.cpp@b8a032363ba2 (annotated)

gfx/skia/trunk/src/effects/gradients/SkGradientShader.cpp