Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)

src/effects/gradients/SkGradientShader.cpp

 /*
  * 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, const SkMatrix* localMatrix)
     : INHERITED(localMatrix)
 {
     SkASSERT(desc.fCount > 1);
 
+    fMapper = desc.fMapper;
+    SkSafeRef(fMapper);
     fGradFlags = SkToU8(desc.fGradFlags);
 
     SkASSERT((unsigned)desc.fTileMode < SkShader::kTileModeCount);
     SkASSERT(SkShader::kTileModeCount == SK_ARRAY_COUNT(gTileProcs));
     fTileMode = desc.fTileMode;
     fTileProc = gTileProcs[desc.fTileMode];
 
     /*  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
@@ skipping 103 matching lines @@
 
 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) {
-    if (buffer.isVersionLT(SkReadBuffer::kNoUnitMappers_Version)) {
-        // skip the old SkUnitMapper slot
-        buffer.skipFlattenable();
-    }
+    fMapper = buffer.readUnitMapper();
 
     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;
         }
@@ skipping 18 matching lines @@
         }
     }
     buffer.readMatrix(&fPtsToUnit);
     this->initCommon();
 }
 
 SkGradientShaderBase::~SkGradientShaderBase() {
     if (fOrigColors != fStorage) {
         sk_free(fOrigColors);
     }
+    SkSafeUnref(fMapper);
 }
 
 void SkGradientShaderBase::initCommon() {
     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);
@@ skipping 313 matching lines @@
         for (int i = 1; i < cache->fShader.fColorCount; i++) {
             int nextIndex = SkFixedToFFFF(rec[i].fPos) >> kCache16Shift;
             SkASSERT(nextIndex < kCache16Count);
 
             if (nextIndex > prevIndex)
                 Build16bitCache(cache->fCache16 + prevIndex, cache->fShader.fOrigColors[i-1],
                                 cache->fShader.fOrigColors[i], nextIndex - prevIndex + 1);
             prevIndex = nextIndex;
         }
     }
+
+    if (cache->fShader.fMapper) {
+        cache->fCache16Storage = (uint16_t*)sk_malloc_throw(allocSize);
+        uint16_t* linear = cache->fCache16;         // just computed linear data
+        uint16_t* mapped = cache->fCache16Storage;  // storage for mapped data
+        SkUnitMapper* map = cache->fShader.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(cache->fCache16);
+        cache->fCache16 = cache->fCache16Storage;
+    }
 }
 
 const SkPMColor* SkGradientShaderBase::GradientShaderCache::getCache32() {
     SkOnce(&fCache32Inited, &fCache32Mutex, SkGradientShaderBase::GradientShaderCache::initCache32,
            this);
     SkASSERT(fCache32);
     return fCache32;
 }
 
 void SkGradientShaderBase::GradientShaderCache::initCache32(GradientShaderCache* cache) {
@@ skipping 17 matching lines @@
             int nextIndex = SkFixedToFFFF(rec[i].fPos) >> kCache32Shift;
             SkASSERT(nextIndex < kCache32Count);
 
             if (nextIndex > prevIndex)
                 Build32bitCache(cache->fCache32 + prevIndex, cache->fShader.fOrigColors[i-1],
                                 cache->fShader.fOrigColors[i], nextIndex - prevIndex + 1,
                                 cache->fCacheAlpha, cache->fShader.fGradFlags);
             prevIndex = nextIndex;
         }
     }
+
+    if (cache->fShader.fMapper) {
+        SkMallocPixelRef* newPR = SkMallocPixelRef::NewAllocate(info, 0, NULL);
+        SkPMColor* linear = cache->fCache32;           // just computed linear data
+        SkPMColor* mapped = (SkPMColor*)newPR->getAddr();    // storage for mapped data
+        SkUnitMapper* map = cache->fShader.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];
+        }
+        cache->fCache32PixelRef->unref();
+        cache->fCache32PixelRef = newPR;
+        cache->fCache32 = (SkPMColor*)newPR->getAddr();
+    }
 }
 
 /*
  *  The gradient holds a cache for the most recent value of alpha. Successive
  *  callers with the same alpha value will share the same cache.
  */
 SkGradientShaderBase::GradientShaderCache* SkGradientShaderBase::refCache(U8CPU alpha) const {
     SkAutoMutexAcquire ama(fCacheMutex);
     if (!fCache || fCache->getAlpha() != alpha) {
         fCache.reset(SkNEW_ARGS(GradientShaderCache, (alpha, *this)));
@@ skipping 11 matching lines @@
  *  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
     SkAutoTUnref<GradientShaderCache> cache(this->refCache(0xFF));
 
+    // don't have a way to put the mapper into our cache-key yet
+    if (fMapper) {
+        // force our cache32pixelref to be built
+        (void)cache->getCache32();
+        bitmap->setConfig(SkImageInfo::MakeN32Premul(kCache32Count, 1));
+        bitmap->setPixelRef(cache->getCache32PixelRef());
+        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;
@@ skipping 88 matching lines @@
         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, uint32_t flags) {
+                      SkShader::TileMode mode,
+                      SkUnitMapper* mapper, uint32_t flags) {
     desc->fColors       = colors;
     desc->fPos          = pos;
     desc->fCount        = colorCount;
     desc->fTileMode     = mode;
+    desc->fMapper       = mapper;
     desc->fGradFlags    = flags;
 }
 
 SkShader* SkGradientShader::CreateLinear(const SkPoint pts[2],
                                          const SkColor colors[],
                                          const SkScalar pos[], int colorCount,
                                          SkShader::TileMode mode,
+                                         SkUnitMapper* mapper,
                                          uint32_t flags,
                                          const SkMatrix* localMatrix) {
     if (NULL == pts || NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
 
     SkGradientShaderBase::Descriptor desc;
-    desc_init(&desc, colors, pos, colorCount, mode, flags);
+    desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkLinearGradient, (pts, desc, localMatrix));
 }
 
 SkShader* SkGradientShader::CreateRadial(const SkPoint& center, SkScalar radius,
                                          const SkColor colors[],
                                          const SkScalar pos[], int colorCount,
                                          SkShader::TileMode mode,
+                                         SkUnitMapper* mapper,
                                          uint32_t flags,
                                          const SkMatrix* localMatrix) {
     if (radius <= 0 || NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
 
     SkGradientShaderBase::Descriptor desc;
-    desc_init(&desc, colors, pos, colorCount, mode, flags);
+    desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkRadialGradient, (center, radius, desc, localMatrix));
 }
 
 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,
                                                  const SkMatrix* localMatrix) {
     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, flags);
+    desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
     return SkNEW_ARGS(SkTwoPointRadialGradient,
                       (start, startRadius, end, endRadius, desc, localMatrix));
 }
 
 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,
                                                   const SkMatrix* localMatrix) {
     if (startRadius < 0 || endRadius < 0 || NULL == colors || colorCount < 1) {
         return NULL;
     }
     if (start == end && startRadius == endRadius) {
         return SkNEW(SkEmptyShader);
     }
 
     EXPAND_1_COLOR(colorCount);
 
     bool flipGradient = startRadius > endRadius;
 
     SkGradientShaderBase::Descriptor desc;
 
     if (!flipGradient) {
-        desc_init(&desc, colors, pos, colorCount, mode, flags);
+        desc_init(&desc, colors, pos, colorCount, mode, mapper, flags);
         return SkNEW_ARGS(SkTwoPointConicalGradient,
                           (start, startRadius, end, endRadius, flipGradient, desc, localMatrix));
     } else {
         SkAutoSTArray<8, SkColor> colorsNew(colorCount);
         SkAutoSTArray<8, SkScalar> posNew(colorCount);
         for (int i = 0; i < colorCount; ++i) {
             colorsNew[i] = colors[colorCount - i - 1];
         }
 
         if (pos) {
             for (int i = 0; i < colorCount; ++i) {
                 posNew[i] = 1 - pos[colorCount - i - 1];
             }
-            desc_init(&desc, colorsNew.get(), posNew.get(), colorCount, mode, flags);
+            desc_init(&desc, colorsNew.get(), posNew.get(), colorCount, mode, mapper, flags);
         } else {
-            desc_init(&desc, colorsNew.get(), NULL, colorCount, mode, flags);
+            desc_init(&desc, colorsNew.get(), NULL, colorCount, mode, mapper, flags);
         }
 
         return SkNEW_ARGS(SkTwoPointConicalGradient,
                           (end, endRadius, start, startRadius, flipGradient, desc, localMatrix));
     }
 }
 
 SkShader* SkGradientShader::CreateSweep(SkScalar cx, SkScalar cy,
                                         const SkColor colors[],
                                         const SkScalar pos[],
-                                        int colorCount,
+                                        int colorCount, SkUnitMapper* mapper,
                                         uint32_t flags,
                                         const SkMatrix* localMatrix) {
     if (NULL == colors || colorCount < 1) {
         return NULL;
     }
     EXPAND_1_COLOR(colorCount);
 
     SkGradientShaderBase::Descriptor desc;
-    desc_init(&desc, colors, pos, colorCount, SkShader::kClamp_TileMode, flags);
+    desc_init(&desc, colors, pos, colorCount, SkShader::kClamp_TileMode, mapper, flags);
     return SkNEW_ARGS(SkSweepGradient, (cx, cy, desc, localMatrix));
 }
 
 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
@@ skipping 299 matching lines @@
             (*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