Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/) (https://codereview.chromium.org/288343009/)

Reason for revert:
required blink change failed to land

Original issue's description:
> Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)
>
> This reverts commit dd50c83b5b34dab3a077741861b50ed1f2bc6b8f.
>
> BUG=skia:
>
> Committed: http://code.google.com/p/skia/source/detail?r=14830

R=scroggo@google.com, reed@google.com
TBR=reed@google.com, scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/296823008

git-svn-id: http://skia.googlecode.com/svn/trunk@14838 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 65 insertions, 13 deletions

diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index ada9859017..e43a0264de 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -17,6 +17,8 @@ SkGradientShaderBase::SkGradientShaderBase(const Descriptor& desc, const SkMatri
 {
     SkASSERT(desc.fCount > 1);
 
+    fMapper = desc.fMapper;
+    SkSafeRef(fMapper);
     fGradFlags = SkToU8(desc.fGradFlags);
 
     SkASSERT((unsigned)desc.fTileMode < SkShader::kTileModeCount);
@@ -140,10 +142,7 @@ static uint32_t unpack_flags(uint32_t packed) {
 }
 
 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) {
@@ -182,6 +181,7 @@ SkGradientShaderBase::~SkGradientShaderBase() {
     if (fOrigColors != fStorage) {
         sk_free(fOrigColors);
     }
+    SkSafeUnref(fMapper);
 }
 
 void SkGradientShaderBase::initCommon() {
@@ -194,6 +194,7 @@ void SkGradientShaderBase::initCommon() {
 
 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) {
@@ -515,6 +516,20 @@ void SkGradientShaderBase::GradientShaderCache::initCache16(GradientShaderCache*
             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() {
@@ -552,6 +567,23 @@ void SkGradientShaderBase::GradientShaderCache::initCache32(GradientShaderCache*
             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();
+    }
 }
 
 /*
@@ -583,6 +615,15 @@ void SkGradientShaderBase::getGradientTableBitmap(SkBitmap* bitmap) const {
     // 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) {
@@ -691,6 +732,8 @@ void SkGradientShaderBase::toString(SkString* str) const {
     str->append(" ");
     str->append(gTileModeName[fTileMode]);
 
+    // TODO: add "fMapper->toString(str);" when SkUnitMapper::toString is added
+
     this->INHERITED::toString(str);
 }
 #endif
@@ -715,11 +758,13 @@ void SkGradientShaderBase::toString(SkString* str) const {
 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;
 }
 
@@ -727,6 +772,7 @@ 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) {
@@ -735,7 +781,7 @@ SkShader* SkGradientShader::CreateLinear(const SkPoint pts[2],
     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));
 }
 
@@ -743,6 +789,7 @@ 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) {
@@ -751,7 +798,7 @@ SkShader* SkGradientShader::CreateRadial(const SkPoint& center, SkScalar radius,
     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));
 }
 
@@ -763,6 +810,7 @@ SkShader* SkGradientShader::CreateTwoPointRadial(const SkPoint& start,
                                                  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) {
@@ -771,7 +819,7 @@ SkShader* SkGradientShader::CreateTwoPointRadial(const SkPoint& start,
     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));
 }
@@ -784,6 +832,7 @@ SkShader* SkGradientShader::CreateTwoPointConical(const SkPoint& start,
                                                   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) {
@@ -800,7 +849,7 @@ SkShader* SkGradientShader::CreateTwoPointConical(const SkPoint& start,
     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 {
@@ -814,9 +863,9 @@ SkShader* SkGradientShader::CreateTwoPointConical(const SkPoint& start,
             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,
@@ -827,7 +876,7 @@ SkShader* SkGradientShader::CreateTwoPointConical(const SkPoint& start,
 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) {
@@ -836,7 +885,7 @@ SkShader* SkGradientShader::CreateSweep(SkScalar cx, SkScalar cy,
     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));
 }
 
diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index 9613537803..a699c4ce00 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -14,6 +14,7 @@
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMallocPixelRef.h"
+#include "SkUnitMapper.h"
 #include "SkUtils.h"
 #include "SkTemplates.h"
 #include "SkBitmapCache.h"
@@ -93,6 +94,7 @@ public:
         const SkScalar*     fPos;
         int                 fCount;
         SkShader::TileMode  fTileMode;
+        SkUnitMapper*       fMapper;
         uint32_t            fGradFlags;
     };
 
@@ -199,6 +201,7 @@ protected:
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
 
+    SkUnitMapper* fMapper;
     SkMatrix    fPtsToUnit;     // set by subclass
     TileMode    fTileMode;
     TileProc    fTileProc;