use pixmaps in mipmap api

src/core/SkMipMap.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMipMap.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
@@ skipping 165 matching lines @@
     }
     int64_t size = sk_64_mul(levelCount + 1, sizeof(Level)) + pixelSize;
     if (!sk_64_isS32(size)) {
         return 0;
     }
     return sk_64_asS32(size);
 }
 
 typedef void SkDownSampleProc(void*, int x, int y, const void* srcPtr, const SkPixmap& srcPM);
 
-SkMipMap* SkMipMap::Build(const SkBitmap& src, SkDiscardableFactoryProc fact) {
+SkMipMap* SkMipMap::Build(const SkPixmap& src, SkDiscardableFactoryProc fact) {
     SkDownSampleProc* proc_nocheck, *proc_check;
 
     const SkColorType ct = src.colorType();
     const SkAlphaType at = src.alphaType();
     switch (ct) {
         case kRGBA_8888_SkColorType:
         case kBGRA_8888_SkColorType:
             proc_check = downsample32_check;
             proc_nocheck = downsample32_nocheck;
             break;
@@ skipping 32 matching lines @@
     }
     if (0 == countLevels) {
         return nullptr;
     }
 
     size_t storageSize = SkMipMap::AllocLevelsSize(countLevels, size);
     if (0 == storageSize) {
         return nullptr;
     }
 
-    SkAutoPixmapUnlock srcUnlocker;
-    if (!src.requestLock(&srcUnlocker)) {
-        return nullptr;
-    }
-    const SkPixmap& srcPixmap = srcUnlocker.pixmap();
-    // Try to catch where we might have returned nullptr for src crbug.com/492818
-    if (nullptr == srcPixmap.addr()) {
-        sk_throw();
-    }
-
     SkMipMap* mipmap;
     if (fact) {
         SkDiscardableMemory* dm = fact(storageSize);
         if (nullptr == dm) {
             return nullptr;
         }
         mipmap = new SkMipMap(storageSize, dm);
     } else {
         mipmap = new SkMipMap(sk_malloc_throw(storageSize), storageSize);
     }
 
     // init
     mipmap->fCount = countLevels;
     mipmap->fLevels = (Level*)mipmap->writable_data();
 
     Level* levels = mipmap->fLevels;
     uint8_t*    baseAddr = (uint8_t*)&levels[countLevels];
     uint8_t*    addr = baseAddr;
     int         width = src.width();
     int         height = src.height();
     uint32_t    rowBytes;
-    SkPixmap    srcPM(srcPixmap);
+    SkPixmap    srcPM(src);
 
     for (int i = 0; i < countLevels; ++i) {
         width >>= 1;
         height >>= 1;
         rowBytes = SkToU32(SkColorTypeMinRowBytes(ct, width));
 
-        levels[i].fPixels   = addr;
-        levels[i].fWidth    = width;
-        levels[i].fHeight   = height;
-        levels[i].fRowBytes = rowBytes;
+        levels[i].fPixmap = SkPixmap(SkImageInfo::Make(width, height, ct, at), addr, rowBytes);
         levels[i].fScale    = (float)width / src.width();
 
         SkPixmap dstPM(SkImageInfo::Make(width, height, ct, at), addr, rowBytes);
 
         const int widthEven = width & ~1;
         const int heightEven = height & ~1;
         const size_t pixelSize = srcPM.info().bytesPerPixel();
 
         const void* srcBasePtr = srcPM.addr();
         void* dstBasePtr = dstPM.writable_addr();
@@ skipping 189 matching lines @@
     if (levelCount < 0) {
         return 0;
     }
     int64_t size = sk_64_mul(levelCount + 1, sizeof(Level)) + pixelSize;
     if (!sk_64_isS32(size)) {
         return 0;
     }
     return sk_64_asS32(size);
 }
 
-SkMipMap* SkMipMap::Build(const SkBitmap& src, SkDiscardableFactoryProc fact) {
+SkMipMap* SkMipMap::Build(const SkPixmap& src, SkDiscardableFactoryProc fact) {
     typedef void FilterProc(void*, const void* srcPtr, size_t srcRB, int count);
 
     FilterProc* proc_2_2 = nullptr;
     FilterProc* proc_2_3 = nullptr;
     FilterProc* proc_3_2 = nullptr;
     FilterProc* proc_3_3 = nullptr;
 
     const SkColorType ct = src.colorType();
     const SkAlphaType at = src.alphaType();
     switch (ct) {
@@ skipping 47 matching lines @@
     }
     if (0 == countLevels) {
         return nullptr;
     }
 
     size_t storageSize = SkMipMap::AllocLevelsSize(countLevels, size);
     if (0 == storageSize) {
         return nullptr;
     }
 
-    SkAutoPixmapUnlock srcUnlocker;
-    if (!src.requestLock(&srcUnlocker)) {
-        return nullptr;
-    }
-    const SkPixmap& srcPixmap = srcUnlocker.pixmap();
-    // Try to catch where we might have returned nullptr for src crbug.com/492818
-    if (nullptr == srcPixmap.addr()) {
-        sk_throw();
-    }
-
     SkMipMap* mipmap;
     if (fact) {
         SkDiscardableMemory* dm = fact(storageSize);
         if (nullptr == dm) {
             return nullptr;
         }
         mipmap = new SkMipMap(storageSize, dm);
     } else {
         mipmap = new SkMipMap(sk_malloc_throw(storageSize), storageSize);
     }
 
     // init
     mipmap->fCount = countLevels;
     mipmap->fLevels = (Level*)mipmap->writable_data();
 
     Level* levels = mipmap->fLevels;
     uint8_t*    baseAddr = (uint8_t*)&levels[countLevels];
     uint8_t*    addr = baseAddr;
     int         width = src.width();
     int         height = src.height();
     uint32_t    rowBytes;
-    SkPixmap    srcPM(srcPixmap);
+    SkPixmap    srcPM(src);
 
     for (int i = 0; i < countLevels; ++i) {
         FilterProc* proc;
         if (height & 1) {        // src-height is 3
             if (width & 1) {    // src-width is 3
                 proc = proc_3_3;
             } else {            // src-width is 2
                 proc = proc_2_3;
             }
         } else {                // src-height is 2
             if (width & 1) {    // src-width is 3
                 proc = proc_3_2;
             } else {            // src-width is 2
                 proc = proc_2_2;
             }
         }
         width >>= 1;
         height >>= 1;
         rowBytes = SkToU32(SkColorTypeMinRowBytes(ct, width));
 
-        levels[i].fPixels   = addr;
-        levels[i].fWidth    = width;
-        levels[i].fHeight   = height;
-        levels[i].fRowBytes = rowBytes;
-        levels[i].fScale    = (float)width / src.width();
+        levels[i].fPixmap = SkPixmap(SkImageInfo::Make(width, height, ct, at), addr, rowBytes);
+        levels[i].fScale  = (float)width / src.width();
 
-        SkPixmap dstPM(SkImageInfo::Make(width, height, ct, at), addr, rowBytes);
-
+        const SkPixmap& dstPM = levels[i].fPixmap;
         const void* srcBasePtr = srcPM.addr();
         void* dstBasePtr = dstPM.writable_addr();
 
         const size_t srcRB = srcPM.rowBytes();
         for (int y = 0; y < height; y++) {
             proc(dstBasePtr, srcBasePtr, srcRB, width);
             srcBasePtr = (char*)srcBasePtr + srcRB * 2; // jump two rows
             dstBasePtr = (char*)dstBasePtr + dstPM.rowBytes();
         }
         srcPM = dstPM;
@@ skipping 31 matching lines @@
     }
 
     if (level > fCount) {
         level = fCount;
     }
     if (levelPtr) {
         *levelPtr = fLevels[level - 1];
     }
     return true;
 }
+
+// Helper which extacts a pixmap from the src bitmap
+//
+SkMipMap* SkMipMap::Build(const SkBitmap& src, SkDiscardableFactoryProc fact) {
+    SkAutoPixmapUnlock srcUnlocker;
+    if (!src.requestLock(&srcUnlocker)) {
+        return nullptr;
+    }
+    const SkPixmap& srcPixmap = srcUnlocker.pixmap();
+    // Try to catch where we might have returned nullptr for src crbug.com/492818
+    if (nullptr == srcPixmap.addr()) {
+        sk_throw();
+    }
+    return Build(srcPixmap, fact);
+}
+