add new readPixels with direct memory parameters

src/core/SkBitmapDevice.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 "SkBitmapDevice.h"
 #include "SkConfig8888.h"
 #include "SkDraw.h"
@@ skipping 155 matching lines @@
 bool SkBitmapDevice::filterImage(const SkImageFilter* filter, const SkBitmap& src,
                                  const SkImageFilter::Context& ctx, SkBitmap* result,
                                  SkIPoint* offset) {
     return false;
 }
 
 bool SkBitmapDevice::allowImageFilter(const SkImageFilter*) {
     return true;
 }
 
+#ifdef SK_SUPPORT_LEGACY_READPIXELSCONFIG
 bool SkBitmapDevice::onReadPixels(const SkBitmap& bitmap,
                                   int x, int y,
                                   SkCanvas::Config8888 config8888) {
     SkASSERT(SkBitmap::kARGB_8888_Config == bitmap.config());
     SkASSERT(!bitmap.isNull());
     SkASSERT(SkIRect::MakeWH(this->width(), this->height()).contains(SkIRect::MakeXYWH(x, y,
                                                                           bitmap.width(),
                                                                           bitmap.height())));
 
     SkIRect srcRect = SkIRect::MakeXYWH(x, y, bitmap.width(), bitmap.height());
     const SkBitmap& src = this->accessBitmap(false);
 
     SkBitmap subset;
     if (!src.extractSubset(&subset, srcRect)) {
         return false;
     }
     if (kPMColor_SkColorType != subset.colorType()) {
         // It'd be preferable to do this directly to bitmap.
         subset.copyTo(&subset, kPMColor_SkColorType);
     }
     SkAutoLockPixels alp(bitmap);
     uint32_t* bmpPixels = reinterpret_cast<uint32_t*>(bitmap.getPixels());
     SkCopyBitmapToConfig8888(bmpPixels, bitmap.rowBytes(), config8888, subset);
     return true;
 }
+#endif
 
 void* SkBitmapDevice::onAccessPixels(SkImageInfo* info, size_t* rowBytes) {
     if (fBitmap.getPixels()) {
         *info = fBitmap.info();
         *rowBytes = fBitmap.rowBytes();
         return fBitmap.getPixels();
     }
     return NULL;
 }
 
@@ skipping 28 matching lines @@
         case kBGRA_8888_SkColorType:
             *config = pre ? SkCanvas::kBGRA_Premul_Config8888 : SkCanvas::kBGRA_Unpremul_Config8888;
             return true;
         default:
             return false;
     }
 }
 
 // TODO: make this guy real, and not rely on legacy config8888 utility
 #include "SkConfig8888.h"
-static bool write_pixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
-                         const SkImageInfo& srcInfo, const void* srcPixels, size_t srcRowBytes) {
+static bool copy_pixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
+                        const SkImageInfo& srcInfo, const void* srcPixels, size_t srcRowBytes) {
     if (srcInfo.dimensions() != dstInfo.dimensions()) {
         return false;
     }
     if (4 == srcInfo.bytesPerPixel() && 4 == dstInfo.bytesPerPixel()) {
         SkCanvas::Config8888 srcConfig, dstConfig;
         if (!info2config8888(srcInfo, &srcConfig) || !info2config8888(dstInfo, &dstConfig)) {
             return false;
         }
         SkConvertConfig8888Pixels((uint32_t*)dstPixels, dstRowBytes, dstConfig,
                                   (const uint32_t*)srcPixels, srcRowBytes, srcConfig,
@@ skipping 27 matching lines @@
         return false;
     }
 
     SkImageInfo dstInfo = fBitmap.info();
     dstInfo.fWidth = srcInfo.width();
     dstInfo.fHeight = srcInfo.height();
 
     void* dstPixels = fBitmap.getAddr(x, y);
     size_t dstRowBytes = fBitmap.rowBytes();
 
-    if (write_pixels(dstInfo, dstPixels, dstRowBytes, srcInfo, srcPixels, srcRowBytes)) {
+    if (copy_pixels(dstInfo, dstPixels, dstRowBytes, srcInfo, srcPixels, srcRowBytes)) {
         fBitmap.notifyPixelsChanged();
         return true;
     }
     return false;
 }
 
+bool SkBitmapDevice::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
+                                  int x, int y) {
+    // since we don't stop creating un-pixeled devices yet, check for no pixels here
+    if (NULL == fBitmap.getPixels()) {
+        return false;
+    }
+    
+    SkImageInfo srcInfo = fBitmap.info();
+
+    // perhaps can relax these in the future
+    if (4 != dstInfo.bytesPerPixel()) {
+        return false;
+    }
+    if (4 != srcInfo.bytesPerPixel()) {
+        return false;
+    }
+
+    srcInfo.fWidth = dstInfo.width();
+    srcInfo.fHeight = dstInfo.height();
+    
+    const void* srcPixels = fBitmap.getAddr(x, y);
+    const size_t srcRowBytes = fBitmap.rowBytes();
+
+    return copy_pixels(dstInfo, dstPixels, dstRowBytes, srcInfo, srcPixels, srcRowBytes);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkBitmapDevice::drawPaint(const SkDraw& draw, const SkPaint& paint) {
     draw.drawPaint(paint);
 }
 
 void SkBitmapDevice::drawPoints(const SkDraw& draw, SkCanvas::PointMode mode, size_t count,
                                 const SkPoint pts[], const SkPaint& paint) {
     CHECK_FOR_ANNOTATION(paint);
     draw.drawPoints(mode, count, pts, paint);
@@ skipping 196 matching lines @@
         paint.getStyle() != SkPaint::kFill_Style ||
         !SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode)) {
         // turn off lcd
         flags->fFlags = paint.getFlags() & ~SkPaint::kLCDRenderText_Flag;
         flags->fHinting = paint.getHinting();
         return true;
     }
     // we're cool with the paint as is
     return false;
 }