Add SkCanvas::writePixels that takes info+pixels directly

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 248 matching lines @@
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     SkRasterClip clip(SkIRect::MakeWH(fBitmap.width(), fBitmap.height()));
     SkDraw  draw;
     draw.fRC = &clip;
     draw.fClip = &clip.bwRgn();
     draw.fBitmap = &fBitmap; // canvas should have already called accessBitmap
     draw.fMatrix = &SkMatrix::I();
     this->drawSprite(draw, *sprite, x, y, paint);
 }
 
+static void rect_memcpy(void* dst, size_t dstRB, const void* src, size_t srcRB, size_t bytesPerRow,
+                        int rowCount) {
+    SkASSERT(bytesPerRow <= srcRB);
+    SkASSERT(bytesPerRow <= dstRB);
+    for (int i = 0; i < rowCount; ++i) {
+        memcpy(dst, src, bytesPerRow);
+        dst = (char*)dst + dstRB;
+        src = (const char*)src + srcRB;
+    }
+}
+
+static bool info2config8888(const SkImageInfo& info, SkCanvas::Config8888* config) {
+    bool pre;
+    switch (info.alphaType()) {
+        case kPremul_SkAlphaType:
+        case kOpaque_SkAlphaType:
+            pre = true;
+            break;
+        case kUnpremul_SkAlphaType:
+            pre = false;
+            break;
+        default:
+            return false;
+    }
+    switch (info.colorType()) {
+        case kRGBA_8888_SkColorType:
+            *config = pre ? SkCanvas::kRGBA_Premul_Config8888 : SkCanvas::kRGBA_Unpremul_Config8888;
+            return true;
+        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) {
+    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,
+                                  srcInfo.width(), srcInfo.height());
+        return true;
+    }
+    if (srcInfo.colorType() == dstInfo.colorType()) {
+        switch (srcInfo.colorType()) {
+            case kRGB_565_SkColorType:
+            case kAlpha_8_SkColorType:
+                break;
+            case kARGB_4444_SkColorType:
+                if (srcInfo.alphaType() != dstInfo.alphaType()) {
+                    return false;
+                }
+                break;
+            default:
+                return false;
+        }
+        rect_memcpy(dstPixels, dstRowBytes, srcPixels, srcRowBytes,
+                    srcInfo.width() * srcInfo.bytesPerPixel(), srcInfo.height());
+    }
+    // TODO: add support for more conversions as needed
+    return false;
+}
+
+bool SkBitmapDevice::onWritePixelsDirect(const SkImageInfo& srcInfo, const void* srcPixels,
+                                         size_t srcRowBytes, int x, int y) {
+    SkImageInfo dstInfo = fBitmap.info();
+    dstInfo.fWidth = srcInfo.width();
+    dstInfo.fHeight = srcInfo.height();
+
+    void* dstPixels = fBitmap.getAddr(x, y);
+    size_t dstRowBytes = fBitmap.rowBytes();
+
+    return write_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;
 }