implement MakeOpaque at the canvas level, respecting matrix and clip

Review URL: http://codereview.chromium.org/7799023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@99009 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 16 insertions, 72 deletions

diff --git a/skia/ext/bitmap_platform_device.cc b/skia/ext/bitmap_platform_device.cc
index 05037c6..91b419a 100644
--- a/skia/ext/bitmap_platform_device.cc
+++ b/skia/ext/bitmap_platform_device.cc
@@ -7,65 +7,3 @@
 #include "skia/ext/bitmap_platform_device_data.h"
 #include "third_party/skia/include/core/SkUtils.h"
 
-namespace {
-
-// Constrains position and size to fit within available_size. If |size| is -1,
-// all the available_size is used. Returns false if the position is out of
-// available_size.
-bool Constrain(int available_size, int* position, int *size) {
-  if (*size < -2)
-    return false;
-
-  if (*position < 0) {
-    if (*size != -1)
-      *size += *position;
-    *position = 0;
-  }
-  if (*size == 0 || *position >= available_size)
-    return false;
-
-  if (*size > 0) {
-    int overflow = (*position + *size) - available_size;
-    if (overflow > 0) {
-      *size -= overflow;
-    }
-  } else {
-    // Fill up available size.
-    *size = available_size - *position;
-  }
-  return true;
-}
-
-}  // namespace
-
-namespace skia {
-
-void BitmapPlatformDevice::MakeOpaque(int x, int y, int width, int height) {
-  const SkBitmap& bitmap = accessBitmap(true);
-  SkASSERT(bitmap.config() == SkBitmap::kARGB_8888_Config);
-
-  // FIXME(brettw): This is kind of lame, we shouldn't be dealing with
-  // transforms at this level. Probably there should be a PlatformCanvas
-  // function that does the transform (using the actual transform not just the
-  // translation) and calls us with the transformed rect.
-  const SkMatrix& matrix = data_->transform();
-  int bitmap_start_x = SkScalarRound(matrix.getTranslateX()) + x;
-  int bitmap_start_y = SkScalarRound(matrix.getTranslateY()) + y;
-
-  if (Constrain(bitmap.width(), &bitmap_start_x, &width) &&
-      Constrain(bitmap.height(), &bitmap_start_y, &height)) {
-    SkAutoLockPixels lock(bitmap);
-    SkASSERT(bitmap.rowBytes() % sizeof(uint32_t) == 0u);
-    size_t row_words = bitmap.rowBytes() / sizeof(uint32_t);
-    // Set data to the first pixel to be modified.
-    uint32_t* data = bitmap.getAddr32(0, 0) + (bitmap_start_y * row_words) +
-                     bitmap_start_x;
-    for (int i = 0; i < height; i++) {
-      for (int j = 0; j < width; j++)
-        data[j] |= (0xFF << SK_A32_SHIFT);
-      data += row_words;
-    }
-  }
-}
-
-}
diff --git a/skia/ext/bitmap_platform_device_linux.h b/skia/ext/bitmap_platform_device_linux.h
index 57c12ce..80f4793 100644
--- a/skia/ext/bitmap_platform_device_linux.h
+++ b/skia/ext/bitmap_platform_device_linux.h
@@ -77,8 +77,6 @@ class BitmapPlatformDevice : public PlatformDevice, public SkDevice {
   static BitmapPlatformDevice* Create(int width, int height, bool is_opaque,
                                       uint8_t* data);
 
-  virtual void MakeOpaque(int x, int y, int width, int height) OVERRIDE;
-
   // Overridden from SkDevice:
   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
                              const SkClipStack&) OVERRIDE;
diff --git a/skia/ext/bitmap_platform_device_mac.h b/skia/ext/bitmap_platform_device_mac.h
index da14528..baa99ad 100644
--- a/skia/ext/bitmap_platform_device_mac.h
+++ b/skia/ext/bitmap_platform_device_mac.h
@@ -44,7 +44,6 @@ class BitmapPlatformDevice : public PlatformDevice, public SkDevice {
   virtual CGContextRef GetBitmapContext();
   virtual void DrawToNativeContext(CGContextRef context, int x, int y,
                                    const CGRect* src_rect) OVERRIDE;
-  virtual void MakeOpaque(int x, int y, int width, int height) OVERRIDE;
 
   // SkDevice overrides
   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
diff --git a/skia/ext/bitmap_platform_device_win.h b/skia/ext/bitmap_platform_device_win.h
index 5a5e466..a5415c9 100644
--- a/skia/ext/bitmap_platform_device_win.h
+++ b/skia/ext/bitmap_platform_device_win.h
@@ -52,7 +52,6 @@ class SK_API BitmapPlatformDevice : public PlatformDevice, public SkDevice {
 
   virtual void DrawToNativeContext(HDC dc, int x, int y,
                                    const RECT* src_rect) OVERRIDE;
-  virtual void MakeOpaque(int x, int y, int width, int height) OVERRIDE;
 
   // Loads the given transform and clipping region into the HDC. This is
   // overridden from SkDevice.
diff --git a/skia/ext/platform_canvas.cc b/skia/ext/platform_canvas.cc
index 279af45..f4510744 100644
--- a/skia/ext/platform_canvas.cc
+++ b/skia/ext/platform_canvas.cc
@@ -76,10 +76,23 @@ void DrawToNativeContext(SkCanvas* canvas, PlatformSurface context, int x,
     platform_device->DrawToNativeContext(context, x, y, src_rect);
 }
 
+static SkPMColor MakeOpaqueXfermodeProc(SkPMColor src, SkPMColor dst) {
+    return dst | (0xFF << SK_A32_SHIFT);
+}
+
 void MakeOpaque(SkCanvas* canvas, int x, int y, int width, int height) {
-  PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
-  if (platform_device)
-    platform_device->MakeOpaque(x, y, width, height);
+  if (width <= 0 || height <= 0)
+    return;
+
+  SkRect rect;
+  rect.setXYWH(SkIntToScalar(x), SkIntToScalar(y),
+               SkIntToScalar(width), SkIntToScalar(height));
+  SkPaint paint;
+  // so we don't draw anything on a device that ignores xfermodes
+  paint.setColor(0);
+  // install our custom mode
+  paint.setXfermode(new SkProcXfermode(MakeOpaqueXfermodeProc))->unref();
+  canvas->drawRect(rect, paint);
 }
 
 }  // namespace skia
diff --git a/skia/ext/platform_device.h b/skia/ext/platform_device.h
index 55ef1f8..2e441be 100644
--- a/skia/ext/platform_device.h
+++ b/skia/ext/platform_device.h
@@ -109,9 +109,6 @@ class SK_API PlatformDevice {
   virtual void DrawToNativeContext(PlatformSurface surface, int x, int y,
                                    const PlatformRect* src_rect) = 0;
 
-  // Sets the opacity of each pixel in the specified region to be opaque.
-  virtual void MakeOpaque(int x, int y, int width, int height) { }
-
   // Returns if GDI is allowed to render text to this device.
   virtual bool IsNativeFontRenderingAllowed();