Replace setMatrixClip() with BeginPlatformPaint() logic

skia/ext/bitmap_platform_device_mac.cc

Index: skia/ext/bitmap_platform_device_mac.cc
diff --git a/skia/ext/bitmap_platform_device_mac.cc b/skia/ext/bitmap_platform_device_mac.cc
index e1df85e6807b7f5a4875386c4816dd6ac413766a..06a41390b5db0dc44810b7a373df9537238a49bf 100644
--- a/skia/ext/bitmap_platform_device_mac.cc
+++ b/skia/ext/bitmap_platform_device_mac.cc
@@ -15,7 +15,7 @@
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkPath.h"
-#include "third_party/skia/include/core/SkRegion.h"
+#include "third_party/skia/include/core/SkRect.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
 namespace skia {
@@ -77,14 +77,6 @@ void BitmapPlatformDevice::ReleaseBitmapContext() {
   bitmap_context_ = NULL;
 }
 
-void BitmapPlatformDevice::SetMatrixClip(
-    const SkMatrix& transform,
-    const SkRegion& region) {
-  transform_ = transform;
-  clip_region_ = region;
-  config_dirty_ = true;
-}
-
 // Loads the specified Skia transform into the device context
 static void LoadTransformToCGContext(CGContextRef context,
                                      const SkMatrix& matrix) {
@@ -118,49 +110,29 @@ static void LoadTransformToCGContext(CGContextRef context,
   CGContextConcatCTM(context, cg_matrix);
 }
 
-// Loads a SkRegion into the CG context.
 static void LoadClippingRegionToCGContext(CGContextRef context,
-                                          const SkRegion& region,
+                                          const SkIRect& clip_bounds,
                                           const SkMatrix& transformation) {
-  if (region.isEmpty()) {
-    // region can be empty, in which case everything will be clipped.
-    SkRect rect;
-    rect.setEmpty();
-    CGContextClipToRect(context, skia::SkRectToCGRect(rect));
-  } else if (region.isRect()) {
-    // CoreGraphics applies the current transform to clip rects, which is
-    // unwanted. Inverse-transform the rect before sending it to CG. This only
-    // works for translations and scaling, but not for rotations (but the
-    // viewport is never rotated anyway).
-    SkMatrix t;
-    bool did_invert = transformation.invert(&t);
-    if (!did_invert)
-      t.reset();
-    // Do the transformation.
-    SkRect rect;
-    rect.set(region.getBounds());
-    t.mapRect(&rect);
-    SkIRect irect;
-    rect.round(&irect);
-    CGContextClipToRect(context, skia::SkIRectToCGRect(irect));
-  } else {
-    // It is complex.
-    SkPath path;
-    region.getBoundaryPath(&path);
-    // Clip. Note that windows clipping regions are not affected by the
-    // transform so apply it manually.
-    path.transform(transformation);
-    // TODO(playmobil): Implement.
-    SkASSERT(false);
-    // LoadPathToDC(context, path);
-    // hrgn = PathToRegion(context);
-  }
+  // CoreGraphics applies the current transform to clip rects, which is
+  // unwanted. Inverse-transform the rect before sending it to CG. This only
+  // works for translations and scaling, but not for rotations (but the
+  // viewport is never rotated anyway).
+  SkMatrix t;
+  bool did_invert = transformation.invert(&t);
+  if (!did_invert)
+    t.reset();
+
+  SkRect rect = SkRect::Make(clip_bounds);
+  t.mapRect(&rect);
+  SkIRect irect;
+  rect.round(&irect);
+  CGContextClipToRect(context, skia::SkIRectToCGRect(irect));
 }
 
-void BitmapPlatformDevice::LoadConfig() {
-  if (!config_dirty_ || !bitmap_context_)
+void BitmapPlatformDevice::LoadConfig(const SkMatrix& transform,
+                                      const SkIRect& clip_bounds) {
+  if (!bitmap_context_)
     return;  // Nothing to do.
-  config_dirty_ = false;
 
   // We must restore and then save the state of the graphics context since the
   // calls to Load the clipping region to the context are strictly cummulative,
@@ -170,8 +142,8 @@ void BitmapPlatformDevice::LoadConfig() {
   // calls in LoadClippingRegionToCGContext() with an image mask instead.
   CGContextRestoreGState(bitmap_context_);
   CGContextSaveGState(bitmap_context_);
-  LoadTransformToCGContext(bitmap_context_, transform_);
-  LoadClippingRegionToCGContext(bitmap_context_, clip_region_, transform_);
+  LoadTransformToCGContext(bitmap_context_, transform);
+  LoadClippingRegionToCGContext(bitmap_context_, clip_bounds, transform);
 }
 
 
@@ -252,9 +224,7 @@ BitmapPlatformDevice* BitmapPlatformDevice::CreateWithData(uint8_t* data,
 BitmapPlatformDevice::BitmapPlatformDevice(
     CGContextRef context, const SkBitmap& bitmap)
     : SkBitmapDevice(bitmap),
-      bitmap_context_(context),
-      config_dirty_(true),  // Want to load the config next time.
-      transform_(SkMatrix::I()) {
+      bitmap_context_(context) {
   SetPlatformDevice(this, this);
   SkASSERT(bitmap_context_);
   // Initialize the clip region to the entire bitmap.
@@ -263,7 +233,6 @@ BitmapPlatformDevice::BitmapPlatformDevice(
   rect.set(0, 0,
            CGBitmapContextGetWidth(bitmap_context_),
            CGBitmapContextGetHeight(bitmap_context_));
-  clip_region_ = SkRegion(rect);
   CGContextRetain(bitmap_context_);
   // We must save the state once so that we can use the restore/save trick
   // in LoadConfig().
@@ -275,17 +244,12 @@ BitmapPlatformDevice::~BitmapPlatformDevice() {
     CGContextRelease(bitmap_context_);
 }
 
-CGContextRef BitmapPlatformDevice::GetBitmapContext() {
-  LoadConfig();
+CGContextRef BitmapPlatformDevice::GetBitmapContext(const SkMatrix& transform,
+                                                    const SkIRect& clip_bounds) {
+  LoadConfig(transform, clip_bounds);
   return bitmap_context_;
 }
 
-void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
-                                         const SkRegion& region,
-                                         const SkClipStack&) {
-  SetMatrixClip(transform, region);
-}
-
 SkBaseDevice* BitmapPlatformDevice::onCreateDevice(const CreateInfo& cinfo,
                                                    const SkPaint*) {
   const SkImageInfo& info = cinfo.fInfo;