Bug 1451761. Only paint the dirty rect. r=mstange

gfx/webrender_bindings/Moz2DImageRenderer.cpp

@@ -168,6 +168,7 @@ static bool Moz2DRenderCallback(const Range<const uint8_t> aBlob,
                                 gfx::SurfaceFormat aFormat,
                                 const uint16_t *aTileSize,
                                 const mozilla::wr::TileOffset *aTileOffset,
+                                const mozilla::wr::DeviceUintRect *aDirtyRect,
                                 Range<uint8_t> aOutput)
 {
   MOZ_ASSERT(aSize.width > 0 && aSize.height > 0);
@@ -197,6 +198,11 @@ static bool Moz2DRenderCallback(const Range<const uint8_t> aBlob,
     return false;
   }
 
+  if (aDirtyRect) {
+    Rect dirty(aDirtyRect->origin.x, aDirtyRect->origin.y, aDirtyRect->size.width, aDirtyRect->size.height);
+    dt->PushClipRect(dirty);
+  }
+
   if (aTileOffset) {
     // It's overkill to use a TiledDrawTarget for a single tile
     // but it was the easiest way to get the offset handling working
@@ -262,6 +268,18 @@ static bool Moz2DRenderCallback(const Range<const uint8_t> aBlob,
     offset = extra_end;
   }
 
+#if 0
+  dt->SetTransform(gfx::Matrix());
+  float r = float(rand()) / RAND_MAX;
+  float g = float(rand()) / RAND_MAX;
+  float b = float(rand()) / RAND_MAX;
+  dt->FillRect(gfx::Rect(0, 0, aSize.width, aSize.height), gfx::ColorPattern(gfx::Color(r, g, b, 0.5)));
+#endif
+
+  if (aDirtyRect) {
+    dt->PopClip();
+  }
+
 #if 0
   static int i = 0;
   char filename[40];
@@ -282,6 +300,7 @@ bool wr_moz2d_render_cb(const mozilla::wr::ByteSlice blob,
                         mozilla::wr::ImageFormat aFormat,
                         const uint16_t *aTileSize,
                         const mozilla::wr::TileOffset *aTileOffset,
+                        const mozilla::wr::DeviceUintRect *aDirtyRect,
                         mozilla::wr::MutByteSlice output)
 {
   return mozilla::wr::Moz2DRenderCallback(mozilla::wr::ByteSliceToRange(blob),
@@ -289,6 +308,7 @@ bool wr_moz2d_render_cb(const mozilla::wr::ByteSlice blob,
                                           mozilla::wr::ImageFormatToSurfaceFormat(aFormat),
                                           aTileSize,
                                           aTileOffset,
+                                          aDirtyRect,
                                           mozilla::wr::MutByteSliceToRange(output));
 }
 

gfx/webrender_bindings/src/bindings.rs

@@ -2177,6 +2177,7 @@ extern "C" {
                                format: ImageFormat,
                                tile_size: *const u16,
                                tile_offset: *const TileOffset,
+                               dirty_rect: *const DeviceUintRect,
                                output: MutByteSlice)
                                -> bool;
 }

gfx/webrender_bindings/src/moz2d_renderer.rs

@@ -366,7 +366,7 @@ impl BlobImageRenderer for Moz2dImageRenderer {
                resources: &BlobImageResources,
                request: BlobImageRequest,
                descriptor: &BlobImageDescriptor,
-               _dirty_rect: Option<DeviceUintRect>) {
+               dirty_rect: Option<DeviceUintRect>) {
         debug_assert!(!self.rendered_images.contains_key(&request), "{:?}", request);
         // TODO: implement tiling.
 
@@ -440,6 +440,7 @@ impl BlobImageRenderer for Moz2dImageRenderer {
                     descriptor.format,
                     option_to_nullable(&tile_size),
                     option_to_nullable(&request.tile),
+                    option_to_nullable(&dirty_rect),
                     MutByteSlice::new(output.as_mut_slice())
                 ) {
 

gfx/webrender_bindings/webrender_ffi_generated.h

@@ -733,6 +733,8 @@ struct ByteSlice {
 
 using TileOffset = TypedPoint2D<uint16_t, Tiles>;
 
+using DeviceUintRect = TypedRect<uint32_t, DevicePixel>;
+
 struct MutByteSlice {
   uint8_t *buffer;
   uintptr_t len;
@@ -909,8 +911,6 @@ struct FontInstancePlatformOptions {
 };
 #endif
 
-using DeviceUintRect = TypedRect<uint32_t, DevicePixel>;
-
 struct WrOpacityProperty {
   uint64_t id;
   float opacity;
@@ -1344,6 +1344,7 @@ extern bool wr_moz2d_render_cb(ByteSlice aBlob,
                                ImageFormat aFormat,
                                const uint16_t *aTileSize,
                                const TileOffset *aTileOffset,
+                               const DeviceUintRect *aDirtyRect,
                                MutByteSlice aOutput);
 
 extern void wr_notifier_external_event(WrWindowId aWindowId,