Index: cc/resources/raster_source_helper.cc |
diff --git a/cc/resources/raster_source_helper.cc b/cc/resources/raster_source_helper.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f7ef305a65a4cdc1dc7d8e4263f852d564b201ba |
--- /dev/null |
+++ b/cc/resources/raster_source_helper.cc |
@@ -0,0 +1,81 @@ |
+// Copyright 2014 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#include "cc/resources/raster_source_helper.h" |
+ |
+#include "base/debug/trace_event.h" |
+#include "cc/debug/debug_colors.h" |
+#include "third_party/skia/include/core/SkCanvas.h" |
+#include "ui/gfx/geometry/rect_conversions.h" |
+#include "ui/gfx/skia_util.h" |
+ |
+namespace cc { |
+ |
+void RasterSourceHelper::PrepareForPlaybackToCanvas( |
+ SkCanvas* canvas, |
+ const gfx::Rect& canvas_rect, |
+ const gfx::Rect& source_rect, |
+ float contents_scale, |
+ SkColor background_color, |
+ bool clear_canvas_with_debug_color, |
+ bool requires_clear) { |
+ canvas->discard(); |
+ if (clear_canvas_with_debug_color) { |
+ // Any non-painted areas in the content bounds will be left in this color. |
+ canvas->clear(DebugColors::NonPaintedFillColor()); |
+ } |
+ |
+ // If this raster source has opaque contents, it is guaranteeing that it will |
+ // draw an opaque rect the size of the layer. If it is not, then we must |
+ // clear this canvas ourselves. |
+ if (requires_clear) { |
+ TRACE_EVENT_INSTANT0("cc", "SkCanvas::clear", TRACE_EVENT_SCOPE_THREAD); |
+ // Clearing is about ~4x faster than drawing a rect even if the content |
+ // isn't covering a majority of the canvas. |
+ canvas->clear(SK_ColorTRANSPARENT); |
+ } else { |
+ // Even if completely covered, for rasterizations that touch the edge of the |
+ // layer, we also need to raster the background color underneath the last |
+ // texel (since the recording won't cover it) and outside the last texel |
+ // (due to linear filtering when using this texture). |
+ gfx::Rect content_rect = |
+ gfx::ToEnclosingRect(gfx::ScaleRect(source_rect, contents_scale)); |
+ |
+ // The final texel of content may only be partially covered by a |
+ // rasterization; this rect represents the content rect that is fully |
+ // covered by content. |
+ gfx::Rect deflated_content_rect = content_rect; |
+ deflated_content_rect.Inset(0, 0, 1, 1); |
+ if (!deflated_content_rect.Contains(canvas_rect)) { |
+ if (clear_canvas_with_debug_color) { |
+ // Any non-painted areas outside of the content bounds are left in |
+ // this color. If this is seen then it means that cc neglected to |
+ // rerasterize a tile that used to intersect with the content rect |
+ // after the content bounds grew. |
+ canvas->save(); |
+ canvas->translate(-canvas_rect.x(), -canvas_rect.y()); |
+ canvas->clipRect(gfx::RectToSkRect(content_rect), |
+ SkRegion::kDifference_Op); |
+ canvas->drawColor(DebugColors::MissingResizeInvalidations(), |
+ SkXfermode::kSrc_Mode); |
+ canvas->restore(); |
+ } |
+ |
+ // Drawing at most 2 x 2 x (canvas width + canvas height) texels is 2-3X |
+ // faster than clearing, so special case this. |
+ canvas->save(); |
+ canvas->translate(-canvas_rect.x(), -canvas_rect.y()); |
+ gfx::Rect inflated_content_rect = content_rect; |
+ inflated_content_rect.Inset(0, 0, -1, -1); |
+ canvas->clipRect(gfx::RectToSkRect(inflated_content_rect), |
+ SkRegion::kReplace_Op); |
+ canvas->clipRect(gfx::RectToSkRect(deflated_content_rect), |
+ SkRegion::kDifference_Op); |
+ canvas->drawColor(background_color, SkXfermode::kSrc_Mode); |
+ canvas->restore(); |
+ } |
+ } |
+} |
+ |
+} // namespace cc |