1 files changed, 226 insertions, 0 deletions
diff --git a/gfx/2d/DrawTargetOffset.cpp b/gfx/2d/DrawTargetOffset.cpp
new file mode 100644
index 0000000000..cc49cf0493
--- /dev/null
+++ b/gfx/2d/DrawTargetOffset.cpp
@@ -0,0 +1,226 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DrawTargetOffset.h"
+#include "Logging.h"
+#include "PathHelpers.h"
+
+namespace mozilla {
+namespace gfx {
+
+DrawTargetOffset::DrawTargetOffset() = default;
+
+bool DrawTargetOffset::Init(DrawTarget* aDrawTarget, IntPoint aOrigin) {
+  mDrawTarget = aDrawTarget;
+  mOrigin = aOrigin;
+  mDrawTarget->SetTransform(Matrix::Translation(-mOrigin.x, -mOrigin.y));
+  mFormat = mDrawTarget->GetFormat();
+  SetPermitSubpixelAA(IsOpaque(mFormat));
+  return true;
+}
+
+already_AddRefed<SourceSurface> DrawTargetOffset::Snapshot() {
+  RefPtr<SourceSurface> snapshot = mDrawTarget->Snapshot();
+
+  if (!snapshot) {
+    return nullptr;
+  }
+
+  return MakeAndAddRef<SourceSurfaceOffset>(snapshot, mOrigin);
+}
+
+void DrawTargetOffset::DetachAllSnapshots() {}
+
+// Skip the mClippedOut check since this is only used for Flush() which
+// should happen even if we're clipped.
+#define OFFSET_COMMAND(command) \
+  void DrawTargetOffset::command() { mDrawTarget->command(); }
+#define OFFSET_COMMAND1(command, type1) \
+  void DrawTargetOffset::command(type1 arg1) { mDrawTarget->command(arg1); }
+#define OFFSET_COMMAND3(command, type1, type2, type3)                  \
+  void DrawTargetOffset::command(type1 arg1, type2 arg2, type3 arg3) { \
+    mDrawTarget->command(arg1, arg2, arg3);                            \
+  }
+#define OFFSET_COMMAND4(command, type1, type2, type3, type4)         \
+  void DrawTargetOffset::command(type1 arg1, type2 arg2, type3 arg3, \
+                                 type4 arg4) {                       \
+    mDrawTarget->command(arg1, arg2, arg3, arg4);                    \
+  }
+#define OFFSET_COMMAND5(command, type1, type2, type3, type4, type5)  \
+  void DrawTargetOffset::command(type1 arg1, type2 arg2, type3 arg3, \
+                                 type4 arg4, type5 arg5) {           \
+    mDrawTarget->command(arg1, arg2, arg3, arg4, arg5);              \
+  }
+
+OFFSET_COMMAND(Flush)
+OFFSET_COMMAND1(ClearRect, const Rect&)
+OFFSET_COMMAND4(MaskSurface, const Pattern&, SourceSurface*, Point,
+                const DrawOptions&)
+OFFSET_COMMAND4(FillGlyphs, ScaledFont*, const GlyphBuffer&, const Pattern&,
+                const DrawOptions&)
+OFFSET_COMMAND5(StrokeGlyphs, ScaledFont*, const GlyphBuffer&, const Pattern&,
+                const StrokeOptions&, const DrawOptions&)
+OFFSET_COMMAND3(FillRoundedRect, const RoundedRect&, const Pattern&,
+                const DrawOptions&)
+
+bool DrawTargetOffset::Draw3DTransformedSurface(SourceSurface* aSrc,
+                                                const Matrix4x4& aMatrix) {
+  return mDrawTarget->Draw3DTransformedSurface(aSrc, aMatrix);
+}
+
+OFFSET_COMMAND3(Mask, const Pattern&, const Pattern&, const DrawOptions&)
+
+void DrawTargetOffset::DrawFilter(FilterNode* aNode, const Rect& aSourceRect,
+                                  const Point& aDestPoint,
+                                  const DrawOptions& aOptions) {
+  auto clone = mTransform;
+  bool invertible = clone.Invert();
+  // aSourceRect is in filter space. The filter outputs from aSourceRect need
+  // to be drawn at aDestPoint in user space.
+  Rect userSpaceSource = Rect(aDestPoint, aSourceRect.Size());
+  if (invertible) {
+    // Try to reduce the source rect so that it's not much bigger
+    // than the draw target. The result is not minimal. Examples
+    // are left as an exercise for the reader.
+    auto destRect = Rect(mDrawTarget->GetRect() + mOrigin);
+    Rect userSpaceBounds = clone.TransformBounds(destRect);
+    userSpaceSource = userSpaceSource.Intersect(userSpaceBounds);
+  }
+
+  // Compute how much we moved the top-left of the source rect by, and use that
+  // to compute the new dest point, and move our intersected source rect back
+  // into the (new) filter space.
+  Point shift = userSpaceSource.TopLeft() - aDestPoint;
+  Rect filterSpaceSource =
+      Rect(aSourceRect.TopLeft() + shift, userSpaceSource.Size());
+  mDrawTarget->DrawFilter(aNode, filterSpaceSource, aDestPoint + shift,
+                          aOptions);
+}
+
+void DrawTargetOffset::PushClip(const Path* aPath) {
+  mDrawTarget->PushClip(aPath);
+}
+
+void DrawTargetOffset::PushClipRect(const Rect& aRect) {
+  mDrawTarget->PushClipRect(aRect);
+}
+
+void DrawTargetOffset::PopClip() { mDrawTarget->PopClip(); }
+
+void DrawTargetOffset::CopySurface(SourceSurface* aSurface,
+                                   const IntRect& aSourceRect,
+                                   const IntPoint& aDestination) {
+  IntPoint tileOrigin = mOrigin;
+  // CopySurface ignores the transform, account for that here.
+  mDrawTarget->CopySurface(aSurface, aSourceRect, aDestination - tileOrigin);
+}
+
+void DrawTargetOffset::SetTransform(const Matrix& aTransform) {
+  Matrix mat = aTransform;
+  mat.PostTranslate(Float(-mOrigin.x), Float(-mOrigin.y));
+  mDrawTarget->SetTransform(mat);
+
+  DrawTarget::SetTransform(aTransform);
+}
+
+void DrawTargetOffset::SetPermitSubpixelAA(bool aPermitSubpixelAA) {
+  mDrawTarget->SetPermitSubpixelAA(aPermitSubpixelAA);
+}
+
+void DrawTargetOffset::DrawSurface(SourceSurface* aSurface, const Rect& aDest,
+                                   const Rect& aSource,
+                                   const DrawSurfaceOptions& aSurfaceOptions,
+                                   const DrawOptions& aDrawOptions) {
+  mDrawTarget->DrawSurface(aSurface, aDest, aSource, aSurfaceOptions,
+                           aDrawOptions);
+}
+
+void DrawTargetOffset::FillRect(const Rect& aRect, const Pattern& aPattern,
+                                const DrawOptions& aDrawOptions) {
+  mDrawTarget->FillRect(aRect, aPattern, aDrawOptions);
+}
+
+void DrawTargetOffset::Stroke(const Path* aPath, const Pattern& aPattern,
+                              const StrokeOptions& aStrokeOptions,
+                              const DrawOptions& aDrawOptions) {
+  mDrawTarget->Stroke(aPath, aPattern, aStrokeOptions, aDrawOptions);
+}
+
+void DrawTargetOffset::StrokeRect(const Rect& aRect, const Pattern& aPattern,
+                                  const StrokeOptions& aStrokeOptions,
+                                  const DrawOptions& aDrawOptions) {
+  mDrawTarget->StrokeRect(aRect, aPattern, aStrokeOptions, aDrawOptions);
+}
+
+void DrawTargetOffset::StrokeLine(const Point& aStart, const Point& aEnd,
+                                  const Pattern& aPattern,
+                                  const StrokeOptions& aStrokeOptions,
+                                  const DrawOptions& aDrawOptions) {
+  mDrawTarget->StrokeLine(aStart, aEnd, aPattern, aStrokeOptions, aDrawOptions);
+}
+
+void DrawTargetOffset::Fill(const Path* aPath, const Pattern& aPattern,
+                            const DrawOptions& aDrawOptions) {
+  mDrawTarget->Fill(aPath, aPattern, aDrawOptions);
+}
+
+void DrawTargetOffset::PushLayer(bool aOpaque, Float aOpacity,
+                                 SourceSurface* aMask,
+                                 const Matrix& aMaskTransform,
+                                 const IntRect& aBounds, bool aCopyBackground) {
+  IntRect bounds = aBounds - mOrigin;
+
+  mDrawTarget->PushLayer(aOpaque, aOpacity, aMask, aMaskTransform, bounds,
+                         aCopyBackground);
+  SetPermitSubpixelAA(mDrawTarget->GetPermitSubpixelAA());
+}
+
+already_AddRefed<SourceSurface> DrawTargetOffset::IntoLuminanceSource(
+    LuminanceType aLuminanceType, float aOpacity) {
+  RefPtr<SourceSurface> surface =
+      mDrawTarget->IntoLuminanceSource(aLuminanceType, aOpacity);
+
+  if (!surface) {
+    return nullptr;
+  }
+
+  return MakeAndAddRef<SourceSurfaceOffset>(surface, mOrigin);
+}
+
+void DrawTargetOffset::PushLayerWithBlend(bool aOpaque, Float aOpacity,
+                                          SourceSurface* aMask,
+                                          const Matrix& aMaskTransform,
+                                          const IntRect& aBounds,
+                                          bool aCopyBackground,
+                                          CompositionOp aOp) {
+  IntRect bounds = aBounds - mOrigin;
+
+  mDrawTarget->PushLayerWithBlend(aOpaque, aOpacity, aMask, aMaskTransform,
+                                  bounds, aCopyBackground, aOp);
+  SetPermitSubpixelAA(mDrawTarget->GetPermitSubpixelAA());
+}
+
+void DrawTargetOffset::PopLayer() {
+  mDrawTarget->PopLayer();
+  SetPermitSubpixelAA(mDrawTarget->GetPermitSubpixelAA());
+}
+
+RefPtr<DrawTarget> DrawTargetOffset::CreateClippedDrawTarget(
+    const Rect& aBounds, SurfaceFormat aFormat) {
+  RefPtr<DrawTarget> result;
+  RefPtr<DrawTarget> dt =
+      mDrawTarget->CreateClippedDrawTarget(aBounds, aFormat);
+  if (dt) {
+    result = gfx::Factory::CreateOffsetDrawTarget(dt, mOrigin);
+    if (result) {
+      result->SetTransform(mTransform);
+    }
+  }
+  return result;
+}
+
+}  // namespace gfx
+}  // namespace mozilla