gfx/thebes/gfxQuartzNativeDrawing.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "gfxQuartzNativeDrawing.h"
   7 #include "gfxPlatform.h"
   8 #include "mozilla/gfx/Helpers.h"
   9
  10 using namespace mozilla::gfx;
  11 using namespace mozilla;
  12
  13 gfxQuartzNativeDrawing::gfxQuartzNativeDrawing(DrawTarget& aDrawTarget,
  14                                                const Rect& nativeRect)
  15     : mDrawTarget(&aDrawTarget), mNativeRect(nativeRect), mCGContext(nullptr) {}
  16
  17 CGContextRef gfxQuartzNativeDrawing::BeginNativeDrawing() {
  18   NS_ASSERTION(!mCGContext,
  19                "BeginNativeDrawing called when drawing already in progress");
  20
  21   DrawTarget* dt = mDrawTarget;
  22   if (dt->IsTiledDrawTarget() || dt->GetBackendType() != BackendType::SKIA ||
  23       dt->IsRecording()) {
  24     // We need a DrawTarget that we can get a CGContextRef from:
  25     Matrix transform = dt->GetTransform();
  26
  27     mNativeRect = transform.TransformBounds(mNativeRect);
  28     mNativeRect.RoundOut();
  29     if (mNativeRect.IsEmpty()) {
  30       return nullptr;
  31     }
  32
  33     mTempDrawTarget = Factory::CreateDrawTarget(
  34         BackendType::SKIA,
  35         IntSize::Truncate(mNativeRect.width, mNativeRect.height),
  36         SurfaceFormat::B8G8R8A8);
  37     if (!mTempDrawTarget) {
  38       return nullptr;
  39     }
  40
  41     transform.PostTranslate(-mNativeRect.x, -mNativeRect.y);
  42     mTempDrawTarget->SetTransform(transform);
  43
  44     dt = mTempDrawTarget;
  45   } else {
  46     // Clip the DT in case BorrowedCGContext needs to create a new layer.
  47     // This prevents it from creating a new layer the size of the window.
  48     // But make sure that this clip is device pixel aligned.
  49     Matrix transform = dt->GetTransform();
  50
  51     Rect deviceRect = transform.TransformBounds(mNativeRect);
  52     deviceRect.RoundOut();
  53     mNativeRect = transform.Inverse().TransformBounds(deviceRect);
  54     mDrawTarget->PushClipRect(mNativeRect);
  55   }
  56
  57   MOZ_ASSERT(dt->GetBackendType() == BackendType::SKIA);
  58   mCGContext = mBorrowedContext.Init(dt);
  59
  60   if (NS_WARN_IF(!mCGContext)) {
  61     // Failed borrowing CG context, so we need to clean up.
  62     if (!mTempDrawTarget) {
  63       mDrawTarget->PopClip();
  64     }
  65     return nullptr;
  66   }
  67
  68   return mCGContext;
  69 }
  70
  71 void gfxQuartzNativeDrawing::EndNativeDrawing() {
  72   NS_ASSERTION(mCGContext,
  73                "EndNativeDrawing called without BeginNativeDrawing");
  74
  75   mBorrowedContext.Finish();
  76   if (mTempDrawTarget) {
  77     RefPtr<SourceSurface> source = mTempDrawTarget->Snapshot();
  78
  79     AutoRestoreTransform autoRestore(mDrawTarget);
  80     mDrawTarget->SetTransform(Matrix());
  81     mDrawTarget->DrawSurface(source, mNativeRect,
  82                              Rect(0, 0, mNativeRect.width, mNativeRect.height));
  83   } else {
  84     mDrawTarget->PopClip();
  85   }
  86 }