Line data    Source code

       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 "LayersHelpers.h"
       7             : 
       8             : namespace mozilla {
       9             : namespace layers {
      10             : 
      11             : using namespace gfx;
      12             : 
      13             : gfx::IntRect
      14           0 : ComputeBackdropCopyRect(const gfx::Rect& aRect,
      15             :                         const gfx::IntRect& aClipRect,
      16             :                         const gfx::Matrix4x4& aTransform,
      17             :                         const gfx::IntRect& aRenderTargetRect,
      18             :                         gfx::Matrix4x4* aOutTransform,
      19             :                         gfx::Rect* aOutLayerQuad)
      20             : {
      21             :   // Compute the clip.
      22           0 :   IntPoint rtOffset = aRenderTargetRect.TopLeft();
      23           0 :   IntSize rtSize = aRenderTargetRect.Size();
      24             : 
      25           0 :   gfx::IntRect renderBounds(0, 0, rtSize.width, rtSize.height);
      26           0 :   renderBounds.IntersectRect(renderBounds, aClipRect);
      27           0 :   renderBounds.MoveBy(rtOffset);
      28             : 
      29             :   // Apply the layer transform.
      30             :   RectDouble dest = aTransform.TransformAndClipBounds(
      31           0 :     RectDouble(aRect.x, aRect.y, aRect.width, aRect.height),
      32           0 :     RectDouble(renderBounds.x, renderBounds.y, renderBounds.width, renderBounds.height));
      33           0 :   dest -= rtOffset;
      34             : 
      35             :   // Ensure we don't round out to -1, which trips up Direct3D.
      36           0 :   dest.IntersectRect(dest, RectDouble(0, 0, rtSize.width, rtSize.height));
      37             : 
      38           0 :   if (aOutLayerQuad) {
      39           0 :     *aOutLayerQuad = Rect(dest.x, dest.y, dest.width, dest.height);
      40             :   }
      41             : 
      42             :   // Round out to integer.
      43           0 :   IntRect result;
      44           0 :   dest.RoundOut();
      45           0 :   dest.ToIntRect(&result);
      46             : 
      47             :   // Create a transform from adjusted clip space to render target space,
      48             :   // translate it for the backdrop rect, then transform it into the backdrop's
      49             :   // uv-space.
      50           0 :   Matrix4x4 transform;
      51           0 :   transform.PostScale(rtSize.width, rtSize.height, 1.0);
      52           0 :   transform.PostTranslate(-result.x, -result.y, 0.0);
      53           0 :   transform.PostScale(1 / float(result.width), 1 / float(result.height), 1.0);
      54           0 :   *aOutTransform = transform;
      55           0 :   return result;
      56             : }
      57             : 
      58             : } // namespace layers
      59             : } // namespace mozilla