зеркало из https://github.com/mozilla/gecko-dev.git
60 строки
2.0 KiB
C++
60 строки
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* 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 "LayersHelpers.h"
|
|
|
|
namespace mozilla {
|
|
namespace layers {
|
|
|
|
using namespace gfx;
|
|
|
|
gfx::IntRect
|
|
ComputeBackdropCopyRect(const gfx::Rect& aRect,
|
|
const gfx::IntRect& aClipRect,
|
|
const gfx::Matrix4x4& aTransform,
|
|
const gfx::IntRect& aRenderTargetRect,
|
|
gfx::Matrix4x4* aOutTransform,
|
|
gfx::Rect* aOutLayerQuad)
|
|
{
|
|
// Compute the clip.
|
|
IntPoint rtOffset = aRenderTargetRect.TopLeft();
|
|
IntSize rtSize = aRenderTargetRect.Size();
|
|
|
|
gfx::IntRect renderBounds(0, 0, rtSize.width, rtSize.height);
|
|
renderBounds.IntersectRect(renderBounds, aClipRect);
|
|
renderBounds.MoveBy(rtOffset);
|
|
|
|
// Apply the layer transform.
|
|
RectDouble dest = aTransform.TransformAndClipBounds(
|
|
RectDouble(aRect.x, aRect.y, aRect.Width(), aRect.Height()),
|
|
RectDouble(renderBounds.x, renderBounds.y, renderBounds.Width(), renderBounds.Height()));
|
|
dest -= rtOffset;
|
|
|
|
// Ensure we don't round out to -1, which trips up Direct3D.
|
|
dest.IntersectRect(dest, RectDouble(0, 0, rtSize.width, rtSize.height));
|
|
|
|
if (aOutLayerQuad) {
|
|
*aOutLayerQuad = Rect(dest.x, dest.y, dest.Width(), dest.Height());
|
|
}
|
|
|
|
// Round out to integer.
|
|
IntRect result;
|
|
dest.RoundOut();
|
|
dest.ToIntRect(&result);
|
|
|
|
// Create a transform from adjusted clip space to render target space,
|
|
// translate it for the backdrop rect, then transform it into the backdrop's
|
|
// uv-space.
|
|
Matrix4x4 transform;
|
|
transform.PostScale(rtSize.width, rtSize.height, 1.0);
|
|
transform.PostTranslate(-result.x, -result.y, 0.0);
|
|
transform.PostScale(1 / float(result.Width()), 1 / float(result.Height()), 1.0);
|
|
*aOutTransform = transform;
|
|
return result;
|
|
}
|
|
|
|
} // namespace layers
|
|
} // namespace mozilla
|