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 -*-
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "LayersHelpers.h"
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namespace mozilla {
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namespace layers {
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using namespace gfx;
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gfx::IntRect
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ComputeBackdropCopyRect(const gfx::Rect& aRect,
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const gfx::IntRect& aClipRect,
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const gfx::Matrix4x4& aTransform,
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const gfx::IntRect& aRenderTargetRect,
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gfx::Matrix4x4* aOutTransform,
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gfx::Rect* aOutLayerQuad)
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{
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// Compute the clip.
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IntPoint rtOffset = aRenderTargetRect.TopLeft();
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IntSize rtSize = aRenderTargetRect.Size();
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gfx::IntRect renderBounds(0, 0, rtSize.width, rtSize.height);
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renderBounds.IntersectRect(renderBounds, aClipRect);
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renderBounds.MoveBy(rtOffset);
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// Apply the layer transform.
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RectDouble dest = aTransform.TransformAndClipBounds(
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RectDouble(aRect.x, aRect.y, aRect.width, aRect.height),
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RectDouble(renderBounds.x, renderBounds.y, renderBounds.width, renderBounds.height));
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dest -= rtOffset;
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// Ensure we don't round out to -1, which trips up Direct3D.
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dest.IntersectRect(dest, RectDouble(0, 0, rtSize.width, rtSize.height));
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if (aOutLayerQuad) {
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*aOutLayerQuad = Rect(dest.x, dest.y, dest.width, dest.height);
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}
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// Round out to integer.
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IntRect result;
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dest.RoundOut();
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dest.ToIntRect(&result);
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// Create a transform from adjusted clip space to render target space,
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// translate it for the backdrop rect, then transform it into the backdrop's
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// uv-space.
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Matrix4x4 transform;
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transform.PostScale(rtSize.width, rtSize.height, 1.0);
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transform.PostTranslate(-result.x, -result.y, 0.0);
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transform.PostScale(1 / float(result.width), 1 / float(result.height), 1.0);
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*aOutTransform = transform;
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return result;
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}
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} // namespace layers
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} // namespace mozilla
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