mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-08 12:37:37 +00:00
228 lines
8.1 KiB
C++
228 lines
8.1 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* ***** BEGIN LICENSE BLOCK *****
|
|
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version
|
|
* 1.1 (the "License"); you may not use this file except in compliance with
|
|
* the License. You may obtain a copy of the License at
|
|
* http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the
|
|
* License.
|
|
*
|
|
* The Original Code is Mozilla Corporation code.
|
|
*
|
|
* The Initial Developer of the Original Code is Mozilla Foundation.
|
|
* Portions created by the Initial Developer are Copyright (C) 2010
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Robert O'Callahan <robert@ocallahan.org>
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either the GNU General Public License Version 2 or later (the "GPL"), or
|
|
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
|
* in which case the provisions of the GPL or the LGPL are applicable instead
|
|
* of those above. If you wish to allow use of your version of this file only
|
|
* under the terms of either the GPL or the LGPL, and not to allow others to
|
|
* use your version of this file under the terms of the MPL, indicate your
|
|
* decision by deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL or the LGPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this file under
|
|
* the terms of any one of the MPL, the GPL or the LGPL.
|
|
*
|
|
* ***** END LICENSE BLOCK ***** */
|
|
|
|
#ifndef THEBESLAYERBUFFER_H_
|
|
#define THEBESLAYERBUFFER_H_
|
|
|
|
#include "gfxContext.h"
|
|
#include "gfxASurface.h"
|
|
#include "nsRegion.h"
|
|
|
|
namespace mozilla {
|
|
namespace layers {
|
|
|
|
class ThebesLayer;
|
|
|
|
/**
|
|
* This class encapsulates the buffer used to retain ThebesLayer contents,
|
|
* i.e., the contents of the layer's GetVisibleRegion().
|
|
*
|
|
* This is a cairo/Thebes surface, but with a literal twist. Scrolling
|
|
* causes the layer's visible region to move. We want to keep
|
|
* reusing the same surface if the region size hasn't changed, but we don't
|
|
* want to keep moving the contents of the surface around in memory. So
|
|
* we use a trick.
|
|
* Consider just the vertical case, and suppose the buffer is H pixels
|
|
* high and we're scrolling down by N pixels. Instead of copying the
|
|
* buffer contents up by N pixels, we leave the buffer contents in place,
|
|
* and paint content rows H to H+N-1 into rows 0 to N-1 of the buffer.
|
|
* Then we can refresh the screen by painting rows N to H-1 of the buffer
|
|
* at row 0 on the screen, and then painting rows 0 to N-1 of the buffer
|
|
* at row H-N on the screen.
|
|
* mBufferRotation.y would be N in this example.
|
|
*/
|
|
class ThebesLayerBuffer {
|
|
public:
|
|
typedef gfxASurface::gfxContentType ContentType;
|
|
|
|
/**
|
|
* Controls the size of the backing buffer of this.
|
|
* - SizedToVisibleBounds: the backing buffer is exactly the same
|
|
* size as the bounds of ThebesLayer's visible region
|
|
* - ContainsVisibleBounds: the backing buffer is large enough to
|
|
* fit visible bounds. May be larger.
|
|
*/
|
|
enum BufferSizePolicy {
|
|
SizedToVisibleBounds,
|
|
ContainsVisibleBounds
|
|
};
|
|
|
|
ThebesLayerBuffer(BufferSizePolicy aBufferSizePolicy)
|
|
: mBufferDims(0,0)
|
|
, mBufferRotation(0,0)
|
|
, mBufferSizePolicy(aBufferSizePolicy)
|
|
{
|
|
MOZ_COUNT_CTOR(ThebesLayerBuffer);
|
|
}
|
|
virtual ~ThebesLayerBuffer()
|
|
{
|
|
MOZ_COUNT_DTOR(ThebesLayerBuffer);
|
|
}
|
|
|
|
/**
|
|
* Wipe out all retained contents. Call this when the entire
|
|
* buffer becomes invalid.
|
|
*/
|
|
void Clear()
|
|
{
|
|
mBuffer = nsnull;
|
|
mBufferDims.SizeTo(0, 0);
|
|
mBufferRect.Empty();
|
|
}
|
|
|
|
/**
|
|
* This is returned by BeginPaint. The caller should draw into mContext.
|
|
* mRegionToDraw must be drawn. mRegionToInvalidate has been invalidated
|
|
* by ThebesLayerBuffer and must be redrawn on the screen.
|
|
* mRegionToInvalidate is set when the buffer has changed from
|
|
* opaque to transparent or vice versa, since the details of rendering can
|
|
* depend on the buffer type.
|
|
*/
|
|
struct PaintState {
|
|
nsRefPtr<gfxContext> mContext;
|
|
nsIntRegion mRegionToDraw;
|
|
nsIntRegion mRegionToInvalidate;
|
|
};
|
|
|
|
/**
|
|
* Start a drawing operation. This returns a PaintState describing what
|
|
* needs to be drawn to bring the buffer up to date in the visible region.
|
|
* This queries aLayer to get the currently valid and visible regions.
|
|
* The returned mContext may be null if mRegionToDraw is empty.
|
|
* Otherwise it must not be null.
|
|
* mRegionToInvalidate will contain mRegionToDraw.
|
|
*/
|
|
PaintState BeginPaint(ThebesLayer* aLayer, ContentType aContentType,
|
|
float aXResolution, float aYResolution);
|
|
|
|
/**
|
|
* Return a new surface of |aSize| and |aType|.
|
|
*/
|
|
virtual already_AddRefed<gfxASurface>
|
|
CreateBuffer(ContentType aType, const nsIntSize& aSize) = 0;
|
|
|
|
/**
|
|
* Get the underlying buffer, if any. This is useful because we can pass
|
|
* in the buffer as the default "reference surface" if there is one.
|
|
* Don't use it for anything else!
|
|
*/
|
|
gfxASurface* GetBuffer() { return mBuffer; }
|
|
|
|
protected:
|
|
enum XSide {
|
|
LEFT, RIGHT
|
|
};
|
|
enum YSide {
|
|
TOP, BOTTOM
|
|
};
|
|
nsIntRect GetQuadrantRectangle(XSide aXSide, YSide aYSide);
|
|
void DrawBufferQuadrant(gfxContext* aTarget, XSide aXSide, YSide aYSide,
|
|
float aOpacity, float aXRes, float aYRes);
|
|
void DrawBufferWithRotation(gfxContext* aTarget, float aOpacity,
|
|
float aXRes, float aYRes);
|
|
|
|
/**
|
|
* |BufferRect()| is the rect of device pixels that this
|
|
* ThebesLayerBuffer covers. That is what DrawBufferWithRotation()
|
|
* will paint when it's called.
|
|
*
|
|
* |BufferDims()| is the actual dimensions of the underlying surface
|
|
* maintained by this, also in device pixels. It is *not*
|
|
* necessarily true that |BufferRect().Size() == BufferDims()|.
|
|
* They may differ if a ThebesLayer is drawn at a non-1.0
|
|
* resolution.
|
|
*/
|
|
const nsIntSize& BufferDims() const { return mBufferDims; }
|
|
const nsIntRect& BufferRect() const { return mBufferRect; }
|
|
const nsIntPoint& BufferRotation() const { return mBufferRotation; }
|
|
|
|
already_AddRefed<gfxASurface>
|
|
SetBuffer(gfxASurface* aBuffer, const nsIntSize& aBufferDims,
|
|
const nsIntRect& aBufferRect, const nsIntPoint& aBufferRotation)
|
|
{
|
|
nsRefPtr<gfxASurface> tmp = mBuffer.forget();
|
|
mBuffer = aBuffer;
|
|
mBufferDims = aBufferDims;
|
|
mBufferRect = aBufferRect;
|
|
mBufferRotation = aBufferRotation;
|
|
return tmp.forget();
|
|
}
|
|
|
|
/**
|
|
* Get a context at the specified resolution for updating |aBounds|,
|
|
* which must be contained within a single quadrant.
|
|
*/
|
|
already_AddRefed<gfxContext>
|
|
GetContextForQuadrantUpdate(const nsIntRect& aBounds,
|
|
float aXResolution, float aYResolution);
|
|
|
|
private:
|
|
PRBool BufferSizeOkFor(const nsIntSize& aSize)
|
|
{
|
|
return (aSize == mBufferDims ||
|
|
(SizedToVisibleBounds != mBufferSizePolicy &&
|
|
aSize < mBufferDims));
|
|
}
|
|
|
|
nsRefPtr<gfxASurface> mBuffer;
|
|
/**
|
|
* The actual dimensions of mBuffer. For the ContainsVisibleBounds
|
|
* policy or with resolution-scaled drawing, mBufferDims might be
|
|
* different than mBufferRect.Size().
|
|
*/
|
|
nsIntSize mBufferDims;
|
|
/** The area of the ThebesLayer that is covered by the buffer as a whole */
|
|
nsIntRect mBufferRect;
|
|
/**
|
|
* The x and y rotation of the buffer. Conceptually the buffer
|
|
* has its origin translated to mBufferRect.TopLeft() - mBufferRotation,
|
|
* is tiled to fill the plane, and the result is clipped to mBufferRect.
|
|
* So the pixel at mBufferRotation within the buffer is what gets painted at
|
|
* mBufferRect.TopLeft().
|
|
* This is "rotation" in the sense of rotating items in a linear buffer,
|
|
* where items falling off the end of the buffer are returned to the
|
|
* buffer at the other end, not 2D rotation!
|
|
*/
|
|
nsIntPoint mBufferRotation;
|
|
BufferSizePolicy mBufferSizePolicy;
|
|
};
|
|
|
|
}
|
|
}
|
|
|
|
#endif /* THEBESLAYERBUFFER_H_ */
|