gecko/gfx/thebes/gfxUtils.h
Robert O'Callahan fcf2510a5d Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel
FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters
passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale
up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents
constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer.

For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters.
If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling.
If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the
child layer's transform.

For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that
the child ThebesLayers are simply larger or smaller (larger or smaller visible regions).

We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent
ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates.

When a ThebesLayer's resolution changes we need to rerender the whole thing.

nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree
with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we
adjust the root layer transform to scale back down by the resolution.
2011-06-23 00:11:27 +12:00

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** 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) 2008
* 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
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* 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.
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* ***** END LICENSE BLOCK ***** */
#ifndef GFX_UTILS_H
#define GFX_UTILS_H
#include "gfxTypes.h"
#include "gfxPattern.h"
#include "gfxImageSurface.h"
class gfxDrawable;
class nsIntRegion;
struct nsIntRect;
class THEBES_API gfxUtils {
public:
/*
* Premultiply or Unpremultiply aSourceSurface, writing the result
* to aDestSurface or back into aSourceSurface if aDestSurface is null.
*
* If aDestSurface is given, it must have identical format, dimensions, and
* stride as the source.
*
* If the source is not ImageFormatARGB32, no operation is performed. If
* aDestSurface is given, the data is copied over.
*/
static void PremultiplyImageSurface(gfxImageSurface *aSourceSurface,
gfxImageSurface *aDestSurface = nsnull);
static void UnpremultiplyImageSurface(gfxImageSurface *aSurface,
gfxImageSurface *aDestSurface = nsnull);
/**
* Draw something drawable while working around limitations like bad support
* for EXTEND_PAD, lack of source-clipping, or cairo / pixman bugs with
* extreme user-space-to-image-space transforms.
*
* The input parameters here usually come from the output of our image
* snapping algorithm in nsLayoutUtils.cpp.
* This method is split from nsLayoutUtils::DrawPixelSnapped to allow for
* adjusting the parameters. For example, certain images with transparent
* margins only have a drawable subimage. For those images, imgFrame::Draw
* will tweak the rects and transforms that it gets from the pixel snapping
* algorithm before passing them on to this method.
*/
static void DrawPixelSnapped(gfxContext* aContext,
gfxDrawable* aDrawable,
const gfxMatrix& aUserSpaceToImageSpace,
const gfxRect& aSubimage,
const gfxRect& aSourceRect,
const gfxRect& aImageRect,
const gfxRect& aFill,
const gfxImageSurface::gfxImageFormat aFormat,
const gfxPattern::GraphicsFilter& aFilter);
/**
* Clip aContext to the region aRegion.
*/
static void ClipToRegion(gfxContext* aContext, const nsIntRegion& aRegion);
/**
* Clip aContext to the region aRegion, snapping the rectangles.
*/
static void ClipToRegionSnapped(gfxContext* aContext, const nsIntRegion& aRegion);
/**
* Create a path consisting of rectangles in |aRegion|.
*/
static void PathFromRegion(gfxContext* aContext, const nsIntRegion& aRegion);
/**
* Create a path consisting of rectangles in |aRegion|, snapping the rectangles.
*/
static void PathFromRegionSnapped(gfxContext* aContext, const nsIntRegion& aRegion);
/*
* Convert image format to depth value
*/
static int ImageFormatToDepth(gfxASurface::gfxImageFormat aFormat);
/**
* If aIn can be represented exactly using an nsIntRect (i.e.
* integer-aligned edges and coordinates in the PRInt32 range) then we
* set aOut to that rectangle, otherwise return failure.
*/
static PRBool GfxRectToIntRect(const gfxRect& aIn, nsIntRect* aOut);
/**
* Return the smallest power of kScaleResolution (2) greater than or equal to
* aVal.
*/
static gfxFloat ClampToScaleFactor(gfxFloat aVal);
};
#endif