gecko/gfx/thebes/gfxBlur.cpp

132 lines
4.6 KiB
C++

/* -*- Mode: C++; tab-width: 4; 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 gfx thebes 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):
* Eric Butler <zantifon@gmail.com>
*
* 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 ***** */
#include "gfxBlur.h"
#include "mozilla/gfx/Blur.h"
using namespace mozilla::gfx;
gfxAlphaBoxBlur::gfxAlphaBoxBlur()
: mBlur(nsnull)
{
}
gfxAlphaBoxBlur::~gfxAlphaBoxBlur()
{
delete mBlur;
}
gfxContext*
gfxAlphaBoxBlur::Init(const gfxRect& aRect,
const gfxIntSize& aSpreadRadius,
const gfxIntSize& aBlurRadius,
const gfxRect* aDirtyRect,
const gfxRect* aSkipRect)
{
Rect rect(aRect.x, aRect.y, aRect.width, aRect.height);
IntSize spreadRadius(aSpreadRadius.width, aSpreadRadius.height);
IntSize blurRadius(aBlurRadius.width, aBlurRadius.height);
nsAutoPtr<Rect> dirtyRect;
if (aDirtyRect) {
dirtyRect = new Rect(aDirtyRect->x, aDirtyRect->y, aDirtyRect->width, aDirtyRect->height);
}
nsAutoPtr<Rect> skipRect;
if (aSkipRect) {
skipRect = new Rect(aSkipRect->x, aSkipRect->y, aSkipRect->width, aSkipRect->height);
}
mBlur = new AlphaBoxBlur(rect, spreadRadius, blurRadius, dirtyRect, skipRect);
unsigned char* data = mBlur->GetData();
if (!data)
return nsnull;
IntSize size = mBlur->GetSize();
// Make an alpha-only surface to draw on. We will play with the data after
// everything is drawn to create a blur effect.
mImageSurface = new gfxImageSurface(data, gfxIntSize(size.width, size.height),
mBlur->GetStride(),
gfxASurface::ImageFormatA8);
if (mImageSurface->CairoStatus())
return nsnull;
IntRect irect = mBlur->GetRect();
gfxPoint topleft(irect.TopLeft().x, irect.TopLeft().y);
// Use a device offset so callers don't need to worry about translating
// coordinates, they can draw as if this was part of the destination context
// at the coordinates of rect.
mImageSurface->SetDeviceOffset(-topleft);
mContext = new gfxContext(mImageSurface);
return mContext;
}
void
gfxAlphaBoxBlur::Paint(gfxContext* aDestinationCtx, const gfxPoint& offset)
{
if (!mContext)
return;
mBlur->Blur();
Rect* dirtyrect = mBlur->GetDirtyRect();
// Avoid a semi-expensive clip operation if we can, otherwise
// clip to the dirty rect
if (dirtyrect) {
aDestinationCtx->Save();
aDestinationCtx->NewPath();
gfxRect dirty(dirtyrect->x, dirtyrect->y, dirtyrect->width, dirtyrect->height);
aDestinationCtx->Rectangle(dirty);
aDestinationCtx->Clip();
aDestinationCtx->Mask(mImageSurface, offset);
aDestinationCtx->Restore();
} else {
aDestinationCtx->Mask(mImageSurface, offset);
}
}
gfxIntSize gfxAlphaBoxBlur::CalculateBlurRadius(const gfxPoint& aStd)
{
Point std(aStd.x, aStd.y);
IntSize size = AlphaBoxBlur::CalculateBlurRadius(std);
return gfxIntSize(size.width, size.height);
}