gfx/thebes/src/gfxQuartzNativeDrawing.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Thebes gfx.
  16  *
  17  * The Initial Developer of the Original Code is Mozilla Corporation.
  18  * Portions created by the Initial Developer are Copyright (C) 2008
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *   Matthew Gregan <kinetik@flim.org>
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsMathUtils.h"
  39
  40 #include "gfxQuartzNativeDrawing.h"
  41 #include "gfxQuartzSurface.h"
  42
  43 // see cairo-quartz-surface.c for the complete list of these
  44 enum {
  45     kPrivateCGCompositeSourceOver = 2
  46 };
  47
  48 // private Quartz routine needed here
  49 extern "C" {
  50     CG_EXTERN void CGContextSetCompositeOperation(CGContextRef, int);
  51 }
  52
  53 gfxQuartzNativeDrawing::gfxQuartzNativeDrawing(gfxContext* ctx,
  54                                                const gfxRect& nativeRect)
  55     : mContext(ctx), mNativeRect(nativeRect)
  56 {
  57 }
  58
  59 CGContextRef
  60 gfxQuartzNativeDrawing::BeginNativeDrawing()
  61 {
  62     NS_ASSERTION(!mQuartzSurface, "BeginNativeDrawing called when drawing already in progress");
  63
  64     gfxPoint deviceOffset;
  65     nsRefPtr<gfxASurface> surf = mContext->CurrentSurface(&deviceOffset.x, &deviceOffset.y);
  66     if (!surf || surf->CairoStatus())
  67         return nsnull;
  68
  69     // if this is a native Quartz surface, we don't have to redirect
  70     // rendering to our own CGContextRef; in most cases, we are able to
  71     // use the CGContextRef from the surface directly.  we can extend
  72     // this to support offscreen drawing fairly easily in the future.
  73     if (surf->GetType() == gfxASurface::SurfaceTypeQuartz &&
  74         (surf->GetContentType() == gfxASurface::CONTENT_COLOR ||
  75          (surf->GetContentType() == gfxASurface::CONTENT_COLOR_ALPHA))) {
  76         mQuartzSurface = static_cast<gfxQuartzSurface*>(static_cast<gfxASurface*>(surf.get()));
  77     } else {
  78         // XXXkinetik we could create and use a temp surface here and draw
  79         // it back to the gfxContext in EndNativeDrawing like the Windows
  80         // version of this class
  81         NS_WARNING("unhandled surface type");
  82         return nsnull;
  83     }
  84
  85     // Need to force the clip to be set
  86     mContext->UpdateSurfaceClip();
  87
  88     // grab the CGContextRef
  89     mCGContext = mQuartzSurface->GetCGContext();
  90     if (!mCGContext)
  91         return nsnull;
  92
  93     gfxMatrix m = mContext->CurrentMatrix();
  94     CGContextSaveGState(mCGContext);
  95     CGContextTranslateCTM(mCGContext, deviceOffset.x, deviceOffset.y);
  96
  97     // I -think- that this context will always have an identity
  98     // transform (since we don't maintain a transform on it in
  99     // cairo-land, and instead push/pop as needed)
 100
 101     gfxFloat x0 = m.x0;
 102     gfxFloat y0 = m.y0;
 103
 104     // We round x0/y0 if we don't have a scale, because otherwise things get
 105     // rendered badly
 106     // XXX how should we be rounding x0/y0?
 107     if (!m.HasNonTranslationOrFlip()) {
 108         x0 = floor(x0 + 0.5);
 109         y0 = floor(y0 + 0.5);
 110     }
 111
 112     CGContextConcatCTM(mCGContext, CGAffineTransformMake(m.xx, m.yx,
 113                                                          m.xy, m.yy,
 114                                                          x0, y0));
 115
 116     // bug 382049 - need to explicity set the composite operation to sourceOver
 117     CGContextSetCompositeOperation(mCGContext, kPrivateCGCompositeSourceOver);
 118
 119     return mCGContext;
 120 }
 121
 122 void
 123 gfxQuartzNativeDrawing::EndNativeDrawing()
 124 {
 125     NS_ASSERTION(mQuartzSurface, "EndNativeDrawing called without BeginNativeDrawing");
 126
 127     // we drew directly to a shared CGContextRef; restore previous context state
 128     CGContextRestoreGState(mCGContext);
 129     mQuartzSurface->MarkDirty();
 130     mQuartzSurface = nsnull;
 131 }