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      1 /*
      2  * Copyright (c) 2008, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef SkiaFontWin_h
     32 #define SkiaFontWin_h
     33 
     34 #include <windows.h>
     35 #include <usp10.h>
     36 
     37 class SkPath;
     38 class SkPoint;
     39 
     40 namespace WebCore {
     41 
     42 class GraphicsContext;
     43 class PlatformContextSkia;
     44 
     45 // FIXME: Rename file to SkiaWinOutlineCache
     46 class SkiaWinOutlineCache {
     47 public:
     48     static const SkPath* lookupOrCreatePathForGlyph(HDC, HFONT, WORD);
     49     // Removes any cached glyphs from the outline cache corresponding to the
     50     // given font handle.
     51     static void removePathsForFont(HFONT);
     52 
     53 private:
     54     SkiaWinOutlineCache();
     55 };
     56 
     57 // The functions below are used for more complex font drawing (effects such as
     58 // stroking and more complex transforms) than Windows supports directly.  Since
     59 // Windows drawing is faster you should use windowsCanHandleTextDrawing first to
     60 // check if using Skia is required at all.
     61 // Note that the text will look different (no ClearType) so this should only be
     62 // used when necessary.
     63 //
     64 // When you call a Skia* text drawing function, various glyph outlines will be
     65 // cached. As a result, you should call SkiaWinOutlineCache::removePathsForFont
     66 // when the font is destroyed so that the cache does not outlive the font (since
     67 // the HFONTs are recycled).
     68 //
     69 // Remember that Skia's text drawing origin is the baseline, like WebKit, not
     70 // the top, like Windows.
     71 
     72 // Returns true if the fillColor and shadowColor are opaque and the text-shadow
     73 // is not blurred.
     74 bool windowsCanHandleDrawTextShadow(GraphicsContext*);
     75 
     76 // Returns true if advanced font rendering is recommended.
     77 bool windowsCanHandleTextDrawing(GraphicsContext*);
     78 
     79 // Returns true if advanced font rendering is recommended if shadows are
     80 // disregarded.
     81 bool windowsCanHandleTextDrawingWithoutShadow(GraphicsContext*);
     82 
     83 // Note that the offsets parameter is optional.  If not NULL it represents a
     84 // per glyph offset (such as returned by ScriptPlace Windows API function).
     85 //
     86 // Returns true of the text was drawn successfully. False indicates an error
     87 // from Windows.
     88 bool paintSkiaText(GraphicsContext* graphicsContext,
     89                    HFONT hfont,
     90                    int numGlyphs,
     91                    const WORD* glyphs,
     92                    const int* advances,
     93                    const GOFFSET* offsets,
     94                    const SkPoint* origin);
     95 
     96 }  // namespace WebCore
     97 
     98 #endif  // SkiaFontWin_h
     99