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// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CC_FONT_ATLAS_H_
#define CC_FONT_ATLAS_H_
#include <string>
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "cc/cc_export.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/gfx/rect.h"
class SkCanvas;
namespace gfx {
class Point;
class Size;
}
namespace cc {
// This class provides basic ability to draw text onto the heads-up display.
class CC_EXPORT FontAtlas {
public:
static scoped_ptr<FontAtlas> create(SkBitmap bitmap, gfx::Rect asciiToRectTable[128], int fontHeight)
{
return make_scoped_ptr(new FontAtlas(bitmap, asciiToRectTable, fontHeight));
}
~FontAtlas();
// Current font height.
int fontHeight() const { return m_fontHeight; }
// Draws multiple lines of text where each line of text is separated by '\n'.
// - Correct glyphs will be drawn for ASCII codes in the range 32-127; any characters
// outside that range will be displayed as a default rectangle glyph.
// - gfx::Size clip is used to avoid wasting time drawing things that are outside the
// target canvas bounds.
// - Should only be called only on the impl thread.
void drawText(SkCanvas*, const SkPaint&, const std::string& text, const gfx::Point& destPosition, const gfx::Size& clip) const;
// Gives a text's width and height on the canvas.
gfx::Size textSize(const std::string& text);
// Draws the entire atlas at the specified position, just for debugging purposes.
void drawDebugAtlas(SkCanvas*, const gfx::Point& destPosition) const;
private:
FontAtlas(SkBitmap, gfx::Rect asciiToRectTable[128], int fontHeight);
void drawOneLineOfTextInternal(SkCanvas*, const SkPaint&, const std::string&, const gfx::Point& destPosition) const;
// The actual texture atlas containing all the pre-rendered glyphs.
SkBitmap m_atlas;
// The look-up tables mapping ascii characters to their gfx::Rect locations on the atlas.
gfx::Rect m_asciiToRectTable[128];
int m_fontHeight;
DISALLOW_COPY_AND_ASSIGN(FontAtlas);
};
} // namespace cc
#endif // CC_FONT_ATLAS_H_
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