1 files changed, 95 insertions, 0 deletions
diff --git a/gfx/layers/composite/TextRenderer.h b/gfx/layers/composite/TextRenderer.h
new file mode 100644
index 0000000000..e88fc1d8f5
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+++ b/gfx/layers/composite/TextRenderer.h
@@ -0,0 +1,95 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_TextRenderer_H
+#define GFX_TextRenderer_H
+
+#include "mozilla/EnumeratedArray.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/UniquePtr.h"
+#include "nsISupportsImpl.h"
+#include <string>
+
+namespace mozilla {
+namespace layers {
+
+class Compositor;
+class TextureSource;
+class TextureSourceProvider;
+struct FontBitmapInfo;
+
+class TextRenderer final {
+  ~TextRenderer();
+
+ public:
+  NS_INLINE_DECL_REFCOUNTING(TextRenderer)
+
+  enum class FontType { Default, FixedWidth, NumTypes };
+
+  TextRenderer() = default;
+
+  RefPtr<TextureSource> RenderText(TextureSourceProvider* aProvider,
+                                   const std::string& aText,
+                                   uint32_t aTargetPixelWidth,
+                                   FontType aFontType);
+
+  void RenderText(Compositor* aCompositor, const std::string& aText,
+                  const gfx::IntPoint& aOrigin,
+                  const gfx::Matrix4x4& aTransform, uint32_t aTextSize,
+                  uint32_t aTargetPixelWidth,
+                  FontType aFontType = FontType::Default);
+
+  gfx::IntSize ComputeSurfaceSize(const std::string& aText,
+                                  uint32_t aTargetPixelWidth,
+                                  FontType aFontType = FontType::Default);
+
+  void RenderTextToDrawTarget(gfx::DrawTarget* aDrawTarget,
+                              const std::string& aText,
+                              uint32_t aTargetPixelWidth,
+                              FontType aFontType = FontType::Default);
+
+  struct FontCache {
+    ~FontCache();
+    RefPtr<gfx::DataSourceSurface> mGlyphBitmaps;
+    gfx::DataSourceSurface::MappedSurface mMap;
+    const FontBitmapInfo* mInfo;
+  };
+
+ protected:
+  // Note that this may still fail to set mGlyphBitmaps to a valid value
+  // if the underlying CreateDataSourceSurface fails for some reason.
+  bool EnsureInitialized(FontType aType);
+
+  static const FontBitmapInfo* GetFontInfo(FontType aType);
+
+ private:
+  EnumeratedArray<FontType, FontType::NumTypes, UniquePtr<FontCache>> mFonts;
+};
+
+struct FontBitmapInfo {
+  Maybe<unsigned int> mGlyphWidth;
+  Maybe<const unsigned short*> mGlyphWidths;
+  unsigned int mTextureWidth;
+  unsigned int mTextureHeight;
+  unsigned int mCellWidth;
+  unsigned int mCellHeight;
+  unsigned int mFirstChar;
+  const unsigned char* mPNG;
+  size_t mPNGLength;
+
+  unsigned int GetGlyphWidth(char aGlyph) const {
+    if (mGlyphWidth) {
+      return mGlyphWidth.value();
+    }
+    MOZ_ASSERT(unsigned(aGlyph) >= mFirstChar);
+    return mGlyphWidths.value()[unsigned(aGlyph) - mFirstChar];
+  }
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif