add gpu backend (not hooked up yet)



git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrTextContext.h b/gpu/include/GrTextContext.h
new file mode 100644
index 0000000..6b7446b
--- /dev/null
+++ b/gpu/include/GrTextContext.h
@@ -0,0 +1,67 @@
+/*
+    Copyright 2010 Google Inc.
+
+    Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+ */
+
+
+#ifndef GrTextContext_DEFINED
+#define GrTextContext_DEFINED
+
+#include "GrGlyph.h"
+#include "GrGpuVertex.h"
+
+class GrContext;
+class GrTextStrike;
+class GrFontScaler;
+
+class GrTextContext {
+public:
+    GrTextContext(GrContext*, const GrMatrix* extMatrix = NULL);
+    ~GrTextContext();
+
+    void drawPackedGlyph(GrGlyph::PackedID, GrFixed left, GrFixed top,
+                         GrFontScaler*);
+
+    void flush();   // optional; automatically called by destructor
+
+private:
+    GrContext*      fContext;
+    GrDrawTarget*   fDrawTarget;
+
+    GrMatrix        fExtMatrix;
+    GrFontScaler*   fScaler;
+    GrTextStrike*   fStrike;
+
+    inline void flushGlyphs();
+
+    enum {
+        kMinRequestedGlyphs      = 1,
+        kDefaultRequestedGlyphs  = 64,
+        kMinRequestedVerts       = kMinRequestedGlyphs * 4,
+        kDefaultRequestedVerts   = kDefaultRequestedGlyphs * 4,
+    };
+
+    GrGpuTextVertex* fVertices;
+    
+    int32_t     fMaxVertices;
+    GrTexture*  fCurrTexture;
+    int         fCurrVertex;
+
+    GrIRect     fClipRect;
+    GrMatrix    fOrigViewMatrix;    // restore previous viewmatrix
+};
+
+#endif
+
+