Add GrAASmallPathRenderer.

Uses cached signed distance fields to render scaled and rotated versions
of small paths.

BUG=skia:2935

Review URL: https://codereview.chromium.org/589103004

1 files changed, 77 insertions, 0 deletions

diff --git a/src/gpu/GrAADistanceFieldPathRenderer.h b/src/gpu/GrAADistanceFieldPathRenderer.h
new file mode 100755
index 0000000000..4c09f127c9
--- /dev/null
+++ b/src/gpu/GrAADistanceFieldPathRenderer.h
@@ -0,0 +1,77 @@
+
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrAADistanceFieldPathRenderer_DEFINED
+#define GrAADistanceFieldPathRenderer_DEFINED
+
+#include "GrAllocPool.h"
+#include "GrAtlas.h"
+#include "GrPathRenderer.h"
+#include "GrRect.h"
+
+#include "SkChecksum.h"
+
+class GrContext;
+class GrPlot;
+
+class GrAADistanceFieldPathRenderer : public GrPathRenderer {
+public:
+    GrAADistanceFieldPathRenderer(GrContext* context)
+        : fContext(context)
+        , fAtlas(NULL) {
+    }
+    
+    virtual ~GrAADistanceFieldPathRenderer();
+    
+    virtual bool canDrawPath(const SkPath& path,
+                             const SkStrokeRec& stroke,
+                             const GrDrawTarget* target,
+                             bool antiAlias) const SK_OVERRIDE;
+
+protected:
+    virtual StencilSupport onGetStencilSupport(const SkPath&,
+                                               const SkStrokeRec&,
+                                               const GrDrawTarget*) const SK_OVERRIDE;
+    
+    virtual bool onDrawPath(const SkPath& path,
+                            const SkStrokeRec& stroke,
+                            GrDrawTarget* target,
+                            bool antiAlias) SK_OVERRIDE;
+
+private:
+    struct PathData {
+        uint32_t   fGenID;
+        GrPlot*    fPlot;
+        SkRect     fBounds;
+        SkIPoint16 fAtlasLocation;
+        SK_DECLARE_INTERNAL_LLIST_INTERFACE(PathData);
+        
+        static inline const uint32_t& GetKey(const PathData& data) {
+            return data.fGenID;
+        }
+        
+        static inline uint32_t Hash(uint32_t key) {
+            return SkChecksum::Murmur3(&key, sizeof(key));
+        }
+    };
+    typedef SkTInternalLList<PathData> PathDataList;
+    
+    GrContext*                         fContext;
+    GrAtlas*                           fAtlas;
+    GrAtlas::ClientPlotUsage           fPlotUsage;
+    SkTDynamicHash<PathData, uint32_t> fPathCache;
+    PathDataList                       fPathList;
+    
+    bool internalDrawPath(const SkPath& path, const PathData* pathData, GrDrawTarget* target);
+    PathData* addPathToAtlas(const SkPath& path, const SkStrokeRec& stroke, bool antiAlias);
+    bool freeUnusedPlot();
+    
+    typedef GrPathRenderer INHERITED;
+};
+
+#endif