Separate GL path rendering state from GrGpuGL to GrGLPathRendering

src/gpu/GrPathRendering.h

+/*
+ * 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 GrPathRendering_DEFINED
+#define GrPathRendering_DEFINED
+
+#include "SkPath.h"
+
+class SkStrokeRec;
+class GrPath;
+class GrPathRange;
+class GrGpu;
+
+/**
+ * Abstract class wrapping HW path rendering API.
+ *
+ * The subclasses of this class use the possible HW API to render paths (as opposed to path
+ * rendering implemented in Skia on top of a "3d" HW API).
+ * The subclasses hold the global state needed to render paths, including shadow of the global HW
+ * API state. Similar to GrGpu.
+ *
+ * It is expected that there is 1:1 relation with GrGpuXX:GrXXPathRendering. The call context 

[Chris Dalton, 2014/08/14 16:22:09]

I'm not sure I understand what this means here by 1:1 relation

[Kimmo Kinnunen, 2014/08/15 06:19:25]

Done.

+ * interface (eg.  * the concrete instance of GrGpu subclass) should be provided to the instance 
+ * during construction.
+ */
+class GrPathRendering {
+public:
+    virtual ~GrPathRendering() { }
+
+    enum PathTransformType {
+        kNone_PathTransformType,        //!< []
+        kTranslateX_PathTransformType,  //!< [kMTransX]
+        kTranslateY_PathTransformType,  //!< [kMTransY]
+        kTranslate_PathTransformType,   //!< [kMTransX, kMTransY]
+        kAffine_PathTransformType,      //!< [kMScaleX, kMSkewX, kMTransX, kMSkewY, kMScaleY, kMTransY]
+
+        kLast_PathTransformType = kAffine_PathTransformType
+    };
+
+    static inline int PathTransformSize(PathTransformType type) {
+        switch (type) {
+            case kNone_PathTransformType:
+                return 0;
+            case kTranslateX_PathTransformType:
+            case kTranslateY_PathTransformType:
+                return 1;
+            case kTranslate_PathTransformType:
+                return 2;
+            case kAffine_PathTransformType:
+                return 6;
+
+            default:
+                SkFAIL("Unknown path transform type");
+                return 0;
+        }
+    }
+
+    virtual GrPath* createPath(const SkPath&, const SkStrokeRec&) = 0;
+    virtual GrPathRange* createPathRange(size_t size, const SkStrokeRec&) = 0;
+    virtual void stencilPath(const GrPath*, SkPath::FillType) = 0;
+    virtual void drawPath(const GrPath*, SkPath::FillType) = 0;
+    virtual void drawPaths(const GrPathRange*, const uint32_t indices[], int count,
+                           const float transforms[], PathTransformType, SkPath::FillType) = 0;
+protected:
+    GrPathRendering() { }
+
+private:
+    GrPathRendering& operator=(const GrPathRendering&);
+};
+
+#endif