Implement path cover with nv_path_rendering

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 309 matching lines @@
                         int vertexCount,
                         const SkRect* devBounds = NULL);
 
     /**
      * Draws path into the stencil buffer. The fill must be either even/odd or
      * winding (not inverse or hairline). It will respect the HW antialias flag
      * on the draw state (if possible in the 3D API).
      */
     void stencilPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill);
 
     /**

[Mark Kilgard, 2013/09/13 15:42:24]

Kimmo, I notice other method explanation comments wrap to a narrower line width
which may be the Skia code style convention.

[Chris Dalton, 2013/09/13 19:49:58]

About a year ago the convention changed from 80 lines to 100. However, if you're
in a file that still wraps at 80, they want you to either wrap your new lines at
80, or promote all the surrounding code to 100.

Here's the style guide:

https://sites.google.com/site/skiadocs/developer-documentation/contributing-c...

[bsalomon, 2013/09/13 20:25:28]

In practice it's not quite so strict as whole-file at 80 or 100 it would
probably look better if this matched the other method comments.

[Kimmo Kinnunen, 2013/09/18 07:52:38]

Done.

+     * Draws a path definedy by the path and the bits in the stencil buffer. The fill must be
+     * either even/odd or winding (not inverse or hairline). It will respect the HW antialias flag
+     * on the draw state (if possible in the 3D API).
+     */
+    void drawPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill);

[Mark Kilgard, 2013/09/13 15:42:24]

Really drawPath is filling the path so does fillPath make more sense here?

Perhaps it should be named that way?

For another commit...

I'd like to see a similar strokePath version so we can do
glStencilStrokePathNV/glCoverStrokePathNV similarly.

[Kimmo Kinnunen, 2013/09/18 07:52:38]

The fillPath does not seem to differ that significantly from strokePath to
justify the extra boilerplate that would be needed IMO.

I'll call this fillPath now and then rename the function to drawPath in the
later commit, just to pre-empt discussing this comment now.

+
+    /**
      * Helper function for drawing rects. It performs a geometry src push and pop
      * and thus will finalize any reserved geometry.
      *
      * @param rect        the rect to draw
      * @param matrix      optional matrix applied to rect (before viewMatrix)
      * @param localRect   optional rect that specifies local coords to map onto
      *                    rect. If NULL then rect serves as the local coords.
      * @param localMatrix optional matrix applied to localRect. If
      *                    srcRect is non-NULL and srcMatrix is non-NULL
      *                    then srcRect will be transformed by srcMatrix.
@@ skipping 485 matching lines @@
     // be saved before this is called and restored afterwards. A subclass may override
     // this to perform more optimal rect rendering. Its draws should be funneled through
     // one of the public GrDrawTarget draw methods (e.g. drawNonIndexed,
     // drawIndexedInstances, ...). The base class draws a two triangle fan using
     // drawNonIndexed from reserved vertex space.
     virtual void onDrawRect(const SkRect& rect,
                             const SkMatrix* matrix,
                             const SkRect* localRect,
                             const SkMatrix* localMatrix);
     virtual void onStencilPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill) = 0;
+    virtual void onDrawPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill) = 0;
 
     // helpers for reserving vertex and index space.
     bool reserveVertexSpace(size_t vertexSize,
                             int vertexCount,
                             void** vertices);
     bool reserveIndexSpace(int indexCount, void** indices);
 
     // called by drawIndexed and drawNonIndexed. Use a negative indexCount to
     // indicate non-indexed drawing.
     bool checkDraw(GrPrimitiveType type, int startVertex,
@@ skipping 17 matching lines @@
     const GrClipData*                                               fClip;
     GrDrawState*                                                    fDrawState;
     GrDrawState                                                     fDefaultDrawState;
     // The context owns us, not vice-versa, so this ptr is not ref'ed by DrawTarget.
     GrContext*                                                      fContext;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif