Make it possible to draw multiple paths at once to a draw target

src/gpu/GrDrawTarget.h

Index: src/gpu/GrDrawTarget.h
diff --git a/src/gpu/GrDrawTarget.h b/src/gpu/GrDrawTarget.h
index 19ce16f64a68818512f0d32b7192c90a06dd6b4e..97c4f5a640fff3ce52eefe2d64c58278714e222e 100644
--- a/src/gpu/GrDrawTarget.h
+++ b/src/gpu/GrDrawTarget.h
@@ -15,6 +15,7 @@
 #include "SkClipStack.h"
 #include "SkMatrix.h"
 #include "SkPath.h"
+#include "SkStrokeRec.h"
 #include "SkTArray.h"
 #include "SkTLazy.h"
 #include "SkTypes.h"
@@ -24,7 +25,6 @@ class GrClipData;
 class GrDrawTargetCaps;
 class GrPath;
 class GrVertexBuffer;
-class SkStrokeRec;
 
 class GrDrawTarget : public SkRefCnt {
 protected:
@@ -344,6 +344,19 @@ public:
     void drawPath(const GrPath*, SkPath::FillType fill);
 
     /**
+     * Draws many paths. It will respect the HW
+     * antialias flag on the draw state (if possible in the 3D API).
+     *
+     * @param transforms array of 2d affine transformations, one for each path.

[bsalomon, 2014/03/24 13:53:24]

Is it required that the transforms are affine? If so, I'd feel better about a
SkScalar[] param with 6 values per matrix (unless this really complicates life
for the callers).

[Kimmo Kinnunen, 2014/03/24 13:58:50]

See the reply in the .cpp ->


Also:
API-wise, the commit msg insinuates multiple uses (drawpath "compacting") for
the api. if this becomes reality, the full expressivity is needed. Of course,
this needs a modification to the docstring, so we could also modify the API too,
at that point..

Which ever is the best from your FOV is fine for me.

+     * @param fill the fill type for drawing all the paths. Fill must not be a
+     *             hairline.
+     * @param stroke the stroke for drawing all the paths.
+     */
+    void drawPaths(size_t pathCount, const GrPath** paths,
+                   const SkMatrix* transforms, SkPath::FillType fill,
+                   SkStrokeRec::Style stroke);
+
+    /**
      * Helper function for drawing rects. It performs a geometry src push and pop
      * and thus will finalize any reserved geometry.
      *
@@ -487,6 +500,16 @@ public:
         this->onDrawPath(path, fill, dstCopy);
     }
 
+    /**
+     * For subclass internal use to invoke a call to onDrawPaths().
+     */
+    void executeDrawPaths(size_t pathCount, const GrPath** paths,
+                          const SkMatrix* transforms, SkPath::FillType fill,
+                          SkStrokeRec::Style stroke,
+                          const GrDeviceCoordTexture* dstCopy) {
+        this->onDrawPaths(pathCount, paths, transforms, fill, stroke, dstCopy);
+    }
+
     ////////////////////////////////////////////////////////////////////////////
 
     /**
@@ -867,6 +890,9 @@ private:
     virtual void onStencilPath(const GrPath*, SkPath::FillType) = 0;
     virtual void onDrawPath(const GrPath*, SkPath::FillType,
                             const GrDeviceCoordTexture* dstCopy) = 0;
+    virtual void onDrawPaths(size_t, const GrPath**, const SkMatrix*,
+                             SkPath::FillType, SkStrokeRec::Style,
+                             const GrDeviceCoordTexture*) = 0;

[bsalomon, 2014/03/24 13:53:24]

Can you name the GrDeviceCoordTexture? It's not completely obvious without some
context why there is a texture param here.

[Kimmo Kinnunen, 2014/03/25 11:18:24]

Done.

 
     virtual void onInstantGpuTraceEvent(const char* marker) = 0;
     virtual void onPushGpuTraceEvent(const char* marker) = 0;