Creating framework for drawShadowedPicture

include/core/SkCanvas.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCanvas_DEFINED
 #define SkCanvas_DEFINED
 
 #include "SkTypes.h"
 #include "SkBitmap.h"
 #include "SkDeque.h"
 #include "SkImage.h"
 #include "SkPaint.h"
 #include "SkRefCnt.h"
 #include "SkRegion.h"
 #include "SkSurfaceProps.h"
 #include "SkXfermode.h"
+#include "SkLights.h"
 
 class GrContext;
 class GrDrawContext;
 class SkBaseDevice;
 class SkCanvasClipVisitor;
 class SkClipStack;
 class SkData;
 class SkDraw;
 class SkDrawable;
 class SkDrawFilter;
@@ skipping 1012 matching lines @@
      *  If paint is non-null, draw the picture into a temporary buffer, and then apply the paint's
      *  alpha/colorfilter/imagefilter/xfermode to that buffer as it is drawn to the canvas.
      *  This is logically equivalent to
      *      saveLayer(paint)/drawPicture/restore
      */
     void drawPicture(const SkPicture*, const SkMatrix* matrix, const SkPaint* paint);
     void drawPicture(const sk_sp<SkPicture>& picture, const SkMatrix* matrix, const SkPaint* paint) {
         this->drawPicture(picture.get(), matrix, paint);
     }
 
+    /**
+     *  Draw the picture into this canvas.
+     *
+     *  However, this time, we will use the passed-in lights to generate shadows!

[jvanverth1, 2016/07/14 17:27:09]

This is a little too vague. Suggestion: Will use the list of lights and the
picture content to generate shadow maps for each light. Even that might not be
enough detail.

[vjiaoblack, 2016/07/14 20:38:17]

Done.

+     */
+    void drawShadowedPicture(const SkPicture*, sk_sp<SkLights>);

[jvanverth1, 2016/07/14 17:27:09]

Do we not need a matrix or paint?

[vjiaoblack, 2016/07/14 20:38:18]

I originally thought the proposed function didn't, but I realized that's just
pseudocode. Fixing...

+    void drawShadowedPicture(const sk_sp<SkPicture>& picture, sk_sp<SkLights> lights) {
+        this->drawShadowedPicture(picture.get(), lights);
+    }
+
     enum VertexMode {
         kTriangles_VertexMode,
         kTriangleStrip_VertexMode,
         kTriangleFan_VertexMode
     };
 
     /** Draw the array of vertices, interpreted as triangles (based on mode).
 
         If both textures and vertex-colors are NULL, it strokes hairlines with
         the paint's color. This behavior is a useful debugging mode to visualize
@@ skipping 333 matching lines @@
     };
 
     virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle);
     virtual void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle);
     virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle);
     virtual void onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op);
 
     virtual void onDiscard();
 
     virtual void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*);
+    virtual void onDrawShadowedPicture(const SkPicture*, sk_sp<SkLights>);
 
     // Returns the canvas to be used by DrawIter. Default implementation
     // returns this. Subclasses that encapsulate an indirect canvas may
     // need to overload this method. The impl must keep track of this, as it
     // is not released or deleted by the caller.
     virtual SkCanvas* canvasForDrawIter();
 
     // Clip rectangle bounds. Called internally by saveLayer.
     // returns false if the entire rectangle is entirely clipped out
     // If non-NULL, The imageFilter parameter will be used to expand the clip
@@ skipping 202 matching lines @@
 
 class SkCanvasClipVisitor {
 public:
     virtual ~SkCanvasClipVisitor();
     virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0;
 };
 
 #endif