drawTextRSXform

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
 
@@ skipping 968 matching lines @@
     /** Draw the text, with origin at (x,y), using the specified paint, along
         the specified path. The paint's Align setting determins where along the
         path to start the text.
         @param text The text to be drawn
         @param byteLength   The number of bytes to read from the text parameter
         @param path         The path the text should follow for its baseline
         @param matrix       (may be null) Applied to the text before it is
                             mapped onto the path
         @param paint        The paint used for the text
         */
     void drawTextOnPath(const void* text, size_t byteLength, const SkPath& path,

[f(malita), 2016/07/07 16:51:05]

Could this be refactored as a drawTextRSXform wrapper at some point?

[reed1, 2016/07/07 18:51:50]

Oddly, no. This guy warps each glyph, bending straight-lines etc. It looks way
pretty, but is very slow (impossible to cache).

What we can do is offer a (non-virtual) helper that looks like
drawTextOnPathRigidRotation, which would call through to drawTextRSXform. This
is basically what I've written in the GM.

                         const SkMatrix* matrix, const SkPaint& paint);
 
+    void drawTextRSXform(const void* text, size_t byteLength, const SkRSXform[],

[f(malita), 2016/07/07 16:51:05]

+ Docs.

[reed1, 2016/07/07 18:51:50]

Done.

+                         const SkPaint& paint);
+
     /** Draw the text blob, offset by (x,y), using the specified paint.
         @param blob     The text blob to be drawn
         @param x        The x-offset of the text being drawn
         @param y        The y-offset of the text being drawn
         @param paint    The paint used for the text (e.g. color, size, style)
     */
     void drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint);
 
     /** Draw the picture into this canvas. This method effective brackets the
         playback of the picture's draw calls with save/restore, so the state
@@ skipping 315 matching lines @@
     virtual void onDrawPosText(const void* text, size_t byteLength,
                                const SkPoint pos[], const SkPaint& paint);
 
     virtual void onDrawPosTextH(const void* text, size_t byteLength,
                                 const SkScalar xpos[], SkScalar constY,
                                 const SkPaint& paint);
 
     virtual void onDrawTextOnPath(const void* text, size_t byteLength,
                                   const SkPath& path, const SkMatrix* matrix,
                                   const SkPaint& paint);
+    virtual void onDrawTextRSXform(const void* text, size_t byteLength, const SkRSXform[],

[f(malita), 2016/07/07 16:51:04]

+ 100000000 overrides in all SkCanvas subclasses.

[reed1, 2016/07/07 18:51:50]

Eventually. The base impl calls through to a base-impl for device, which is
backward compatible. The only canvases that won't work are ones w/o a device
(e.g. NWay, Picture, some chrome analysis ones). Picture is now updated, and I
will update the others in time... if the client doesn't call this new API, they
won't notice the missing overrides.

+                                   const SkPaint& paint);
 
     virtual void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                                 const SkPaint& paint);
 
     virtual void onDrawPatch(const SkPoint cubics[12], const SkColor colors[4],
                            const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint);
 
     virtual void onDrawDrawable(SkDrawable*, const SkMatrix*);
 
     virtual void onDrawPaint(const SkPaint&);
@@ skipping 248 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