Use vertex attributes for dash effect in gpu

gm/dashing.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkPaint.h"
@@ skipping 44 matching lines @@
         } gData[] = {
             { 1, 1 },
             { 4, 1 },
         };
 
         SkPaint paint;
         paint.setStyle(SkPaint::kStroke_Style);
 
         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
         canvas->translate(0, SK_ScalarHalf);
-
         for (int width = 0; width <= 2; ++width) {
             for (size_t data = 0; data < SK_ARRAY_COUNT(gData); ++data) {
                 for (int aa = 0; aa <= 1; ++aa) {
                     int w = width * width * width;
                     paint.setAntiAlias(SkToBool(aa));
                     paint.setStrokeWidth(SkIntToScalar(w));
 
                     int scale = w ? w : 1;
 
                     drawline(canvas, gData[data].fOnInterval * scale,
@@ skipping 151 matching lines @@
         }
 
         p.setAntiAlias(true);
 
         for (int x = 0; x < 100; x += 14*strokeWidth) {
             pts[0].set(SkIntToScalar(x), 0);
             pts[1].set(SkIntToScalar(x), lineLength);
 
             canvas->drawPoints(SkCanvas::kLines_PointMode, 2, pts, p);
         }
-
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         // 1on/1off 1x1 squares with phase of 0 - points fastpath
         canvas->save();
             canvas->translate(2, 0);
             this->drawDashedLines(canvas, 100, 0, SK_Scalar1, 1, false);
         canvas->restore();
 
         // 1on/1off 1x1 squares with phase of .5 - rects fastpath (due to partial squares)
@@ skipping 117 matching lines @@
                         canvas->translate(0, SkIntToScalar(20));
                     }
                 }
             }
         }
 
         for (int aa = 0; aa <= 1; ++aa) {
             paint.setAntiAlias(SkToBool(aa));
             paint.setStrokeWidth(8.f);
             paint.setStrokeCap(SkPaint::kSquare_Cap);
-
             // Single dash element that is cut off at start and end
             drawline(canvas, 32, 16, paint, 20.f, 0, 5.f);
             canvas->translate(0, SkIntToScalar(20));
 
             // Two dash elements where each one is cut off at beginning and end respectively
             drawline(canvas, 32, 16, paint, 56.f, 0, 5.f);
             canvas->translate(0, SkIntToScalar(20));
 
             // Many dash elements where first and last are cut off at beginning and end respectively
             drawline(canvas, 32, 16, paint, 584.f, 0, 5.f);
@@ skipping 15 matching lines @@
 
 static skiagm::GM* F0(void*) { return new DashingGM; }
 static skiagm::GM* F1(void*) { return new Dashing2GM; }
 static skiagm::GM* F2(void*) { return new Dashing3GM; }
 static skiagm::GM* F3(void*) { return new Dashing4GM; }
 
 static skiagm::GMRegistry gR0(F0);
 static skiagm::GMRegistry gR1(F1);
 static skiagm::GMRegistry gR2(F2);
 static skiagm::GMRegistry gR3(F3);