make test random calls deterministic

gm/hittestpath.cpp

 /*
  * Copyright 2011 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 "SkCullPoints.h"
@@ skipping 29 matching lines @@
     }
 
     SkISize onISize() override { return SkISize::Make(700, 460); }
 
     void onDraw(SkCanvas* canvas) override {
         SkPath path;
         SkRandom rand;
 
         int scale = 300;
         for (int i = 0; i < 4; ++i) {
-            path.lineTo(rand.nextUScalar1() * scale, rand.nextUScalar1() * scale);
-            path.quadTo(rand.nextUScalar1() * scale, rand.nextUScalar1() * scale,
-                        rand.nextUScalar1() * scale, rand.nextUScalar1() * scale);
-            path.cubicTo(rand.nextUScalar1() * scale, rand.nextUScalar1() * scale,
-                         rand.nextUScalar1() * scale, rand.nextUScalar1() * scale,
-                         rand.nextUScalar1() * scale, rand.nextUScalar1() * scale);
+            // get the random values deterministically
+            SkScalar randoms[12];
+            for (int index = 0; index < (int) SK_ARRAY_COUNT(randoms); ++index) {
+                randoms[index] = rand.nextUScalar1();
+            }
+            path.lineTo(randoms[0] * scale, randoms[1] * scale);
+            path.quadTo(randoms[2] * scale, randoms[3] * scale,
+                        randoms[4] * scale, randoms[5] * scale);
+            path.cubicTo(randoms[6] * scale, randoms[7] * scale,
+                         randoms[8] * scale, randoms[9] * scale,
+                         randoms[10] * scale, randoms[11] * scale);
         }
 
         path.setFillType(SkPath::kEvenOdd_FillType);
         path.offset(SkIntToScalar(20), SkIntToScalar(20));
 
         test_hittest(canvas, path);
 
         canvas->translate(SkIntToScalar(scale), 0);
         path.setFillType(SkPath::kWinding_FillType);
 
         test_hittest(canvas, path);
     }
 
 private:
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static skiagm::GM* MyFactory(void*) { return new HitTestPathGM; }
 static skiagm::GMRegistry reg(MyFactory);