use pinned value during lerp for vertical gradients

gm/gradients.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 "SkGradientShader.h"
 
@@ skipping 592 matching lines @@
     }
 
     void onDraw(SkCanvas* canvas) override {
         const SkScalar kRectSize = 100;
         const unsigned kStopCount = 3;
         const SkColor colors[kStopCount] = { SK_ColorGREEN, SK_ColorRED, SK_ColorGREEN };
         const struct {
             SkPoint pts[2];
             SkScalar pos[kStopCount];
         } configs[] = {
-            { { SkPoint::Make(0, 0), SkPoint::Make(10, 0) }, { 0, 0.999999f,    1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(10, 0) }, { 0, 0.000001f,    1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(10, 0) }, { 0, 0.999999999f, 1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(10, 0) }, { 0, 0.000000001f, 1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(0, 10) }, { 0, 0.999999f,    1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(0, 10) }, { 0, 0.000001f,    1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(0, 10) }, { 0, 0.999999999f, 1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(0, 10) }, { 0, 0.000000001f, 1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.999999f,    1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.000001f,    1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.999999999f, 1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(10, 0) },       { 0, 0.000000001f, 1 }},
 
-            { { SkPoint::Make(0, 0), SkPoint::Make(0.00001f, 0) } , { 0, 0.5f, 1 }},
-            { { SkPoint::Make(9.99999f, 0), SkPoint::Make(10, 0) }, { 0, 0.5f, 1 }},
-            { { SkPoint::Make(0, 0), SkPoint::Make(0, 0.00001f) },  { 0, 0.5f, 1 }},
-            { { SkPoint::Make(0, 9.99999f), SkPoint::Make(0, 10) }, { 0, 0.5f, 1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.999999f,    1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.000001f,    1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.999999999f, 1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0, 10) },       { 0, 0.000000001f, 1 }},
+
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0.00001f, 0) }, { 0, 0.5f, 1 }},
+            { { SkPoint::Make(9.99999f, 0), SkPoint::Make(10, 0) },       { 0, 0.5f, 1 }},
+            { { SkPoint::Make(0, 0),        SkPoint::Make(0, 0.00001f) }, { 0, 0.5f, 1 }},
+            { { SkPoint::Make(0, 9.99999f), SkPoint::Make(0, 10) },       { 0, 0.5f, 1 }},
         };
 
         SkPaint paint;
         for (unsigned i = 0; i < SK_ARRAY_COUNT(configs); ++i) {
             SkAutoCanvasRestore acr(canvas, true);
             SkAutoTUnref<SkShader> gradient(
                 SkGradientShader::CreateLinear(configs[i].pts, colors, configs[i].pos, kStopCount,
                                                SkShader::kClamp_TileMode));
             canvas->translate(kRectSize * ((i % 4) * 1.5f + 0.25f),
                               kRectSize * ((i / 4) * 1.5f + 0.25f));
 
             paint.setShader(gradient);
             canvas->drawRect(SkRect::MakeWH(kRectSize, kRectSize), paint);
         }
     }
 
 private:
     typedef GM INHERITED;
 };
 DEF_GM( return new LinearGradientTinyGM(); )
 
 }