'g' key toggles showgrid for PerlinPatch

samplecode/PerlinPatch.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleCode.h"
 #include "SkAnimTimer.h"
 #include "SkCanvas.h"
@@ skipping 53 matching lines @@
     sk_sp<SkShader> fShader1;
     sk_sp<SkShader> fShaderCompose;
     SkScalar fXFreq;
     SkScalar fYFreq;
     SkScalar fSeed;
     SkPoint  fPts[SkPatchUtils::kNumCtrlPts];
     SkScalar fTexX;
     SkScalar fTexY;
     SkScalar fTexScale;
     SkMatrix fInvMatrix;
+    bool     fShowGrid = false;
+
 public:
     PerlinPatchView() : fXFreq(0.025f), fYFreq(0.025f), fSeed(0.0f),
                         fTexX(100.0), fTexY(50.0), fTexScale(1.0f) {
         const SkScalar s = 2;
         // The order of the colors and points is clockwise starting at upper-left corner.
         //top points
         fPts[0].set(100 * s, 100 * s);
         fPts[1].set(150 * s, 50 * s);
         fPts[2].set(250 * s, 150 * s);
         fPts[3].set(300 * s, 100 * s);
@@ skipping 23 matching lines @@
                                                   NULL);
     }
 
 protected:
     // overrides from SkEventSink
     bool onQuery(SkEvent* evt)  override {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "PerlinPatch");
             return true;
         }
+        SkUnichar uni;
+        if (SampleCode::CharQ(*evt, &uni)) {
+            switch (uni) {
+                case 'g': fShowGrid = !fShowGrid; this->inval(nullptr); return true;
+                default: break;
+            }
+        }
         return this->INHERITED::onQuery(evt);
     }
 
     bool onAnimate(const SkAnimTimer& timer) override {
         fSeed += 0.005f;
         return true;
     }
 
 
     void onDrawContent(SkCanvas* canvas) override {
@@ skipping 13 matching lines @@
         ;
         
         sk_sp<SkXfermode> xfer(SkXfermode::Make(SkXfermode::kSrc_Mode));
 
         SkScalar scaleFreq = 2.0;
         fShader1 = SkPerlinNoiseShader2::MakeImprovedNoise(fXFreq/scaleFreq, fYFreq/scaleFreq, 4,
                                                              fSeed);
         fShaderCompose = SkShader::MakeComposeShader(fShader0, fShader1, nullptr);
 
         paint.setShader(fShaderCompose);
-        canvas->drawPatch(fPts, nullptr, texCoords, xfer, paint);
+
+        const SkPoint* tex = texCoords;
+        if (fShowGrid) {
+            tex = nullptr;
+        }
+        canvas->drawPatch(fPts, nullptr, tex, xfer, paint);
 
         draw_control_points(canvas, fPts);
     }
 
     class PtClick : public Click {
     public:
         int fIndex;
         PtClick(SkView* view, int index) : Click(view), fIndex(index) {}
     };
 
@@ skipping 36 matching lines @@
         }
         this->inval(nullptr);
         return true;
     }
 
 private:
     typedef SampleView INHERITED;
 };
 
 DEF_SAMPLE( return new PerlinPatchView(); )