Make some GMs animate

gm/lighting.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 "SkAnimTimer.h"
 #include "SkLightingImageFilter.h"
 #include "SkOffsetImageFilter.h"
 #include "SkPoint3.h"
 
 #define WIDTH 330
 #define HEIGHT 660
 
 namespace skiagm {
 
 class ImageLightingGM : public GM {
 public:
-    ImageLightingGM() {
+    ImageLightingGM()
+        : fAzimuth(SkIntToScalar(kStartAzimuth)) {
         this->setBGColor(0xFF000000);
     }
 
 protected:
 
     SkString onShortName() override {
         return SkString("lighting");
     }
 
     SkISize onISize() override {
@@ skipping 19 matching lines @@
         checkPaint.setColor(sk_tool_utils::color_to_565(0xFF202020));
         for (int y = 0; y < HEIGHT; y += 16) {
           for (int x = 0; x < WIDTH; x += 16) {
             canvas->save();
             canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
             canvas->drawRect(SkRect::MakeXYWH(8, 0, 8, 8), checkPaint);
             canvas->drawRect(SkRect::MakeXYWH(0, 8, 8, 8), checkPaint);
             canvas->restore();
           }
         }
-        SkPoint3 pointLocation = SkPoint3::Make(0, 0, SkIntToScalar(10));
-        SkScalar azimuthRad = SkDegreesToRadians(SkIntToScalar(225));
+        SkScalar cosAzimuth;
+        SkScalar sinAzimuth = SkScalarSinCos(SkDegreesToRadians(fAzimuth), &cosAzimuth);
+
+        SkPoint3 spotTarget = SkPoint3::Make(SkIntToScalar(40), SkIntToScalar(40), 0);
+        SkPoint3 spotLocation = SkPoint3::Make(spotTarget.fX + 70.7214f * cosAzimuth,
+                                               spotTarget.fY + 70.7214f * sinAzimuth,
+                                               spotTarget.fZ + SkIntToScalar(20));
+        SkScalar spotExponent = SK_Scalar1;
+
+        SkPoint3 pointLocation = SkPoint3::Make(spotTarget.fX + 50 * cosAzimuth,
+                                                spotTarget.fY + 50 * sinAzimuth,
+                                                SkIntToScalar(10));
         SkScalar elevationRad = SkDegreesToRadians(SkIntToScalar(5));
-        SkPoint3 distantDirection = SkPoint3::Make(SkScalarMul(SkScalarCos(azimuthRad),
+
+        SkPoint3 distantDirection = SkPoint3::Make(SkScalarMul(cosAzimuth,
                                                                SkScalarCos(elevationRad)),
-                                                   SkScalarMul(SkScalarSin(azimuthRad),
+                                                   SkScalarMul(sinAzimuth,
                                                                SkScalarCos(elevationRad)),
                                                    SkScalarSin(elevationRad));
-        SkPoint3 spotLocation = SkPoint3::Make(SkIntToScalar(-10),
-                                               SkIntToScalar(-10),
-                                               SkIntToScalar(20));
-        SkPoint3 spotTarget = SkPoint3::Make(SkIntToScalar(40), SkIntToScalar(40), 0);
-        SkScalar spotExponent = SK_Scalar1;
         SkScalar cutoffAngle = SkIntToScalar(15);
         SkScalar kd = SkIntToScalar(2);
         SkScalar ks = SkIntToScalar(1);
         SkScalar shininess = SkIntToScalar(8);
         SkScalar surfaceScale = SkIntToScalar(1);
         SkColor white(0xFFFFFFFF);
         SkPaint paint;
 
         SkImageFilter::CropRect cropRect(SkRect::MakeXYWH(20, 10, 60, 65));
         SkImageFilter::CropRect fullSizeCropRect(SkRect::MakeXYWH(0, 0, 100, 100));
@@ skipping 59 matching lines @@
                                                                               ks,
                                                                               shininess,
                                                                               input,
                                                                               cr))->unref();
             drawClippedBitmap(canvas, paint, 220, y);
 
             y += 110;
         }
     }
 
+    bool onAnimate(const SkAnimTimer& timer) override {
+        static const SkScalar kDesiredDurationSecs = 15.0f;
+
+        fAzimuth = kStartAzimuth + timer.scaled(360.0f/kDesiredDurationSecs, 360.0f);
+        return true;
+    }
+
 private:
+    static const int kStartAzimuth = 225;
+
     SkBitmap fBitmap;
+    SkScalar fAzimuth;
 
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM(return new ImageLightingGM;)
 }