More cleanup in the Vulkan viewer

tools/vulkan/viewer/VulkanViewer.h

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #ifndef VulkanViewer_DEFINED
 #define VulkanViewer_DEFINED
 
 #include "../Application.h"
 #include "../Window.h"
 #include "gm.h"
+#include "SkAnimTimer.h"
 #include "Slide.h"
 
 class SkCanvas;
 
 class VulkanViewer : public Application {
 public:
     VulkanViewer(int argc, char** argv, void* platformData);
     ~VulkanViewer() override;
 
     bool onKey(Window::Key key, Window::InputState state, uint32_t modifiers);
+    bool onChar(SkUnichar, uint32_t modifiers);
     void onPaint(SkCanvas* canvas);
-
     void onIdle(double ms) override;
 
 private:
     void initSlides();
+    void setupCurrentSlide(int previousSlide);
 
     void drawStats(SkCanvas* canvas);
 
+    void changeZoomLevel(float delta);
+    void updateMatrix();
+
     Window*      fWindow;
 
     static const int kMeasurementCount = 64;  // should be power of 2 for fast mod
     double fMeasurements[kMeasurementCount];
     int fCurrentMeasurement;
 
+    SkAnimTimer            fAnimTimer;
     SkTArray<sk_sp<Slide>> fSlides;
     int                    fCurrentSlide;
+
+    bool                   fDisplayStats;
+
+    // transform data
+    SkMatrix               fLocalMatrix;
+    SkScalar               fZoomCenterX;
+    SkScalar               fZoomCenterY;
+    SkScalar               fZoomLevel;
+    SkScalar               fZoomScale;
+
 };
 
 
 #endif