add SkAnimTimer, SPACE = pause/resume, ESP = stop

BUG=skia:

Review URL: https://codereview.chromium.org/894083003

16 files changed, 241 insertions, 147 deletions

diff --git a/gm/SkAnimTimer.h b/gm/SkAnimTimer.h
new file mode 100644
index 0000000000..725171a8fe
--- /dev/null
+++ b/gm/SkAnimTimer.h
@@ -0,0 +1,139 @@
+/*
+ * 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 "SkTime.h"
+
+#ifndef SkAnimTimer_DEFINED
+#define SkAnimTimer_DEFINED
+
+/**
+ *  Class to track a "timer". It supports 3 states: stopped, paused, running.
+ *
+ *  The caller must call updateTime() to resync with the clock (typically just before
+ *  using the timer). Forcing the caller to do this ensures that the timer's return values
+ *  are consistent if called repeatedly, as they only reflect the time since the last
+ *  calle to updateTimer().
+ */
+class SkAnimTimer {
+public:
+    enum State {
+        kStopped_State,
+        kPaused_State,
+        kRunning_State
+    };
+
+    /**
+     *  Class begins in the "stopped" state.
+     */
+    SkAnimTimer() : fBaseTime(0), fCurrTime(0), fState(kStopped_State) {}
+
+    bool isStopped() const { return kStopped_State == fState; }
+    bool isRunning() const { return kRunning_State == fState; }
+    bool isPaused() const { return kPaused_State == fState; }
+
+    /**
+     *  Stops the timer, and resets it, such that the next call to run or togglePauseResume
+     *  will begin at time 0.
+     */
+    void stop() {
+        this->setState(kStopped_State);
+    }
+
+    /**
+     *  If the timer is paused or stopped, it will resume (or start if it was stopped).
+     */
+    void run() {
+        this->setState(kRunning_State);
+    }
+
+    /**
+     *  If the timer is stopped, this has no effect, else it toggles between paused and running.
+     */
+    void togglePauseResume() {
+        if (kRunning_State == fState) {
+            this->setState(kPaused_State);
+        } else {
+            this->setState(kRunning_State);
+        }
+    }
+
+    /**
+     *  Call this each time you want to sample the clock for the timer. This is NOT done
+     *  automatically, so that repeated calls to msec() or secs() will always return the
+     *  same value.
+     *
+     *  This may safely be called with the timer in any state.
+     */
+    void updateTime() {
+        if (kRunning_State == fState) {
+            fCurrTime = SkTime::GetMSecs();
+        }
+    }
+
+    /**
+     *  Return the time in milliseconds the timer has been in the running state.
+     *  Returns 0 if the timer is stopped.
+     */
+    SkMSec msec() const { return fCurrTime - fBaseTime; }
+
+    /**
+     *  Return the time in seconds the timer has been in the running state.
+     *  Returns 0 if the timer is stopped.
+     */
+    double secs() const {
+        return this->msec() * 0.001;
+    }
+
+    /**
+     *  Return the time in seconds the timer has been in the running state,
+     *  scaled by "speed" and (if not zero) mod by period.
+     *  Returns 0 if the timer is stopped.
+     */
+    SkScalar scaled(SkScalar speed, SkScalar period = 0) const {
+        double value = this->secs() * speed;
+        if (period) {
+            value = ::fmod(value, SkScalarToDouble(period));
+        }
+        return SkDoubleToScalar(value);
+    }
+
+private:
+    SkMSec  fBaseTime;
+    SkMSec  fCurrTime;
+    State   fState;
+
+    void setState(State newState) {
+        switch (newState) {
+            case kStopped_State:
+                fBaseTime = fCurrTime = 0;
+                fState = kStopped_State;
+                break;
+            case kPaused_State:
+                if (kRunning_State == fState) {
+                    fState = kPaused_State;
+                } // else stay stopped or paused
+                break;
+            case kRunning_State:
+                switch (fState) {
+                    case kStopped_State:
+                        fBaseTime = fCurrTime = SkTime::GetMSecs();
+                        break;
+                    case kPaused_State: {// they want "resume"
+                        SkMSec now = SkTime::GetMSecs();
+                        fBaseTime += now - fCurrTime;
+                        fCurrTime = now;
+                    } break;
+                    case kRunning_State:
+                        break;
+                }
+                fState = kRunning_State;
+                break;
+        }
+    }
+};
+
+#endif
diff --git a/gm/addarc.cpp b/gm/addarc.cpp
index 1386cdd0e7..e6fad25772 100644
--- a/gm/addarc.cpp
+++ b/gm/addarc.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "gm.h"
+#include "SkAnimTimer.h"
 #include "SkCanvas.h"
 #include "SkRandom.h"
 
@@ -49,8 +50,8 @@ protected:
         }
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fRotate = SkDoubleToScalar(fmod(curr * 0.001, 360));
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        fRotate = timer.scaled(1, 360);
         return true;
     }
 
diff --git a/gm/gm.cpp b/gm/gm.cpp
index c8109a7e26..8d269d977d 100644
--- a/gm/gm.cpp
+++ b/gm/gm.cpp
@@ -51,8 +51,8 @@ void GM::setBGColor(SkColor color) {
     fBGColor = color;
 }
 
-bool GM::animatePulse(SkMSec curr, SkMSec prev) {
-    return this->onAnimatePulse(curr, prev);
+bool GM::animate(const SkAnimTimer& timer) {
+    return this->onAnimate(timer);
 }
 
 /////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/gm/gm.h b/gm/gm.h
index c7dca6d276..e263528f90 100644
--- a/gm/gm.h
+++ b/gm/gm.h
@@ -16,6 +16,8 @@
 #include "SkTRegistry.h"
 #include "sk_tool_utils.h"
 
+class SkAnimTimer;
+
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #endif
@@ -92,7 +94,7 @@ namespace skiagm {
             fStarterMatrix = matrix;
         }
 
-        bool animatePulse(SkMSec curr, SkMSec prev);
+        bool animate(const SkAnimTimer&);
 
     protected:
         /** draws a standard message that the GM is only intended to be used with the GPU.*/
@@ -103,7 +105,7 @@ namespace skiagm {
         virtual SkISize onISize() = 0;
         virtual SkString onShortName() = 0;
 
-        virtual bool onAnimatePulse(SkMSec curr, SkMSec prev) { return false; }
+        virtual bool onAnimate(const SkAnimTimer&) { return false; }
         virtual SkMatrix onGetInitialTransform() const { return SkMatrix::I(); }
 
     private:
diff --git a/samplecode/GMSampleView.h b/samplecode/GMSampleView.h
index a03628e05b..adaf23d43f 100644
--- a/samplecode/GMSampleView.h
+++ b/samplecode/GMSampleView.h
@@ -70,8 +70,8 @@ protected:
         fGM->drawBackground(canvas);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        return fGM->animatePulse(curr, prev);
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        return fGM->animate(timer);
     }
 
 private:
diff --git a/samplecode/SampleAnimBlur.cpp b/samplecode/SampleAnimBlur.cpp
index 527d4300e7..3c0be83768 100644
--- a/samplecode/SampleAnimBlur.cpp
+++ b/samplecode/SampleAnimBlur.cpp
@@ -1,21 +1,22 @@
-
 /*
  * 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 "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkBlurMaskFilter.h"
 #include "SkColorPriv.h"
 #include "SkCanvas.h"
 #include "SkRandom.h"
 
-SkScalar get_anim_sin(SkMSec time, SkScalar amplitude, SkScalar periodInSec, SkScalar phaseInSec) {
+SkScalar get_anim_sin(double secs, SkScalar amplitude, SkScalar periodInSec, SkScalar phaseInSec) {
     if (!periodInSec) {
         return 0;
     }
-    double t = (double)time / 1000.0 + phaseInSec;
+    double t = secs + phaseInSec;
     t *= SkScalarToFloat(2 * SK_ScalarPI) / periodInSec;
     amplitude = SK_ScalarHalf * amplitude;
     return amplitude * SkDoubleToScalar(sin(t)) + amplitude;
@@ -58,9 +59,9 @@ protected:
         }
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fBlurSigma = get_anim_sin(curr, 100, 4, 5);
-        fCircleRadius = 3 + get_anim_sin(curr, 150, 25, 3);
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        fBlurSigma = get_anim_sin(timer.secs(), 100, 4, 5);
+        fCircleRadius = 3 + get_anim_sin(timer.secs(), 150, 25, 3);
         return true;
     }
 
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 5b8ed96905..cd5793f6a3 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -11,6 +11,7 @@
 #include "Resources.h"
 #include "SampleCode.h"
 #include "SamplePipeControllers.h"
+#include "SkAnimTimer.h"
 #include "SkCanvas.h"
 #include "SkCommandLineFlags.h"
 #include "SkData.h"
@@ -102,6 +103,8 @@ static void post_event_to_sink(SkEvent* evt, SkEventSink* sink) {
     evt->setTargetID(sink->getSinkID())->post();
 }
 
+static SkAnimTimer gAnimTimer;
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static const char* skip_until(const char* str, const char* skip) {
@@ -577,39 +580,6 @@ bool SampleCode::FastTextQ(const SkEvent& evt) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static SkMSec gAnimTime;
-static SkMSec gAnimTimePrev;
-
-SkMSec SampleCode::GetAnimTime() { return gAnimTime; }
-SkMSec SampleCode::GetAnimTimeDelta() { return gAnimTime - gAnimTimePrev; }
-SkScalar SampleCode::GetAnimSecondsDelta() {
-    return SkDoubleToScalar(GetAnimTimeDelta() / 1000.0);
-}
-
-SkScalar SampleCode::GetAnimScalar(SkScalar speed, SkScalar period) {
-    // since gAnimTime can be up to 32 bits, we can't convert it to a float
-    // or we'll lose the low bits. Hence we use doubles for the intermediate
-    // calculations
-    double seconds = (double)gAnimTime / 1000.0;
-    double value = SkScalarToDouble(speed) * seconds;
-    if (period) {
-        value = ::fmod(value, SkScalarToDouble(period));
-    }
-    return SkDoubleToScalar(value);
-}
-
-SkScalar SampleCode::GetAnimSinScalar(SkScalar amplitude,
-                                      SkScalar periodInSec,
-                                      SkScalar phaseInSec) {
-    if (!periodInSec) {
-        return 0;
-    }
-    double t = (double)gAnimTime / 1000.0 + phaseInSec;
-    t *= SkScalarToFloat(2 * SK_ScalarPI) / periodInSec;
-    amplitude = SK_ScalarHalf * amplitude;
-    return SkScalarMul(amplitude, SkDoubleToScalar(sin(t))) + amplitude;
-}
-
 enum TilingMode {
     kNo_Tiling,
     kAbs_128x128_Tiling,
@@ -665,12 +635,7 @@ static bool curr_title(SkWindow* wind, SkString* title) {
 bool SampleWindow::sendAnimatePulse() {
     SkView* view = curr_view(this);
     if (SampleView::IsSampleView(view)) {
-        if (fDoAnimate) {
-            return ((SampleView*)view)->animatePulse(gAnimTime, gAnimTimePrev);
-        } else {
-            // 0 signals the view that we are no longer animating
-            ((SampleView*)view)->animatePulse(0, 0);
-        }
+        return ((SampleView*)view)->animate(gAnimTimer);
     }
     return false;
 }
@@ -836,14 +801,11 @@ SampleWindow::SampleWindow(void* hwnd, int argc, char** argv, DeviceManager* dev
     fDeviceType = kANGLE_DeviceType;
 #endif
 
-    fDoAnimate = true;
     fUseClip = false;
     fNClip = false;
     fAnimating = false;
     fRotate = false;
-    fRotateAnimTime = 0;
     fPerspAnim = false;
-    fPerspAnimTime = 0;
     fRequestGrabImage = false;
     fPipeState = SkOSMenu::kOffState;
     fTilingMode = kNo_Tiling;
@@ -974,6 +936,8 @@ SampleWindow::SampleWindow(void* hwnd, int argc, char** argv, DeviceManager* dev
     // constructor first. Hence we post an event to ourselves.
 //    this->updateTitle();
     post_event_to_sink(new SkEvent(gUpdateWindowTitleEvtName), this);
+
+    gAnimTimer.run();
 }
 
 SampleWindow::~SampleWindow() {
@@ -1050,15 +1014,7 @@ static void drawText(SkCanvas* canvas, SkString string, SkScalar left, SkScalar
 #define YCLIP_N  8
 
 void SampleWindow::draw(SkCanvas* canvas) {
-    // update the animation time
-    if (!gAnimTimePrev && !gAnimTime) {
-        // first time make delta be 0
-        gAnimTime = SkTime::GetMSecs();
-        gAnimTimePrev = gAnimTime;
-    } else {
-        gAnimTimePrev = gAnimTime;
-        gAnimTime = SkTime::GetMSecs();
-    }
+    gAnimTimer.updateTime();
 
     if (fGesture.isActive()) {
         this->updateMatrix();
@@ -1408,22 +1364,20 @@ void SampleWindow::afterChildren(SkCanvas* orig) {
 
 void SampleWindow::beforeChild(SkView* child, SkCanvas* canvas) {
     if (fRotate) {
-        fRotateAnimTime += SampleCode::GetAnimSecondsDelta();
-
         SkScalar cx = this->width() / 2;
         SkScalar cy = this->height() / 2;
         canvas->translate(cx, cy);
-        canvas->rotate(fRotateAnimTime * 10);
+        canvas->rotate(gAnimTimer.scaled(10));
         canvas->translate(-cx, -cy);
     }
 
     if (fPerspAnim) {
-        fPerspAnimTime += SampleCode::GetAnimSecondsDelta();
+        SkScalar secs = gAnimTimer.scaled(1);
 
         static const SkScalar gAnimPeriod = 10 * SK_Scalar1;
         static const SkScalar gAnimMag = SK_Scalar1 / 1000;
-        SkScalar t = SkScalarMod(fPerspAnimTime, gAnimPeriod);
-        if (SkScalarFloorToInt(SkScalarDiv(fPerspAnimTime, gAnimPeriod)) & 0x1) {
+        SkScalar t = SkScalarMod(secs, gAnimPeriod);
+        if (SkScalarFloorToInt(SkScalarDiv(secs, gAnimPeriod)) & 0x1) {
             t = gAnimPeriod - t;
         }
         t = 2 * t - gAnimPeriod;
@@ -1669,20 +1623,6 @@ bool SampleWindow::onQuery(SkEvent* query) {
     return this->INHERITED::onQuery(query);
 }
 
-#if 0 // UNUSED
-static void cleanup_for_filename(SkString* name) {
-    char* str = name->writable_str();
-    for (size_t i = 0; i < name->size(); i++) {
-        switch (str[i]) {
-            case ':': str[i] = '-'; break;
-            case '/': str[i] = '-'; break;
-            case ' ': str[i] = '_'; break;
-            default: break;
-        }
-    }
-}
-#endif
-
 DECLARE_bool(portableFonts);
 
 bool SampleWindow::onHandleChar(SkUnichar uni) {
@@ -1727,8 +1667,14 @@ bool SampleWindow::onHandleChar(SkUnichar uni) {
     }
 
     switch (uni) {
+        case 27:    // ESC
+            gAnimTimer.stop();
+            if (this->sendAnimatePulse()) {
+                this->inval(NULL);
+            }
+            break;
         case ' ':
-            fDoAnimate = !fDoAnimate;
+            gAnimTimer.togglePauseResume();
             if (this->sendAnimatePulse()) {
                 this->inval(NULL);
             }
@@ -1769,7 +1715,6 @@ bool SampleWindow::onHandleChar(SkUnichar uni) {
             break;
         case 'r':
             fRotate = !fRotate;
-            fRotateAnimTime = 0;
             this->inval(NULL);
             this->updateTitle();
             return true;
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index d75e1495c3..b6530a3d5f 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -175,14 +175,11 @@ private:
     bool fSaveToPdf;
     SkAutoTUnref<SkDocument> fPDFDocument;
 
-    bool fDoAnimate;
     bool fUseClip;
     bool fNClip;
     bool fAnimating;
     bool fRotate;
-    SkScalar fRotateAnimTime;
     bool fPerspAnim;
-    SkScalar fPerspAnimTime;
     bool fRequestGrabImage;
     bool fMeasureFPS;
     SkMSec fMeasureFPS_Time;
diff --git a/samplecode/SampleArc.cpp b/samplecode/SampleArc.cpp
index 9f922ae2d6..3775de50c8 100644
--- a/samplecode/SampleArc.cpp
+++ b/samplecode/SampleArc.cpp
@@ -1,11 +1,12 @@
-
 /*
  * 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 "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
@@ -198,8 +199,8 @@ protected:
         canvas->EXPERIMENTAL_drawDrawable(fRootDrawable);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        SkScalar angle = SkDoubleToScalar(fmod(curr * 0.36 / 24, 360));
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        SkScalar angle = SkDoubleToScalar(fmod(timer.secs() * 360 / 24, 360));
         fAnimatingDrawable->setSweep(angle);
         return true;
     }
diff --git a/samplecode/SampleBitmapRect.cpp b/samplecode/SampleBitmapRect.cpp
index 006b919554..82d1098a35 100644
--- a/samplecode/SampleBitmapRect.cpp
+++ b/samplecode/SampleBitmapRect.cpp
@@ -1,11 +1,12 @@
-
 /*
  * 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 "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
@@ -75,15 +76,19 @@ class BitmapRectView : public SampleView {
         bounce_pt(&fSrcPts[1], &fSrcVec[1], fSrcLimit);
     }
 
-public:
-    BitmapRectView() {
-        this->setBGColor(SK_ColorGRAY);
-
+    void resetBounce() {
         fSrcPts[0].set(0, 0);
         fSrcPts[1].set(SCALAR_SIZE, SCALAR_SIZE);
-
+        
         fSrcVec[0] = unit_vec(30);
         fSrcVec[1] = unit_vec(107);
+    }
+
+public:
+    BitmapRectView() {
+        this->setBGColor(SK_ColorGRAY);
+
+        this->resetBounce();
 
         fSrcLimit.set(-SCALAR_SIZE/4, -SCALAR_SIZE/4,
                       SCALAR_SIZE*5/4, SCALAR_SIZE*5/4);
@@ -98,8 +103,7 @@ public:
     }
 
 protected:
-    // overrides from SkEventSink
-    virtual bool onQuery(SkEvent* evt) {
+    bool onQuery(SkEvent* evt) SK_OVERRIDE {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "BitmapRect");
             return true;
@@ -107,7 +111,7 @@ protected:
         return this->INHERITED::onQuery(evt);
     }
 
-    virtual void onDrawContent(SkCanvas* canvas) {
+    void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
         SkRect srcR;
         srcR.set(fSrcPts[0], fSrcPts[1]);
         srcR = SkRect::MakeXYWH(fSrcPts[0].fX, fSrcPts[0].fY, 32, 32);
@@ -130,13 +134,19 @@ protected:
             canvas->drawBitmapRectToRect(bitmap, &srcR, fDstR[i], &paint);
             canvas->drawRect(fDstR[i], paint);
         }
+    }
 
-        this->bounce();
-        this->inval(NULL);
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        if (timer.isStopped()) {
+            this->resetBounce();
+        } else if (timer.isRunning()) {
+            this->bounce();
+        }
+        return true;
     }
 
 private:
-    typedef SkView INHERITED;
+    typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
@@ -179,32 +189,28 @@ class BitmapRectView2 : public SampleView {
         fSrcR.fRight = fSrcR.fLeft + width;
     }
 
+    void resetBounce() {
+        fSrcR.iset(0, 0, fBitmap.height() * 3, fBitmap.height());
+        fDX = SK_Scalar1;
+    }
+
 public:
     BitmapRectView2() {
         make_big_bitmap(&fBitmap);
 
         this->setBGColor(SK_ColorGRAY);
 
-        fSrcR.fLeft = 0;
-        fSrcR.fTop = 0;
-        fSrcR.fRight = SkIntToScalar(fBitmap.height()) * 3;
-        fSrcR.fBottom = SkIntToScalar(fBitmap.height());
-
-        fLimitR.set(0, 0,
-                    SkIntToScalar(fBitmap.width()),
-                    SkIntToScalar(fBitmap.height()));
+        this->resetBounce();
 
-        fDX = SK_Scalar1;
+        fLimitR.iset(0, 0, fBitmap.width(), fBitmap.height());
 
-        fDstR[0] = SkRect::MakeXYWH(SkIntToScalar(20), SkIntToScalar(20),
-                                    SkIntToScalar(600), SkIntToScalar(200));
+        fDstR[0] = SkRect::MakeXYWH(20, 20, 600, 200);
         fDstR[1] = fDstR[0];
         fDstR[1].offset(0, fDstR[0].height() * 5/4);
     }
 
 protected:
-    // overrides from SkEventSink
-    virtual bool onQuery(SkEvent* evt) {
+    bool onQuery(SkEvent* evt) SK_OVERRIDE {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "BigBitmapRect");
             return true;
@@ -212,7 +218,7 @@ protected:
         return this->INHERITED::onQuery(evt);
     }
 
-    virtual void onDrawContent(SkCanvas* canvas) {
+    void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
         SkPaint paint;
         paint.setStyle(SkPaint::kStroke_Style);
         paint.setColor(SK_ColorYELLOW);
@@ -222,13 +228,19 @@ protected:
             canvas->drawBitmapRectToRect(fBitmap, &fSrcR, fDstR[i], &paint);
             canvas->drawRect(fDstR[i], paint);
         }
+    }
 
-        this->bounceMe();
-        this->inval(NULL);
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        if (timer.isStopped()) {
+            this->resetBounce();
+        } else if (timer.isRunning()) {
+            this->bounceMe();
+        }
+        return true;
     }
 
 private:
-    typedef SkView INHERITED;
+    typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/samplecode/SampleCamera.cpp b/samplecode/SampleCamera.cpp
index 35fa719479..af9dbe8d65 100644
--- a/samplecode/SampleCamera.cpp
+++ b/samplecode/SampleCamera.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkCamera.h"
@@ -88,10 +89,11 @@ protected:
         }
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fRY += (curr - prev) * 0.09f;
-        if (fRY >= 360) {
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        if (timer.isStopped()) {
             fRY = 0;
+        } else {
+            fRY = timer.scaled(90, 360);
         }
         return true;
     }
diff --git a/samplecode/SampleCode.h b/samplecode/SampleCode.h
index 02590f17a9..e65919a765 100644
--- a/samplecode/SampleCode.h
+++ b/samplecode/SampleCode.h
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2011 Google Inc.
  *
@@ -6,7 +5,6 @@
  * found in the LICENSE file.
  */
 
-
 #ifndef SampleCode_DEFINED
 #define SampleCode_DEFINED
 
@@ -15,7 +13,9 @@
 #include "SkKey.h"
 #include "SkView.h"
 #include "SkOSMenu.h"
+
 class GrContext;
+class SkAnimTimer;
 
 #define DEF_SAMPLE(code) \
     static SkView*          SK_MACRO_APPEND_LINE(F_)() { code } \
@@ -36,16 +36,6 @@ public:
 
     static bool FastTextQ(const SkEvent&);
 
-private:
-    static SkMSec GetAnimTime();
-    static SkMSec GetAnimTimeDelta();
-    static SkScalar GetAnimSecondsDelta();
-    static SkScalar GetAnimScalar(SkScalar speedPerSec, SkScalar period = 0);
-    // gives a sinusoidal value between 0 and amplitude
-    static SkScalar GetAnimSinScalar(SkScalar amplitude,
-                                     SkScalar periodInSec,
-                                     SkScalar phaseInSec = 0);
-
     friend class SampleWindow;
 };
 
@@ -120,7 +110,7 @@ public:
     {}
 
     void setBGColor(SkColor color) { fBGColor = color; }
-    bool animatePulse(SkMSec curr, SkMSec prev) { return this->onAnimatePulse(curr, prev); }
+    bool animate(const SkAnimTimer& timer) { return this->onAnimate(timer); }
 
     static bool IsSampleView(SkView*);
     static bool SetRepeatDraw(SkView*, int count);
@@ -140,7 +130,7 @@ public:
 protected:
     virtual void onDrawBackground(SkCanvas*);
     virtual void onDrawContent(SkCanvas*) = 0;
-    virtual bool onAnimatePulse(SkMSec curr, SkMSec prev) { return false; }
+    virtual bool onAnimate(const SkAnimTimer&) { return false; }
 
     // overrides
     virtual bool onEvent(const SkEvent& evt);
diff --git a/samplecode/SampleDegenerateTwoPtRadials.cpp b/samplecode/SampleDegenerateTwoPtRadials.cpp
index 71c03b016a..dec985029e 100644
--- a/samplecode/SampleDegenerateTwoPtRadials.cpp
+++ b/samplecode/SampleDegenerateTwoPtRadials.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
@@ -76,8 +77,8 @@ protected:
         canvas->drawText(txt.c_str(), txt.size(), l + w/2 + w*DELTA_SCALE*delta, t + h + SK_Scalar1 * 10, paint);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fTime += (curr - prev) * 0.001f;
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        fTime = SkDoubleToScalar(timer.secs() / 15);
         return true;
     }
 
diff --git a/samplecode/SampleHT.cpp b/samplecode/SampleHT.cpp
index 07605fe1ed..1436817e76 100644
--- a/samplecode/SampleHT.cpp
+++ b/samplecode/SampleHT.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkCanvasDrawable.h"
@@ -155,8 +156,8 @@ protected:
         canvas->EXPERIMENTAL_drawDrawable(fRoot);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fTime = curr;
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        fTime = timer.msec();
         for (int i = 0; i < N; ++i) {
             fArray[i].fDrawable->setTime(fTime);
         }
diff --git a/samplecode/SampleHairline.cpp b/samplecode/SampleHairline.cpp
index 3c254472fa..76876339b4 100644
--- a/samplecode/SampleHairline.cpp
+++ b/samplecode/SampleHairline.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkCornerPathEffect.h"
@@ -221,7 +222,7 @@ protected:
         canvas->drawBitmap(bm2, SkIntToScalar(10), SkIntToScalar(10), NULL);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
+    bool onAnimate(const SkAnimTimer&) SK_OVERRIDE {
         if (fDoAA) {
             fProcIndex = cycle_hairproc_index(fProcIndex);
             // todo: signal that we want to rebuild our TITLE
diff --git a/samplecode/SamplePathEffects.cpp b/samplecode/SamplePathEffects.cpp
index f07cd6ce40..a5f91c296e 100644
--- a/samplecode/SamplePathEffects.cpp
+++ b/samplecode/SamplePathEffects.cpp
@@ -1,11 +1,12 @@
-
 /*
  * 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 "SampleCode.h"
+#include "SkAnimTimer.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
@@ -158,8 +159,8 @@ protected:
         canvas->drawPath(fPath, paint);
     }
 
-    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
-        fPhase -= (curr - prev) * 0.04f;
+    bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
+        fPhase = timer.scaled(40);
         return true;
     }