Add ship sample

samplecode/SampleShip.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 "Resources.h"
+#include "SkAnimTimer.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkRSXform.h"
+#include "SkSurface.h"
+#include "Timer.h"
+
+#include <stdio.h>
+
+static const int kGrid = 100;
+static const int kWidth = 960;
+static const int kHeight = 640;
+
+class DrawShipView : public SampleView {
+    const char*         fName;
+
+public:
+    DrawShipView(const char name[]) : fName(name) {
+        fAtlas.reset(GetResourceAsImage("ship.png"));
+        if (!fAtlas) {
+            SkDebugf("\nCould not decode file ship.png. Falling back to penguin mode.\n");
+            fAtlas.reset(GetResourceAsImage("baby_tux.png"));
+            if (!fAtlas) {
+                SkDebugf("\nCould not decode file baby_tux.png. Did you forget"
+                         " to set the resourcePath?\n");
+                return;
+            }
+        }
+        
+        SkScalar anchorX = fAtlas->width()*0.5f;
+        SkScalar anchorY = fAtlas->height()*0.5f;
+        int currIndex = 0;
+        for (int x = 0; x < kGrid; x++) {
+            for (int y = 0; y < kGrid; y++) {
+                float xPos = (x / (kGrid - 1.0f)) * kWidth;
+                float yPos = (y / (kGrid - 1.0f)) * kWidth;
+                
+                fTex[currIndex] = SkRect::MakeLTRB(0.0f, 0.0f,
+                                                   SkIntToScalar(fAtlas->width()),
+                                                   SkIntToScalar(fAtlas->height()));
+                fXform[currIndex] = SkRSXform::MakeFromRadians(2.0f, SK_ScalarPI*0.5f,
+                                                               xPos, yPos, anchorX, anchorY);
+                currIndex++;
+            }
+        }
+        fTex[currIndex] = SkRect::MakeLTRB(0.0f, 0.0f,
+                                           SkIntToScalar(fAtlas->width()),
+                                           SkIntToScalar(fAtlas->height()));
+        fXform[currIndex] = SkRSXform::MakeFromRadians(2.0f, SK_ScalarPI*0.5f,
+                                                       kWidth*0.5f, kHeight*0.5f, anchorX, anchorY);
+        
+        fCurrentTime = 0;
+        fTimer.start();
+    }
+
+    ~DrawShipView() override {}
+    
+protected:
+    // overrides from SkEventSink
+    bool onQuery(SkEvent* evt) override {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, fName);
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    void onDrawContent(SkCanvas* canvas) override {
+        const float kCosDiff = 0.99984769515f;
+        const float kSinDiff = 0.01745240643f;
+        
+        if (!fAtlas) {
+            return;
+        }
+        
+        SkPaint paint;
+        paint.setFilterQuality(kLow_SkFilterQuality);
+        paint.setColor(SK_ColorWHITE);
+        paint.setTextSize(15.0f);
+        
+        fTimer.end();
+        
+        fTimes[fCurrentTime] = (float)(fTimer.fWall);
+        fCurrentTime = (fCurrentTime + 1) & 0x1f;
+        
+        float meanTime = 0.0f;
+        for (int i = 0; i < 32; ++i) {
+            meanTime += fTimes[i];
+        }
+        meanTime /= 32.f;
+        SkString outString("fps: ");
+        SkScalar fps = 1000.f/meanTime;
+        outString.appendScalar(fps);
+        outString.append(" ms: ");
+        outString.appendScalar(meanTime);
+        
+        fTimer.start();
+        
+        SkScalar anchorX = fAtlas->width()*0.5f;
+        SkScalar anchorY = fAtlas->height()*0.5f;
+        for (int i = 0; i < kGrid*kGrid+1; ++i) {
+            SkScalar c = fXform[i].fSCos;
+            SkScalar s = fXform[i].fSSin;
+            
+            SkScalar dx = c*anchorX - s*anchorY;
+            SkScalar dy = s*anchorX + c*anchorY;
+            
+            fXform[i].fSCos = kCosDiff*c - kSinDiff*s;
+            fXform[i].fSSin = kSinDiff*c + kCosDiff*s;
+            
+            dx -= fXform[i].fSCos*anchorX - fXform[i].fSSin*anchorY;
+            dy -= fXform[i].fSSin*anchorX + fXform[i].fSCos*anchorY;
+            fXform[i].fTx += dx;
+            fXform[i].fTy += dy;
+        }
+        
+        canvas->drawAtlas(fAtlas, fXform, fTex, nullptr, kGrid*kGrid+1, SkXfermode::kSrcOver_Mode,
+                          nullptr, &paint);
+        canvas->drawText(outString.c_str(), outString.size(), 100.f, 100.f, paint);
+
+        this->inval(nullptr);
+    }
+
+#if 0
+    // TODO: switch over to use this for our animation
+    bool onAnimate(const SkAnimTimer& timer) override {
+        SkScalar angle = SkDoubleToScalar(fmod(timer.secs() * 360 / 24, 360));
+        fAnimatingDrawable->setSweep(angle);
+        return true;
+    }
+#endif
+
+private:
+    SkAutoTUnref<SkImage> fAtlas;
+    SkRSXform   fXform[kGrid*kGrid+1];
+    SkRect      fTex[kGrid*kGrid+1];
+    WallTimer   fTimer;
+    float       fTimes[32];
+    int         fCurrentTime;
+    
+    
+    typedef SampleView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_SAMPLE( return new DrawShipView("DrawShip"); )