add sample for mipmaps

git-svn-id: http://skia.googlecode.com/svn/trunk@218 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 136 insertions, 0 deletions

diff --git a/samplecode/SampleMipMap.cpp b/samplecode/SampleMipMap.cpp
new file mode 100644
index 0000000000..025cb0714a
--- /dev/null
+++ b/samplecode/SampleMipMap.cpp
@@ -0,0 +1,136 @@
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkDevice.h"
+#include "SkPaint.h"
+
+static SkBitmap createBitmap(int n) {
+    SkBitmap bitmap;
+    bitmap.setConfig(SkBitmap::kARGB_8888_Config, n, n);
+    bitmap.allocPixels();
+    bitmap.eraseColor(0);
+    
+    SkCanvas canvas(bitmap);
+    SkRect r;
+    r.set(0, 0, SkIntToScalar(n), SkIntToScalar(n));
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    
+    paint.setColor(SK_ColorRED);
+    canvas.drawOval(r, paint);
+    paint.setColor(SK_ColorBLUE);
+    paint.setStrokeWidth(SkIntToScalar(n)/15);
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas.drawLine(0, 0, r.fRight, r.fBottom, paint);
+    canvas.drawLine(0, r.fBottom, r.fRight, 0, paint);
+    
+    return bitmap;
+}
+
+class MipMapView : public SkView {
+    SkBitmap fBitmap;
+    enum {
+        N = 128
+    };
+public:
+    MipMapView() {
+        fBitmap = createBitmap(N);
+        
+        fWidth = N;
+        fDW = -1;
+    }
+    
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "MapMaps");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    void drawN(SkCanvas* canvas, const SkBitmap& bitmap) {
+        SkAutoCanvasRestore acr(canvas, true);
+        for (int i = N; i > 1; i >>= 1) {
+            canvas->drawBitmap(bitmap, 0, 0, NULL);
+            canvas->translate(SkIntToScalar(N + 8), 0);
+            canvas->scale(SK_ScalarHalf, SK_ScalarHalf);
+        }
+    }
+    
+    void drawN2(SkCanvas* canvas, const SkBitmap& bitmap) {
+        SkBitmap bg;
+        bg.setConfig(SkBitmap::kARGB_8888_Config, N, N);
+        bg.allocPixels();
+        
+        SkAutoCanvasRestore acr(canvas, true);
+        for (int i = 0; i < N-2; i++) {
+            bg.eraseColor(0);
+            SkCanvas c(bg);
+            c.scale(SK_Scalar1 / (1 << i), SK_Scalar1 / (1 << i));
+            c.drawBitmap(bitmap, 0, 0, NULL);
+
+            canvas->save();
+            canvas->scale(SkIntToScalar(1 << i), SkIntToScalar(1 << i));
+            canvas->drawBitmap(bg, 0, 0, NULL);
+            canvas->restore();
+            canvas->translate(SkIntToScalar(N + 8), 0);
+        }
+    }
+    
+    void drawBG(SkCanvas* canvas) {
+        canvas->drawColor(SK_ColorWHITE);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        this->drawBG(canvas);
+        
+        canvas->translate(SkIntToScalar(10), SkIntToScalar(10));
+
+        drawN2(canvas, fBitmap);
+
+        canvas->translate(0, SkIntToScalar(N + 8));
+        SkBitmap bitmap(fBitmap);
+        bitmap.buildMipMap();
+        drawN2(canvas, bitmap);
+        
+        fWidth += fDW;
+        if (fDW > 0 && fWidth > N) {
+            fDW = -fDW;
+            fWidth = N;
+        } else if (fDW < 0 && fWidth < 8) {
+            fDW = -fDW;
+            fWidth = 8;
+        }
+
+        SkRect dst;
+        dst.set(0, 0, SkIntToScalar(fWidth), SkIntToScalar(fWidth));
+
+        SkPaint paint;
+        paint.setFilterBitmap(true);
+        paint.setAntiAlias(true);
+
+        canvas->translate(0, SkIntToScalar(N + 8));
+        canvas->drawBitmapRect(fBitmap, NULL, dst, NULL);
+        canvas->translate(SkIntToScalar(N + 8), 0);
+        canvas->drawBitmapRect(fBitmap, NULL, dst, &paint);
+        canvas->translate(SkIntToScalar(N + 8), 0);
+        canvas->drawBitmapRect(bitmap, NULL, dst, NULL);
+        canvas->translate(SkIntToScalar(N + 8), 0);
+        canvas->drawBitmapRect(bitmap, NULL, dst, &paint);
+        
+        this->inval(NULL);
+    }
+    
+private:
+    int fWidth, fDW;
+
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new MipMapView; }
+static SkViewRegister reg(MyFactory);
+