Factor out checkerboard function in gm and sampleapp into tools.

gm/tileimagefilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
+#include "Checkerboard.h"
+#include "SkBitmapSource.h"
+#include "SkColorFilterImageFilter.h"
+#include "SkColorMatrixFilter.h"
+#include "SkTileImageFilter.h"
 #include "gm.h"
-#include "SkColorMatrixFilter.h"
-#include "SkColorFilterImageFilter.h"
-#include "SkTileImageFilter.h"
-#include "SkBitmapSource.h"
 
 #define WIDTH 400
 #define HEIGHT 100
 #define MARGIN 12
 
 namespace skiagm {
 
 class TileImageFilterGM : public GM {
 public:
     TileImageFilterGM() : fInitialized(false) {
@@ skipping 11 matching lines @@
         canvas.clear(0xFF000000);
         SkPaint paint;
         paint.setAntiAlias(true);
         sk_tool_utils::set_portable_typeface(&paint);
         paint.setColor(0xD000D000);
         paint.setTextSize(SkIntToScalar(50));
         const char* str = "e";
         canvas.drawText(str, strlen(str), SkIntToScalar(10), SkIntToScalar(45), paint);
     }
 
-    void make_checkerboard() {
-        fCheckerboard.allocN32Pixels(80, 80);
-        SkCanvas canvas(fCheckerboard);
-        canvas.clear(0x00000000);
-        SkPaint darkPaint;
-        darkPaint.setColor(0xFF404040);
-        SkPaint lightPaint;
-        lightPaint.setColor(0xFFA0A0A0);
-        for (int y = 0; y < 80; y += 16) {
-          for (int x = 0; x < 80; x += 16) {
-            canvas.save();
-            canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
-            canvas.drawRect(SkRect::MakeXYWH(0, 0, 8, 8), darkPaint);
-            canvas.drawRect(SkRect::MakeXYWH(8, 0, 8, 8), lightPaint);
-            canvas.drawRect(SkRect::MakeXYWH(0, 8, 8, 8), lightPaint);
-            canvas.drawRect(SkRect::MakeXYWH(8, 8, 8, 8), darkPaint);
-            canvas.restore();
-          }
-        }
-    }
-
     virtual SkISize onISize() {
         return SkISize::Make(WIDTH, HEIGHT);
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         if (!fInitialized) {
             make_bitmap();
-            make_checkerboard();
+
+            fCheckerboard.allocN32Pixels(80, 80);
+            SkCanvas checkerboardCanvas(fCheckerboard);
+            sk_tools::DrawCheckerboard(&checkerboardCanvas, 0xFFA0A0A0, 0xFF404040, 8);
+
             fInitialized = true;
         }
         canvas->clear(0x00000000);
 
         int x = 0, y = 0;
         for (size_t i = 0; i < 4; i++) {
             SkBitmap* bitmap = (i & 0x01) ? &fCheckerboard : &fBitmap;
             SkRect srcRect = SkRect::MakeXYWH(SkIntToScalar(bitmap->width()/4),
                                               SkIntToScalar(bitmap->height()/4),
                                               SkIntToScalar(bitmap->width()/(i+1)),
@@ skipping 46 matching lines @@
     SkBitmap fBitmap, fCheckerboard;
     bool fInitialized;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new TileImageFilterGM; }
 static GMRegistry reg(MyFactory);
 
 }