Factor out checkerboard function in gm and sampleapp into tools.

samplecode/SampleFatBits.cpp

 /*
  * 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 "Checkerboard.h"
 #include "SampleCode.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkPath.h"
 #include "SkRegion.h"
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "SkImage.h"
 #include "SkSurface.h"
 
@@ skipping 10 matching lines @@
 static void apply_grid(SkPoint pts[], int count) {
     for (int i = 0; i < count; ++i) {
         pts[i].set(apply_grid(pts[i].fX), apply_grid(pts[i].fY));
     }
 }
 
 static void erase(SkSurface* surface) {
     surface->getCanvas()->clear(SK_ColorTRANSPARENT);
 }
 
-static SkShader* createChecker(const SkMatrix& localMatrix) {
-//    SkColor colors[] = { 0xFFFDFDFD, 0xFFF4F4F4 };
-    SkColor colors[] = { 0xFFFFFFFF, 0xFFFFFFFF };
-    SkBitmap bm;
-    bm.allocN32Pixels(2, 2);
-    bm.lockPixels();
-    *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = SkPreMultiplyColor(colors[0]);
-    *bm.getAddr32(0, 1) = *bm.getAddr32(1, 0) = SkPreMultiplyColor(colors[1]);
-    return SkShader::CreateBitmapShader(bm, SkShader::kRepeat_TileMode,
-                                        SkShader::kRepeat_TileMode, &localMatrix);
-}
-
 class FatBits {
 public:
     FatBits() {
         fAA = false;
         fStyle = kHair_Style;
         fGrid = true;
         fShowSkeleton = true;
         fUseGPU = false;
         fUseClip = false;
         fRectAsOval = false;
@@ skipping 31 matching lines @@
     Style getStyle() const { return fStyle; }
     void setStyle(Style s) { fStyle = s; }
 
     void setWHZ(int width, int height, int zoom) {
         fW = width;
         fH = height;
         fZoom = zoom;
         fBounds.set(0, 0, SkIntToScalar(width * zoom), SkIntToScalar(height * zoom));
         fMatrix.setScale(SkIntToScalar(zoom), SkIntToScalar(zoom));
         fInverse.setScale(SK_Scalar1 / zoom, SK_Scalar1 / zoom);
-        fShader.reset(createChecker(fMatrix));
+        fShader.reset(sk_tools::CreateCheckerboardShader(
+                              0xFFCCCCCC, 0xFFFFFFFF, zoom));
 
         SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
         fMinSurface.reset(SkSurface::NewRaster(info));
         info = info.makeWH(width * zoom, height * zoom);
         fMaxSurface.reset(SkSurface::NewRaster(info));
     }
 
     void drawBG(SkCanvas*);
     void drawFG(SkCanvas*);
     void drawLine(SkCanvas*, SkPoint pts[2]);
@@ skipping 404 matching lines @@
 
 private:
 
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new DrawLineView; }
 static SkViewRegister reg(MyFactory);