Factor code to rotate a canvas about a point.

samplecode/SampleFontScalerTest.cpp

 /*
  * 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 "SkView.h"
 #include "SkCanvas.h"
 #include "SkTypeface.h"
 #include "SkPath.h"
 #include "SkRegion.h"
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "Sk1DPathEffect.h"
 #include "SkCornerPathEffect.h"
 #include "SkPathMeasure.h"
 #include "SkRandom.h"
 #include "SkColorPriv.h"
 #include "SkColorFilter.h"
 #include "SkDither.h"
+#include "sk_tool_utils.h"
 
 static const struct {
     const char* fName;
     SkTypeface::Style   fStyle;
 } gFaces[] = {
     { nullptr, SkTypeface::kNormal },
     { nullptr, SkTypeface::kBold },
     { "serif", SkTypeface::kNormal },
     { "serif", SkTypeface::kBold },
     { "serif", SkTypeface::kItalic },
     { "serif", SkTypeface::kBoldItalic },
     { "monospace", SkTypeface::kNormal }
 };
 
 static const int gFaceCount = SK_ARRAY_COUNT(gFaces);
 
 class FontScalerTestView : public SampleView {
     sk_sp<SkTypeface> fFaces[gFaceCount];
 
 public:
     FontScalerTestView() {
         for (int i = 0; i < gFaceCount; i++) {
             fFaces[i] = SkTypeface::MakeFromName(
                 gFaces[i].fName, SkFontStyle::FromOldStyle(gFaces[i].fStyle));
         }
-//        this->setBGColor(0xFFDDDDDD);
     }
 
 protected:
     // overrides from SkEventSink
     virtual bool onQuery(SkEvent* evt) {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "FontScaler Test");
             return true;
         }
         return this->INHERITED::onQuery(evt);
     }
 
-    static void rotate_about(SkCanvas* canvas, SkScalar degrees, SkScalar px, SkScalar py) {
-        canvas->translate(px, py);
-        canvas->rotate(degrees);
-        canvas->translate(-px, -py);
-    }
-
     virtual void onDrawContent(SkCanvas* canvas) {
         SkPaint paint;
 
         // test handling of obscene cubic values (currently broken)
         if (false) {
             SkPoint pts[4];
             pts[0].set(1.61061274e+09f, 6291456);
             pts[1].set(-7.18397061e+15f,
                        -1.53091184e+13f);
             pts[2].set(-1.30077315e+16f,
@@ skipping 17 matching lines @@
         const size_t textLen = strlen(text);
 
         for (int j = 0; j < 2; ++j) {
             for (int i = 0; i < 6; ++i) {
                 SkScalar x = SkIntToScalar(10);
                 SkScalar y = SkIntToScalar(20);
 
                 SkAutoCanvasRestore acr(canvas, true);
                 canvas->translate(SkIntToScalar(50 + i * 230),
                                   SkIntToScalar(20));
-                rotate_about(canvas, SkIntToScalar(i * 5), x, y * 10);
+                sk_tool_utils::rotate_about(canvas, SkIntToScalar(i * 5), x, y * 10);
 
                 {
                     SkPaint p;
                     p.setAntiAlias(true);
                     SkRect r;
                     r.set(x-3, 15, x-1, 280);
                     canvas->drawRect(r, p);
                 }
 
                 int index = 0;
@@ skipping 10 matching lines @@
     }
 
 private:
     typedef SkView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new FontScalerTestView; }
 static SkViewRegister reg(MyFactory);