/* * 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 "include/core/SkCanvas.h" #include "include/core/SkPaint.h" #include "include/core/SkPath.h" #include "samplecode/Sample.h" // ensure that we don't accidentally screw up the bounds when the oval is // fractional, and the impl computes the center and radii, and uses them to // reconstruct the edges of the circle. // see bug# 1504910 static void test_circlebounds(SkCanvas*) { SkRect r = { 1.39999998f, 1, 21.3999996f, 21 }; SkPath p; p.addOval(r); SkASSERT(r == p.getBounds()); } class CircleView : public Sample { SkString name() override { return SkString("Circles"); } void circle(SkCanvas* canvas, int width, bool aa) { SkPaint paint; paint.setAntiAlias(aa); if (width < 0) { paint.setStyle(SkPaint::kFill_Style); } else { paint.setStyle(SkPaint::kStroke_Style); paint.setStrokeWidth(SkIntToScalar(width)); } canvas->drawCircle(0, 0, 9.0f, paint); if ((false)) { // avoid bit rot, suppress warning test_circlebounds(canvas); } } void drawSix(SkCanvas* canvas, SkScalar dx, SkScalar dy) { for (int width = -1; width <= 1; width++) { canvas->save(); circle(canvas, width, false); canvas->translate(0, dy); circle(canvas, width, true); canvas->restore(); canvas->translate(dx, 0); } } static void make_poly(SkPath* path, int n) { if (n <= 0) { return; } path->incReserve(n + 1); path->moveTo(SK_Scalar1, 0); SkScalar step = SK_ScalarPI * 2 / n; SkScalar angle = 0; for (int i = 1; i < n; i++) { angle += step; path->lineTo(SkScalarCos(angle), SkScalarSin(angle)); } path->close(); } void onDrawContent(SkCanvas* canvas) override { SkPaint paint; paint.setAntiAlias(true); paint.setStyle(SkPaint::kStroke_Style); SkMatrix matrix; matrix.setScale(SkIntToScalar(100), SkIntToScalar(100)); matrix.postTranslate(SkIntToScalar(200), SkIntToScalar(200)); canvas->concat(matrix); for (int n = 3; n < 20; n++) { SkPath path; make_poly(&path, n); SkAutoCanvasRestore acr(canvas, true); canvas->rotate(SkIntToScalar(10) * (n - 3)); canvas->translate(-SK_Scalar1, 0); canvas->drawPath(path, paint); } } }; DEF_SAMPLE( return new CircleView(); )