// Copyright 2020 Google LLC. // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. #include "tools/fiddle/examples.h" REG_FIDDLE(mapradius, 256, 256, false, 0) { void draw(SkCanvas* canvas) { SkPaint paint; paint.setAntiAlias(true); paint.setStyle(SkPaint::kStroke_Style); SkMatrix matrix; const SkPoint center = {128, 103}; matrix.setScale(2, .5f, center.fX, center.fY); matrix.postRotate(45, center.fX, center.fY); const SkScalar circleRadius = 60; SkScalar mappedRadius = matrix.mapRadius(circleRadius); SkVector minorAxis, majorAxis; matrix.mapVector(0, circleRadius, &minorAxis); matrix.mapVector(circleRadius, 0, &majorAxis); paint.setColor(SK_ColorRED); canvas->drawLine(40, 240, 40 + minorAxis.length(), 240, paint); canvas->drawLine(42 + minorAxis.length(), 240, 42 + minorAxis.length() + majorAxis.length(), 240, paint); paint.setColor(SK_ColorBLACK); canvas->drawLine(center.fX, center.fY, center.fX + mappedRadius, center.fY, paint); canvas->drawLine(center.fX, center.fY, center.fX, center.fY + mappedRadius, paint); canvas->drawLine(40, 220, 40 + mappedRadius, 220, paint); canvas->drawLine(42 + mappedRadius, 220, 42 + mappedRadius * 2, 220, paint); canvas->concat(matrix); canvas->drawCircle(center.fX, center.fY, circleRadius, paint); paint.setColor(SK_ColorRED); canvas->drawLine(center.fX, center.fY, center.fX + circleRadius, center.fY, paint); canvas->drawLine(center.fX, center.fY, center.fX, center.fY + circleRadius, paint); } } // END FIDDLE