| /* |
| * 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 "gm/gm.h" |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkPaint.h" |
| #include "include/core/SkPath.h" |
| #include "include/core/SkPoint.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkSize.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkTypes.h" |
| #include "tools/ToolUtils.h" |
| #include "tools/timer/TimeUtils.h" |
| |
| // Reproduces https://code.google.com/p/chromium/issues/detail?id=279014 |
| |
| constexpr int kWidth = 440; |
| constexpr int kHeight = 440; |
| constexpr SkScalar kAngle = 0.305f; |
| constexpr int kMaxNumSteps = 140; |
| |
| // Renders a string art shape. |
| // The particular shape rendered can be controlled by adjusting kAngle, from 0 to 1 |
| |
| class StringArtGM : public skiagm::GM { |
| public: |
| StringArtGM() : fNumSteps(kMaxNumSteps) {} |
| |
| protected: |
| SkString getName() const override { return SkString("stringart"); } |
| |
| SkISize getISize() override { return SkISize::Make(kWidth, kHeight); } |
| |
| void onDraw(SkCanvas* canvas) override { |
| SkScalar angle = kAngle*SK_ScalarPI + SkScalarHalf(SK_ScalarPI); |
| SkScalar size = SkIntToScalar(std::min(kWidth, kHeight)); |
| SkPoint center = SkPoint::Make(SkScalarHalf(kWidth), SkScalarHalf(kHeight)); |
| SkScalar length = 5; |
| SkScalar step = angle; |
| |
| SkPath path; |
| path.moveTo(center); |
| |
| for (int i = 0; i < fNumSteps && length < (SkScalarHalf(size) - 10.f); ++i) { |
| SkPoint rp = SkPoint::Make(length*SkScalarCos(step) + center.fX, |
| length*SkScalarSin(step) + center.fY); |
| path.lineTo(rp); |
| length += angle / SkScalarHalf(SK_ScalarPI); |
| step += angle; |
| } |
| |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setColor(ToolUtils::color_to_565(0xFF007700)); |
| |
| canvas->drawPath(path, paint); |
| } |
| |
| bool onAnimate(double nanos) override { |
| constexpr SkScalar kDesiredDurationSecs = 3.0f; |
| |
| // Make the animation ping-pong back and forth but start in the fully drawn state |
| SkScalar fraction = 1.0f - TimeUtils::Scaled(1e-9 * nanos, 2.0f/kDesiredDurationSecs, 2.0f); |
| if (fraction <= 0.0f) { |
| fraction = -fraction; |
| } |
| |
| SkASSERT(fraction >= 0.0f && fraction <= 1.0f); |
| |
| fNumSteps = (int) (fraction * kMaxNumSteps); |
| return true; |
| } |
| |
| private: |
| int fNumSteps; |
| |
| using INHERITED = GM; |
| }; |
| |
| DEF_GM( return new StringArtGM; ) |