| // 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(picture_shader, 256, 256, false, 5) { |
| static void draw_centered( |
| const char* s, const SkFont& font, SkColor color, SkPoint xy, SkCanvas* c) { |
| sk_sp<SkTextBlob> b = SkTextBlob::MakeFromString(s, font); |
| xy -= SkPoint{b->bounds().centerX(), b->bounds().centerY()}; |
| SkPaint p; |
| p.setColor(color); |
| c->drawTextBlob(b.get(), xy.x(), xy.y(), p); |
| } |
| |
| SkPoint from_polar_deg(float r, float d) { |
| float a = d * 0.017453292519943295; |
| return {r * cosf(a), r * sinf(a)}; |
| } |
| |
| void draw_wheel(SkCanvas* c) { |
| const SkScalar scale = 512; |
| SkAutoCanvasRestore autoCanvasRestore(c, true); |
| c->translate(0.5f * scale, 0.5f * scale); |
| SkPaint p; |
| p.setAntiAlias(true); |
| p.setColor(SK_ColorWHITE); |
| c->drawCircle(0.0f, 0.0f, scale * 0.475f, p); |
| |
| const SkColor sweep_colors[] = {SK_ColorRED, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorCYAN, |
| SK_ColorBLUE, SK_ColorMAGENTA, SK_ColorRED}; |
| SkMatrix rot; |
| rot.setRotate(90.0f); |
| p.setShader(SkGradientShader::MakeSweep(0, 0, sweep_colors, nullptr, |
| SK_ARRAY_COUNT(sweep_colors), 0, &rot)); |
| p.setStrokeWidth(0.05f * scale); |
| p.setStyle(SkPaint::kStroke_Style); |
| c->drawCircle(0.0f, 0.0f, 0.475f * scale, p); |
| |
| SkFont f(nullptr, 0.28125f * scale); |
| draw_centered("K", f, SK_ColorBLACK, {0.0f, 0.0f}, c); |
| draw_centered("R", f, SK_ColorRED, from_polar_deg(0.3f * scale, 90), c); |
| draw_centered("G", f, SK_ColorGREEN, from_polar_deg(0.3f * scale, 210), c); |
| draw_centered("B", f, SK_ColorBLUE, from_polar_deg(0.3f * scale, 330), c); |
| draw_centered("C", f, SK_ColorCYAN, from_polar_deg(0.3f * scale, 270), c); |
| draw_centered("M", f, SK_ColorMAGENTA, from_polar_deg(0.3f * scale, 30), c); |
| draw_centered("Y", f, SK_ColorYELLOW, from_polar_deg(0.3f * scale, 150), c); |
| } |
| |
| void draw(SkCanvas* canvas) { |
| canvas->clear(SK_ColorWHITE); |
| SkMatrix matrix; |
| matrix.setScale(0.25f, 0.25f); |
| matrix.preRotate(30.0f); |
| SkPaint paint; |
| SkPictureRecorder rec; |
| draw_wheel(rec.beginRecording(512, 512)); |
| paint.setShader(rec.finishRecordingAsPicture()->makeShader( |
| SkTileMode::kRepeat, SkTileMode::kRepeat, SkFilterMode::kNearest, &matrix, nullptr)); |
| canvas->drawPaint(paint); |
| } |
| } // END FIDDLE |