Hal Canary | 8800042 | 2020-01-15 11:51:12 -0500 | [diff] [blame] | 1 | // Copyright 2020 Google LLC. |
| 2 | // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. |
| 3 | #include "tools/fiddle/examples.h" |
| 4 | REG_FIDDLE(Color_Wheel, 256, 256, false, 0) { |
Hal Canary | 2cd5d43 | 2020-01-15 15:34:55 -0500 | [diff] [blame] | 5 | void draw_color_wheel(SkCanvas* canvas, float scale) { |
| 6 | const float stroke = scale * 3 / 64; |
| 7 | const float size = scale * 9 / 32; |
| 8 | SkAutoCanvasRestore autoCanvasRestore(canvas, true); |
| 9 | canvas->translate(0.5f * scale, 0.5f * scale); |
| 10 | canvas->clear(0); |
| 11 | canvas->drawCircle({0, 0}, (scale - stroke) * 0.5f, SkPaint(SkColors::kWhite)); |
| 12 | { |
| 13 | SkPaint sweep; |
| 14 | const SkMatrix rotate = SkMatrix::MakeAll(0, -1, 0, 1, 0, 0, 0, 0, 1); |
| 15 | constexpr unsigned kColorCount = 7; |
| 16 | static const SkColor4f kColors[kColorCount] = { |
| 17 | SkColors::kRed, SkColors::kYellow, SkColors::kGreen, SkColors::kCyan, |
| 18 | SkColors::kBlue, SkColors::kMagenta, SkColors::kRed}; |
| 19 | sweep.setShader(SkGradientShader::MakeSweep(0, 0, kColors, nullptr, nullptr, |
| 20 | kColorCount, 0, &rotate)); |
| 21 | sweep.setStyle(SkPaint::kStroke_Style); |
| 22 | sweep.setStrokeWidth(stroke); |
| 23 | sweep.setAntiAlias(true); |
| 24 | canvas->drawCircle({0, 0}, (scale - stroke) * 0.5f, sweep); |
| 25 | } |
| 26 | sk_sp<SkFontMgr> fontMgr = SkFontMgr::RefDefault(); |
| 27 | SkFont font(fontMgr->legacyMakeTypeface(nullptr, SkFontStyle::Bold()), size); |
| 28 | const struct { const char* str; float radius; float angle; SkColor4f color;} kLetters[] = { |
| 29 | {"K", 0, 0, SkColors::kBlack}, |
| 30 | {"R", 1, 90, SkColors::kRed}, |
| 31 | {"Y", 1, 150, SkColors::kYellow}, |
| 32 | {"G", 1, 210, SkColors::kGreen}, |
| 33 | {"C", 1, 270, SkColors::kCyan}, |
| 34 | {"B", 1, 330, SkColors::kBlue}, |
| 35 | {"M", 1, 30, SkColors::kMagenta}, |
| 36 | }; |
| 37 | for (const auto& v : kLetters) { |
| 38 | SkRect bnds; |
| 39 | font.measureText(v.str, strlen(v.str), SkTextEncoding::kUTF8, &bnds); |
| 40 | constexpr double pi_over_180 = 3.141592653589793 / 180; |
| 41 | float x = (float)(0.3 * scale * v.radius * cos(pi_over_180 * v.angle) - bnds.centerX()); |
| 42 | float y = (float)(0.3 * scale * v.radius * sin(pi_over_180 * v.angle) - bnds.centerY()); |
| 43 | canvas->drawString(v.str, x, y, font, SkPaint(v.color)); |
| 44 | } |
Hal Canary | 8800042 | 2020-01-15 11:51:12 -0500 | [diff] [blame] | 45 | } |
Hal Canary | 2cd5d43 | 2020-01-15 15:34:55 -0500 | [diff] [blame] | 46 | void draw(SkCanvas* canvas) { draw_color_wheel(canvas, 256); } |
Hal Canary | 8800042 | 2020-01-15 11:51:12 -0500 | [diff] [blame] | 47 | } // END FIDDLE |