61 lines
2.4 KiB
C++
61 lines
2.4 KiB
C++
// Copyright 2020 Google LLC.
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// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
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#include "tools/fiddle/examples.h"
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REG_FIDDLE(picture_shader, 256, 256, false, 5) {
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static void draw_centered(
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const char* s, const SkFont& font, SkColor color, SkPoint xy, SkCanvas* c) {
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sk_sp<SkTextBlob> b = SkTextBlob::MakeFromString(s, font);
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xy -= SkPoint{b->bounds().centerX(), b->bounds().centerY()};
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SkPaint p;
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p.setColor(color);
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c->drawTextBlob(b.get(), xy.x(), xy.y(), p);
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}
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SkPoint from_polar_deg(float r, float d) {
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float a = d * 0.017453292519943295;
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return {r * cosf(a), r * sinf(a)};
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}
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void draw_wheel(SkCanvas* c) {
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const SkScalar scale = 512;
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SkAutoCanvasRestore autoCanvasRestore(c, true);
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c->translate(0.5f * scale, 0.5f * scale);
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SkPaint p;
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p.setAntiAlias(true);
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p.setColor(SK_ColorWHITE);
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c->drawCircle(0.0f, 0.0f, scale * 0.475f, p);
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const SkColor sweep_colors[] = {SK_ColorRED, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorCYAN,
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SK_ColorBLUE, SK_ColorMAGENTA, SK_ColorRED};
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SkMatrix rot;
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rot.setRotate(90.0f);
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p.setShader(SkGradientShader::MakeSweep(0, 0, sweep_colors, nullptr,
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SK_ARRAY_COUNT(sweep_colors), 0, &rot));
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p.setStrokeWidth(0.05f * scale);
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p.setStyle(SkPaint::kStroke_Style);
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c->drawCircle(0.0f, 0.0f, 0.475f * scale, p);
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SkFont f(nullptr, 0.28125f * scale);
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draw_centered("K", f, SK_ColorBLACK, {0.0f, 0.0f}, c);
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draw_centered("R", f, SK_ColorRED, from_polar_deg(0.3f * scale, 90), c);
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draw_centered("G", f, SK_ColorGREEN, from_polar_deg(0.3f * scale, 210), c);
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draw_centered("B", f, SK_ColorBLUE, from_polar_deg(0.3f * scale, 330), c);
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draw_centered("C", f, SK_ColorCYAN, from_polar_deg(0.3f * scale, 270), c);
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draw_centered("M", f, SK_ColorMAGENTA, from_polar_deg(0.3f * scale, 30), c);
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draw_centered("Y", f, SK_ColorYELLOW, from_polar_deg(0.3f * scale, 150), c);
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}
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void draw(SkCanvas* canvas) {
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canvas->clear(SK_ColorWHITE);
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SkMatrix matrix;
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matrix.setScale(0.25f, 0.25f);
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matrix.preRotate(30.0f);
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SkPaint paint;
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SkPictureRecorder rec;
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draw_wheel(rec.beginRecording(512, 512));
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paint.setShader(rec.finishRecordingAsPicture()->makeShader(
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SkTileMode::kRepeat, SkTileMode::kRepeat, SkFilterMode::kNearest, &matrix, nullptr));
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canvas->drawPaint(paint);
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}
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} // END FIDDLE
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