73e6a66146
Change-Id: Ibfa2c0efa3e4addf21aa400e3d323675ac0185ef Reviewed-on: https://skia-review.googlesource.com/c/skia/+/551886 Reviewed-by: John Stiles <johnstiles@google.com> Commit-Queue: Herb Derby <herb@google.com>
82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
/*
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* Copyright 2011 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "include/core/SkCanvas.h"
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#include "include/core/SkFont.h"
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#include "include/core/SkString.h"
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#include "include/effects/SkGradientShader.h"
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#include "samplecode/Sample.h"
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static void draw_gradient2(SkCanvas* canvas, const SkRect& rect, SkScalar delta) {
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SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorMAGENTA };
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SkScalar pos[] = { 0, 0.25f, 0.75f, SK_Scalar1 };
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SkScalar l = rect.fLeft;
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SkScalar t = rect.fTop;
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SkScalar w = rect.width();
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SkScalar h = rect.height();
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SkASSERT(0 == SkScalarMod(w, SK_Scalar1 * 5));
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SkPoint c0 = { l + 2 * w / 5 + delta, t + h / 2 };
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SkPoint c1 = { l + 3 * w / 5, t + h / 2 };
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SkScalar r0 = w / 5;
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SkScalar r1 = 2 * w / 5;
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SkPaint paint;
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paint.setShader(SkGradientShader::MakeTwoPointConical(c0, r0, c1, r1, colors,
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pos, std::size(pos),
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SkTileMode::kClamp));
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canvas->drawRect(rect, paint);
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}
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class DegenerateTwoPtRadialsView : public Sample {
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public:
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DegenerateTwoPtRadialsView() {
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fTime = 0;
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this->setBGColor(0xFFDDDDDD);
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}
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protected:
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SkString name() override { return SkString("DegenerateTwoPtRadials"); }
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void onDrawContent(SkCanvas* canvas) override {
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SkScalar delta = fTime / 15.f;
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int intPart = SkScalarFloorToInt(delta);
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delta = delta - SK_Scalar1 * intPart;
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if (intPart % 2) {
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delta = SK_Scalar1 - delta;
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}
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delta -= SK_ScalarHalf;
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static const int DELTA_SCALE = 500;
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delta /= DELTA_SCALE;
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SkScalar w = SK_Scalar1 * 500;
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SkScalar h = SK_Scalar1 * 500;
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SkScalar l = SK_Scalar1 * 100;
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SkScalar t = SK_Scalar1 * 100;
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draw_gradient2(canvas, SkRect::MakeXYWH(l, t, w, h), delta);
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SkString txt;
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txt.appendf("gap at \"tangent\" pt = %f", SkScalarToFloat(delta));
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canvas->drawString(txt, l + w / 2 + w * DELTA_SCALE * delta, t + h + SK_Scalar1 * 10,
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SkFont(), SkPaint());
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}
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bool onAnimate(double nanos) override {
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fTime = SkDoubleToScalar(1e-9 * nanos / 15);
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return true;
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}
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private:
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SkScalar fTime;
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using INHERITED = Sample;
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};
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//////////////////////////////////////////////////////////////////////////////
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DEF_SAMPLE( return new DegenerateTwoPtRadialsView(); )
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