зеркало из https://github.com/mozilla/moz-skia.git
92 строки
2.8 KiB
C++
92 строки
2.8 KiB
C++
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/*
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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 "SampleCode.h"
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#include "SkView.h"
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#include "SkCanvas.h"
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#include "Sk64.h"
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#include "SkGradientShader.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, SkFloatToScalar(0.25f), SkFloatToScalar(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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SkShader* s = SkGradientShader::CreateTwoPointRadial(c0, r0, c1, r1, colors,
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pos, SK_ARRAY_COUNT(pos),
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SkShader::kClamp_TileMode);
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SkPaint paint;
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paint.setShader(s)->unref();
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canvas->drawRect(rect, paint);
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}
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class DegenerateTwoPtRadialsView : public SampleView {
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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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// overrides from SkEventSink
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virtual bool onQuery(SkEvent* evt) {
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if (SampleCode::TitleQ(*evt)) {
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SampleCode::TitleR(evt, "DegenerateTwoPtRadials");
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return true;
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}
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return this->INHERITED::onQuery(evt);
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}
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virtual void onDrawContent(SkCanvas* canvas) {
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fTime += SampleCode::GetAnimSecondsDelta();
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SkScalar delta = fTime / 15.f;
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int intPart = SkScalarFloor(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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char txt[512];
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sprintf(txt, "gap at \"tangent\" pt = %f", SkScalarToFloat(delta));
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SkPaint paint;
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paint.setAntiAlias(true);
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paint.setColor(SK_ColorBLACK);
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canvas->drawText(txt, strlen(txt), l + w/2 + w*DELTA_SCALE*delta, t + h + SK_Scalar1 * 10, paint);
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this->inval(NULL);
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}
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private:
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SkScalar fTime;
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typedef SampleView INHERITED;
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};
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//////////////////////////////////////////////////////////////////////////////
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static SkView* MyFactory() { return new DegenerateTwoPtRadialsView; }
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static SkViewRegister reg(MyFactory);
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