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