/* * 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/effects/SkGradientShader.h" #include "samplecode/Sample.h" static sk_sp setgrad(const SkRect& r, SkColor c0, SkColor c1) { SkColor colors[] = { c0, c1 }; SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fTop } }; return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkTileMode::kClamp); } static void test_alphagradients(SkCanvas* canvas) { SkRect r; r.set(SkIntToScalar(10), SkIntToScalar(10), SkIntToScalar(410), SkIntToScalar(30)); SkPaint p, p2; p2.setStyle(SkPaint::kStroke_Style); p.setShader(setgrad(r, 0xFF00FF00, 0x0000FF00)); canvas->drawRect(r, p); canvas->drawRect(r, p2); r.offset(0, r.height() + SkIntToScalar(4)); p.setShader(setgrad(r, 0xFF00FF00, 0x00000000)); canvas->drawRect(r, p); canvas->drawRect(r, p2); r.offset(0, r.height() + SkIntToScalar(4)); p.setShader(setgrad(r, 0xFF00FF00, 0x00FF0000)); canvas->drawRect(r, p); canvas->drawRect(r, p2); } /////////////////////////////////////////////////////////////////////////////// struct GradData { int fCount; const SkColor* fColors; const SkScalar* fPos; }; static const SkColor gColors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK }; static const SkScalar gPos0[] = { 0, SK_Scalar1 }; static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 }; static const SkScalar gPos2[] = { 0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1 }; static const GradData gGradData[] = { { 2, gColors, nullptr }, { 2, gColors, gPos0 }, { 2, gColors, gPos1 }, { 5, gColors, nullptr }, { 5, gColors, gPos2 } }; static sk_sp MakeLinear(const SkPoint pts[2], const GradData& data, SkTileMode tm) { return SkGradientShader::MakeLinear(pts, data.fColors, data.fPos, data.fCount, tm); } static sk_sp MakeRadial(const SkPoint pts[2], const GradData& data, SkTileMode tm) { SkPoint center; center.set(SkScalarAve(pts[0].fX, pts[1].fX), SkScalarAve(pts[0].fY, pts[1].fY)); return SkGradientShader::MakeRadial(center, center.fX, data.fColors, data.fPos, data.fCount, tm); } static sk_sp MakeSweep(const SkPoint pts[2], const GradData& data, SkTileMode tm) { SkPoint center; center.set(SkScalarAve(pts[0].fX, pts[1].fX), SkScalarAve(pts[0].fY, pts[1].fY)); return SkGradientShader::MakeSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount); } static sk_sp Make2Conical(const SkPoint pts[2], const GradData& data, SkTileMode tm) { SkPoint center0, center1; center0.set(SkScalarAve(pts[0].fX, pts[1].fX), SkScalarAve(pts[0].fY, pts[1].fY)); center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5), SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4)); return SkGradientShader::MakeTwoPointConical( center1, (pts[1].fX - pts[0].fX) / 7, center0, (pts[1].fX - pts[0].fX) / 2, data.fColors, data.fPos, data.fCount, tm); } static sk_sp Make2ConicalConcentric(const SkPoint pts[2], const GradData& data, SkTileMode tm) { SkPoint center; center.set(SkScalarAve(pts[0].fX, pts[1].fX), SkScalarAve(pts[0].fY, pts[1].fY)); return SkGradientShader::MakeTwoPointConical( center, (pts[1].fX - pts[0].fX) / 7, center, (pts[1].fX - pts[0].fX) / 2, data.fColors, data.fPos, data.fCount, tm); } typedef sk_sp (*GradMaker)(const SkPoint pts[2], const GradData& data, SkTileMode tm); static const GradMaker gGradMakers[] = { MakeLinear, MakeRadial, MakeSweep, Make2Conical, Make2ConicalConcentric }; /////////////////////////////////////////////////////////////////////////////// class GradientsView : public Sample { public: GradientsView() { this->setBGColor(0xFFDDDDDD); } protected: SkString name() override { return SkString("Gradients"); } void onDrawContent(SkCanvas* canvas) override { SkPoint pts[2] = { { 0, 0 }, { SkIntToScalar(100), SkIntToScalar(100) } }; SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) }; SkPaint paint; paint.setDither(true); canvas->save(); canvas->translate(SkIntToScalar(20), SkIntToScalar(10)); for (int tm = 0; tm < kSkTileModeCount; ++tm) { canvas->save(); for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) { canvas->save(); for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) { paint.setShader(gGradMakers[j](pts, gGradData[i], (SkTileMode)tm)); canvas->drawRect(r, paint); canvas->translate(0, SkIntToScalar(120)); } canvas->restore(); canvas->translate(SkIntToScalar(120), 0); } canvas->restore(); canvas->translate(SK_ARRAY_COUNT(gGradData)*SkIntToScalar(120), 0); } canvas->restore(); canvas->translate(0, SkIntToScalar(370)); if (false) { // avoid bit rot, suppress warning test_alphagradients(canvas); } } private: typedef Sample INHERITED; }; /////////////////////////////////////////////////////////////////////////////// DEF_SAMPLE( return new GradientsView(); )