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/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm.h"
#include "SkGradientShader.h"
#include "SkPatchUtils.h"
static SkShader* make_shader() {
const SkColor colors[] = {
SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE, SK_ColorMAGENTA, SK_ColorBLUE,
SK_ColorYELLOW,
};
const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } };
return SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
SkShader::kMirror_TileMode);
}
static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) {
//draw control points
SkPaint paint;
SkPoint bottom[SkPatchUtils::kNumPtsCubic];
SkPatchUtils::getBottomCubic(cubics, bottom);
SkPoint top[SkPatchUtils::kNumPtsCubic];
SkPatchUtils::getTopCubic(cubics, top);
SkPoint left[SkPatchUtils::kNumPtsCubic];
SkPatchUtils::getLeftCubic(cubics, left);
SkPoint right[SkPatchUtils::kNumPtsCubic];
SkPatchUtils::getRightCubic(cubics, right);
paint.setColor(SK_ColorBLACK);
paint.setStrokeWidth(0.5f);
SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom + 1, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top + 1, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left + 1, paint);
canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right + 1, paint);
paint.setStrokeWidth(2);
paint.setColor(SK_ColorRED);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
paint.setColor(SK_ColorBLUE);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint);
paint.setColor(SK_ColorCYAN);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint);
paint.setColor(SK_ColorYELLOW);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint);
paint.setColor(SK_ColorGREEN);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint);
}
namespace skiagm {
/**
* This GM draws a cubics coons patch using the specialized call SkCanvas::drawPatch.
*/
class SkPatchGM : public GM {
public:
SkPatchGM() {
this->setBGColor(0xFFFFFFFF);
}
protected:
SkString onShortName() override {
return SkString("patch_primitive");
}
SkISize onISize() override {
return SkISize::Make(800, 800);
}
void onDraw(SkCanvas* canvas) override {
SkPaint paint;
// The order of the colors and points is clockwise starting at upper-left corner.
const SkPoint cubics[SkPatchUtils::kNumCtrlPts] = {
//top points
{100,100},{150,50},{250,150}, {300,100},
//right points
{250, 150},{350,250},
//bottom points
{300,300},{250,250},{150,350},{100,300},
//left points
{50,250},{150,150}
};
const SkColor colors[SkPatchUtils::kNumCorners] = {
SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
};
const SkPoint texCoords[SkPatchUtils::kNumCorners] = {
{0.0f, 0.0f}, {100.0f, 0.0f}, {100.0f,100.0f}, {0.0f, 100.0f}}
;
const SkXfermode::Mode modes[] = {
SkXfermode::kSrc_Mode,
SkXfermode::kDst_Mode,
SkXfermode::kModulate_Mode,
};
SkAutoTUnref<SkShader> shader(make_shader());
canvas->save();
for (int y = 0; y < 3; y++) {
SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(modes[y]));
for (int x = 0; x < 4; x++) {
canvas->save();
canvas->translate(x * 350.0f, y * 350.0f);
switch (x) {
case 0:
canvas->drawPatch(cubics, nullptr, nullptr, xfer, paint);
break;
case 1:
canvas->drawPatch(cubics, colors, nullptr, xfer, paint);
break;
case 2:
paint.setShader(shader);
canvas->drawPatch(cubics, nullptr, texCoords, xfer, paint);
paint.setShader(nullptr);
break;
case 3:
paint.setShader(shader);
canvas->drawPatch(cubics, colors, texCoords, xfer, paint);
paint.setShader(nullptr);
break;
default:
break;
}
draw_control_points(canvas, cubics);
canvas->restore();
}
}
canvas->restore();
}
private:
typedef GM INHERITED;
};
DEF_GM(return new SkPatchGM;)
}
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