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/*
* Copyright 2019 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkImageFilter.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkGradientShader.h"
#include "include/effects/SkImageFilters.h"
#include <initializer_list>
// Make a noisy (with hard-edges) background, so we can see the effect of the blur
//
static sk_sp<SkShader> make_shader(SkScalar cx, SkScalar cy, SkScalar rad) {
const SkColor colors[] = {
SK_ColorRED, SK_ColorRED, SK_ColorBLUE, SK_ColorBLUE, SK_ColorGREEN, SK_ColorGREEN,
SK_ColorRED, SK_ColorRED, SK_ColorBLUE, SK_ColorBLUE, SK_ColorGREEN, SK_ColorGREEN,
};
constexpr int count = SK_ARRAY_COUNT(colors);
SkScalar pos[count] = { 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6 };
for (int i = 0; i < count; ++i) {
pos[i] *= 1.0f/6;
}
return SkGradientShader::MakeSweep(cx, cy, colors, pos, count);
}
static void do_draw(SkCanvas* canvas, bool useClip, bool useHintRect) {
SkAutoCanvasRestore acr(canvas, true);
canvas->clipRect({0, 0, 256, 256});
const SkScalar cx = 128, cy = 128, rad = 100;
SkPaint p;
p.setShader(make_shader(cx, cy, rad));
p.setAntiAlias(true);
canvas->drawCircle(cx, cy, rad, p);
// now setup a saveLayer that will pull in the backdrop and blur it
//
const SkRect r = {cx-50, cy-50, cx+50, cy+50};
const SkRect* drawrptr = useHintRect ? &r : nullptr;
const SkScalar sigma = 10;
if (useClip) {
canvas->clipRect(r);
}
// Using kClamp because kDecal, the default, produces transparency near the edge of the canvas's
// device.
auto blur = SkImageFilters::Blur(sigma, sigma, SkTileMode::kClamp, nullptr);
auto rec = SkCanvas::SaveLayerRec(drawrptr, nullptr, blur.get(), 0);
canvas->saveLayer(rec);
// draw something inside, just to demonstrate that we don't blur the new contents,
// just the backdrop.
p.setColor(SK_ColorYELLOW);
p.setShader(nullptr);
canvas->drawCircle(cx, cy, 30, p);
canvas->restore();
}
/*
* Draws a 2x4 grid of sweep circles.
* - for a given row, each col should be identical (canvas, picture)
* - row:0 no-hint-rect no-clip-rect expect big blur (except inner circle)
* - row:1 no-hint-rect clip-rect expect small blur (except inner circle)
* - row:2 hint-rect no-clip-rect expect big blur (except inner circle)
* - row:3 hint-rect clip-rect expect small blur (except inner circle)
*
* The test is that backdrop effects should be independent of the hint-rect, but should
* respect the clip-rect.
*/
DEF_SIMPLE_GM(backdrop_hintrect_clipping, canvas, 512, 1024) {
for (bool useHintRect : {false, true}) {
for (bool useClip : {false, true}) {
canvas->save();
do_draw(canvas, useClip, useHintRect);
SkPictureRecorder rec;
do_draw(rec.beginRecording(256, 256), useClip, useHintRect);
canvas->translate(256, 0);
canvas->drawPicture(rec.finishRecordingAsPicture());
canvas->restore();
canvas->translate(0, 256);
}
}
}