You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
48 lines
1.6 KiB
48 lines
1.6 KiB
4 months ago
|
/*
|
||
|
|
* Copyright 2017 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 "SkSurface.h"
|
||
|
|
|
||
|
|
// This GM reproduces skia:6783, which demonstrated a bug in repeat and mirror
|
||
|
|
// image sampling tiling modes as implemented in software. We want to tile to
|
||
|
|
// [0,limit), and the old incorrect logic was:
|
||
|
|
//
|
||
|
|
// limit = ulp_before(limit)
|
||
|
|
// val = val - floor(val/limit)*limit (This is repeat; mirror is similar.)
|
||
|
|
//
|
||
|
|
// while the correct logic is more like:
|
||
|
|
//
|
||
|
|
// val = val - floor(val/limit)*limit
|
||
|
|
// val = min(val, ulp_before(limit))
|
||
|
|
//
|
||
|
|
// You would see ugly jaggies on the blue/yellow edge near the bottom left if
|
||
|
|
// the bug were still present. All stripes should now look roughly the same.
|
||
|
|
|
||
|
|
DEF_SIMPLE_GM(bug6783, canvas, 500, 500) {
|
||
|
|
sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(100, 100);
|
||
|
|
|
||
|
|
SkPaint p;
|
||
|
|
p.setColor(SK_ColorYELLOW);
|
||
|
|
surface->getCanvas()->drawPaint(p);
|
||
|
|
p.setColor(SK_ColorBLUE);
|
||
|
|
surface->getCanvas()->drawRect(SkRect::MakeWH(50, 100), p);
|
||
|
|
|
||
|
|
sk_sp<SkImage> img = surface->makeImageSnapshot();
|
||
|
|
|
||
|
|
SkMatrix m = SkMatrix::Concat(SkMatrix::MakeTrans(25, 214),
|
||
|
|
SkMatrix::MakeScale(2, 2));
|
||
|
|
m.preSkew(0.5f, 0.5f);
|
||
|
|
|
||
|
|
// The bug was present at all filter levels, but you might not notice it at kNone.
|
||
|
|
p.setFilterQuality(kLow_SkFilterQuality);
|
||
|
|
|
||
|
|
// It's only important to repeat or mirror in x to show off the bug.
|
||
|
|
p.setShader(img->makeShader(SkShader::kRepeat_TileMode, SkShader::kClamp_TileMode, &m));
|
||
|
|
canvas->drawPaint(p);
|
||
|
|
}
|