skia2/tests/PreChopPathCurvesTest.cpp
Chris Dalton c7a849319f Make path pre-chopping more robust
Exceptionally large control points might require us to chop the path
very deeply. This CL converts the recursive chopping to loop with a
stack of control points on the heap, in order to avoid the risk of
stack overflow. It also adds a bail condition to avoid getting stuck
in endless recursion due to fp32 precision issues.

Bug: chromium:1266446
Change-Id: I005be4bc29de51d3c89f04b5d6c553a921a92aa3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/473197
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
2021-11-18 16:42:19 +00:00

39 lines
2.0 KiB
C++

/*
* Copyright 2021 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "src/gpu/tessellate/Tessellation.h"
#include "tests/Test.h"
DEF_TEST(PreChopPathCurves, reporter) {
// These particular test cases can get stuck in infinite recursion due to limited fp32
// precision. (Although they will not with the provided tessellationPrecision values; we had to
// lower precision in order to avoid the "viewport size" assert in PreChopPathCurves.) Bump the
// tessellationPreciion up to 4 and run these tests in order to verify our bail condition for
// infinite recursion caused by bad fp32 precision. If the test completes, it passed.
SkPath p = SkPath().moveTo(11.171727877046647f, -11.78621173228717f)
.quadTo(11.171727877046647f, -11.78621173228717f,
8.33583747124031f, 77.27177002747368f)
.cubicTo(8.33583747124031f, 77.27177002747368f,
8.33583747124031f, 77.27177002747368f,
11.171727877046647f, -11.78621173228717f)
.conicTo(11.171727877046647f, -11.78621173228717f,
8.33583747124031f, 77.27177002747368f,
1e-6f)
.conicTo(8.33583747124031f, 77.27177002747368f,
11.171727877046647f, -11.78621173228717f,
1e6f);
SkMatrix m = SkMatrix::Scale(138.68622826903837f, 74192976757580.44189f);
skgpu::PreChopPathCurves(1/16.f, p, m, {1000, -74088852800000.f, 3000, -74088852700000.f});
m = SkMatrix::Scale(138.68622826903837f, 74192976757580.44189f*.3f);
skgpu::PreChopPathCurves(.25f, p, m, {1000, -22226658140000.f, 3000, -22226658130000.f});
m = SkMatrix::Scale(138.68622826903837f, 74192976757580.44189f/4);
skgpu::PreChopPathCurves(.25f, p, m, {1000, -18522213200000.f, 3000, -18522213100000.f});
}