Most changes stem from working on an examples bracketed
by #if DEBUG_UNDER_DEVELOPMENT // tiger
These exposed many problems with coincident curves,
as well as errors throughout the code.
Fixing these errors also fixed a number of fuzzer-inspired
bug reports.
* Line/Curve Intersections
Check to see if the end of the line nearly intersects
the curve. This was a FIXME in the old code.
* Performance
Use a central chunk allocator.
Plumb the allocator into the global variable state
so that it can be shared. (Note that 'SkGlobalState'
is allocated on the stack and is visible to children
functions but not other threads.)
* Refactor
Let SkOpAngle grow up from a structure to a class.
Let SkCoincidentSpans grow up from a structure to a class.
Rename enum Alias to AliasMatch.
* Coincidence Rewrite
Add more debugging to coincidence detection.
Parallel debugging routines have read-only logic to report
the current coincidence state so that steps through the
logic can expose whether things got better or worse.
More functions can error-out and cause the pathops
engine to non-destructively exit.
* Accuracy
Remove code that adjusted point locations. Instead,
offset the curve part so that sorted curves all use
the same origin.
Reduce the size (and influence) of magic numbers.
* Testing
The debug suite with verify and the full release suite
./out/Debug/pathops_unittest -v -V
./out/Release/pathops_unittest -v -V -x
expose one error. That error is captured as cubics_d3.
This error exists in the checked in code as well.
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2128633003
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2128633003
Review-Url: https://codereview.chromium.org/2128633003
This fix is a tradeoff. It changes intersection to
treat a case where one coincident run is intersected at one point
and the other edge is not as continuing to be a span.
The old code tried to treat this as a single point.
The old code is probably right, but this change alone
made the data structures inconsistent. Later, extending
the coincident runs would fail by incorrectly discarding
the single point intersection.
As a result, this fixes the security test and one other, but
makes a different test fail. Isolating the failure uncovered
a reduced case that fails with and without the change, so
there are more serious problems here. Those problems are
addressed in a separate CL.
Many of the test edits below remove ill-thought out debugging
messaging that fire off global state, which isn't usable
in a multi-threaded test environment.
In the end, with this fix, all existing tests (modulo one
new failure and one new non-failure) pass in debug and
in the extended release test suites.
TBR=reed@google.com
BUG=614248
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2018513003
Review-Url: https://codereview.chromium.org/2018513003
Confirm that no path ops tests are flaky, and clean up errors around
that. The test framework was incorrectly checking for >= MAX_ERRORS for
failure and <= MAX_ERRORS for success.
TBR=reed@google.com
Review URL: https://codereview.chromium.org/1140563003
This replacement shoots axis-aligned rays through all intersecting edges to find the outermost one either horizontally or vertically. The resulting code is smaller and twice as fast.
To support this, most of the horizontal / vertical intersection code was rewritten and standardized, and old code supporting the top-directed winding was deleted.
Contours were pointed to by an SkTDArray. Instead, put them in a linked list, and designate the list head with its own class to ensure that methods that take lists of contours start at the top. This change removed a large percentage of memory allocations used by path ops.
TBR=reed@google.com
BUG=skia:3588
Review URL: https://codereview.chromium.org/1111333002
Extended tests (150M+) run to completion in release in about 6 minutes; the standard test suite exceeds 100K and finishes in a few seconds on desktops.
TBR=reed
BUG=skia:3588
Review URL: https://codereview.chromium.org/1037953004
Replace the implicit curve intersection with a geometric curve intersection. The implicit intersection proved mathematically unstable and took a long time to zero in on an answer.
Use pointers instead of indices to refer to parts of curves. Indices required awkward renumbering.
Unify t and point values so that small intervals can be eliminated in one pass.
Break cubics up front to eliminate loops and cusps.
Make the Simplify and Op code more regular and eliminate arbitrary differences.
Add a builder that takes an array of paths and operators.
Delete unused code.
BUG=skia:3588
R=reed@google.com
Review URL: https://codereview.chromium.org/1037573004
these tests fail on a nexus 9 in release only. It's probably related
to the fused multiply-add instruction
TBR=
Review URL: https://codereview.chromium.org/722303002
The fixes include
- detect when finding the active top loops between two possible answers
- preflight chasing winding to ensure answer is consistent
- binary search more often when quadratic intersection fails
- add more failure paths when an intersect is missed
While this fixes the chrome bug, reenabling path ops in svg should be deferred until additional fixes are landed.
TBR=
BUG=421132
Committed: https://skia.googlesource.com/skia/+/6f726addf3178b01949bb389ef83cf14a1d7b6b2
Review URL: https://codereview.chromium.org/633393002
