Fix harmless ASAN error. #24042
For an empty radius, &v[0] would be accessed (though the called functions would not use it due to v.size() being 0). Also add checks for emptyness and fix the first element checks, in case we get INT_MAX to compare to.
### Pull Request Readiness Checklist
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- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake
* LineVirtualIterator
Proposal of LineVirtualIterator, an alternative to "LineIterator not attached to any mat".
This is basically the same implementation, replacing the address difference by a single "offset" variable. elemsize becomes irrelevant and considered to be 1. "step" is thus equal to size.width since no stride is expected.
* Update drawing.cpp
fixed warning
* improvement of LineVirtualIterator
instead of being too conservative, the new implementation gets rid of "offset/step" and only keeps a "Point currentPos" up to date.
left_to_right is renamed to forceLeftToRight as suggested (even for the old LineIterator)
assert() replaced by CV_Assert() (even for the old LineIterator)
* fixed implementation
+fixed last commit so that LineVirtualIterator gives at least the same results as LineIterator
+added a new constructor that does not require any Size, so that no clipping is done and iteration occurs from pt1 to pt2. This is done by adding a spatial offset to pt1 and pt2 so that the same implementation is used, the size being in that case the spatial size between pt1 and pt2
* Update imgproc.hpp
fixed warnings
* Update drawing.cpp
fixed whitespace
* Update drawing.cpp
trailing whitespace
* Update imgproc.hpp
+added a new constructor that takes a Rect rather than a Size. It computes the line pt1->pt2 that clips that rect.
Yet again, this is still based on the same implementation, thanks to the Size and the currentPosOffset that can artifically consider the origin of the rect at (0,0)
* revert changes
revert changes on original LineIterator implementation, that will be superseded by the new LineVirtualIterator anyway
* added test of LineVirtualIterator
* More tests
* refactoring
Use C++11 chained constructors
Improved code style
* improve test
Added offset as random test data.
* fixed order of initialization
* merged LineIterator and VirtualLineIterator
* merged LineIterator & VirtualLineIterator
* merged LineIterator & VirtualLineIterator
* merged LineIterator & VirtualLineIterator
* made LineIterator::operator ++() more efficient
added one perfectly predictable check; in theory, since ptmode is set in the end of the constructor in the header file, the compiler can figure out that it's always true/false and eliminate the check from the inline `LineIterator::operator++()` completely
* optimized Line() function
in the most common case (CV_8UC3) eliminated the check from the loop
Co-authored-by: Vadim Pisarevsky <vadim.pisarevsky@gmail.com>
- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers
