Add new angled-point marker placement mode for lines #3782
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@bmharper - great feature, thanks for contributing! My only concern after skimming through the code is the use of pointer logic to select angled placement. Could we use |
This adds a new mode called 'angled-point' to the marker-placement modes. The full list of modes is then: point, angled-point, interior, line, vertex-first, vertex-last Angled point is identical to point, except that when placing a marker on a line, the marker's angle is taken from the angle of the line segment. There is another possible use of the "angled-point" concept for polygons, and that is for placing labels on stand (aka erf) polygons. By computing a dominant angle for a mostly rectangular polygon, this can produce quite good results. I'm not sure whether I should implement that now, or if I could do that later.
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Codecov Report
@@ Coverage Diff @@
## master #3782 +/- ##
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- Coverage 61.48% 61.47% -0.01%
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Files 426 426
Lines 22756 22761 +5
Branches 3254 3254
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+ Hits 13992 13993 +1
- Misses 7259 7263 +4
Partials 1505 1505
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This is a test that accompanies the pull request mapnik/mapnik#3782
This is a test that accompanies the pull request mapnik/mapnik#3782
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I've modified the code to use |
Details are inside the commit message. I have created a visual test for this, but will rather wait for feedback before sending a PR for that.
We use this kind of rendering for drawing symbols on top of water pipes - for example, when a pipe is actually a valve, or when a pipe is closed, etc. In this case, we always want just a single symbol drawn in the center of the polyline, and we want the symbol's angle to be aligned to the line.
New
angled-pointmarker-placement mode:Existing
pointmarker-placement mode: