svg-flatten: Add 'complete pattern tiles only' switch

This is not part of the SVG spec, but it is useful for generating proto
boards using SVG patterns.

2 files changed, 28 insertions, 0 deletions

diff --git a/svg-flatten/src/main.cpp b/svg-flatten/src/main.cpp
index 188aa57..35fcbfb 100644
--- a/svg-flatten/src/main.cpp
+++ b/svg-flatten/src/main.cpp
@@ -73,6 +73,9 @@ int main(int argc, char **argv) {
             {"flip_svg_color_interpretation", {"-i", "--svg-white-is-gerber-dark"},
                 "Flip polarity of SVG color interpretation. This affects only SVG primitives like paths and NOT embedded bitmaps. With -i: white -> silk there/\"dark\" gerber primitive.",
                 0},
+            {"pattern_complete_tiles_only", {"--pattern-complete-tiles-only"},
+                "Break SVG spec by only rendering complete pattern tiles, i.e. pattern tiles that entirely fit the target area, instead of performing clipping.",
+                0},
             {"min_feature_size", {"-d", "--trace-space"},
                 "Minimum feature size of elements in vectorized graphics (trace/space) in mm. Default: 0.1mm.",
                 1},
@@ -423,6 +426,7 @@ int main(int argc, char **argv) {
 
     VectorizerSelectorizer vec_sel(vectorizer, args["vectorizer_map"] ? args["vectorizer_map"].as<string>() : "");
     bool flip_svg_colors = args["flip_svg_color_interpretation"];
+    bool pattern_complete_tiles_only = args["pattern_complete_tiles_only"];
 
     RenderSettings rset {
         min_feature_size,
@@ -431,6 +435,7 @@ int main(int argc, char **argv) {
         vec_sel,
         outline_mode,
         flip_svg_colors,
+        pattern_complete_tiles_only,
     };
 
     SVGDocument doc;
diff --git a/svg-flatten/src/svg_pattern.cpp b/svg-flatten/src/svg_pattern.cpp
index cdff7a7..fc74d73 100644
--- a/svg-flatten/src/svg_pattern.cpp
+++ b/svg-flatten/src/svg_pattern.cpp
@@ -108,6 +108,29 @@ void gerbolyze::Pattern::tile (gerbolyze::RenderContext &ctx) {
 
             /* Export the pattern tile's content like a group */
             RenderContext elem_ctx(pat_ctx, elem_xf);
+
+            if (ctx.settings().pattern_complete_tiles_only) {
+                ClipperLib::Clipper c;
+
+                double eps = 1e-6;
+                Polygon poly = {{eps, eps}, {inst_w-eps, eps}, {inst_w-eps, inst_h-eps}, {eps, inst_h-eps}};
+                elem_ctx.mat().transform_polygon(poly);
+                ClipperLib::Path path(poly.size());
+                for (size_t i=0; i<poly.size(); i++) {
+                    long long int x = poly[i][0] * clipper_scale, y = poly[i][1] * clipper_scale;
+                    path[i] = {x, y};
+                }
+
+                ClipperLib::Paths out;
+                c.StrictlySimple(true);
+                c.AddPath(path, ClipperLib::ptSubject, /* closed */ true);
+                c.AddPaths(elem_ctx.clip(), ClipperLib::ptClip, /* closed */ true);
+                c.Execute(ClipperLib::ctDifference, out, ClipperLib::pftNonZero);
+                if (out.size() > 0) {
+                    continue;
+                }
+            }
+
             doc->export_svg_group(elem_ctx, _node);
         }
     }