Merge pull request #59 from iShape-Rust/fix/ogc_self_touch

Fix/ogc self touch

Author: NailxSharipov

iOverlay/src/core/extract.rs

@@ -31,6 +31,7 @@ pub(crate) enum VisitState {
 pub struct BooleanExtractionBuffer {
     pub(crate) points: Vec<IntPoint>,
     pub(crate) visited: Vec<VisitState>,
+    pub(crate) contour_visited: Option<Vec<VisitState>>,
 }
 
 impl OverlayGraph<'_> {
@@ -120,7 +121,13 @@ impl OverlayGraph<'_> {
             let direction = is_hole == clockwise;
             let start_data = StartPathData::new(direction, link, left_top_link);
 
-            self.find_contour(&start_data, direction, visited_state, buffer);
+            self.find_contour(
+                &start_data,
+                direction,
+                visited_state,
+                &mut buffer.visited,
+                &mut buffer.points,
+            );
             let (is_valid, is_modified) = buffer.points.validate(
                 self.options.min_output_area,
                 self.options.preserve_output_collinear,
@@ -176,35 +183,29 @@ impl OverlayGraph<'_> {
         start_data: &StartPathData,
         clockwise: bool,
         visited_state: VisitState,
-        buffer: &mut BooleanExtractionBuffer,
+        visited: &mut Vec<VisitState>,
+        points: &mut Vec<IntPoint>,
     ) {
         let mut link_id = start_data.link_id;
         let mut node_id = start_data.node_id;
         let last_node_id = start_data.last_node_id;
 
-        buffer.visited.visit_edge(link_id, visited_state);
-        buffer.points.clear();
-        buffer.points.push(start_data.begin);
+        visited.visit_edge(link_id, visited_state);
+        points.clear();
+        points.push(start_data.begin);
 
         // Find a closed tour
         while node_id != last_node_id {
-            link_id = GraphUtil::next_link(
-                self.links,
-                self.nodes,
-                link_id,
-                node_id,
-                clockwise,
-                &buffer.visited,
-            );
+            link_id = GraphUtil::next_link(self.links, self.nodes, link_id, node_id, clockwise, &visited);
 
             let link = unsafe {
                 // Safety: `link_id` is always derived from a previous in-bounds index or
                 // from `find_left_top_link`, so it remains in `0..self.links.len()`.
                 self.links.get_unchecked(link_id)
             };
-            node_id = buffer.points.push_node_and_get_other(link, node_id);
+            node_id = points.push_node_and_get_other(link, node_id);
 
-            buffer.visited.visit_edge(link_id, visited_state);
+            visited.visit_edge(link_id, visited_state);
         }
     }
 
@@ -242,7 +243,13 @@ impl OverlayGraph<'_> {
             let direction = is_hole == clockwise;
             let start_data = StartPathData::new(direction, link, left_top_link);
 
-            self.find_contour(&start_data, direction, visited_state, buffer);
+            self.find_contour(
+                &start_data,
+                direction,
+                visited_state,
+                &mut buffer.visited,
+                &mut buffer.points,
+            );
             let (is_valid, _) = buffer.points.validate(
                 self.options.min_output_area,
                 self.options.preserve_output_collinear,

iOverlay/src/core/extract_ogc.rs

@@ -9,7 +9,8 @@ use crate::core::overlay_rule::OverlayRule;
 use crate::geom::v_segment::VSegment;
 use alloc::vec;
 use alloc::vec::Vec;
-use i_shape::int::shape::IntShapes;
+use i_float::int::point::IntPoint;
+use i_shape::int::shape::{IntShape, IntShapes};
 use i_shape::util::reserve::Reserve;
 
 impl OverlayGraph<'_> {
@@ -20,10 +21,21 @@ impl OverlayGraph<'_> {
     ) -> IntShapes {
         let is_main_dir_cw = self.options.output_direction == ContourDirection::Clockwise;
 
+        let mut contour_visited = if let Some(mut visited) = buffer.contour_visited.take() {
+            let target_len = buffer.visited.len();
+            if visited.len() != target_len {
+                visited.resize(target_len, VisitState::Skipped);
+            }
+            visited.fill(VisitState::Skipped);
+            visited
+        } else {
+            vec![VisitState::Skipped; buffer.visited.len()]
+        };
+
         let mut shapes = Vec::new();
 
         buffer.points.reserve_capacity(buffer.visited.len());
-        let mut avg_holes_count = 0;
+        let mut hole_count_hint = 0;
 
         let mut link_index = 0;
         while link_index < buffer.visited.len() {
@@ -58,26 +70,24 @@ impl OverlayGraph<'_> {
                     visited_state,
                     &mut buffer.visited,
                 );
-                avg_holes_count += 1;
+                hole_count_hint += 1;
                 continue;
             }
 
-            self.find_contour(&start_data, traversal_direction, visited_state, buffer);
-            let (is_valid, _) = buffer.points.validate(
-                self.options.min_output_area,
-                self.options.preserve_output_collinear,
-            );
-
-            if !is_valid {
+            if let Some(shape) = self.collect_shape(
+                &start_data,
+                traversal_direction,
+                &mut buffer.visited,
+                &mut contour_visited,
+                &mut buffer.points,
+            ) {
+                shapes.push(shape);
+            } else {
                 link_index += 1;
-                continue;
-            }
-
-            let contour = buffer.points.as_slice().to_vec();
-            shapes.push(vec![contour]);
+            };
         }
 
-        if avg_holes_count > 0 {
+        if hole_count_hint > 0 {
             // Keep only hole edges; skip everything else for the second pass.
             for state in buffer.visited.iter_mut() {
                 *state = match *state {
@@ -86,8 +96,8 @@ impl OverlayGraph<'_> {
                 };
             }
 
-            let mut holes = Vec::with_capacity(avg_holes_count);
-            let mut anchors = Vec::with_capacity(avg_holes_count);
+            let mut holes = Vec::with_capacity(hole_count_hint);
+            let mut anchors = Vec::with_capacity(hole_count_hint);
             let mut anchors_already_sorted = true;
             link_index = 0;
 
@@ -112,7 +122,14 @@ impl OverlayGraph<'_> {
 
                 let start_data = StartPathData::new(is_main_dir_cw, link, left_top_link);
 
-                self.find_contour(&start_data, is_main_dir_cw, VisitState::HullVisited, buffer);
+                self.find_contour(
+                    &start_data,
+                    is_main_dir_cw,
+                    VisitState::HullVisited,
+                    &mut buffer.visited,
+                    &mut buffer.points,
+                );
+
                 let (is_valid, is_modified) = buffer.points.validate(
                     self.options.min_output_area,
                     self.options.preserve_output_collinear,
@@ -157,6 +174,8 @@ impl OverlayGraph<'_> {
             shapes.join_sorted_holes(holes, anchors, is_main_dir_cw);
         }
 
+        buffer.contour_visited = Some(contour_visited);
+
         shapes
     }
 
@@ -192,4 +211,133 @@ impl OverlayGraph<'_> {
             visited.visit_edge(link_id, visited_state);
         }
     }
+
+    fn collect_shape(
+        &self,
+        start_data: &StartPathData,
+        clockwise: bool,
+        global_visited: &mut Vec<VisitState>,
+        contour_visited: &mut Vec<VisitState>,
+        points: &mut Vec<IntPoint>,
+    ) -> Option<IntShape> {
+        let mut link_id = start_data.link_id;
+        let mut node_id = start_data.node_id;
+        let last_node_id = start_data.last_node_id;
+
+        // First, mark all edges that belong to the contour.
+
+        let mut end_link_id = start_data.link_id;
+
+        global_visited.visit_edge(link_id, VisitState::HullVisited);
+        contour_visited.visit_edge(link_id, VisitState::Unvisited);
+
+        let mut original_contour_len = 1;
+
+        // Find a closed tour
+        while node_id != last_node_id {
+            link_id = GraphUtil::next_link(
+                self.links,
+                self.nodes,
+                link_id,
+                node_id,
+                clockwise,
+                global_visited,
+            );
+
+            let link = unsafe {
+                // Safety: `link_id` is always derived from a previous in-bounds index or
+                // from `find_left_top_link`, so it remains in `0..self.links.len()`.
+                self.links.get_unchecked(link_id)
+            };
+
+            node_id = if link.a.id == node_id {
+                link.b.id
+            } else {
+                link.a.id
+            };
+            end_link_id = end_link_id.max(link_id);
+            contour_visited.visit_edge(link_id, VisitState::Unvisited);
+            global_visited.visit_edge(link_id, VisitState::HullVisited);
+            original_contour_len += 1;
+        }
+
+        // Revisit the contour in reverse;
+        // all links escape current contour are skipped in `contour_visited`.
+
+        points.reserve_capacity(original_contour_len);
+        self.find_contour(
+            &start_data,
+            !clockwise,
+            VisitState::HullVisited,
+            contour_visited,
+            points,
+        );
+
+        let (is_valid, _) = points.validate(
+            self.options.min_output_area,
+            self.options.preserve_output_collinear,
+        );
+
+        let contour_len = points.len();
+
+        let mut shape = if is_valid {
+            let mut shape = vec![];
+            let contour = points.as_slice().to_vec();
+            shape.push(contour);
+            Some(shape)
+        } else {
+            None
+        };
+
+        if contour_len < original_contour_len {
+            // contour has self touches
+            let mut link_index = start_data.link_id;
+            while link_index <= end_link_id {
+                if contour_visited.is_visited(link_index) {
+                    link_index += 1;
+                    continue;
+                }
+
+                let left_top_link = unsafe {
+                    // Safety: `link_index` walks 0..buffer.visited.len(), and buffer.visited.len() <= self.links.len().
+                    GraphUtil::find_left_top_link(self.links, self.nodes, link_index, contour_visited)
+                };
+
+                let link = unsafe {
+                    // Safety: `left_top_link` originates from `find_left_top_link`, which only returns
+                    // indices in 0..self.links.len(), so this lookup cannot go out of bounds.
+                    self.links.get_unchecked(left_top_link)
+                };
+
+                // Self-touch splits can only produce holes inside this contour.
+
+                let hole_start_data = StartPathData::new(clockwise, link, left_top_link);
+                self.find_contour(
+                    &hole_start_data,
+                    clockwise,
+                    VisitState::HoleVisited,
+                    contour_visited,
+                    points,
+                );
+
+                // Hole have to belong to this shape.
+                if let Some(shape) = shape.as_mut() {
+                    let (is_valid, _) = points.validate(
+                        self.options.min_output_area,
+                        self.options.preserve_output_collinear,
+                    );
+
+                    if !is_valid {
+                        link_index += 1;
+                        continue;
+                    }
+
+                    let contour = points.as_slice().to_vec();
+                    shape.push(contour);
+                }
+            }
+        }
+
+        shape
+    }
 }