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BLADERUNNER: Better fix for bug in pathfinding

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Basically just more robust (but slower) fix to the intermittent assert
in pathfinding code when polygons were touching only by a single corner.
This commit is contained in:
Peter Kohaut 2019-03-09 19:03:18 +01:00
parent 664dd4a8aa
commit 1630cf0e6c
1 changed files with 6 additions and 9 deletions
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15
engines/bladerunner/obstacles.cpp
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@ -191,7 +191,6 @@ bool Obstacles::mergePolygons(Polygon &polyA, Polygon &polyB) {
bool flagAddVertexToVertexList = true; bool flagAddVertexToVertexList = true;
bool flagDidFindIntersection = false; bool flagDidFindIntersection = false;
int vertIndex = 0; int vertIndex = 0;
int lastIntersectionIndex = -1;
Polygon *startingPolygon = polyPrimary; Polygon *startingPolygon = polyPrimary;
int flagDone = false; int flagDone = false;
@ -205,7 +204,12 @@ bool Obstacles::mergePolygons(Polygon &polyA, Polygon &polyB) {
polyPrimaryType = polyPrimary->vertexType[vertIndex]; polyPrimaryType = polyPrimary->vertexType[vertIndex];
if (flagAddVertexToVertexList) { if (flagAddVertexToVertexList) {
assert(polyMerged.verticeCount < kPolygonVertexCount); // In some cases polygons will have only one intersection (touching corners) and because of that second SWAP never occure,
// algorithm will stop only when the merged polygon is full.
if (polyMerged.verticeCount >= kPolygonVertexCount) {
flagDidMergePolygons = false;
break;
}
polyMerged.vertices[polyMerged.verticeCount] = polyLine.start; polyMerged.vertices[polyMerged.verticeCount] = polyLine.start;
polyMerged.vertexType[polyMerged.verticeCount] = polyPrimaryType; polyMerged.vertexType[polyMerged.verticeCount] = polyPrimaryType;
polyMerged.verticeCount++; polyMerged.verticeCount++;
@ -227,15 +231,8 @@ bool Obstacles::mergePolygons(Polygon &polyA, Polygon &polyB) {
SWAP(polyPrimary, polySecondary); SWAP(polyPrimary, polySecondary);
flagDidMergePolygons = true; flagDidMergePolygons = true;
lastIntersectionIndex = polySecondaryIntersectionIndex;
} else { } else {
vertIndex = (vertIndex + 1) % polyPrimary->verticeCount; vertIndex = (vertIndex + 1) % polyPrimary->verticeCount;
// In some cases polygons will have only one intersection (touching corners) and because of that second SWAP never occure and algorithm will never stop.
// This can be avoided by stopping the algorithm after looping over whole polygon. Such polygons will not merge.
if (vertIndex == lastIntersectionIndex) {
flagDidMergePolygons = false;
break;
}
flagDidFindIntersection = false; flagDidFindIntersection = false;
} }
if (polyPrimary->vertices[vertIndex] == startingPolygon->vertices[0]) { if (polyPrimary->vertices[vertIndex] == startingPolygon->vertices[0]) {