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fixed triangle location bug

This commit is contained in:
zzzzrrr 2009-08-04 11:40:24 -04:00
parent 6517956535
commit 324fb8207e
2 changed files with 78 additions and 46 deletions
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118
src/org/poly2tri/cdt/CDT.scala
View File

@ -124,12 +124,12 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
// Implement sweep-line
private def sweep {
for(i <- 1 until 10 /*points.size*/) {
for(i <- 1 until 11 /*points.size*/) {
val point = points(i)
// Process Point event
val triangle = pointEvent(point)
// Process edge events
point.edges.foreach(e => edgeEvent(e, triangle))
point.edges.foreach(e => if(!triangle.contains(e)) edgeEvent(e, triangle))
}
}
@ -137,31 +137,60 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
private def pointEvent(point: Point): Triangle = {
val node = aFront.locate(point)
var newNode: Node = null
// Neightbor points (ccw & cw) and triangle(i)
val cwPoint = node.next.point
val ccwPoint = node.point
val nTri = node.triangle
if(point.x == node.point.x) {
// Projected point coincides with existing point; create two triangles
val rPts = Array(point, node.point, node.next.point)
val rNeighbors = Array(node.triangle, null, null)
val rTriangle = new Triangle(rPts, rNeighbors)
val lPts = Array(node.prev.point, node.point, point)
val lNeighbors = Array(rTriangle, null, node.prev.triangle)
val lTriangle = new Triangle(lPts, lNeighbors)
rTriangle.neighbors(2) = lTriangle
mesh.map += lTriangle
mesh.map += rTriangle
// Legalize new triangles
legalization(rTriangle, rTriangle.neighbors(0))
legalization(lTriangle, lTriangle.neighbors(2))
// Update neighbor pointers
node.triangle.updateNeighbors(node.point, node.next.point, lTriangle)
node.prev.triangle.updateNeighbors(node.point, node.prev.point, rTriangle)
// Update advancing front
newNode = aFront.insert(point, rTriangle, node)
aFront -= (node.prev, node, rTriangle)
} else {
// Projected point hits advancing front; create new triangle
val cwPoint = node.next.point
val ccwPoint = node.point
val nTri = node.triangle
val pts = Array(point, ccwPoint, cwPoint)
val neighbors = Array(nTri, null, null)
val triangle = new Triangle(pts, neighbors)
mesh.map += triangle
// Legalize
legalization(triangle, nTri)
// Update neighbor pointers
nTri.updateNeighbors(ccwPoint, cwPoint, triangle)
// Update advancing front
newNode = aFront.insert(point, triangle, node)
}
val pts = Array(point, ccwPoint, cwPoint)
val neighbors = Array(nTri, null, null)
val triangle = new Triangle(pts, neighbors)
mesh.map += triangle
// Check if edges need to be swapped to preserve CDT
// TODO: Make sure AFront pointers are updated correctly
val oPoint = nTri oppositePoint triangle
if(illegal(ccwPoint, oPoint, cwPoint, point)) {
legalization(triangle, nTri, oPoint)
}
nTri.updateNeighbors(ccwPoint, cwPoint, triangle)
// Update advancing front
val newNode = aFront.insert(point, triangle, node)
// Fill in adjacent triangles if required
scan(newNode)
triangle
newNode.triangle
}
// EdgeEvent
@ -169,7 +198,6 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
// STEP 1: Locate the first intersected triangle
val firstTriangle = triangle.locateFirst(edge)
// STEP 2: Remove intersected triangles
if(firstTriangle != null && !firstTriangle.contains(edge)) {
// Collect intersected triangles
@ -182,21 +210,21 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
//triangles.foreach(t => mesh.map -= t)
} else if(firstTriangle == null) {
// Traverse the AFront, and build triangle list
// Traverse the AFront, and build triangles
var node = aFront.locate(edge.q)
node = node.next
val points = new ArrayBuffer[Point]
if(edge.p.x > edge.q.x) {
// Search right
while(node.point != edge.p) {
while(node != null && node.point != edge.p) {
// Collect points
points += node.point
node = node.next
}
} else {
// Search left
while(node.point != edge.p) {
while(node != null && node.point != edge.p) {
// Collect points
points += node.point
node = node.prev
@ -209,6 +237,7 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
}
// STEP 3: Triangulate empty areas.
}
// Marc Vigo Anglada's triangulatePseudopolygonDelaunay algo
@ -293,22 +322,25 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
false
}
// Flip edges and rotate everything clockwise
private def legalization(t1: Triangle, t2: Triangle, oPoint: Point) {
// Rotate points
val point = t1.points(0)
t1.points(1) = t1.points(0)
t1.points(0) = t1.points(2)
t1.points(2) = oPoint
val tmp = t2.points(1)
t2.points(1) = point
t2.points(0) = t2.points(2)
t2.points(2) = tmp
t1.updatePoints
t2.updatePoints
// TODO: Rotate neighbors
println("legalize")
// Ensure new adjacent triangles are legal
private def legalization(t1: Triangle, t2: Triangle) {
val oPoint = t2 oppositePoint t1
if(illegal(t1.points(1), oPoint, t1.points(2), t1.points(0))) {
// Flip edges and rotate everything clockwise
val point = t1.points(0)
t1.points(1) = t1.points(0)
t1.points(0) = t1.points(2)
t1.points(2) = oPoint
val tmp = t2.points(1)
t2.points(1) = point
t2.points(0) = t2.points(2)
t2.points(2) = tmp
t1.updatePoints
t2.updatePoints
// TODO: Rotate neighbors
println("legalize")
}
}
private def finalization {

6
src/org/poly2tri/shapes/Triangle.scala
View File

@ -54,9 +54,9 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
// Update neighbor pointers
def updateNeighbors(ccwPoint: Point, cwPoint: Point, triangle: Triangle) {
if(ccwPoint == points(2) && cwPoint == points(1))
if((ccwPoint == points(2) && cwPoint == points(1)) || (ccwPoint == points(1) && cwPoint == points(2)))
neighbors(0) = triangle
else if(ccwPoint == points(0) && cwPoint == points(2))
else if((ccwPoint == points(0) && cwPoint == points(2)) || (ccwPoint == points(0) && cwPoint == points(2)))
neighbors(1) = triangle
else
neighbors(2) = triangle
@ -91,7 +91,7 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
def locateFirst(edge: Segment): Triangle = {
val p = edge.p
if(contains(p)) return this
if(contains(p) || contains(edge)) return this
val q = edge.q
val e = p - q
if(q == points(0)) {