712 lines
21 KiB
C#

using UnityEngine;
using Unity.Collections;
using Unity.Jobs;
using Unity.Burst;
using Pathfinding.Util;
using Pathfinding.Collections;
namespace Pathfinding.Graphs.Navmesh.Voxelization.Burst {
/// <summary>VoxelContour used for recast graphs.</summary>
public struct VoxelContour {
public int nverts;
/// <summary>Vertex coordinates, each vertex contains 4 components.</summary>
public int vertexStartIndex;
/// <summary>Region ID of the contour</summary>
public int reg;
/// <summary>Area ID of the contour.</summary>
public int area;
}
[BurstCompile(CompileSynchronously = true)]
public struct JobBuildContours : IJob {
public CompactVoxelField field;
public float maxError;
public float maxEdgeLength;
public int buildFlags;
public float cellSize;
public NativeList<VoxelContour> outputContours;
public NativeList<int> outputVerts;
public void Execute () {
outputContours.Clear();
outputVerts.Clear();
int w = field.width;
int d = field.depth;
int wd = w*d;
const ushort BorderReg = VoxelUtilityBurst.BorderReg;
// NOTE: This array may contain uninitialized data, but since we explicitly set all data in it before we use it, it's OK.
var flags = new NativeArray<ushort>(field.spans.Length, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
// Mark boundaries. (@?)
for (int z = 0; z < wd; z += field.width) {
for (int x = 0; x < field.width; x++) {
CompactVoxelCell c = field.cells[x+z];
for (int i = (int)c.index, ci = (int)(c.index+c.count); i < ci; i++) {
ushort res = 0;
CompactVoxelSpan s = field.spans[i];
if (s.reg == 0 || (s.reg & BorderReg) == BorderReg) {
flags[i] = 0;
continue;
}
for (int dir = 0; dir < 4; dir++) {
int r = 0;
if (s.GetConnection(dir) != CompactVoxelField.NotConnected) {
int ni = field.cells[field.GetNeighbourIndex(x+z, dir)].index + s.GetConnection(dir);
r = field.spans[ni].reg;
}
//@TODO - Why isn't this inside the previous IF
if (r == s.reg) {
res |= (ushort)(1 << dir);
}
}
//Inverse, mark non connected edges.
flags[i] = (ushort)(res ^ 0xf);
}
}
}
NativeList<int> verts = new NativeList<int>(256, Allocator.Temp);
NativeList<int> simplified = new NativeList<int>(64, Allocator.Temp);
for (int z = 0; z < wd; z += field.width) {
for (int x = 0; x < field.width; x++) {
CompactVoxelCell c = field.cells[x+z];
for (int i = c.index, ci = c.index+c.count; i < ci; i++) {
if (flags[i] == 0 || flags[i] == 0xf) {
flags[i] = 0;
continue;
}
int reg = field.spans[i].reg;
if (reg == 0 || (reg & BorderReg) == BorderReg) {
continue;
}
int area = field.areaTypes[i];
verts.Clear();
simplified.Clear();
WalkContour(x, z, i, flags, verts);
SimplifyContour(verts, simplified, maxError, buildFlags);
RemoveDegenerateSegments(simplified);
VoxelContour contour = new VoxelContour {
vertexStartIndex = outputVerts.Length,
nverts = simplified.Length/4,
reg = reg,
area = area,
};
outputVerts.AddRange(simplified.AsArray());
outputContours.Add(contour);
}
}
}
verts.Dispose();
simplified.Dispose();
// Check and merge droppings.
// Sometimes the previous algorithms can fail and create several outputContours
// per area. This pass will try to merge the holes into the main region.
for (int i = 0; i < outputContours.Length; i++) {
VoxelContour cont = outputContours[i];
// Check if the contour is would backwards.
var outputVertsArr = outputVerts.AsArray();
if (CalcAreaOfPolygon2D(outputVertsArr, cont.vertexStartIndex, cont.nverts) < 0) {
// Find another contour which has the same region ID.
int mergeIdx = -1;
for (int j = 0; j < outputContours.Length; j++) {
if (i == j) continue;
if (outputContours[j].nverts > 0 && outputContours[j].reg == cont.reg) {
// Make sure the polygon is correctly oriented.
if (CalcAreaOfPolygon2D(outputVertsArr, outputContours[j].vertexStartIndex, outputContours[j].nverts) > 0) {
mergeIdx = j;
break;
}
}
}
if (mergeIdx == -1) {
// Debug.LogError("rcBuildContours: Could not find merge target for bad contour "+i+".");
} else {
// Debugging
// Debug.LogWarning ("Fixing contour");
VoxelContour mcont = outputContours[mergeIdx];
// Merge by closest points.
GetClosestIndices(outputVertsArr, mcont.vertexStartIndex, mcont.nverts, cont.vertexStartIndex, cont.nverts, out var ia, out var ib);
if (ia == -1 || ib == -1) {
// Debug.LogWarning("rcBuildContours: Failed to find merge points for "+i+" and "+mergeIdx+".");
continue;
}
if (!MergeContours(outputVerts, ref mcont, ref cont, ia, ib)) {
//Debug.LogWarning("rcBuildContours: Failed to merge contours "+i+" and "+mergeIdx+".");
continue;
}
outputContours[mergeIdx] = mcont;
outputContours[i] = cont;
}
}
}
}
void GetClosestIndices (NativeArray<int> verts, int vertexStartIndexA, int nvertsa,
int vertexStartIndexB, int nvertsb,
out int ia, out int ib) {
int closestDist = 0xfffffff;
ia = -1;
ib = -1;
for (int i = 0; i < nvertsa; i++) {
//in is a keyword in C#, so I can't use that as a variable name
int in2 = (i+1) % nvertsa;
int ip = (i+nvertsa-1) % nvertsa;
int va = vertexStartIndexA + i*4;
int van = vertexStartIndexA + in2*4;
int vap = vertexStartIndexA + ip*4;
for (int j = 0; j < nvertsb; ++j) {
int vb = vertexStartIndexB + j*4;
// vb must be "infront" of va.
if (Ileft(verts, vap, va, vb) && Ileft(verts, va, van, vb)) {
int dx = verts[vb+0] - verts[va+0];
int dz = (verts[vb+2]/field.width) - (verts[va+2]/field.width);
int d = dx*dx + dz*dz;
if (d < closestDist) {
ia = i;
ib = j;
closestDist = d;
}
}
}
}
}
public static bool MergeContours (NativeList<int> verts, ref VoxelContour ca, ref VoxelContour cb, int ia, int ib) {
// Note: this will essentially leave junk data in the verts array where the contours were previously.
// This shouldn't be a big problem because MergeContours is normally not called for that many contours (usually none).
int nv = 0;
var startIndex = verts.Length;
// Copy contour A.
for (int i = 0; i <= ca.nverts; i++) {
int src = ca.vertexStartIndex + ((ia+i) % ca.nverts)*4;
verts.Add(verts[src+0]);
verts.Add(verts[src+1]);
verts.Add(verts[src+2]);
verts.Add(verts[src+3]);
nv++;
}
// Copy contour B
for (int i = 0; i <= cb.nverts; i++) {
int src = cb.vertexStartIndex + ((ib+i) % cb.nverts)*4;
verts.Add(verts[src+0]);
verts.Add(verts[src+1]);
verts.Add(verts[src+2]);
verts.Add(verts[src+3]);
nv++;
}
ca.vertexStartIndex = startIndex;
ca.nverts = nv;
cb.vertexStartIndex = 0;
cb.nverts = 0;
return true;
}
public void SimplifyContour (NativeList<int> verts, NativeList<int> simplified, float maxError, int buildFlags) {
// Add initial points.
bool hasConnections = false;
for (int i = 0; i < verts.Length; i += 4) {
if ((verts[i+3] & VoxelUtilityBurst.ContourRegMask) != 0) {
hasConnections = true;
break;
}
}
if (hasConnections) {
// The contour has some portals to other regions.
// Add a new point to every location where the region changes.
for (int i = 0, ni = verts.Length/4; i < ni; i++) {
int ii = (i+1) % ni;
bool differentRegs = (verts[i*4+3] & VoxelUtilityBurst.ContourRegMask) != (verts[ii*4+3] & VoxelUtilityBurst.ContourRegMask);
bool areaBorders = (verts[i*4+3] & VoxelUtilityBurst.RC_AREA_BORDER) != (verts[ii*4+3] & VoxelUtilityBurst.RC_AREA_BORDER);
if (differentRegs || areaBorders) {
simplified.Add(verts[i*4+0]);
simplified.Add(verts[i*4+1]);
simplified.Add(verts[i*4+2]);
simplified.Add(i);
}
}
}
if (simplified.Length == 0) {
// If there is no connections at all,
// create some initial points for the simplification process.
// Find lower-left and upper-right vertices of the contour.
int llx = verts[0];
int lly = verts[1];
int llz = verts[2];
int lli = 0;
int urx = verts[0];
int ury = verts[1];
int urz = verts[2];
int uri = 0;
for (int i = 0; i < verts.Length; i += 4) {
int x = verts[i+0];
int y = verts[i+1];
int z = verts[i+2];
if (x < llx || (x == llx && z < llz)) {
llx = x;
lly = y;
llz = z;
lli = i/4;
}
if (x > urx || (x == urx && z > urz)) {
urx = x;
ury = y;
urz = z;
uri = i/4;
}
}
simplified.Add(llx);
simplified.Add(lly);
simplified.Add(llz);
simplified.Add(lli);
simplified.Add(urx);
simplified.Add(ury);
simplified.Add(urz);
simplified.Add(uri);
}
// Add points until all raw points are within
// error tolerance to the simplified shape.
// This uses the Douglas-Peucker algorithm.
int pn = verts.Length/4;
//Use the max squared error instead
maxError *= maxError;
for (int i = 0; i < simplified.Length/4;) {
int ii = (i+1) % (simplified.Length/4);
int ax = simplified[i*4+0];
int ay = simplified[i*4+1];
int az = simplified[i*4+2];
int ai = simplified[i*4+3];
int bx = simplified[ii*4+0];
int by = simplified[ii*4+1];
int bz = simplified[ii*4+2];
int bi = simplified[ii*4+3];
// Find maximum deviation from the segment.
float maxd = 0;
int maxi = -1;
int ci, cinc, endi;
// Traverse the segment in lexilogical order so that the
// max deviation is calculated similarly when traversing
// opposite segments.
if (bx > ax || (bx == ax && bz > az)) {
cinc = 1;
ci = (ai+cinc) % pn;
endi = bi;
} else {
cinc = pn-1;
ci = (bi+cinc) % pn;
endi = ai;
Memory.Swap(ref ax, ref bx);
Memory.Swap(ref az, ref bz);
}
// Tessellate only outer edges or edges between areas.
if ((verts[ci*4+3] & VoxelUtilityBurst.ContourRegMask) == 0 ||
(verts[ci*4+3] & VoxelUtilityBurst.RC_AREA_BORDER) == VoxelUtilityBurst.RC_AREA_BORDER) {
while (ci != endi) {
float d2 = VectorMath.SqrDistancePointSegmentApproximate(verts[ci*4+0], verts[ci*4+2]/field.width, ax, az/field.width, bx, bz/field.width);
if (d2 > maxd) {
maxd = d2;
maxi = ci;
}
ci = (ci+cinc) % pn;
}
}
// If the max deviation is larger than accepted error,
// add new point, else continue to next segment.
if (maxi != -1 && maxd > maxError) {
// Add space for the new point.
simplified.ResizeUninitialized(simplified.Length + 4);
// Move all points after this one, to leave space to insert the new point
simplified.AsUnsafeSpan().Move((i+1)*4, (i+2)*4, simplified.Length-(i+2)*4);
// Add the point.
simplified[(i+1)*4+0] = verts[maxi*4+0];
simplified[(i+1)*4+1] = verts[maxi*4+1];
simplified[(i+1)*4+2] = verts[maxi*4+2];
simplified[(i+1)*4+3] = maxi;
} else {
i++;
}
}
// Split too long edges
float maxEdgeLen = maxEdgeLength / cellSize;
if (maxEdgeLen > 0 && (buildFlags & (VoxelUtilityBurst.RC_CONTOUR_TESS_WALL_EDGES|VoxelUtilityBurst.RC_CONTOUR_TESS_AREA_EDGES|VoxelUtilityBurst.RC_CONTOUR_TESS_TILE_EDGES)) != 0) {
for (int i = 0; i < simplified.Length/4;) {
if (simplified.Length/4 > 200) {
break;
}
int ii = (i+1) % (simplified.Length/4);
int ax = simplified[i*4+0];
int az = simplified[i*4+2];
int ai = simplified[i*4+3];
int bx = simplified[ii*4+0];
int bz = simplified[ii*4+2];
int bi = simplified[ii*4+3];
// Find maximum deviation from the segment.
int maxi = -1;
int ci = (ai+1) % pn;
// Tessellate only outer edges or edges between areas.
bool tess = false;
// Wall edges.
if ((buildFlags & VoxelUtilityBurst.RC_CONTOUR_TESS_WALL_EDGES) != 0 && (verts[ci*4+3] & VoxelUtilityBurst.ContourRegMask) == 0)
tess = true;
// Edges between areas.
if ((buildFlags & VoxelUtilityBurst.RC_CONTOUR_TESS_AREA_EDGES) != 0 && (verts[ci*4+3] & VoxelUtilityBurst.RC_AREA_BORDER) == VoxelUtilityBurst.RC_AREA_BORDER)
tess = true;
// Border of tile
if ((buildFlags & VoxelUtilityBurst.RC_CONTOUR_TESS_TILE_EDGES) != 0 && (verts[ci*4+3] & VoxelUtilityBurst.BorderReg) == VoxelUtilityBurst.BorderReg)
tess = true;
if (tess) {
int dx = bx - ax;
int dz = (bz/field.width) - (az/field.width);
if (dx*dx + dz*dz > maxEdgeLen*maxEdgeLen) {
// Round based on the segments in lexilogical order so that the
// max tesselation is consistent regardles in which direction
// segments are traversed.
int n = bi < ai ? (bi+pn - ai) : (bi - ai);
if (n > 1) {
if (bx > ax || (bx == ax && bz > az)) {
maxi = (ai + n/2) % pn;
} else {
maxi = (ai + (n+1)/2) % pn;
}
}
}
}
// If the max deviation is larger than accepted error,
// add new point, else continue to next segment.
if (maxi != -1) {
// Add space for the new point.
//simplified.resize(simplified.size()+4);
simplified.Resize(simplified.Length + 4, NativeArrayOptions.UninitializedMemory);
simplified.AsUnsafeSpan().Move((i+1)*4, (i+2)*4, simplified.Length-(i+2)*4);
// Add the point.
simplified[(i+1)*4+0] = verts[maxi*4+0];
simplified[(i+1)*4+1] = verts[maxi*4+1];
simplified[(i+1)*4+2] = verts[maxi*4+2];
simplified[(i+1)*4+3] = maxi;
} else {
++i;
}
}
}
for (int i = 0; i < simplified.Length/4; i++) {
// The edge vertex flag is take from the current raw point,
// and the neighbour region is take from the next raw point.
int ai = (simplified[i*4+3]+1) % pn;
int bi = simplified[i*4+3];
simplified[i*4+3] = (verts[ai*4+3] & VoxelUtilityBurst.ContourRegMask) | (verts[bi*4+3] & VoxelUtilityBurst.RC_BORDER_VERTEX);
}
}
public void WalkContour (int x, int z, int i, NativeArray<ushort> flags, NativeList<int> verts) {
// Choose the first non-connected edge
int dir = 0;
while ((flags[i] & (ushort)(1 << dir)) == 0) {
dir++;
}
int startDir = dir;
int startI = i;
int area = field.areaTypes[i];
int iter = 0;
while (iter++ < 40000) {
// Are we facing a region edge
if ((flags[i] & (ushort)(1 << dir)) != 0) {
// Choose the edge corner
bool isBorderVertex = false;
bool isAreaBorder = false;
int px = x;
int py = GetCornerHeight(x, z, i, dir, ref isBorderVertex);
int pz = z;
// Offset the vertex to land on the corner of the span.
// The resulting coordinates have an implicit 1/2 voxel offset because all corners
// are in the middle between two adjacent integer voxel coordinates.
switch (dir) {
case 0: pz += field.width; break;
case 1: px++; pz += field.width; break;
case 2: px++; break;
}
int r = 0;
CompactVoxelSpan s = field.spans[i];
if (s.GetConnection(dir) != CompactVoxelField.NotConnected) {
int ni = (int)field.cells[field.GetNeighbourIndex(x+z, dir)].index + s.GetConnection(dir);
r = (int)field.spans[ni].reg;
if (area != field.areaTypes[ni]) {
isAreaBorder = true;
}
}
if (isBorderVertex) {
r |= VoxelUtilityBurst.RC_BORDER_VERTEX;
}
if (isAreaBorder) {
r |= VoxelUtilityBurst.RC_AREA_BORDER;
}
verts.Add(px);
verts.Add(py);
verts.Add(pz);
verts.Add(r);
flags[i] = (ushort)(flags[i] & ~(1 << dir)); // Remove visited edges
// & 0x3 is the same as % 4 (for positive numbers)
dir = (dir+1) & 0x3; // Rotate CW
} else {
int ni = -1;
int nx = x + VoxelUtilityBurst.DX[dir];
int nz = z + VoxelUtilityBurst.DZ[dir]*field.width;
CompactVoxelSpan s = field.spans[i];
if (s.GetConnection(dir) != CompactVoxelField.NotConnected) {
CompactVoxelCell nc = field.cells[nx+nz];
ni = (int)nc.index + s.GetConnection(dir);
}
if (ni == -1) {
Debug.LogWarning("Degenerate triangles might have been generated.\n" +
"Usually this is not a problem, but if you have a static level, try to modify the graph settings slightly to avoid this edge case.");
return;
}
x = nx;
z = nz;
i = ni;
// & 0x3 is the same as % 4 (modulo 4)
dir = (dir+3) & 0x3; // Rotate CCW
}
if (startI == i && startDir == dir) {
break;
}
}
}
public int GetCornerHeight (int x, int z, int i, int dir, ref bool isBorderVertex) {
CompactVoxelSpan s = field.spans[i];
int cornerHeight = (int)s.y;
// dir + 1 step in the clockwise direction
int dirp = (dir+1) & 0x3;
unsafe {
// We need a small buffer to hold regions for each axis aligned neighbour.
// This requires unsafe, though. In future C# versions we can use Span<T>.
//
// dir
// X---->
// dirp |
// v
//
//
// The regs array will contain the regions for the following spans,
// where the 0th span is the current span.
// 'x' signifies the position of the corner we are interested in.
// This is the shared vertex corner the four spans.
// It is conceptually at the current span's position + 0.5*dir + 0.5*dirp
//
//
// 0 --------- 1 -> dir
// | |
// | x |
// | |
// 3 --------- 2
//
// | dirp
// v
//
var regs = stackalloc uint[] { 0, 0, 0, 0 };
regs[0] = (uint)field.spans[i].reg | ((uint)field.areaTypes[i] << 16);
if (s.GetConnection(dir) != CompactVoxelField.NotConnected) {
int neighbourCell = field.GetNeighbourIndex(x+z, dir);
int ni = (int)field.cells[neighbourCell].index + s.GetConnection(dir);
CompactVoxelSpan ns = field.spans[ni];
cornerHeight = System.Math.Max(cornerHeight, (int)ns.y);
regs[1] = (uint)ns.reg | ((uint)field.areaTypes[ni] << 16);
if (ns.GetConnection(dirp) != CompactVoxelField.NotConnected) {
int neighbourCell2 = field.GetNeighbourIndex(neighbourCell, dirp);
int ni2 = (int)field.cells[neighbourCell2].index + ns.GetConnection(dirp);
CompactVoxelSpan ns2 = field.spans[ni2];
cornerHeight = System.Math.Max(cornerHeight, (int)ns2.y);
regs[2] = (uint)ns2.reg | ((uint)field.areaTypes[ni2] << 16);
}
}
if (s.GetConnection(dirp) != CompactVoxelField.NotConnected) {
int neighbourCell = field.GetNeighbourIndex(x+z, dirp);
int ni = (int)field.cells[neighbourCell].index + s.GetConnection(dirp);
CompactVoxelSpan ns = field.spans[ni];
cornerHeight = System.Math.Max(cornerHeight, (int)ns.y);
regs[3] = (uint)ns.reg | ((uint)field.areaTypes[ni] << 16);
if (ns.GetConnection(dir) != CompactVoxelField.NotConnected) {
int neighbourCell2 = field.GetNeighbourIndex(neighbourCell, dir);
int ni2 = (int)field.cells[neighbourCell2].index + ns.GetConnection(dir);
CompactVoxelSpan ns2 = field.spans[ni2];
cornerHeight = System.Math.Max(cornerHeight, (int)ns2.y);
regs[2] = (uint)ns2.reg | ((uint)field.areaTypes[ni2] << 16);
}
}
// Zeroes show up when there are no connections to some spans. E.g. if the current span is on a ledge.
bool noZeros = regs[0] != 0 && regs[1] != 0 && regs[2] != 0 && regs[3] != 0;
// Check if the vertex is special edge vertex, these vertices will be removed later.
for (int j = 0; j < 4; ++j) {
int a = j;
int b = (j+1) & 0x3;
int c = (j+2) & 0x3;
int d = (j+3) & 0x3;
// The vertex is a border vertex there are two same exterior cells in a row,
// followed by two interior cells and none of the regions are out of bounds.
bool twoSameExts = (regs[a] & regs[b] & VoxelUtilityBurst.BorderReg) != 0 && regs[a] == regs[b];
bool twoInts = ((regs[c] | regs[d]) & VoxelUtilityBurst.BorderReg) == 0;
bool intsSameArea = (regs[c]>>16) == (regs[d]>>16);
if (twoSameExts && twoInts && intsSameArea && noZeros) {
isBorderVertex = true;
break;
}
}
}
return cornerHeight;
}
static void RemoveRange (NativeList<int> arr, int index, int count) {
for (int i = index; i < arr.Length - count; i++) {
arr[i] = arr[i+count];
}
arr.Resize(arr.Length - count, NativeArrayOptions.UninitializedMemory);
}
static void RemoveDegenerateSegments (NativeList<int> simplified) {
// Remove adjacent vertices which are equal on xz-plane,
// or else the triangulator will get confused
for (int i = 0; i < simplified.Length/4; i++) {
int ni = i+1;
if (ni >= (simplified.Length/4))
ni = 0;
if (simplified[i*4+0] == simplified[ni*4+0] &&
simplified[i*4+2] == simplified[ni*4+2]) {
// Degenerate segment, remove.
RemoveRange(simplified, i, 4);
}
}
}
int CalcAreaOfPolygon2D (NativeArray<int> verts, int vertexStartIndex, int nverts) {
int area = 0;
for (int i = 0, j = nverts-1; i < nverts; j = i++) {
int vi = vertexStartIndex + i*4;
int vj = vertexStartIndex + j*4;
area += verts[vi+0] * (verts[vj+2]/field.width) - verts[vj+0] * (verts[vi+2]/field.width);
}
return (area+1) / 2;
}
static bool Ileft (NativeArray<int> verts, int a, int b, int c) {
return (verts[b+0] - verts[a+0]) * (verts[c+2] - verts[a+2]) - (verts[c+0] - verts[a+0]) * (verts[b+2] - verts[a+2]) <= 0;
}
}
}