godot/thirdparty/recastnavigation/Recast/Source/RecastMeshDetail.cpp

1464 lines
39 KiB
C++

//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
#include <float.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "Recast.h"
#include "RecastAlloc.h"
#include "RecastAssert.h"
static const unsigned RC_UNSET_HEIGHT = 0xffff;
struct rcHeightPatch
{
inline rcHeightPatch() : data(0), xmin(0), ymin(0), width(0), height(0) {}
inline ~rcHeightPatch() { rcFree(data); }
unsigned short* data;
int xmin, ymin, width, height;
};
inline float vdot2(const float* a, const float* b)
{
return a[0]*b[0] + a[2]*b[2];
}
inline float vdistSq2(const float* p, const float* q)
{
const float dx = q[0] - p[0];
const float dy = q[2] - p[2];
return dx*dx + dy*dy;
}
inline float vdist2(const float* p, const float* q)
{
return sqrtf(vdistSq2(p,q));
}
inline float vcross2(const float* p1, const float* p2, const float* p3)
{
const float u1 = p2[0] - p1[0];
const float v1 = p2[2] - p1[2];
const float u2 = p3[0] - p1[0];
const float v2 = p3[2] - p1[2];
return u1 * v2 - v1 * u2;
}
static bool circumCircle(const float* p1, const float* p2, const float* p3,
float* c, float& r)
{
static const float EPS = 1e-6f;
// Calculate the circle relative to p1, to avoid some precision issues.
const float v1[3] = {0,0,0};
float v2[3], v3[3];
rcVsub(v2, p2,p1);
rcVsub(v3, p3,p1);
const float cp = vcross2(v1, v2, v3);
if (fabsf(cp) > EPS)
{
const float v1Sq = vdot2(v1,v1);
const float v2Sq = vdot2(v2,v2);
const float v3Sq = vdot2(v3,v3);
c[0] = (v1Sq*(v2[2]-v3[2]) + v2Sq*(v3[2]-v1[2]) + v3Sq*(v1[2]-v2[2])) / (2*cp);
c[1] = 0;
c[2] = (v1Sq*(v3[0]-v2[0]) + v2Sq*(v1[0]-v3[0]) + v3Sq*(v2[0]-v1[0])) / (2*cp);
r = vdist2(c, v1);
rcVadd(c, c, p1);
return true;
}
rcVcopy(c, p1);
r = 0;
return false;
}
static float distPtTri(const float* p, const float* a, const float* b, const float* c)
{
float v0[3], v1[3], v2[3];
rcVsub(v0, c,a);
rcVsub(v1, b,a);
rcVsub(v2, p,a);
const float dot00 = vdot2(v0, v0);
const float dot01 = vdot2(v0, v1);
const float dot02 = vdot2(v0, v2);
const float dot11 = vdot2(v1, v1);
const float dot12 = vdot2(v1, v2);
// Compute barycentric coordinates
const float invDenom = 1.0f / (dot00 * dot11 - dot01 * dot01);
const float u = (dot11 * dot02 - dot01 * dot12) * invDenom;
float v = (dot00 * dot12 - dot01 * dot02) * invDenom;
// If point lies inside the triangle, return interpolated y-coord.
static const float EPS = 1e-4f;
if (u >= -EPS && v >= -EPS && (u+v) <= 1+EPS)
{
const float y = a[1] + v0[1]*u + v1[1]*v;
return fabsf(y-p[1]);
}
return FLT_MAX;
}
static float distancePtSeg(const float* pt, const float* p, const float* q)
{
float pqx = q[0] - p[0];
float pqy = q[1] - p[1];
float pqz = q[2] - p[2];
float dx = pt[0] - p[0];
float dy = pt[1] - p[1];
float dz = pt[2] - p[2];
float d = pqx*pqx + pqy*pqy + pqz*pqz;
float t = pqx*dx + pqy*dy + pqz*dz;
if (d > 0)
t /= d;
if (t < 0)
t = 0;
else if (t > 1)
t = 1;
dx = p[0] + t*pqx - pt[0];
dy = p[1] + t*pqy - pt[1];
dz = p[2] + t*pqz - pt[2];
return dx*dx + dy*dy + dz*dz;
}
static float distancePtSeg2d(const float* pt, const float* p, const float* q)
{
float pqx = q[0] - p[0];
float pqz = q[2] - p[2];
float dx = pt[0] - p[0];
float dz = pt[2] - p[2];
float d = pqx*pqx + pqz*pqz;
float t = pqx*dx + pqz*dz;
if (d > 0)
t /= d;
if (t < 0)
t = 0;
else if (t > 1)
t = 1;
dx = p[0] + t*pqx - pt[0];
dz = p[2] + t*pqz - pt[2];
return dx*dx + dz*dz;
}
static float distToTriMesh(const float* p, const float* verts, const int /*nverts*/, const int* tris, const int ntris)
{
float dmin = FLT_MAX;
for (int i = 0; i < ntris; ++i)
{
const float* va = &verts[tris[i*4+0]*3];
const float* vb = &verts[tris[i*4+1]*3];
const float* vc = &verts[tris[i*4+2]*3];
float d = distPtTri(p, va,vb,vc);
if (d < dmin)
dmin = d;
}
if (dmin == FLT_MAX) return -1;
return dmin;
}
static float distToPoly(int nvert, const float* verts, const float* p)
{
float dmin = FLT_MAX;
int i, j, c = 0;
for (i = 0, j = nvert-1; i < nvert; j = i++)
{
const float* vi = &verts[i*3];
const float* vj = &verts[j*3];
if (((vi[2] > p[2]) != (vj[2] > p[2])) &&
(p[0] < (vj[0]-vi[0]) * (p[2]-vi[2]) / (vj[2]-vi[2]) + vi[0]) )
c = !c;
dmin = rcMin(dmin, distancePtSeg2d(p, vj, vi));
}
return c ? -dmin : dmin;
}
static unsigned short getHeight(const float fx, const float fy, const float fz,
const float /*cs*/, const float ics, const float ch,
const int radius, const rcHeightPatch& hp)
{
int ix = (int)floorf(fx*ics + 0.01f);
int iz = (int)floorf(fz*ics + 0.01f);
ix = rcClamp(ix-hp.xmin, 0, hp.width - 1);
iz = rcClamp(iz-hp.ymin, 0, hp.height - 1);
unsigned short h = hp.data[ix+iz*hp.width];
if (h == RC_UNSET_HEIGHT)
{
// Special case when data might be bad.
// Walk adjacent cells in a spiral up to 'radius', and look
// for a pixel which has a valid height.
int x = 1, z = 0, dx = 1, dz = 0;
int maxSize = radius * 2 + 1;
int maxIter = maxSize * maxSize - 1;
int nextRingIterStart = 8;
int nextRingIters = 16;
float dmin = FLT_MAX;
for (int i = 0; i < maxIter; i++)
{
const int nx = ix + x;
const int nz = iz + z;
if (nx >= 0 && nz >= 0 && nx < hp.width && nz < hp.height)
{
const unsigned short nh = hp.data[nx + nz*hp.width];
if (nh != RC_UNSET_HEIGHT)
{
const float d = fabsf(nh*ch - fy);
if (d < dmin)
{
h = nh;
dmin = d;
}
}
}
// We are searching in a grid which looks approximately like this:
// __________
// |2 ______ 2|
// | |1 __ 1| |
// | | |__| | |
// | |______| |
// |__________|
// We want to find the best height as close to the center cell as possible. This means that
// if we find a height in one of the neighbor cells to the center, we don't want to
// expand further out than the 8 neighbors - we want to limit our search to the closest
// of these "rings", but the best height in the ring.
// For example, the center is just 1 cell. We checked that at the entrance to the function.
// The next "ring" contains 8 cells (marked 1 above). Those are all the neighbors to the center cell.
// The next one again contains 16 cells (marked 2). In general each ring has 8 additional cells, which
// can be thought of as adding 2 cells around the "center" of each side when we expand the ring.
// Here we detect if we are about to enter the next ring, and if we are and we have found
// a height, we abort the search.
if (i + 1 == nextRingIterStart)
{
if (h != RC_UNSET_HEIGHT)
break;
nextRingIterStart += nextRingIters;
nextRingIters += 8;
}
if ((x == z) || ((x < 0) && (x == -z)) || ((x > 0) && (x == 1 - z)))
{
int tmp = dx;
dx = -dz;
dz = tmp;
}
x += dx;
z += dz;
}
}
return h;
}
enum EdgeValues
{
EV_UNDEF = -1,
EV_HULL = -2
};
static int findEdge(const int* edges, int nedges, int s, int t)
{
for (int i = 0; i < nedges; i++)
{
const int* e = &edges[i*4];
if ((e[0] == s && e[1] == t) || (e[0] == t && e[1] == s))
return i;
}
return EV_UNDEF;
}
static int addEdge(rcContext* ctx, int* edges, int& nedges, const int maxEdges, int s, int t, int l, int r)
{
if (nedges >= maxEdges)
{
ctx->log(RC_LOG_ERROR, "addEdge: Too many edges (%d/%d).", nedges, maxEdges);
return EV_UNDEF;
}
// Add edge if not already in the triangulation.
int e = findEdge(edges, nedges, s, t);
if (e == EV_UNDEF)
{
int* edge = &edges[nedges*4];
edge[0] = s;
edge[1] = t;
edge[2] = l;
edge[3] = r;
return nedges++;
}
else
{
return EV_UNDEF;
}
}
static void updateLeftFace(int* e, int s, int t, int f)
{
if (e[0] == s && e[1] == t && e[2] == EV_UNDEF)
e[2] = f;
else if (e[1] == s && e[0] == t && e[3] == EV_UNDEF)
e[3] = f;
}
static int overlapSegSeg2d(const float* a, const float* b, const float* c, const float* d)
{
const float a1 = vcross2(a, b, d);
const float a2 = vcross2(a, b, c);
if (a1*a2 < 0.0f)
{
float a3 = vcross2(c, d, a);
float a4 = a3 + a2 - a1;
if (a3 * a4 < 0.0f)
return 1;
}
return 0;
}
static bool overlapEdges(const float* pts, const int* edges, int nedges, int s1, int t1)
{
for (int i = 0; i < nedges; ++i)
{
const int s0 = edges[i*4+0];
const int t0 = edges[i*4+1];
// Same or connected edges do not overlap.
if (s0 == s1 || s0 == t1 || t0 == s1 || t0 == t1)
continue;
if (overlapSegSeg2d(&pts[s0*3],&pts[t0*3], &pts[s1*3],&pts[t1*3]))
return true;
}
return false;
}
static void completeFacet(rcContext* ctx, const float* pts, int npts, int* edges, int& nedges, const int maxEdges, int& nfaces, int e)
{
static const float EPS = 1e-5f;
int* edge = &edges[e*4];
// Cache s and t.
int s,t;
if (edge[2] == EV_UNDEF)
{
s = edge[0];
t = edge[1];
}
else if (edge[3] == EV_UNDEF)
{
s = edge[1];
t = edge[0];
}
else
{
// Edge already completed.
return;
}
// Find best point on left of edge.
int pt = npts;
float c[3] = {0,0,0};
float r = -1;
for (int u = 0; u < npts; ++u)
{
if (u == s || u == t) continue;
if (vcross2(&pts[s*3], &pts[t*3], &pts[u*3]) > EPS)
{
if (r < 0)
{
// The circle is not updated yet, do it now.
pt = u;
circumCircle(&pts[s*3], &pts[t*3], &pts[u*3], c, r);
continue;
}
const float d = vdist2(c, &pts[u*3]);
const float tol = 0.001f;
if (d > r*(1+tol))
{
// Outside current circumcircle, skip.
continue;
}
else if (d < r*(1-tol))
{
// Inside safe circumcircle, update circle.
pt = u;
circumCircle(&pts[s*3], &pts[t*3], &pts[u*3], c, r);
}
else
{
// Inside epsilon circum circle, do extra tests to make sure the edge is valid.
// s-u and t-u cannot overlap with s-pt nor t-pt if they exists.
if (overlapEdges(pts, edges, nedges, s,u))
continue;
if (overlapEdges(pts, edges, nedges, t,u))
continue;
// Edge is valid.
pt = u;
circumCircle(&pts[s*3], &pts[t*3], &pts[u*3], c, r);
}
}
}
// Add new triangle or update edge info if s-t is on hull.
if (pt < npts)
{
// Update face information of edge being completed.
updateLeftFace(&edges[e*4], s, t, nfaces);
// Add new edge or update face info of old edge.
e = findEdge(edges, nedges, pt, s);
if (e == EV_UNDEF)
addEdge(ctx, edges, nedges, maxEdges, pt, s, nfaces, EV_UNDEF);
else
updateLeftFace(&edges[e*4], pt, s, nfaces);
// Add new edge or update face info of old edge.
e = findEdge(edges, nedges, t, pt);
if (e == EV_UNDEF)
addEdge(ctx, edges, nedges, maxEdges, t, pt, nfaces, EV_UNDEF);
else
updateLeftFace(&edges[e*4], t, pt, nfaces);
nfaces++;
}
else
{
updateLeftFace(&edges[e*4], s, t, EV_HULL);
}
}
static void delaunayHull(rcContext* ctx, const int npts, const float* pts,
const int nhull, const int* hull,
rcIntArray& tris, rcIntArray& edges)
{
int nfaces = 0;
int nedges = 0;
const int maxEdges = npts*10;
edges.resize(maxEdges*4);
for (int i = 0, j = nhull-1; i < nhull; j=i++)
addEdge(ctx, &edges[0], nedges, maxEdges, hull[j],hull[i], EV_HULL, EV_UNDEF);
int currentEdge = 0;
while (currentEdge < nedges)
{
if (edges[currentEdge*4+2] == EV_UNDEF)
completeFacet(ctx, pts, npts, &edges[0], nedges, maxEdges, nfaces, currentEdge);
if (edges[currentEdge*4+3] == EV_UNDEF)
completeFacet(ctx, pts, npts, &edges[0], nedges, maxEdges, nfaces, currentEdge);
currentEdge++;
}
// Create tris
tris.resize(nfaces*4);
for (int i = 0; i < nfaces*4; ++i)
tris[i] = -1;
for (int i = 0; i < nedges; ++i)
{
const int* e = &edges[i*4];
if (e[3] >= 0)
{
// Left face
int* t = &tris[e[3]*4];
if (t[0] == -1)
{
t[0] = e[0];
t[1] = e[1];
}
else if (t[0] == e[1])
t[2] = e[0];
else if (t[1] == e[0])
t[2] = e[1];
}
if (e[2] >= 0)
{
// Right
int* t = &tris[e[2]*4];
if (t[0] == -1)
{
t[0] = e[1];
t[1] = e[0];
}
else if (t[0] == e[0])
t[2] = e[1];
else if (t[1] == e[1])
t[2] = e[0];
}
}
for (int i = 0; i < tris.size()/4; ++i)
{
int* t = &tris[i*4];
if (t[0] == -1 || t[1] == -1 || t[2] == -1)
{
ctx->log(RC_LOG_WARNING, "delaunayHull: Removing dangling face %d [%d,%d,%d].", i, t[0],t[1],t[2]);
t[0] = tris[tris.size()-4];
t[1] = tris[tris.size()-3];
t[2] = tris[tris.size()-2];
t[3] = tris[tris.size()-1];
tris.resize(tris.size()-4);
--i;
}
}
}
// Calculate minimum extend of the polygon.
static float polyMinExtent(const float* verts, const int nverts)
{
float minDist = FLT_MAX;
for (int i = 0; i < nverts; i++)
{
const int ni = (i+1) % nverts;
const float* p1 = &verts[i*3];
const float* p2 = &verts[ni*3];
float maxEdgeDist = 0;
for (int j = 0; j < nverts; j++)
{
if (j == i || j == ni) continue;
float d = distancePtSeg2d(&verts[j*3], p1,p2);
maxEdgeDist = rcMax(maxEdgeDist, d);
}
minDist = rcMin(minDist, maxEdgeDist);
}
return rcSqrt(minDist);
}
// Last time I checked the if version got compiled using cmov, which was a lot faster than module (with idiv).
inline int prev(int i, int n) { return i-1 >= 0 ? i-1 : n-1; }
inline int next(int i, int n) { return i+1 < n ? i+1 : 0; }
static void triangulateHull(const int /*nverts*/, const float* verts, const int nhull, const int* hull, const int nin, rcIntArray& tris)
{
int start = 0, left = 1, right = nhull-1;
// Start from an ear with shortest perimeter.
// This tends to favor well formed triangles as starting point.
float dmin = FLT_MAX;
for (int i = 0; i < nhull; i++)
{
if (hull[i] >= nin) continue; // Ears are triangles with original vertices as middle vertex while others are actually line segments on edges
int pi = prev(i, nhull);
int ni = next(i, nhull);
const float* pv = &verts[hull[pi]*3];
const float* cv = &verts[hull[i]*3];
const float* nv = &verts[hull[ni]*3];
const float d = vdist2(pv,cv) + vdist2(cv,nv) + vdist2(nv,pv);
if (d < dmin)
{
start = i;
left = ni;
right = pi;
dmin = d;
}
}
// Add first triangle
tris.push(hull[start]);
tris.push(hull[left]);
tris.push(hull[right]);
tris.push(0);
// Triangulate the polygon by moving left or right,
// depending on which triangle has shorter perimeter.
// This heuristic was chose emprically, since it seems
// handle tesselated straight edges well.
while (next(left, nhull) != right)
{
// Check to see if se should advance left or right.
int nleft = next(left, nhull);
int nright = prev(right, nhull);
const float* cvleft = &verts[hull[left]*3];
const float* nvleft = &verts[hull[nleft]*3];
const float* cvright = &verts[hull[right]*3];
const float* nvright = &verts[hull[nright]*3];
const float dleft = vdist2(cvleft, nvleft) + vdist2(nvleft, cvright);
const float dright = vdist2(cvright, nvright) + vdist2(cvleft, nvright);
if (dleft < dright)
{
tris.push(hull[left]);
tris.push(hull[nleft]);
tris.push(hull[right]);
tris.push(0);
left = nleft;
}
else
{
tris.push(hull[left]);
tris.push(hull[nright]);
tris.push(hull[right]);
tris.push(0);
right = nright;
}
}
}
inline float getJitterX(const int i)
{
return (((i * 0x8da6b343) & 0xffff) / 65535.0f * 2.0f) - 1.0f;
}
inline float getJitterY(const int i)
{
return (((i * 0xd8163841) & 0xffff) / 65535.0f * 2.0f) - 1.0f;
}
static bool buildPolyDetail(rcContext* ctx, const float* in, const int nin,
const float sampleDist, const float sampleMaxError,
const int heightSearchRadius, const rcCompactHeightfield& chf,
const rcHeightPatch& hp, float* verts, int& nverts,
rcIntArray& tris, rcIntArray& edges, rcIntArray& samples)
{
static const int MAX_VERTS = 127;
static const int MAX_TRIS = 255; // Max tris for delaunay is 2n-2-k (n=num verts, k=num hull verts).
static const int MAX_VERTS_PER_EDGE = 32;
float edge[(MAX_VERTS_PER_EDGE+1)*3];
int hull[MAX_VERTS];
int nhull = 0;
nverts = nin;
for (int i = 0; i < nin; ++i)
rcVcopy(&verts[i*3], &in[i*3]);
edges.clear();
tris.clear();
const float cs = chf.cs;
const float ics = 1.0f/cs;
// Calculate minimum extents of the polygon based on input data.
float minExtent = polyMinExtent(verts, nverts);
// Tessellate outlines.
// This is done in separate pass in order to ensure
// seamless height values across the ply boundaries.
if (sampleDist > 0)
{
for (int i = 0, j = nin-1; i < nin; j=i++)
{
const float* vj = &in[j*3];
const float* vi = &in[i*3];
bool swapped = false;
// Make sure the segments are always handled in same order
// using lexological sort or else there will be seams.
if (fabsf(vj[0]-vi[0]) < 1e-6f)
{
if (vj[2] > vi[2])
{
rcSwap(vj,vi);
swapped = true;
}
}
else
{
if (vj[0] > vi[0])
{
rcSwap(vj,vi);
swapped = true;
}
}
// Create samples along the edge.
float dx = vi[0] - vj[0];
float dy = vi[1] - vj[1];
float dz = vi[2] - vj[2];
float d = sqrtf(dx*dx + dz*dz);
int nn = 1 + (int)floorf(d/sampleDist);
if (nn >= MAX_VERTS_PER_EDGE) nn = MAX_VERTS_PER_EDGE-1;
if (nverts+nn >= MAX_VERTS)
nn = MAX_VERTS-1-nverts;
for (int k = 0; k <= nn; ++k)
{
float u = (float)k/(float)nn;
float* pos = &edge[k*3];
pos[0] = vj[0] + dx*u;
pos[1] = vj[1] + dy*u;
pos[2] = vj[2] + dz*u;
pos[1] = getHeight(pos[0],pos[1],pos[2], cs, ics, chf.ch, heightSearchRadius, hp)*chf.ch;
}
// Simplify samples.
int idx[MAX_VERTS_PER_EDGE] = {0,nn};
int nidx = 2;
for (int k = 0; k < nidx-1; )
{
const int a = idx[k];
const int b = idx[k+1];
const float* va = &edge[a*3];
const float* vb = &edge[b*3];
// Find maximum deviation along the segment.
float maxd = 0;
int maxi = -1;
for (int m = a+1; m < b; ++m)
{
float dev = distancePtSeg(&edge[m*3],va,vb);
if (dev > maxd)
{
maxd = dev;
maxi = m;
}
}
// If the max deviation is larger than accepted error,
// add new point, else continue to next segment.
if (maxi != -1 && maxd > rcSqr(sampleMaxError))
{
for (int m = nidx; m > k; --m)
idx[m] = idx[m-1];
idx[k+1] = maxi;
nidx++;
}
else
{
++k;
}
}
hull[nhull++] = j;
// Add new vertices.
if (swapped)
{
for (int k = nidx-2; k > 0; --k)
{
rcVcopy(&verts[nverts*3], &edge[idx[k]*3]);
hull[nhull++] = nverts;
nverts++;
}
}
else
{
for (int k = 1; k < nidx-1; ++k)
{
rcVcopy(&verts[nverts*3], &edge[idx[k]*3]);
hull[nhull++] = nverts;
nverts++;
}
}
}
}
// If the polygon minimum extent is small (sliver or small triangle), do not try to add internal points.
if (minExtent < sampleDist*2)
{
triangulateHull(nverts, verts, nhull, hull, nin, tris);
return true;
}
// Tessellate the base mesh.
// We're using the triangulateHull instead of delaunayHull as it tends to
// create a bit better triangulation for long thin triangles when there
// are no internal points.
triangulateHull(nverts, verts, nhull, hull, nin, tris);
if (tris.size() == 0)
{
// Could not triangulate the poly, make sure there is some valid data there.
ctx->log(RC_LOG_WARNING, "buildPolyDetail: Could not triangulate polygon (%d verts).", nverts);
return true;
}
if (sampleDist > 0)
{
// Create sample locations in a grid.
float bmin[3], bmax[3];
rcVcopy(bmin, in);
rcVcopy(bmax, in);
for (int i = 1; i < nin; ++i)
{
rcVmin(bmin, &in[i*3]);
rcVmax(bmax, &in[i*3]);
}
int x0 = (int)floorf(bmin[0]/sampleDist);
int x1 = (int)ceilf(bmax[0]/sampleDist);
int z0 = (int)floorf(bmin[2]/sampleDist);
int z1 = (int)ceilf(bmax[2]/sampleDist);
samples.clear();
for (int z = z0; z < z1; ++z)
{
for (int x = x0; x < x1; ++x)
{
float pt[3];
pt[0] = x*sampleDist;
pt[1] = (bmax[1]+bmin[1])*0.5f;
pt[2] = z*sampleDist;
// Make sure the samples are not too close to the edges.
if (distToPoly(nin,in,pt) > -sampleDist/2) continue;
samples.push(x);
samples.push(getHeight(pt[0], pt[1], pt[2], cs, ics, chf.ch, heightSearchRadius, hp));
samples.push(z);
samples.push(0); // Not added
}
}
// Add the samples starting from the one that has the most
// error. The procedure stops when all samples are added
// or when the max error is within treshold.
const int nsamples = samples.size()/4;
for (int iter = 0; iter < nsamples; ++iter)
{
if (nverts >= MAX_VERTS)
break;
// Find sample with most error.
float bestpt[3] = {0,0,0};
float bestd = 0;
int besti = -1;
for (int i = 0; i < nsamples; ++i)
{
const int* s = &samples[i*4];
if (s[3]) continue; // skip added.
float pt[3];
// The sample location is jittered to get rid of some bad triangulations
// which are cause by symmetrical data from the grid structure.
pt[0] = s[0]*sampleDist + getJitterX(i)*cs*0.1f;
pt[1] = s[1]*chf.ch;
pt[2] = s[2]*sampleDist + getJitterY(i)*cs*0.1f;
float d = distToTriMesh(pt, verts, nverts, &tris[0], tris.size()/4);
if (d < 0) continue; // did not hit the mesh.
if (d > bestd)
{
bestd = d;
besti = i;
rcVcopy(bestpt,pt);
}
}
// If the max error is within accepted threshold, stop tesselating.
if (bestd <= sampleMaxError || besti == -1)
break;
// Mark sample as added.
samples[besti*4+3] = 1;
// Add the new sample point.
rcVcopy(&verts[nverts*3],bestpt);
nverts++;
// Create new triangulation.
// TODO: Incremental add instead of full rebuild.
edges.clear();
tris.clear();
delaunayHull(ctx, nverts, verts, nhull, hull, tris, edges);
}
}
const int ntris = tris.size()/4;
if (ntris > MAX_TRIS)
{
tris.resize(MAX_TRIS*4);
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Shrinking triangle count from %d to max %d.", ntris, MAX_TRIS);
}
return true;
}
static void seedArrayWithPolyCenter(rcContext* ctx, const rcCompactHeightfield& chf,
const unsigned short* poly, const int npoly,
const unsigned short* verts, const int bs,
rcHeightPatch& hp, rcIntArray& array)
{
// Note: Reads to the compact heightfield are offset by border size (bs)
// since border size offset is already removed from the polymesh vertices.
static const int offset[9*2] =
{
0,0, -1,-1, 0,-1, 1,-1, 1,0, 1,1, 0,1, -1,1, -1,0,
};
// Find cell closest to a poly vertex
int startCellX = 0, startCellY = 0, startSpanIndex = -1;
int dmin = RC_UNSET_HEIGHT;
for (int j = 0; j < npoly && dmin > 0; ++j)
{
for (int k = 0; k < 9 && dmin > 0; ++k)
{
const int ax = (int)verts[poly[j]*3+0] + offset[k*2+0];
const int ay = (int)verts[poly[j]*3+1];
const int az = (int)verts[poly[j]*3+2] + offset[k*2+1];
if (ax < hp.xmin || ax >= hp.xmin+hp.width ||
az < hp.ymin || az >= hp.ymin+hp.height)
continue;
const rcCompactCell& c = chf.cells[(ax+bs)+(az+bs)*chf.width];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni && dmin > 0; ++i)
{
const rcCompactSpan& s = chf.spans[i];
int d = rcAbs(ay - (int)s.y);
if (d < dmin)
{
startCellX = ax;
startCellY = az;
startSpanIndex = i;
dmin = d;
}
}
}
}
rcAssert(startSpanIndex != -1);
// Find center of the polygon
int pcx = 0, pcy = 0;
for (int j = 0; j < npoly; ++j)
{
pcx += (int)verts[poly[j]*3+0];
pcy += (int)verts[poly[j]*3+2];
}
pcx /= npoly;
pcy /= npoly;
// Use seeds array as a stack for DFS
array.clear();
array.push(startCellX);
array.push(startCellY);
array.push(startSpanIndex);
int dirs[] = { 0, 1, 2, 3 };
memset(hp.data, 0, sizeof(unsigned short)*hp.width*hp.height);
// DFS to move to the center. Note that we need a DFS here and can not just move
// directly towards the center without recording intermediate nodes, even though the polygons
// are convex. In very rare we can get stuck due to contour simplification if we do not
// record nodes.
int cx = -1, cy = -1, ci = -1;
while (true)
{
if (array.size() < 3)
{
ctx->log(RC_LOG_WARNING, "Walk towards polygon center failed to reach center");
break;
}
ci = array.pop();
cy = array.pop();
cx = array.pop();
if (cx == pcx && cy == pcy)
break;
// If we are already at the correct X-position, prefer direction
// directly towards the center in the Y-axis; otherwise prefer
// direction in the X-axis
int directDir;
if (cx == pcx)
directDir = rcGetDirForOffset(0, pcy > cy ? 1 : -1);
else
directDir = rcGetDirForOffset(pcx > cx ? 1 : -1, 0);
// Push the direct dir last so we start with this on next iteration
rcSwap(dirs[directDir], dirs[3]);
const rcCompactSpan& cs = chf.spans[ci];
for (int i = 0; i < 4; i++)
{
int dir = dirs[i];
if (rcGetCon(cs, dir) == RC_NOT_CONNECTED)
continue;
int newX = cx + rcGetDirOffsetX(dir);
int newY = cy + rcGetDirOffsetY(dir);
int hpx = newX - hp.xmin;
int hpy = newY - hp.ymin;
if (hpx < 0 || hpx >= hp.width || hpy < 0 || hpy >= hp.height)
continue;
if (hp.data[hpx+hpy*hp.width] != 0)
continue;
hp.data[hpx+hpy*hp.width] = 1;
array.push(newX);
array.push(newY);
array.push((int)chf.cells[(newX+bs)+(newY+bs)*chf.width].index + rcGetCon(cs, dir));
}
rcSwap(dirs[directDir], dirs[3]);
}
array.clear();
// getHeightData seeds are given in coordinates with borders
array.push(cx+bs);
array.push(cy+bs);
array.push(ci);
memset(hp.data, 0xff, sizeof(unsigned short)*hp.width*hp.height);
const rcCompactSpan& cs = chf.spans[ci];
hp.data[cx-hp.xmin+(cy-hp.ymin)*hp.width] = cs.y;
}
static void push3(rcIntArray& queue, int v1, int v2, int v3)
{
queue.resize(queue.size() + 3);
queue[queue.size() - 3] = v1;
queue[queue.size() - 2] = v2;
queue[queue.size() - 1] = v3;
}
static void getHeightData(rcContext* ctx, const rcCompactHeightfield& chf,
const unsigned short* poly, const int npoly,
const unsigned short* verts, const int bs,
rcHeightPatch& hp, rcIntArray& queue,
int region)
{
// Note: Reads to the compact heightfield are offset by border size (bs)
// since border size offset is already removed from the polymesh vertices.
queue.clear();
// Set all heights to RC_UNSET_HEIGHT.
memset(hp.data, 0xff, sizeof(unsigned short)*hp.width*hp.height);
bool empty = true;
// We cannot sample from this poly if it was created from polys
// of different regions. If it was then it could potentially be overlapping
// with polys of that region and the heights sampled here could be wrong.
if (region != RC_MULTIPLE_REGS)
{
// Copy the height from the same region, and mark region borders
// as seed points to fill the rest.
for (int hy = 0; hy < hp.height; hy++)
{
int y = hp.ymin + hy + bs;
for (int hx = 0; hx < hp.width; hx++)
{
int x = hp.xmin + hx + bs;
const rcCompactCell& c = chf.cells[x + y*chf.width];
for (int i = (int)c.index, ni = (int)(c.index + c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
if (s.reg == region)
{
// Store height
hp.data[hx + hy*hp.width] = s.y;
empty = false;
// If any of the neighbours is not in same region,
// add the current location as flood fill start
bool border = false;
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax + ay*chf.width].index + rcGetCon(s, dir);
const rcCompactSpan& as = chf.spans[ai];
if (as.reg != region)
{
border = true;
break;
}
}
}
if (border)
push3(queue, x, y, i);
break;
}
}
}
}
}
// if the polygon does not contain any points from the current region (rare, but happens)
// or if it could potentially be overlapping polygons of the same region,
// then use the center as the seed point.
if (empty)
seedArrayWithPolyCenter(ctx, chf, poly, npoly, verts, bs, hp, queue);
static const int RETRACT_SIZE = 256;
int head = 0;
// We assume the seed is centered in the polygon, so a BFS to collect
// height data will ensure we do not move onto overlapping polygons and
// sample wrong heights.
while (head*3 < queue.size())
{
int cx = queue[head*3+0];
int cy = queue[head*3+1];
int ci = queue[head*3+2];
head++;
if (head >= RETRACT_SIZE)
{
head = 0;
if (queue.size() > RETRACT_SIZE*3)
memmove(&queue[0], &queue[RETRACT_SIZE*3], sizeof(int)*(queue.size()-RETRACT_SIZE*3));
queue.resize(queue.size()-RETRACT_SIZE*3);
}
const rcCompactSpan& cs = chf.spans[ci];
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(cs, dir) == RC_NOT_CONNECTED) continue;
const int ax = cx + rcGetDirOffsetX(dir);
const int ay = cy + rcGetDirOffsetY(dir);
const int hx = ax - hp.xmin - bs;
const int hy = ay - hp.ymin - bs;
if ((unsigned int)hx >= (unsigned int)hp.width || (unsigned int)hy >= (unsigned int)hp.height)
continue;
if (hp.data[hx + hy*hp.width] != RC_UNSET_HEIGHT)
continue;
const int ai = (int)chf.cells[ax + ay*chf.width].index + rcGetCon(cs, dir);
const rcCompactSpan& as = chf.spans[ai];
hp.data[hx + hy*hp.width] = as.y;
push3(queue, ax, ay, ai);
}
}
}
static unsigned char getEdgeFlags(const float* va, const float* vb,
const float* vpoly, const int npoly)
{
// The flag returned by this function matches dtDetailTriEdgeFlags in Detour.
// Figure out if edge (va,vb) is part of the polygon boundary.
static const float thrSqr = rcSqr(0.001f);
for (int i = 0, j = npoly-1; i < npoly; j=i++)
{
if (distancePtSeg2d(va, &vpoly[j*3], &vpoly[i*3]) < thrSqr &&
distancePtSeg2d(vb, &vpoly[j*3], &vpoly[i*3]) < thrSqr)
return 1;
}
return 0;
}
static unsigned char getTriFlags(const float* va, const float* vb, const float* vc,
const float* vpoly, const int npoly)
{
unsigned char flags = 0;
flags |= getEdgeFlags(va,vb,vpoly,npoly) << 0;
flags |= getEdgeFlags(vb,vc,vpoly,npoly) << 2;
flags |= getEdgeFlags(vc,va,vpoly,npoly) << 4;
return flags;
}
/// @par
///
/// See the #rcConfig documentation for more information on the configuration parameters.
///
/// @see rcAllocPolyMeshDetail, rcPolyMesh, rcCompactHeightfield, rcPolyMeshDetail, rcConfig
bool rcBuildPolyMeshDetail(rcContext* ctx, const rcPolyMesh& mesh, const rcCompactHeightfield& chf,
const float sampleDist, const float sampleMaxError,
rcPolyMeshDetail& dmesh)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_POLYMESHDETAIL);
if (mesh.nverts == 0 || mesh.npolys == 0)
return true;
const int nvp = mesh.nvp;
const float cs = mesh.cs;
const float ch = mesh.ch;
const float* orig = mesh.bmin;
const int borderSize = mesh.borderSize;
const int heightSearchRadius = rcMax(1, (int)ceilf(mesh.maxEdgeError));
rcIntArray edges(64);
rcIntArray tris(512);
rcIntArray arr(512);
rcIntArray samples(512);
float verts[256*3];
rcHeightPatch hp;
int nPolyVerts = 0;
int maxhw = 0, maxhh = 0;
rcScopedDelete<int> bounds((int*)rcAlloc(sizeof(int)*mesh.npolys*4, RC_ALLOC_TEMP));
if (!bounds)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'bounds' (%d).", mesh.npolys*4);
return false;
}
rcScopedDelete<float> poly((float*)rcAlloc(sizeof(float)*nvp*3, RC_ALLOC_TEMP));
if (!poly)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'poly' (%d).", nvp*3);
return false;
}
// Find max size for a polygon area.
for (int i = 0; i < mesh.npolys; ++i)
{
const unsigned short* p = &mesh.polys[i*nvp*2];
int& xmin = bounds[i*4+0];
int& xmax = bounds[i*4+1];
int& ymin = bounds[i*4+2];
int& ymax = bounds[i*4+3];
xmin = chf.width;
xmax = 0;
ymin = chf.height;
ymax = 0;
for (int j = 0; j < nvp; ++j)
{
if(p[j] == RC_MESH_NULL_IDX) break;
const unsigned short* v = &mesh.verts[p[j]*3];
xmin = rcMin(xmin, (int)v[0]);
xmax = rcMax(xmax, (int)v[0]);
ymin = rcMin(ymin, (int)v[2]);
ymax = rcMax(ymax, (int)v[2]);
nPolyVerts++;
}
xmin = rcMax(0,xmin-1);
xmax = rcMin(chf.width,xmax+1);
ymin = rcMax(0,ymin-1);
ymax = rcMin(chf.height,ymax+1);
if (xmin >= xmax || ymin >= ymax) continue;
maxhw = rcMax(maxhw, xmax-xmin);
maxhh = rcMax(maxhh, ymax-ymin);
}
hp.data = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxhw*maxhh, RC_ALLOC_TEMP);
if (!hp.data)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'hp.data' (%d).", maxhw*maxhh);
return false;
}
dmesh.nmeshes = mesh.npolys;
dmesh.nverts = 0;
dmesh.ntris = 0;
dmesh.meshes = (unsigned int*)rcAlloc(sizeof(unsigned int)*dmesh.nmeshes*4, RC_ALLOC_PERM);
if (!dmesh.meshes)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'dmesh.meshes' (%d).", dmesh.nmeshes*4);
return false;
}
int vcap = nPolyVerts+nPolyVerts/2;
int tcap = vcap*2;
dmesh.nverts = 0;
dmesh.verts = (float*)rcAlloc(sizeof(float)*vcap*3, RC_ALLOC_PERM);
if (!dmesh.verts)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'dmesh.verts' (%d).", vcap*3);
return false;
}
dmesh.ntris = 0;
dmesh.tris = (unsigned char*)rcAlloc(sizeof(unsigned char)*tcap*4, RC_ALLOC_PERM);
if (!dmesh.tris)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'dmesh.tris' (%d).", tcap*4);
return false;
}
for (int i = 0; i < mesh.npolys; ++i)
{
const unsigned short* p = &mesh.polys[i*nvp*2];
// Store polygon vertices for processing.
int npoly = 0;
for (int j = 0; j < nvp; ++j)
{
if(p[j] == RC_MESH_NULL_IDX) break;
const unsigned short* v = &mesh.verts[p[j]*3];
poly[j*3+0] = v[0]*cs;
poly[j*3+1] = v[1]*ch;
poly[j*3+2] = v[2]*cs;
npoly++;
}
// Get the height data from the area of the polygon.
hp.xmin = bounds[i*4+0];
hp.ymin = bounds[i*4+2];
hp.width = bounds[i*4+1]-bounds[i*4+0];
hp.height = bounds[i*4+3]-bounds[i*4+2];
getHeightData(ctx, chf, p, npoly, mesh.verts, borderSize, hp, arr, mesh.regs[i]);
// Build detail mesh.
int nverts = 0;
if (!buildPolyDetail(ctx, poly, npoly,
sampleDist, sampleMaxError,
heightSearchRadius, chf, hp,
verts, nverts, tris,
edges, samples))
{
return false;
}
// Move detail verts to world space.
for (int j = 0; j < nverts; ++j)
{
verts[j*3+0] += orig[0];
verts[j*3+1] += orig[1] + chf.ch; // Is this offset necessary?
verts[j*3+2] += orig[2];
}
// Offset poly too, will be used to flag checking.
for (int j = 0; j < npoly; ++j)
{
poly[j*3+0] += orig[0];
poly[j*3+1] += orig[1];
poly[j*3+2] += orig[2];
}
// Store detail submesh.
const int ntris = tris.size()/4;
dmesh.meshes[i*4+0] = (unsigned int)dmesh.nverts;
dmesh.meshes[i*4+1] = (unsigned int)nverts;
dmesh.meshes[i*4+2] = (unsigned int)dmesh.ntris;
dmesh.meshes[i*4+3] = (unsigned int)ntris;
// Store vertices, allocate more memory if necessary.
if (dmesh.nverts+nverts > vcap)
{
while (dmesh.nverts+nverts > vcap)
vcap += 256;
float* newv = (float*)rcAlloc(sizeof(float)*vcap*3, RC_ALLOC_PERM);
if (!newv)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'newv' (%d).", vcap*3);
return false;
}
if (dmesh.nverts)
memcpy(newv, dmesh.verts, sizeof(float)*3*dmesh.nverts);
rcFree(dmesh.verts);
dmesh.verts = newv;
}
for (int j = 0; j < nverts; ++j)
{
dmesh.verts[dmesh.nverts*3+0] = verts[j*3+0];
dmesh.verts[dmesh.nverts*3+1] = verts[j*3+1];
dmesh.verts[dmesh.nverts*3+2] = verts[j*3+2];
dmesh.nverts++;
}
// Store triangles, allocate more memory if necessary.
if (dmesh.ntris+ntris > tcap)
{
while (dmesh.ntris+ntris > tcap)
tcap += 256;
unsigned char* newt = (unsigned char*)rcAlloc(sizeof(unsigned char)*tcap*4, RC_ALLOC_PERM);
if (!newt)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'newt' (%d).", tcap*4);
return false;
}
if (dmesh.ntris)
memcpy(newt, dmesh.tris, sizeof(unsigned char)*4*dmesh.ntris);
rcFree(dmesh.tris);
dmesh.tris = newt;
}
for (int j = 0; j < ntris; ++j)
{
const int* t = &tris[j*4];
dmesh.tris[dmesh.ntris*4+0] = (unsigned char)t[0];
dmesh.tris[dmesh.ntris*4+1] = (unsigned char)t[1];
dmesh.tris[dmesh.ntris*4+2] = (unsigned char)t[2];
dmesh.tris[dmesh.ntris*4+3] = getTriFlags(&verts[t[0]*3], &verts[t[1]*3], &verts[t[2]*3], poly, npoly);
dmesh.ntris++;
}
}
return true;
}
/// @see rcAllocPolyMeshDetail, rcPolyMeshDetail
bool rcMergePolyMeshDetails(rcContext* ctx, rcPolyMeshDetail** meshes, const int nmeshes, rcPolyMeshDetail& mesh)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_MERGE_POLYMESHDETAIL);
int maxVerts = 0;
int maxTris = 0;
int maxMeshes = 0;
for (int i = 0; i < nmeshes; ++i)
{
if (!meshes[i]) continue;
maxVerts += meshes[i]->nverts;
maxTris += meshes[i]->ntris;
maxMeshes += meshes[i]->nmeshes;
}
mesh.nmeshes = 0;
mesh.meshes = (unsigned int*)rcAlloc(sizeof(unsigned int)*maxMeshes*4, RC_ALLOC_PERM);
if (!mesh.meshes)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'pmdtl.meshes' (%d).", maxMeshes*4);
return false;
}
mesh.ntris = 0;
mesh.tris = (unsigned char*)rcAlloc(sizeof(unsigned char)*maxTris*4, RC_ALLOC_PERM);
if (!mesh.tris)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'dmesh.tris' (%d).", maxTris*4);
return false;
}
mesh.nverts = 0;
mesh.verts = (float*)rcAlloc(sizeof(float)*maxVerts*3, RC_ALLOC_PERM);
if (!mesh.verts)
{
ctx->log(RC_LOG_ERROR, "rcBuildPolyMeshDetail: Out of memory 'dmesh.verts' (%d).", maxVerts*3);
return false;
}
// Merge datas.
for (int i = 0; i < nmeshes; ++i)
{
rcPolyMeshDetail* dm = meshes[i];
if (!dm) continue;
for (int j = 0; j < dm->nmeshes; ++j)
{
unsigned int* dst = &mesh.meshes[mesh.nmeshes*4];
unsigned int* src = &dm->meshes[j*4];
dst[0] = (unsigned int)mesh.nverts+src[0];
dst[1] = src[1];
dst[2] = (unsigned int)mesh.ntris+src[2];
dst[3] = src[3];
mesh.nmeshes++;
}
for (int k = 0; k < dm->nverts; ++k)
{
rcVcopy(&mesh.verts[mesh.nverts*3], &dm->verts[k*3]);
mesh.nverts++;
}
for (int k = 0; k < dm->ntris; ++k)
{
mesh.tris[mesh.ntris*4+0] = dm->tris[k*4+0];
mesh.tris[mesh.ntris*4+1] = dm->tris[k*4+1];
mesh.tris[mesh.ntris*4+2] = dm->tris[k*4+2];
mesh.tris[mesh.ntris*4+3] = dm->tris[k*4+3];
mesh.ntris++;
}
}
return true;
}