blender/extern/recastnavigation/Recast/Source/RecastContour.cpp
2010-05-19 01:01:21 +00:00

733 lines
18 KiB
C++

//
// Copyright (c) 2009 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.
//
#define _USE_MATH_DEFINES
#include <math.h>
#include <string.h>
#include <stdio.h>
#include "Recast.h"
#include "RecastLog.h"
#include "RecastTimer.h"
static int getCornerHeight(int x, int y, int i, int dir,
const rcCompactHeightfield& chf,
bool& isBorderVertex)
{
const rcCompactSpan& s = chf.spans[i];
int ch = (int)s.y;
int dirp = (dir+1) & 0x3;
unsigned short regs[4] = {0,0,0,0};
regs[0] = s.reg;
if (rcGetCon(s, dir) != 0xf)
{
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];
ch = rcMax(ch, (int)as.y);
regs[1] = as.reg;
if (rcGetCon(as, dirp) != 0xf)
{
const int ax2 = ax + rcGetDirOffsetX(dirp);
const int ay2 = ay + rcGetDirOffsetY(dirp);
const int ai2 = (int)chf.cells[ax2+ay2*chf.width].index + rcGetCon(as, dirp);
const rcCompactSpan& as2 = chf.spans[ai2];
ch = rcMax(ch, (int)as2.y);
regs[2] = as2.reg;
}
}
if (rcGetCon(s, dirp) != 0xf)
{
const int ax = x + rcGetDirOffsetX(dirp);
const int ay = y + rcGetDirOffsetY(dirp);
const int ai = (int)chf.cells[ax+ay*chf.width].index + rcGetCon(s, dirp);
const rcCompactSpan& as = chf.spans[ai];
ch = rcMax(ch, (int)as.y);
regs[3] = as.reg;
if (rcGetCon(as, dir) != 0xf)
{
const int ax2 = ax + rcGetDirOffsetX(dir);
const int ay2 = ay + rcGetDirOffsetY(dir);
const int ai2 = (int)chf.cells[ax2+ay2*chf.width].index + rcGetCon(as, dir);
const rcCompactSpan& as2 = chf.spans[ai2];
ch = rcMax(ch, (int)as2.y);
regs[2] = as2.reg;
}
}
// Check if the vertex is special edge vertex, these vertices will be removed later.
for (int j = 0; j < 4; ++j)
{
const int a = j;
const int b = (j+1) & 0x3;
const int c = (j+2) & 0x3;
const 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.
const bool twoSameExts = (regs[a] & regs[b] & RC_BORDER_REG) != 0 && regs[a] == regs[b];
const bool twoInts = ((regs[c] | regs[d]) & RC_BORDER_REG) == 0;
const bool noZeros = regs[a] != 0 && regs[b] != 0 && regs[c] != 0 && regs[d] != 0;
if (twoSameExts && twoInts && noZeros)
{
isBorderVertex = true;
break;
}
}
return ch;
}
static void walkContour(int x, int y, int i,
rcCompactHeightfield& chf,
unsigned char* flags, rcIntArray& points)
{
// Choose the first non-connected edge
unsigned char dir = 0;
while ((flags[i] & (1 << dir)) == 0)
dir++;
unsigned char startDir = dir;
int starti = i;
int iter = 0;
while (++iter < 40000)
{
if (flags[i] & (1 << dir))
{
// Choose the edge corner
bool isBorderVertex = false;
int px = x;
int py = getCornerHeight(x, y, i, dir, chf, isBorderVertex);
int pz = y;
switch(dir)
{
case 0: pz++; break;
case 1: px++; pz++; break;
case 2: px++; break;
}
int r = 0;
const rcCompactSpan& s = chf.spans[i];
if (rcGetCon(s, dir) != 0xf)
{
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];
r = (int)as.reg;
}
if (isBorderVertex)
r |= RC_BORDER_VERTEX;
points.push(px);
points.push(py);
points.push(pz);
points.push(r);
flags[i] &= ~(1 << dir); // Remove visited edges
dir = (dir+1) & 0x3; // Rotate CW
}
else
{
int ni = -1;
const int nx = x + rcGetDirOffsetX(dir);
const int ny = y + rcGetDirOffsetY(dir);
const rcCompactSpan& s = chf.spans[i];
if (rcGetCon(s, dir) != 0xf)
{
const rcCompactCell& nc = chf.cells[nx+ny*chf.width];
ni = (int)nc.index + rcGetCon(s, dir);
}
if (ni == -1)
{
// Should not happen.
return;
}
x = nx;
y = ny;
i = ni;
dir = (dir+3) & 0x3; // Rotate CCW
}
if (starti == i && startDir == dir)
{
break;
}
}
}
static float distancePtSeg(int x, int y, int z,
int px, int py, int pz,
int qx, int qy, int qz)
{
/* float pqx = (float)(qx - px);
float pqy = (float)(qy - py);
float pqz = (float)(qz - pz);
float dx = (float)(x - px);
float dy = (float)(y - py);
float dz = (float)(z - pz);
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 = px + t*pqx - x;
dy = py + t*pqy - y;
dz = pz + t*pqz - z;
return dx*dx + dy*dy + dz*dz;*/
float pqx = (float)(qx - px);
float pqz = (float)(qz - pz);
float dx = (float)(x - px);
float dz = (float)(z - pz);
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 = px + t*pqx - x;
dz = pz + t*pqz - z;
return dx*dx + dz*dz;
}
static void simplifyContour(rcIntArray& points, rcIntArray& simplified, float maxError, int maxEdgeLen)
{
// Add initial points.
bool noConnections = true;
for (int i = 0; i < points.size(); i += 4)
{
if ((points[i+3] & 0xffff) != 0)
{
noConnections = false;
break;
}
}
if (noConnections)
{
// 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 = points[0];
int lly = points[1];
int llz = points[2];
int lli = 0;
int urx = points[0];
int ury = points[1];
int urz = points[2];
int uri = 0;
for (int i = 0; i < points.size(); i += 4)
{
int x = points[i+0];
int y = points[i+1];
int z = points[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.push(llx);
simplified.push(lly);
simplified.push(llz);
simplified.push(lli);
simplified.push(urx);
simplified.push(ury);
simplified.push(urz);
simplified.push(uri);
}
else
{
// The contour has some portals to other regions.
// Add a new point to every location where the region changes.
for (int i = 0, ni = points.size()/4; i < ni; ++i)
{
int ii = (i+1) % ni;
if ((points[i*4+3] & 0xffff) != (points[ii*4+3] & 0xffff))
{
simplified.push(points[i*4+0]);
simplified.push(points[i*4+1]);
simplified.push(points[i*4+2]);
simplified.push(i);
}
}
}
// Add points until all raw points are within
// error tolerance to the simplified shape.
const int pn = points.size()/4;
for (int i = 0; i < simplified.size()/4; )
{
int ii = (i+1) % (simplified.size()/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 = (ai+1) % pn;
// Tesselate only outer edges.
if ((points[ci*4+3] & 0xffff) == 0)
{
while (ci != bi)
{
float d = distancePtSeg(points[ci*4+0], points[ci*4+1]/4, points[ci*4+2],
ax, ay/4, az, bx, by/4, bz);
if (d > maxd)
{
maxd = d;
maxi = ci;
}
ci = (ci+1) % pn;
}
}
// If the max deviation is larger than accepted error,
// add new point, else continue to next segment.
if (maxi != -1 && maxd > (maxError*maxError))
{
// Add space for the new point.
simplified.resize(simplified.size()+4);
int n = simplified.size()/4;
for (int j = n-1; j > i; --j)
{
simplified[j*4+0] = simplified[(j-1)*4+0];
simplified[j*4+1] = simplified[(j-1)*4+1];
simplified[j*4+2] = simplified[(j-1)*4+2];
simplified[j*4+3] = simplified[(j-1)*4+3];
}
// Add the point.
simplified[(i+1)*4+0] = points[maxi*4+0];
simplified[(i+1)*4+1] = points[maxi*4+1];
simplified[(i+1)*4+2] = points[maxi*4+2];
simplified[(i+1)*4+3] = maxi;
}
else
{
++i;
}
}
// Split too long edges.
if (maxEdgeLen > 0)
{
for (int i = 0; i < simplified.size()/4; )
{
int ii = (i+1) % (simplified.size()/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;
// Tesselate only outer edges.
if ((points[ci*4+3] & 0xffff) == 0)
{
int dx = bx - ax;
int dz = bz - az;
if (dx*dx + dz*dz > maxEdgeLen*maxEdgeLen)
{
int n = bi < ai ? (bi+pn - ai) : (bi - ai);
maxi = (ai + n/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);
int n = simplified.size()/4;
for (int j = n-1; j > i; --j)
{
simplified[j*4+0] = simplified[(j-1)*4+0];
simplified[j*4+1] = simplified[(j-1)*4+1];
simplified[j*4+2] = simplified[(j-1)*4+2];
simplified[j*4+3] = simplified[(j-1)*4+3];
}
// Add the point.
simplified[(i+1)*4+0] = points[maxi*4+0];
simplified[(i+1)*4+1] = points[maxi*4+1];
simplified[(i+1)*4+2] = points[maxi*4+2];
simplified[(i+1)*4+3] = maxi;
}
else
{
++i;
}
}
}
for (int i = 0; i < simplified.size()/4; ++i)
{
// The edge vertex flag is take from the current raw point,
// and the neighbour region is take from the next raw point.
const int ai = (simplified[i*4+3]+1) % pn;
const int bi = simplified[i*4+3];
simplified[i*4+3] = (points[ai*4+3] & 0xffff) | (points[bi*4+3] & RC_BORDER_VERTEX);
}
}
static void removeDegenerateSegments(rcIntArray& simplified)
{
// Remove adjacent vertices which are equal on xz-plane,
// or else the triangulator will get confused.
for (int i = 0; i < simplified.size()/4; ++i)
{
int ni = i+1;
if (ni >= (simplified.size()/4))
ni = 0;
if (simplified[i*4+0] == simplified[ni*4+0] &&
simplified[i*4+2] == simplified[ni*4+2])
{
// Degenerate segment, remove.
for (int j = i; j < simplified.size()/4-1; ++j)
{
simplified[j*4+0] = simplified[(j+1)*4+0];
simplified[j*4+1] = simplified[(j+1)*4+1];
simplified[j*4+2] = simplified[(j+1)*4+2];
simplified[j*4+3] = simplified[(j+1)*4+3];
}
simplified.pop();
}
}
}
static int calcAreaOfPolygon2D(const int* verts, const int nverts)
{
int area = 0;
for (int i = 0, j = nverts-1; i < nverts; j=i++)
{
const int* vi = &verts[i*4];
const int* vj = &verts[j*4];
area += vi[0] * vj[2] - vj[0] * vi[2];
}
return (area+1) / 2;
}
static void getClosestIndices(const int* vertsa, const int nvertsa,
const int* vertsb, const int nvertsb,
int& ia, int& ib)
{
int closestDist = 0xfffffff;
for (int i = 0; i < nvertsa; ++i)
{
const int* va = &vertsa[i*4];
for (int j = 0; j < nvertsb; ++j)
{
const int* vb = &vertsb[j*4];
const int dx = vb[0] - va[0];
const int dz = vb[2] - va[2];
const int d = dx*dx + dz*dz;
if (d < closestDist)
{
ia = i;
ib = j;
closestDist = d;
}
}
}
}
static bool mergeContours(rcContour& ca, rcContour& cb, int ia, int ib)
{
const int maxVerts = ca.nverts + cb.nverts + 2;
int* verts = new int[maxVerts*4];
if (!verts)
return false;
int nv = 0;
// Copy contour A.
for (int i = 0; i <= ca.nverts; ++i)
{
int* dst = &verts[nv*4];
const int* src = &ca.verts[((ia+i)%ca.nverts)*4];
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
nv++;
}
// Copy contour B
for (int i = 0; i <= cb.nverts; ++i)
{
int* dst = &verts[nv*4];
const int* src = &cb.verts[((ib+i)%cb.nverts)*4];
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
nv++;
}
delete [] ca.verts;
ca.verts = verts;
ca.nverts = nv;
delete [] cb.verts;
cb.verts = 0;
cb.nverts = 0;
return true;
}
bool rcBuildContours(rcCompactHeightfield& chf,
const float maxError, const int maxEdgeLen,
rcContourSet& cset)
{
const int w = chf.width;
const int h = chf.height;
rcTimeVal startTime = rcGetPerformanceTimer();
vcopy(cset.bmin, chf.bmin);
vcopy(cset.bmax, chf.bmax);
cset.cs = chf.cs;
cset.ch = chf.ch;
const int maxContours = chf.maxRegions*2;
cset.conts = new rcContour[maxContours];
if (!cset.conts)
return false;
cset.nconts = 0;
unsigned char* flags = new unsigned char[chf.spanCount];
if (!flags)
{
if (rcGetLog())
rcGetLog()->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'flags'.");
return false;
}
rcTimeVal traceStartTime = rcGetPerformanceTimer();
// Mark boundaries.
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
unsigned char res = 0;
const rcCompactSpan& s = chf.spans[i];
if (!s.reg || (s.reg & RC_BORDER_REG))
{
flags[i] = 0;
continue;
}
for (int dir = 0; dir < 4; ++dir)
{
unsigned short r = 0;
if (rcGetCon(s, dir) != 0xf)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
const rcCompactSpan& as = chf.spans[ai];
r = as.reg;
}
if (r == s.reg)
res |= (1 << dir);
}
flags[i] = res ^ 0xf; // Inverse, mark non connected edges.
}
}
}
rcTimeVal traceEndTime = rcGetPerformanceTimer();
rcTimeVal simplifyStartTime = rcGetPerformanceTimer();
rcIntArray verts(256);
rcIntArray simplified(64);
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (flags[i] == 0 || flags[i] == 0xf)
{
flags[i] = 0;
continue;
}
unsigned short reg = chf.spans[i].reg;
if (!reg || (reg & RC_BORDER_REG))
continue;
verts.resize(0);
simplified.resize(0);
walkContour(x, y, i, chf, flags, verts);
simplifyContour(verts, simplified, maxError, maxEdgeLen);
removeDegenerateSegments(simplified);
// Store region->contour remap info.
// Create contour.
if (simplified.size()/4 >= 3)
{
if (cset.nconts >= maxContours)
{
if (rcGetLog())
rcGetLog()->log(RC_LOG_ERROR, "rcBuildContours: Too many contours %d, max %d.", cset.nconts, maxContours);
return false;
}
rcContour* cont = &cset.conts[cset.nconts++];
cont->nverts = simplified.size()/4;
cont->verts = new int[cont->nverts*4];
memcpy(cont->verts, &simplified[0], sizeof(int)*cont->nverts*4);
cont->nrverts = verts.size()/4;
cont->rverts = new int[cont->nrverts*4];
memcpy(cont->rverts, &verts[0], sizeof(int)*cont->nrverts*4);
/* cont->cx = cont->cy = cont->cz = 0;
for (int i = 0; i < cont->nverts; ++i)
{
cont->cx += cont->verts[i*4+0];
cont->cy += cont->verts[i*4+1];
cont->cz += cont->verts[i*4+2];
}
cont->cx /= cont->nverts;
cont->cy /= cont->nverts;
cont->cz /= cont->nverts;*/
cont->reg = reg;
}
}
}
}
// Check and merge droppings.
// Sometimes the previous algorithms can fail and create several countours
// per area. This pass will try to merge the holes into the main region.
for (int i = 0; i < cset.nconts; ++i)
{
rcContour& cont = cset.conts[i];
// Check if the contour is would backwards.
if (calcAreaOfPolygon2D(cont.verts, cont.nverts) < 0)
{
// Find another contour which has the same region ID.
int mergeIdx = -1;
for (int j = 0; j < cset.nconts; ++j)
{
if (i == j) continue;
if (cset.conts[j].nverts && cset.conts[j].reg == cont.reg)
{
// Make sure the polygon is correctly oriented.
if (calcAreaOfPolygon2D(cset.conts[j].verts, cset.conts[j].nverts))
{
mergeIdx = j;
break;
}
}
}
if (mergeIdx == -1)
{
if (rcGetLog())
rcGetLog()->log(RC_LOG_WARNING, "rcBuildContours: Could not find merge target for bad contour %d.", i);
}
else
{
rcContour& mcont = cset.conts[mergeIdx];
// Merge by closest points.
int ia, ib;
getClosestIndices(mcont.verts, mcont.nverts, cont.verts, cont.nverts, ia, ib);
if (!mergeContours(mcont, cont, ia, ib))
{
if (rcGetLog())
rcGetLog()->log(RC_LOG_WARNING, "rcBuildContours: Failed to merge contours %d and %d.", i, mergeIdx);
}
}
}
}
delete [] flags;
rcTimeVal simplifyEndTime = rcGetPerformanceTimer();
rcTimeVal endTime = rcGetPerformanceTimer();
// if (rcGetLog())
// {
// rcGetLog()->log(RC_LOG_PROGRESS, "Create contours: %.3f ms", rcGetDeltaTimeUsec(startTime, endTime)/1000.0f);
// rcGetLog()->log(RC_LOG_PROGRESS, " - boundary: %.3f ms", rcGetDeltaTimeUsec(boundaryStartTime, boundaryEndTime)/1000.0f);
// rcGetLog()->log(RC_LOG_PROGRESS, " - contour: %.3f ms", rcGetDeltaTimeUsec(contourStartTime, contourEndTime)/1000.0f);
// }
if (rcGetBuildTimes())
{
rcGetBuildTimes()->buildContours += rcGetDeltaTimeUsec(startTime, endTime);
rcGetBuildTimes()->buildContoursTrace += rcGetDeltaTimeUsec(traceStartTime, traceEndTime);
rcGetBuildTimes()->buildContoursSimplify += rcGetDeltaTimeUsec(simplifyStartTime, simplifyEndTime);
}
return true;
}