/// @par
///
/// This is just the beginning of the process of fully building a compact heightfield.
/// Various filters may be applied, then the distance field and regions built.
/// E.g: #rcBuildDistanceField and #rcBuildRegions
///
/// See the #rcConfig documentation for more information on the configuration parameters.
///
/// @see rcAllocCompactHeightfield, rcHeightfield, rcCompactHeightfield, rcConfig
public static CompactHeightfield buildCompactHeightfield(Context ctx, int walkableHeight, int walkableClimb, Heightfield hf)
{
ctx.startTimer("BUILD_COMPACTHEIGHTFIELD");
CompactHeightfield chf = new CompactHeightfield();
int w = hf.width;
int h = hf.height;
int spanCount = getHeightFieldSpanCount(ctx, hf);
// Fill in header.
chf.width = w;
chf.height = h;
chf.spanCount = spanCount;
chf.walkableHeight = walkableHeight;
chf.walkableClimb = walkableClimb;
chf.maxRegions = 0;
RecastVectors.copy(chf.bmin, hf.bmin);
RecastVectors.copy(chf.bmax, hf.bmax);
chf.bmax[1] += walkableHeight * hf.ch;
chf.cs = hf.cs;
chf.ch = hf.ch;
chf.cells = new CompactCell[w * h];
chf.spans = new CompactSpan[spanCount];
chf.areas = new int[spanCount];
int MAX_HEIGHT = 0xffff;
for (int i = 0; i < chf.cells.Length; i++)
{
chf.cells[i] = new CompactCell();
}
for (int i = 0; i < chf.spans.Length; i++)
{
chf.spans[i] = new CompactSpan();
}
// Fill in cells and spans.
int idx = 0;
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
Span s = hf.spans[x + y * w];
// If there are no spans at this cell, just leave the data to index=0, count=0.
if (s == null)
{
continue;
}
CompactCell c = chf.cells[x + y * w];
c.index = idx;
c.count = 0;
while (s != null)
{
if (s.area != RecastConstants.RC_NULL_AREA)
{
int bot = s.smax;
int top = s.next != null ? (int)s.next.smin : MAX_HEIGHT;
chf.spans[idx].y = RecastCommon.clamp(bot, 0, 0xffff);
chf.spans[idx].h = RecastCommon.clamp(top - bot, 0, 0xff);
chf.areas[idx] = s.area;
idx++;
c.count++;
}
s = s.next;
}
}
}
// Find neighbour connections.
int MAX_LAYERS = RecastConstants.RC_NOT_CONNECTED - 1;
int tooHighNeighbour = 0;
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
CompactCell c = chf.cells[x + y * w];
for (int i = c.index, ni = c.index + c.count; i < ni; ++i)
{
CompactSpan s = chf.spans[i];
for (int dir = 0; dir < 4; ++dir)
{
RecastCommon.SetCon(s, dir, RecastConstants.RC_NOT_CONNECTED);
int nx = x + RecastCommon.GetDirOffsetX(dir);
int ny = y + RecastCommon.GetDirOffsetY(dir);
// First check that the neighbour cell is in bounds.
if (nx < 0 || ny < 0 || nx >= w || ny >= h)
{
continue;
}
// Iterate over all neighbour spans and check if any of the is
// accessible from current cell.
CompactCell nc = chf.cells[nx + ny * w];
for (int k = nc.index, nk = nc.index + nc.count; k < nk; ++k)
{
CompactSpan ns = chf.spans[k];
int bot = Math.Max(s.y, ns.y);
int top = Math.Min(s.y + s.h, ns.y + ns.h);
// Check that the gap between the spans is walkable,
// and that the climb height between the gaps is not too high.
if ((top - bot) >= walkableHeight && Math.Abs(ns.y - s.y) <= walkableClimb)
{
// Mark direction as walkable.
int lidx = k - nc.index;
if (lidx < 0 || lidx > MAX_LAYERS)
{
tooHighNeighbour = Math.Max(tooHighNeighbour, lidx);
continue;
}
RecastCommon.SetCon(s, dir, lidx);
break;
}
}
}
}
}
}
if (tooHighNeighbour > MAX_LAYERS)
{
throw new Exception("rcBuildCompactHeightfield: Heightfield has too many layers " + tooHighNeighbour + " (max: " + MAX_LAYERS + ")");
}
ctx.stopTimer("BUILD_COMPACTHEIGHTFIELD");
return(chf);
}
private static void rasterizeTri(float[] verts, int v0, int v1, int v2, int area, Heightfield hf, float[] bmin, float[] bmax, float cs, float ics, float ich, int flagMergeThr)
{
int w = hf.width;
int h = hf.height;
float[] tmin = new float[3]; float[] tmax = new float[3];
float by = bmax[1] - bmin[1];
// Calculate the bounding box of the triangle.
RecastVectors.copy(tmin, verts, v0 * 3);
RecastVectors.copy(tmax, verts, v0 * 3);
RecastVectors.min(tmin, verts, v1 * 3);
RecastVectors.min(tmin, verts, v2 * 3);
RecastVectors.max(tmax, verts, v1 * 3);
RecastVectors.max(tmax, verts, v2 * 3);
// If the triangle does not touch the bbox of the heightfield, skip the triagle.
if (!overlapBounds(bmin, bmax, tmin, tmax))
{
return;
}
// Calculate the footprint of the triangle on the grid's y-axis
int y0 = (int)((tmin[2] - bmin[2]) * ics);
int y1 = (int)((tmax[2] - bmin[2]) * ics);
y0 = RecastCommon.clamp(y0, 0, h - 1);
y1 = RecastCommon.clamp(y1, 0, h - 1);
// Clip the triangle into all grid cells it touches.
float[] buf = new float[7 * 3 * 4];
int @in = 0;
int inrow = 7 * 3;
int p1 = inrow + 7 * 3;
int p2 = p1 + 7 * 3;
RecastVectors.copy(buf, 0, verts, v0 * 3);
RecastVectors.copy(buf, 3, verts, v1 * 3);
RecastVectors.copy(buf, 6, verts, v2 * 3);
int nvrow, nvIn = 3;
for (int y = y0; y <= y1; ++y)
{
// Clip polygon to row. Store the remaining polygon as well
float cz = bmin[2] + y * cs;
int[] nvrowin = dividePoly(buf, @in, nvIn, inrow, p1, cz + cs, 2);
nvrow = nvrowin[0];
nvIn = nvrowin[1];
{
int temp = @in;
@in = p1;
p1 = temp;
}
if (nvrow < 3)
{
continue;
}
// find the horizontal bounds in the row
float minX = buf[inrow], maxX = buf[inrow];
for (int i = 1; i < nvrow; ++i)
{
if (minX > buf[inrow + i * 3])
{
minX = buf[inrow + i * 3];
}
if (maxX < buf[inrow + i * 3])
{
maxX = buf[inrow + i * 3];
}
}
int x0 = (int)((minX - bmin[0]) * ics);
int x1 = (int)((maxX - bmin[0]) * ics);
x0 = RecastCommon.clamp(x0, 0, w - 1);
x1 = RecastCommon.clamp(x1, 0, w - 1);
int nv, nv2 = nvrow;
for (int x = x0; x <= x1; ++x)
{
// Clip polygon to column. store the remaining polygon as well
float cx = bmin[0] + x * cs;
int[] nvnv2 = dividePoly(buf, inrow, nv2, p1, p2, cx + cs, 0);
nv = nvnv2[0];
nv2 = nvnv2[1];
{
int temp = inrow;
inrow = p2;
p2 = temp;
}
if (nv < 3)
{
continue;
}
// Calculate min and max of the span.
float smin = buf[p1 + 1], smax = buf[p1 + 1];
for (int i = 1; i < nv; ++i)
{
smin = Math.Min(smin, buf[p1 + i * 3 + 1]);
smax = Math.Max(smax, buf[p1 + i * 3 + 1]);
}
smin -= bmin[1];
smax -= bmin[1];
// Skip the span if it is outside the heightfield bbox
if (smax < 0.0f)
{
continue;
}
if (smin > by)
{
continue;
}
// Clamp the span to the heightfield bbox.
if (smin < 0.0f)
{
smin = 0;
}
if (smax > by)
{
smax = by;
}
// Snap the span to the heightfield height grid.
int ismin = RecastCommon.clamp((int)Math.Floor(smin * ich), 0, RecastConstants.RC_SPAN_MAX_HEIGHT);
int ismax = RecastCommon.clamp((int)Math.Ceiling(smax * ich), ismin + 1, RecastConstants.RC_SPAN_MAX_HEIGHT);
addSpan(hf, x, y, ismin, ismax, area, flagMergeThr);
}
}
}
