internal static int getHeightFieldSpanCount(Context ctx, Heightfield hf)
{
int w = hf.width;
int h = hf.height;
int spanCount = 0;
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
for (Span s = hf.spans[x + y * w]; s != null; s = s.next)
{
if (s.area != RecastConstants.RC_NULL_AREA)
{
spanCount++;
}
}
}
}
return(spanCount);
}
/// @par
///
/// A ledge is a span with one or more neighbors whose maximum is further away than @p walkableClimb
/// from the current span's maximum.
/// This method removes the impact of the overestimation of conservative voxelization
/// so the resulting mesh will not have regions hanging in the air over ledges.
///
/// A span is a ledge if: <tt>rcAbs(currentSpan.smax - neighborSpan.smax) > walkableClimb</tt>
///
/// @see rcHeightfield, rcConfig
public static void filterLedgeSpans(Context ctx, int walkableHeight, int walkableClimb, Heightfield solid)
{
ctx.startTimer("FILTER_BORDER");
int w = solid.width;
int h = solid.height;
int MAX_HEIGHT = 0xffff;
// Mark border spans.
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
for (Span s = solid.spans[x + y * w]; s != null; s = s.next)
{
// Skip non walkable spans.
if (s.area == RecastConstants.RC_NULL_AREA)
{
continue;
}
int bot = (s.smax);
int top = s.next != null ? s.next.smin : MAX_HEIGHT;
// Find neighbours minimum height.
int minh = MAX_HEIGHT;
// Min and max height of accessible neighbours.
int asmin = s.smax;
int asmax = s.smax;
for (int dir = 0; dir < 4; ++dir)
{
int dx = x + RecastCommon.GetDirOffsetX(dir);
int dy = y + RecastCommon.GetDirOffsetY(dir);
// Skip neighbours which are out of bounds.
if (dx < 0 || dy < 0 || dx >= w || dy >= h)
{
minh = Math.Min(minh, -walkableClimb - bot);
continue;
}
// From minus infinity to the first span.
Span ns = solid.spans[dx + dy * w];
int nbot = -walkableClimb;
int ntop = ns != null ? ns.smin : MAX_HEIGHT;
// Skip neightbour if the gap between the spans is too small.
if (Math.Min(top, ntop) - Math.Max(bot, nbot) > walkableHeight)
{
minh = Math.Min(minh, nbot - bot);
}
// Rest of the spans.
for (ns = solid.spans[dx + dy * w]; ns != null; ns = ns.next)
{
nbot = ns.smax;
ntop = ns.next != null ? ns.next.smin : MAX_HEIGHT;
// Skip neightbour if the gap between the spans is too small.
if (Math.Min(top, ntop) - Math.Max(bot, nbot) > walkableHeight)
{
minh = Math.Min(minh, nbot - bot);
// Find min/max accessible neighbour height.
if (Math.Abs(nbot - bot) <= walkableClimb)
{
if (nbot < asmin)
{
asmin = nbot;
}
if (nbot > asmax)
{
asmax = nbot;
}
}
}
}
}
// The current span is close to a ledge if the drop to any
// neighbour span is less than the walkableClimb.
if (minh < -walkableClimb)
{
s.area = RecastConstants.RC_NULL_AREA;
}
// If the difference between all neighbours is too large,
// we are at steep slope, mark the span as ledge.
if ((asmax - asmin) > walkableClimb)
{
s.area = RecastConstants.RC_NULL_AREA;
}
}
}
}
ctx.stopTimer("FILTER_BORDER");
}
/// @par
///
/// Allows the formation of walkable regions that will flow over low lying
/// objects such as curbs, and up structures such as stairways.
///
/// Two neighboring spans are walkable if: <tt>rcAbs(currentSpan.smax - neighborSpan.smax) < waklableClimb</tt>
///
/// @warning Will override the effect of #rcFilterLedgeSpans. So if both filters are used, call
/// #rcFilterLedgeSpans after calling this filter.
///
/// @see rcHeightfield, rcConfig
public static void filterLowHangingWalkableObstacles(Context ctx, int walkableClimb, Heightfield solid)
{
ctx.startTimer("FILTER_LOW_OBSTACLES");
int w = solid.width;
int h = solid.height;
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
Span ps = null;
bool previousWalkable = false;
int previousArea = RecastConstants.RC_NULL_AREA;
for (Span s = solid.spans[x + y * w]; s != null; ps = s, s = s.next)
{
bool walkable = s.area != RecastConstants.RC_NULL_AREA;
// If current span is not walkable, but there is walkable
// span just below it, mark the span above it walkable too.
if (!walkable && previousWalkable)
{
if (Math.Abs(s.smax - ps.smax) <= walkableClimb)
{
s.area = previousArea;
}
}
// Copy walkable flag so that it cannot propagate
// past multiple non-walkable objects.
previousWalkable = walkable;
previousArea = s.area;
}
}
}
ctx.stopTimer("FILTER_LOW_OBSTACLES");
}
/// @par
///
/// For this filter, the clearance above the span is the distance from the span's
/// maximum to the next higher span's minimum. (Same grid column.)
///
/// @see rcHeightfield, rcConfig
public static void filterWalkableLowHeightSpans(Context ctx, int walkableHeight, Heightfield solid)
{
ctx.startTimer("FILTER_WALKABLE");
int w = solid.width;
int h = solid.height;
int MAX_HEIGHT = 0xffff;
// Remove walkable flag from spans which do not have enough
// space above them for the agent to stand there.
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
for (Span s = solid.spans[x + y * w]; s != null; s = s.next)
{
int bot = (s.smax);
int top = s.next != null ? s.next.smin : MAX_HEIGHT;
if ((top - bot) <= walkableHeight)
{
s.area = RecastConstants.RC_NULL_AREA;
}
}
}
}
ctx.stopTimer("FILTER_WALKABLE");
}
private CompactHeightfield buildCompactHeightfield(InputGeom geom, RecastBuilderConfig bcfg, Context ctx)
{
RecastConfig cfg = bcfg.cfg;
//
// Step 2. Rasterize input polygon soup.
//
// Allocate voxel heightfield where we rasterize our input data to.
Heightfield solid = new Heightfield(bcfg.width, bcfg.height, bcfg.bmin, bcfg.bmax, cfg.cs, cfg.ch);
// Allocate array that can hold triangle area types.
// If you have multiple meshes you need to process, allocate
// and array which can hold the max number of triangles you need to
// process.
// Find triangles which are walkable based on their slope and rasterize
// them.
// If your input data is multiple meshes, you can transform them here,
// calculate
// the are type for each of the meshes and rasterize them.
float[] verts = geom.Verts;
bool tiled = cfg.tileSize > 0;
int totaltris = 0;
if (tiled)
{
ChunkyTriMesh chunkyMesh = geom.ChunkyMesh;
float[] tbmin = new float[2];
float[] tbmax = new float[2];
tbmin[0] = bcfg.bmin[0];
tbmin[1] = bcfg.bmin[2];
tbmax[0] = bcfg.bmax[0];
tbmax[1] = bcfg.bmax[2];
List <ChunkyTriMeshNode> nodes = chunkyMesh.getChunksOverlappingRect(tbmin, tbmax);
foreach (ChunkyTriMeshNode node in nodes)
{
int[] tris = node.tris;
int ntris = tris.Length / 3;
totaltris += ntris;
int[] m_triareas = Recast.markWalkableTriangles(ctx, cfg.walkableSlopeAngle, verts, tris, ntris);
RecastRasterization.rasterizeTriangles(ctx, verts, tris, m_triareas, ntris, solid, cfg.walkableClimb);
}
}
else
{
int[] tris = geom.Tris;
int ntris = tris.Length / 3;
int[] m_triareas = Recast.markWalkableTriangles(ctx, cfg.walkableSlopeAngle, verts, tris, ntris);
totaltris = ntris;
RecastRasterization.rasterizeTriangles(ctx, verts, tris, m_triareas, ntris, solid, cfg.walkableClimb);
}
//
// Step 3. Filter walkables surfaces.
//
// Once all geometry is rasterized, we do initial pass of filtering to
// remove unwanted overhangs caused by the conservative rasterization
// as well as filter spans where the character cannot possibly stand.
RecastFilter.filterLowHangingWalkableObstacles(ctx, cfg.walkableClimb, solid);
RecastFilter.filterLedgeSpans(ctx, cfg.walkableHeight, cfg.walkableClimb, solid);
RecastFilter.filterWalkableLowHeightSpans(ctx, cfg.walkableHeight, solid);
//
// Step 4. Partition walkable surface to simple regions.
//
// Compact the heightfield so that it is faster to handle from now on.
// This will result more cache coherent data as well as the neighbours
// between walkable cells will be calculated.
CompactHeightfield chf = Recast.buildCompactHeightfield(ctx, cfg.walkableHeight, cfg.walkableClimb, solid);
// Erode the walkable area by agent radius.
RecastArea.erodeWalkableArea(ctx, cfg.walkableRadius, chf);
// (Optional) Mark areas.
foreach (ConvexVolume vol in geom.ConvexVolumes)
{
RecastArea.markConvexPolyArea(ctx, vol.verts, vol.hmin, vol.hmax, vol.area, chf);
}
return(chf);
}
/// @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);
}
/// <summary>
/// The span addition can be set to favor flags. If the span is merged to another span and the new 'smax' is
/// within 'flagMergeThr' units from the existing span, the span flags are merged.
/// </summary>
/// <seealso cref= Heightfield, Span. </seealso>
private static void addSpan(Heightfield hf, int x, int y, int smin, int smax, int area, int flagMergeThr)
{
int idx = x + y * hf.width;
Span s = new Span();
s.smin = smin;
s.smax = smax;
s.area = area;
s.next = null;
// Empty cell, add the first span.
if (hf.spans[idx] == null)
{
hf.spans[idx] = s;
return;
}
Span prev = null;
Span cur = hf.spans[idx];
// Insert and merge spans.
while (cur != null)
{
if (cur.smin > s.smax)
{
// Current span is further than the new span, break.
break;
}
else if (cur.smax < s.smin)
{
// Current span is before the new span advance.
prev = cur;
cur = cur.next;
}
else
{
// Merge spans.
if (cur.smin < s.smin)
{
s.smin = cur.smin;
}
if (cur.smax > s.smax)
{
s.smax = cur.smax;
}
// Merge flags.
if (Math.Abs(s.smax - cur.smax) <= flagMergeThr)
{
s.area = Math.Max(s.area, cur.area);
}
// Remove current span.
Span next = cur.next;
if (prev != null)
{
prev.next = next;
}
else
{
hf.spans[idx] = next;
}
cur = next;
}
}
// Insert new span.
if (prev != null)
{
s.next = prev.next;
prev.next = s;
}
else
{
s.next = hf.spans[idx];
hf.spans[idx] = s;
}
}
/// <summary>
/// Spans will only be added for triangles that overlap the heightfield grid.
/// </summary>
/// <seealso cref= Heightfield </seealso>
public static void rasterizeTriangles(Context ctx, float[] verts, int[] areas, int nt, Heightfield solid, int flagMergeThr)
{
ctx.startTimer("RASTERIZE_TRIANGLES");
float ics = 1.0f / solid.cs;
float ich = 1.0f / solid.ch;
// Rasterize triangles.
for (int i = 0; i < nt; ++i)
{
int v0 = (i * 3 + 0);
int v1 = (i * 3 + 1);
int v2 = (i * 3 + 2);
// Rasterize.
rasterizeTri(verts, v0, v1, v2, areas[i], solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr);
}
ctx.stopTimer("RASTERIZE_TRIANGLES");
}
/// <summary>
/// No spans will be added if the triangle does not overlap the heightfield grid.
/// </summary>
/// <seealso cref= Heightfield </seealso>
public static void rasterizeTriangle(Context ctx, float[] verts, int v0, int v1, int v2, int area, Heightfield solid, int flagMergeThr)
{
ctx.startTimer("RASTERIZE_TRIANGLES");
float ics = 1.0f / solid.cs;
float ich = 1.0f / solid.ch;
rasterizeTri(verts, v0, v1, v2, area, solid, solid.bmin, solid.bmax, solid.cs, ics, ich, flagMergeThr);
ctx.stopTimer("RASTERIZE_TRIANGLES");
}
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);
}
}
}
