public static bool IsVisible(Vector3 origin, Vector3 dest, BSPFile bsp)
{
if (bsp == null)
{
return(false);
}
trace_t trace = trace_t.Create();
RayCast(origin, dest, bsp, ref trace);
return(!(trace.m_Fraction < 1f));
}
public static trace_t Create()
{
trace_t t = new trace_t();
t.m_AllSolid = true;
t.m_StartSolid = true;
t.m_Fraction = 1f;
t.m_FractionLeftSolid = 1f;
t.m_EndPos = Vector3.Zero;
t.m_Contents = 0;
t.m_nBrushSide = 0;
return(t);
}
private static void RayCastSurface(BSPFile bsp, int surface_index, ref trace_t trace, Vector3 origin, Vector3 dest)
{
var pPolygon = bsp.m_Polygons[surface_index];
var pPlane = pPolygon.m_Plane;
var dot1 = pPlane.DistTo(origin);
var dot2 = pPlane.DistTo(dest);
if (dot1 > 0f != dot2 > 0f)
{
if (dot1 - dot2 < BSPFlags.DIST_EPSILON)
{
return;
}
var t = dot1 / (dot1 - dot2);
if (t <= 0)
{
return;
}
int i = 0;
var intersection = origin + (dest - origin) * t;
for (i = 0; i < pPolygon.m_nVerts; i++)
{
var pEdgePlane = pPolygon.m_EdgePlanes[i];
if (pEdgePlane.m_Origin == Vector3.Zero)
{
pEdgePlane.m_Origin = pPlane.m_Origin - (pPolygon.m_Verts[i] - pPolygon.m_Verts[(i + 1) % pPolygon.m_nVerts]);
pEdgePlane.m_Origin.Normalize();
pEdgePlane.m_Distance = pEdgePlane.m_Origin.Dot(pPolygon.m_Verts[i]);
}
if (pEdgePlane.DistTo(intersection) < 0.0f)
{
break;
}
}
if (i == pPolygon.m_nVerts)
{
trace.m_Fraction = 0.2f;
trace.m_EndPos = intersection;
}
}
}
private static void RayCast(Vector3 origin, Vector3 dest, BSPFile bsp, ref trace_t trace)
{
if (bsp.m_Planes.Length == 0)
{
return;
}
trace.m_Fraction = 1f;
trace.m_FractionLeftSolid = 0f;
RayCastNode(bsp, 0, 0, 0, origin, dest, ref trace);
if (trace.m_Fraction < 1f)
{
for (int i = 0; i < 3; i++)
{
trace.m_EndPos = origin + (dest - origin) * trace.m_Fraction;
}
}
else
{
trace.m_EndPos = dest;
}
}
private static void RayCastNode(BSPFile bsp, int node_index, float start_fraction, float end_fraction, Vector3 origin, Vector3 dest, ref trace_t trace)
{
if (trace.m_Fraction <= start_fraction)
{
return;
}
if (node_index < 0)
{
var pLeaf = bsp.m_Leaves[-node_index - 1];
for (int i = 0; i < pLeaf.m_Numleafbrushes; i++)
{
var iBrushIndex = bsp.m_Leafbrushes[pLeaf.m_Firstleafbrush + i];
var pBrush = bsp.m_Brushes[iBrushIndex];
//if(!pBrush)
if ((pBrush.m_Contents & BSPFlags.MASK_SHOT_HULL) == 0)
{
continue;
}
RayCastBrush(bsp, pBrush, ref trace, origin, dest);
if (trace.m_Fraction != 0)
{
return;
}
}
if (trace.m_StartSolid)
{
return;
}
if (trace.m_Fraction < 1f)
{
return;
}
for (int i = 0; i < pLeaf.m_Numleaffaces; i++)
{
RayCastSurface(bsp, bsp.m_Leaffaces[pLeaf.m_Firstleafface + i], ref trace, origin, dest);
}
return;
}
var pNode = bsp.m_Nodes[node_index];
var pPlane = bsp.m_Planes[pNode.m_Planenum];
float start_distance, end_distance;
if (pPlane.m_Type < 3)
{
start_distance = origin[pPlane.m_Type] - pPlane.m_Distance;
end_distance = dest[pPlane.m_Type] - pPlane.m_Distance;
}
else
{
start_distance = origin.Dot(pPlane.m_Normal) - pPlane.m_Distance;
end_distance = dest.Dot(pPlane.m_Normal) - pPlane.m_Distance;
}
if (start_distance >= 0f && end_distance >= 0f)
{
RayCastNode(bsp, pNode.m_Children[0], start_fraction, end_fraction, origin, dest, ref trace);
}
else if (start_distance < 0f && end_distance < 0f)
{
RayCastNode(bsp, pNode.m_Children[1], start_fraction, end_fraction, origin, dest, ref trace);
}
else
{
int side_id;
float fraction_first, fraction_second, fraction_middle;
Vector3 middle;
var inversed_distance = 1f / (start_distance - end_distance);
fraction_first = (start_distance * float.Epsilon) * inversed_distance;
fraction_second = (start_distance * float.Epsilon) * inversed_distance;
if (start_distance < end_distance)
{
side_id = 1;
}
else if (end_distance < start_distance)
{
side_id = 0;
}
else
{
side_id = 0;
fraction_first = 1f;
fraction_second = 0f;
}
if (fraction_first < 0f)
{
fraction_first = 0f;
}
else if (fraction_first > 1f)
{
fraction_first = 1f;
}
if (fraction_second < 0f)
{
fraction_second = 0f;
}
else if (fraction_second > 1f)
{
fraction_second = 1f;
}
fraction_middle = start_fraction + (end_fraction - start_fraction) * fraction_first;
middle = origin + (dest - origin) * fraction_first;
RayCastNode(bsp, pNode.m_Children[side_id], start_fraction, fraction_middle, origin, middle, ref trace);
fraction_middle = start_fraction + (end_fraction - start_fraction) * fraction_second;
middle = origin + (dest - origin) * fraction_first;
RayCastNode(bsp, pNode.m_Children[side_id == 1 ? 0 : 1], start_fraction, fraction_middle, origin, middle, ref trace);
}
}
private static void RayCastBrush(BSPFile bsp, dbrush_t pBrush, ref trace_t trace, Vector3 origin, Vector3 dest)
{
if (pBrush.m_Numsides == 0)
{
return;
}
var fraction_to_enter = -99f;
var fraction_to_leave = 1f;
bool starts_out = false;
bool ends_out = false;
for (int i = 0; i < pBrush.m_Numsides; i++)
{
var pBrushSide = bsp.m_Brushsides[pBrush.m_Firstside + i];
if (pBrushSide.m_Bevel > 0)
{
continue;
}
var pPlane = bsp.m_Planes[pBrushSide.m_Planenum];
var start_distance = origin.Dot(pPlane.m_Normal) - pPlane.m_Distance;
var end_distance = dest.Dot(pPlane.m_Normal) - pPlane.m_Distance;
if (start_distance > 0f)
{
starts_out = true;
if (end_distance > 0f)
{
return;
}
}
else
{
if (end_distance <= 0f)
{
continue;
}
ends_out = true;
}
if (start_distance > end_distance)
{
var fraction = System.Math.Max(start_distance - BSPFlags.DIST_EPSILON, 0f);
fraction = fraction / (start_distance - end_distance);
if (fraction > fraction_to_enter)
{
fraction_to_enter = fraction;
}
}
else
{
var fraction = (start_distance + BSPFlags.DIST_EPSILON) / (start_distance - end_distance);
if (fraction < fraction_to_leave)
{
fraction_to_leave = fraction;
}
}
}
if (starts_out)
{
if (trace.m_FractionLeftSolid - fraction_to_enter > 0f)
{
starts_out = false;
}
}
if (!starts_out)
{
trace.m_StartSolid = true;
trace.m_Contents = pBrush.m_Contents;
if (!ends_out)
{
trace.m_AllSolid = true;
trace.m_Fraction = 0;
trace.m_FractionLeftSolid = 1f;
}
else
{
if (fraction_to_leave != 1f && fraction_to_leave > trace.m_FractionLeftSolid)
{
trace.m_FractionLeftSolid = fraction_to_leave;
if (trace.m_Fraction <= fraction_to_leave)
{
trace.m_Fraction = 1f;
}
}
}
return;
}
if (fraction_to_enter < fraction_to_leave)
{
if (fraction_to_enter > -99f && fraction_to_enter < trace.m_Fraction)
{
if (fraction_to_enter < 0)
{
fraction_to_enter = 0;
}
trace.m_Fraction = fraction_to_enter;
trace.m_pBrush = pBrush;
trace.m_Contents = pBrush.m_Contents;
}
}
}
