//private static float HighestAlt(float[] heightmap, int columns, int rows, int xCell, int yCell)
//{
// float height0 = heightmap[yCell * columns + xCell];
// float height1 = heightmap[yCell * columns + xCell + 1];
// float height2 = heightmap[(yCell + 1) * columns + xCell];
// float height3 = heightmap[(yCell + 1) * columns + xCell + 1];
// return Math.Max(height0, Math.Max(height1, Math.Max(height2, height3)));
//}
private static bool Intersects(Vector3 start, Vector3 direction, float[] heightmap, int columns, int rows, int xCell, int yCell, out float dist)
{
xCell = Utils.Clamp(xCell, 0, columns - 2);
yCell = Utils.Clamp(yCell, 0, rows - 2);
// 0--1-
// | /|
// |/ |
// 2--3-
// | |
Vector3 v0 = new Vector3(xCell, yCell, heightmap[yCell * columns + xCell]);
Vector3 v1 = new Vector3(xCell + 1, xCell, heightmap[yCell * columns + (xCell + 1)]);
Vector3 v2 = new Vector3(xCell, yCell + 1, heightmap[(yCell + 1) * columns + xCell]);
Vector3 v3 = new Vector3(xCell + 1, yCell + 1, heightmap[(yCell + 1) * columns + (xCell + 1)]);
return
(RayTriangle.CollisionTestCull(start, direction, v0, v1, v2, out dist) ||
RayTriangle.CollisionTestCull(start, direction, v3, v2, v1, out dist));
}
public static bool CollisionTestSlow(Ray ray, float[] heightmap, int columns, int rows, out float dist)
{
// TODO: Optimize this function with a
Vector3 start = new Vector3(ray.X, ray.Y, ray.Z);
Vector3 direction = new Vector3(ray.I, ray.J, ray.K);
dist = Single.MaxValue;
// Iterate through all of the triangles in the heightmap, doing a ray-triangle intersection
for (int y = 0; y < rows - 1; y++)
{
for (int x = 0; x < columns - 1; x++)
{
// 0--1-
// | /|
// |/ |
// 2--3-
// | |
Vector3 v0 = new Vector3(x, y, heightmap[y * columns + x]);
Vector3 v1 = new Vector3(x + 1, x, heightmap[y * columns + (x + 1)]);
Vector3 v2 = new Vector3(x, y + 1, heightmap[(y + 1) * columns + x]);
Vector3 v3 = new Vector3(x + 1, y + 1, heightmap[(y + 1) * columns + (x + 1)]);
float thisDist;
if (RayTriangle.CollisionTestCull(start, direction, v0, v1, v2, out thisDist))
{
if (thisDist < dist)
{
dist = thisDist;
}
}
if (RayTriangle.CollisionTestCull(start, direction, v3, v2, v1, out thisDist))
{
if (thisDist < dist)
{
dist = thisDist;
}
}
}
}
return(dist < Single.MaxValue);
}
public static bool CollisionTest(Ray ray, IPhysical obj, BasicMesh mesh, out float dist)
{
Vector3 start = new Vector3(ray.X, ray.Y, ray.Z);
Vector3 direction = new Vector3(ray.I, ray.J, ray.K);
dist = Single.MaxValue;
// Construct a matrix to transform to scene space
Matrix4 transform = Matrix4.Identity;
transform *= Matrix4.CreateScale(obj.Scale);
transform *= Matrix4.CreateFromQuaternion(obj.RelativeRotation);
transform *= Matrix4.CreateTranslation(obj.RelativePosition);
ILinkable parent = obj.Parent;
if (parent != null)
{
// Apply parent rotation and translation
transform *= Matrix4.CreateFromQuaternion(parent.RelativeRotation);
transform *= Matrix4.CreateTranslation(parent.RelativePosition);
}
// Iterate through all of the triangles in the mesh, doing a ray-triangle intersection
for (int i = 0; i < mesh.Indices.Length; i += 3)
{
Vector3 point0 = mesh.Vertices[mesh.Indices[i + 0]] * transform;
Vector3 point1 = mesh.Vertices[mesh.Indices[i + 1]] * transform;
Vector3 point2 = mesh.Vertices[mesh.Indices[i + 2]] * transform;
float thisDist;
if (RayTriangle.CollisionTestCull(start, direction, point0, point1, point2, out thisDist))
{
if (thisDist < dist)
{
dist = thisDist;
}
}
}
return(dist < Single.MaxValue);
}
