// Find and return closer intersection of these two. If intersection is null then it's not really an intersection.
public static MyIntersectionResultLineTriangle? GetCloserIntersection(ref MyIntersectionResultLineTriangle? a, ref MyIntersectionResultLineTriangle? b)
{
if (((a == null) && (b != null)) ||
((a != null) && (b != null) && (b.Value.Distance < a.Value.Distance)))
{
// If only "b" contains valid intersection, or when it's closer than "a"
return b;
}
else
{
// This will be returned also when ((a == null) && (b == null))
return a;
}
}
public MyIntersectionResultLineTriangleEx(MyIntersectionResultLineTriangle triangle, MyEntity physObject, ref MyLine line)
{
Triangle = triangle;
Entity = physObject;
InputLineInObjectSpace = line;
NormalInObjectSpace = MyUtils.GetNormalVectorFromTriangle(ref Triangle.InputTriangle);
IntersectionPointInObjectSpace = line.From + line.Direction * Triangle.Distance;
if (Entity is MyVoxelMap)
{
IntersectionPointInWorldSpace = IntersectionPointInObjectSpace;
NormalInWorldSpace = NormalInObjectSpace;
// This will move intersection point from world space into voxel map's object space
IntersectionPointInObjectSpace = IntersectionPointInObjectSpace - ((MyVoxelMap)Entity).PositionLeftBottomCorner;
}
else
{
Matrix worldMatrix = Entity.WorldMatrix;
NormalInWorldSpace = MyUtils.GetTransformNormalNormalized(NormalInObjectSpace, ref worldMatrix);
IntersectionPointInWorldSpace = MyUtils.GetTransform(IntersectionPointInObjectSpace, ref worldMatrix);
}
}
public MyIntersectionResultLineTriangleEx(MyIntersectionResultLineTriangle triangle, MyEntity physObject, ref MyLine line)
{
Triangle = triangle;
Entity = physObject;
InputLineInObjectSpace = line;
NormalInObjectSpace = MyUtils.GetNormalVectorFromTriangle(ref Triangle.InputTriangle);
IntersectionPointInObjectSpace = line.From + line.Direction * Triangle.Distance;
if (Entity is MyVoxelMap)
{
IntersectionPointInWorldSpace = IntersectionPointInObjectSpace;
NormalInWorldSpace = NormalInObjectSpace;
// This will move intersection point from world space into voxel map's object space
IntersectionPointInObjectSpace = IntersectionPointInObjectSpace - ((MyVoxelMap)Entity).PositionLeftBottomCorner;
}
else
{
Matrix worldMatrix = Entity.WorldMatrix;
NormalInWorldSpace = MyUtils.GetTransformNormalNormalized(NormalInObjectSpace, ref worldMatrix);
IntersectionPointInWorldSpace = MyUtils.GetTransform(IntersectionPointInObjectSpace, ref worldMatrix);
}
}
// Finds intersection between line and model, using octree for speedup the lookup.
// Another speedup is, that first we check triangles that are directly in the node and then start
// checking node's childs. But only if child node instersection is less than last know min distance.
MyIntersectionResultLineTriangle? GetIntersectionWithLineRecursive(MyModel model, ref MyLine line, float? minDistanceUntilNow)
{
// Check if line intersects bounding box of this node and if distance to bounding box is less then last know min distance
float? distanceToBoundingBox = MyUtils.GetLineBoundingBoxIntersection(ref line, ref m_boundingBox);
if ((distanceToBoundingBox.HasValue == false) || ((minDistanceUntilNow != null) && (minDistanceUntilNow < distanceToBoundingBox.Value))) return null;
// Triangles that are directly in this node
MyIntersectionResultLineTriangle? foundIntersection = null;
// temporary variable for storing tirngle boundingbox info
BoundingBox triangleBoundingBox = new BoundingBox();
MinerWars.AppCode.Game.Managers.MyPerformanceCounter.PerCameraDraw.RayCastTrianglesProcessed += m_triangleIndices.Count;
for (int i = 0; i < m_triangleIndices.Count; i++)
{
int triangleIndex = m_triangleIndices[i];
model.GetTriangleBoundingBox(triangleIndex, ref triangleBoundingBox);
// First test intersection of triangleVertexes's bounding box with line's bounding box. And only if they overlap or intersect, do further intersection tests.
if (MyUtils.IsBoxIntersectingBox(triangleBoundingBox, ref line.BoundingBox) == true)
{
// See that we swaped vertex indices!!
MyTriangle_Vertexes triangle;
MyTriangleVertexIndices triangleIndices = model.Triangles[triangleIndex];
triangle.Vertex0 = model.GetVertex(triangleIndices.I0);
triangle.Vertex1 = model.GetVertex(triangleIndices.I2);
triangle.Vertex2 = model.GetVertex(triangleIndices.I1);
float? distance = MyUtils.GetLineTriangleIntersection(ref line, ref triangle);
// If intersection occured and if distance to intersection is closer to origin than any previous intersection
if ((distance != null) && ((foundIntersection == null) || (distance.Value < foundIntersection.Value.Distance)))
{
Vector3 calculatedTriangleNormal = MyUtils.GetNormalVectorFromTriangle(ref triangle);
// We need to remember original triangleVertexes coordinates (not transformed by world matrix)
foundIntersection = new MyIntersectionResultLineTriangle(ref triangle, ref calculatedTriangleNormal, distance.Value);
}
}
}
// Get intersection with childs of this node
if (m_childs != null)
{
for (int i = 0; i < m_childs.Count; i++)
{
MyIntersectionResultLineTriangle? childIntersection = m_childs[i].GetIntersectionWithLineRecursive(model, ref line,
(foundIntersection == null) ? (float?)null : foundIntersection.Value.Distance);
// If intersection occured and if distance to intersection is closer to origin than any previous intersection
foundIntersection = MyIntersectionResultLineTriangle.GetCloserIntersection(ref foundIntersection, ref childIntersection);
}
}
return foundIntersection;
}
