private static bool CollideWithTerrainAABB(int axis, AABB aabb, IWorld world, PhysicMaterial material, float time, ref float velocity, out float movement)
{
movement = velocity * time;
if (movement == 0)
{
return(false);
}
Vector3Int start = default;
Vector3Int end = default;
Vector3Int step = default;
if (movement > 0)
{
for (int i = 0; i < 3; i++)
{
if (axis == i)
{
start[i] = Mathf.FloorToInt(aabb.Max[i]);
end[i] = Mathf.FloorToInt(aabb.Max[i] + movement);
}
else
{
start[i] = Mathf.FloorToInt(aabb.Min[i]);
end[i] = Mathf.FloorToInt(aabb.Max[i]);
}
step[i] = 1;
}
}
else
{
for (int i = 0; i < 3; i++)
{
if (axis == i)
{
end[i] = Mathf.FloorToInt(aabb.Min[i] + movement);
step[i] = -1;
}
else
{
end[i] = Mathf.FloorToInt(aabb.Max[i]);
step[i] = 1;
}
start[i] = Mathf.FloorToInt(aabb.Min[i]);
}
}
end += step;
for (int x = start.x; x != end.x; x += step.x)
{
for (int z = start.z; z != end.z; z += step.z)
{
for (int y = start.y; y != end.y; y += step.y)
{
BlockData block = world.RWAccessor.GetBlock(x, y, z);
AABB? blockAABB = block.GetBoundingBox(x, y, z, world, true);
if (blockAABB == null)
{
continue;
}
AABB blockBB = blockAABB.Value;
bool flag = true;
for (int i = 0; i < 3; i++)
{
if (i != axis)
{
flag &= blockBB.Max[i] > aabb.Min[i] && blockBB.Min[i] < aabb.Max[i];
}
}
if (!flag)
{
continue;
}
if (movement > 0 && aabb.Max[axis] <= blockBB.Min[axis])
{
float maxMovement = blockBB.Min[axis] - aabb.Max[axis];
if (movement > maxMovement)
{
CalculateVelocityAfterCollisionWithTerrain(material, block, ref velocity);
movement = maxMovement;
return(true);
}
}
else if (movement < 0 && aabb.Min[axis] >= blockBB.Max[axis])
{
float maxMovement = blockBB.Max[axis] - aabb.Min[axis];
if (movement < maxMovement)
{
CalculateVelocityAfterCollisionWithTerrain(material, block, ref velocity);
movement = maxMovement;
return(true);
}
}
}
}
}
return(false);
}
public static CollisionFlags CollideWithTerrainAABB(Vector3 position, AABB aabb, IWorld world, PhysicMaterial material, float time, ref Vector3 velocity, out Vector3 movement)
{
aabb += position;
for (int i = 0; i < 3; i++)
{
if (Mathf.Abs(velocity[i]) <= Mathf.Epsilon)
{
velocity[i] = 0;
}
}
CollisionFlags flags = CollisionFlags.None;
bool negativeY = velocity.y < 0;
movement = default;
if (CollideWithTerrainAABB(1, aabb, world, material, time, ref velocity.y, out movement.y))
{
flags |= negativeY ? CollisionFlags.Below : CollisionFlags.Above;
}
aabb += new Vector3(0, movement.y, 0);
if (CollideWithTerrainAABB(0, aabb, world, material, time, ref velocity.x, out movement.x))
{
flags |= CollisionFlags.Sides;
}
aabb += new Vector3(movement.x, 0, 0);
if (CollideWithTerrainAABB(2, aabb, world, material, time, ref velocity.z, out movement.z))
{
flags |= CollisionFlags.Sides;
}
return(flags);
}