public Wall( Maze maze, Line2 line, float height, Texture2D texture )
{
Maze = maze;
Line = line;
Height = height;
Texture = texture;
SetUpVertices( line, height );
}
private void SetUpVertices( Line2 line, float height )
{
Vector3[] vertex = new Vector3[ 6 ];
// top left
vertex[ 0 ] = new Vector3( line.X0, height, line.Y0 );
// bottom left
vertex[ 1 ] = new Vector3( line.X0, 0, line.Y0 );
// top right
vertex[ 2 ] = new Vector3( line.X1, height, line.Y1 );
// bottom left
vertex[ 3 ] = new Vector3( line.X0, 0, line.Y0 );
// bottom right
vertex[ 4 ] = new Vector3( line.X1, 0, line.Y1 );
// top right
vertex[ 5 ] = new Vector3( line.X1, height, line.Y1 );
Vector2 texTopLeft = Vector2.Zero;
Vector2 texTopRight = Vector2.UnitX;
Vector2 texBottomLeft = Vector2.UnitY;
Vector2 texBottomRight = Vector2.One;
Vector3 normal = Vector3.Cross(
new Vector3( line.Direction.X, 0, line.Direction.Y ),
Vector3.UnitY );
Color color = Color.White;
mVertexData[ 0 ] = new VertexPositionNormalColorTexture(
vertex[ 0 ], normal, color, texTopLeft );
mVertexData[ 1 ] = new VertexPositionNormalColorTexture(
vertex[ 1 ], normal, color, texBottomLeft );
mVertexData[ 2 ] = new VertexPositionNormalColorTexture(
vertex[ 2 ], normal, color, texTopRight );
mVertexData[ 3 ] = new VertexPositionNormalColorTexture(
vertex[ 3 ], normal, color, texBottomLeft );
mVertexData[ 4 ] = new VertexPositionNormalColorTexture(
vertex[ 4 ], normal, color, texBottomRight );
mVertexData[ 5 ] = new VertexPositionNormalColorTexture(
vertex[ 5 ], normal, color, texTopRight );
}
public void Reverse( out Line2 outLine )
{
outLine.P0 = P1;
outLine.P1 = P0;
}
public Vector2? Intersection( Line2 l )
{
var p = P0;
var r = P1 - P0;
var q = l.P0;
var s = l.P1 - l.P0;
var qp_s = (float) Math.Round( Utils.Cross( q - p, s ), 3 );
var qp_r = (float) Math.Round( Utils.Cross( q - p, r ), 3 );
var r_s = (float) Math.Round( Utils.Cross( r, s ), 3 );
float t = qp_s / r_s;
float u = qp_r / r_s;
if ( r_s == 0 )
{
if ( qp_r == 0 )
{
var t0 = Vector2.Dot( q - p, r ) / Vector2.Dot( r, r );
var t1 = t0 + Vector2.Dot( s, r ) / Vector2.Dot( r, r );
if ( Vector2.Dot( s, r ) >= 0 )
{
if ( t0 <= 1 && t1 >= 0 )
return q;
}
else if ( t1 <= 1 && t0 >= 0 )
{
return q;
}
}
else
{
return null;
}
}
else if ( (0 <= t && t <= 1) && (0 <= u && u <= 1) )
{
return p + t*r;
}
return null;
}