public void BufferAddShadowHull(ShadowHull hull)
{
// Why do we need all of these again? (hint: we don't)
var vertexMatrix = Matrix.Identity;
var normalMatrix = Matrix.Identity;
// Create the matrices (3X speed boost versus prior version)
var cos = (float)Math.Cos(hull.Angle);
var sin = (float)Math.Sin(hull.Angle);
// vertexMatrix = scale * rotation * translation;
vertexMatrix.M11 = hull.Scale.X * cos;
vertexMatrix.M12 = hull.Scale.X * sin;
vertexMatrix.M21 = hull.Scale.Y * -sin;
vertexMatrix.M22 = hull.Scale.Y * cos;
vertexMatrix.M41 = hull.Position.X;
vertexMatrix.M42 = hull.Position.Y;
// normalMatrix = scaleInv * rotation;
normalMatrix.M11 = 1f / hull.Scale.X * cos;
normalMatrix.M12 = 1f / hull.Scale.X * sin;
normalMatrix.M21 = 1f / hull.Scale.Y * -sin;
normalMatrix.M22 = 1f / hull.Scale.Y * cos;
// Where are we in the buffer?
var vertexCount = ShadowHullVertices.Count;
// Add the vertices to the buffer
for (var i = 0; i < hull.NumPoints; i++)
{
// Transform the vertices to screen coordinates
var point = hull.Points[i];
ShadowHullVertex hullVertex;
Vector2.Transform(
ref point.Position,
ref vertexMatrix,
out hullVertex.Position);
Vector2.TransformNormal(
ref point.Normal,
ref normalMatrix,
out hullVertex.Normal);
hullVertex.Color = new Color(
r: 0,
g: 0,
b: 0,
a: 1 - hull.Opacity);
ShadowHullVertices.Add(hullVertex);
}
foreach (var index in hull.Indicies)
{
ShadowHullIndicies.Add(vertexCount + index);
}
}
public void BufferAddBoundOutline(BoundingRect boundingRect)
{
var vertexCount = ShadowHullVertices.Count;
ShadowHullVertices.Add(
new ShadowHullVertex
{
Color = Color.Black,
Normal = Vector2.Zero,
Position = new Vector2(
boundingRect.Left,
boundingRect.Top)
});
ShadowHullVertices.Add(
new ShadowHullVertex
{
Color = Color.Black,
Normal = Vector2.Zero,
Position = new Vector2(
boundingRect.Right,
boundingRect.Top)
});
ShadowHullVertices.Add(
new ShadowHullVertex
{
Color = Color.Black,
Normal = Vector2.Zero,
Position = new Vector2(
boundingRect.Right,
boundingRect.Bottom)
});
ShadowHullVertices.Add(
new ShadowHullVertex
{
Color = Color.Black,
Normal = Vector2.Zero,
Position = new Vector2(
boundingRect.Left,
boundingRect.Bottom)
});
ShadowHullIndicies.Add(vertexCount + 0);
ShadowHullIndicies.Add(vertexCount + 1);
ShadowHullIndicies.Add(vertexCount + 2);
ShadowHullIndicies.Add(vertexCount + 0);
ShadowHullIndicies.Add(vertexCount + 2);
ShadowHullIndicies.Add(vertexCount + 3);
}
public void BufferDraw()
{
if (ShadowHullIndicies.Count >= 3)
{
GraphicsDevice.DrawUserIndexedPrimitives(
primitiveType: PrimitiveType.TriangleList,
vertexData: ShadowHullVertices.ToArray(),
vertexOffset: 0,
numVertices: ShadowHullVertices.Count,
indexData: ShadowHullIndicies.ToArray(),
indexOffset: 0,
primitiveCount: ShadowHullIndicies.Count / 3);
}
}
