/// <summary>
/// Project a Vector4 onto a screen.
/// </summary>
/// <param name="width">The width of the buffer that is being rendered to.</param>
/// <param name="height">The height of the buffer that is being rendered to.</param>
/// <param name="vector">The Vector4 to project.</param>
/// <param name="model">The model matrix of the object that is being rendered.</param>
/// <returns>The projected vector.</returns>
public Vector2 ProjectVector(int width, int height, Vector4 vector, Matrix4 model = null)
{
// different size, update projection matrix
if (width != oldWidth || height != oldHeight)
{
oldWidth = width;
oldHeight = height;
projectionMatrix = Matrix4.Identity;
double aspectRatio = width / height;
double zoomX = 1 / Math.Tan(fov / 2);
double zoomY = zoomX * aspectRatio;
projectionMatrix[0] = zoomX;
projectionMatrix[5] = zoomY;
projectionMatrix[10] = -(far + near) / (far - near);
projectionMatrix[11] = (-2 * near * far) / (far - near);
projectionMatrix[14] = -1;
projectionMatrix[15] = 0;
}
Matrix4 matrix = projectionMatrix * viewMatrix;
matrix *= model;
Vector4 cartesian = vector * matrix;
if (cartesian.W != 0)
{
cartesian.X /= cartesian.W;
cartesian.Y /= cartesian.W;
cartesian.Z /= cartesian.W;
}
else
cartesian.W = 1;
return new Vector2(cartesian.X / (2 * cartesian.W) + width / 2, cartesian.Y / (2 * cartesian.W) + height / 2);
}
public static Matrix4 operator *(Matrix4 a, Matrix4 b)
{
Matrix4 result = new Matrix4();
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
for (int k = 0; k < 4; k++)
result[i, j] = result[i, j] + a[i, k] * b[k, j];
return result;
}
/// <summary>
/// Create a new Camera object.
/// </summary>
/// <param name="fov">The angle of the Field of View of the camera.</param>
/// <param name="near">The distance from the Camera to the near clipping plane.</param>
/// <param name="far">The distance from the Camera to the far clipping plane.</param>
public Camera(int fov, double near, double far)
{
projectionMatrix = Matrix4.Identity;
viewMatrix = Matrix4.Identity;
position = new Vector4(0, 0, 0, 1);
this.near = near;
this.far = far;
this.fov = fov;
}
public Renderable()
{
ModelMatrix = Matrix4.Identity;
}
/// <summary>
/// Project a Vector3 onto a screen.
/// </summary>
/// <param name="width">The width of the buffer that is being rendered to.</param>
/// <param name="height">The height of the buffer that is being rendered to.</param>
/// <param name="vector">The Vector3 to project.</param>
/// <param name="model">The model matrix of the object that is being rendered.</param>
/// <returns>The projected vector.</returns>
public Vector2 ProjectVector(int width, int height, Vector3 vector, Matrix4 model = null)
{
return this.ProjectVector(width, height, new Vector4(vector.X, vector.Y, vector.Z, 1), model);
}