public static float PI = (float)(Math.PI); //PI, used in calculations.
/**
* Converts an entities position to screen co-ordinates. Accepts the matrix(column major), PlayerEntity, Game Window Rect, and a boolean to specify if we are using the zPosFoot or zPosHead
*
* Mostly "borrowed" from 0XDE57
*
* */
public static float[] WorldToScreen(byte[] matrix, LocatableEntity entity, POINTS gameWindow, bool foot = true)
{
int width = gameWindow.Right - gameWindow.Left; //calculate the width of the game window
int height = gameWindow.Bottom - gameWindow.Top; //calculate the height of the game window
/*
* Read the Matrix into variables for later use - it is column major
*/
float m11 = BitConverter.ToSingle(matrix, 0), m12 = BitConverter.ToSingle(matrix, 4), m13 = BitConverter.ToSingle(matrix, 8), m14 = BitConverter.ToSingle(matrix, 12);
float m21 = BitConverter.ToSingle(matrix, 16), m22 = BitConverter.ToSingle(matrix, 20), m23 = BitConverter.ToSingle(matrix, 24), m24 = BitConverter.ToSingle(matrix, 28);
float m31 = BitConverter.ToSingle(matrix, 32), m32 = BitConverter.ToSingle(matrix, 36), m33 = BitConverter.ToSingle(matrix, 40), m34 = BitConverter.ToSingle(matrix, 44);
float m41 = BitConverter.ToSingle(matrix, 48), m42 = BitConverter.ToSingle(matrix, 52), m43 = BitConverter.ToSingle(matrix, 56), m44 = BitConverter.ToSingle(matrix, 60);
float zPos = entity is Player ? ((Player)entity).getZPos(foot) : entity.getZPos(); //get the zPos, foot is only relevant to player entities at this time
//multiply vector against matrix
float screenX = (m11 * entity.xPos) + (m21 * entity.yPos) + (m31 * zPos) + m41;
float screenY = (m12 * entity.xPos) + (m22 * entity.yPos) + (m32 * zPos) + m42;
float screenW = (m14 * entity.xPos) + (m24 * entity.yPos) + (m34 * zPos) + m44;
//camera position (eye level/middle of screen)
float camX = width / 2f;
float camY = height / 2f;
//convert to homogeneous position
float x = camX + (camX * screenX / screenW);
float y = camY - (camY * screenY / screenW);
float[] screenPos = { x, y };
//check it is in the bounds to draw
if (screenW > 0.001f && //not behind us
gameWindow.Left + x > gameWindow.Left && gameWindow.Left + x < gameWindow.Right && //not off the left or right of the window
gameWindow.Top + y > gameWindow.Top && gameWindow.Top + y < gameWindow.Bottom) //not off the top of bottom of the window
{
return(screenPos);
}
return(null);
}
public static extern bool GetWindowRect(IntPtr hwnd, out POINTS lpPoints);
