Unity32 (2D!) Camera problem....

[Pleng]

Well as usual my question had no response from Stack Overflow, so perhaps somebody here can help fill the void...


I am creating a game which has up to 4 orthographic cameras (for up to 4 players), which take up various amounts of the screen, depending on the amount of players, for example...

I have a script which controls all the cameras, setting their position relative to the players they are watching.
What I want to achieve is a simple overhead-runner style of movement, whereby the camera will follow the player, but not go outside the bounds of the map.

I have managed to get the boundaries working in the top-left camera, when the cameras are 'square' (as in the 4-player layout). However, the other cameras don't track properly at all, and in the rectangular 2-player mode, the top camera still goes too far left-and right. I'm pretty sure I know exactly which line of code is causing the problem... but I don't know what I need to do to fix it...

SpriteRenderer spriteBounds = GameObject.Find("Map").GetComponentInChildren<SpriteRenderer>();
float leftBound =0;
float rightBound =0;
float bottomBound =0;
float topBound = 0;
 
if((trackPlayer1 == null))
{
    camPlayer1.transform.position = this.transform.position;
}
else
{
    float vertExtent = camPlayer1.orthographicSize;
    float horzExtent = vertExtent * Screen.width / Screen.height; //I guess the problem is here... but how do I fix this??
 
    leftBound = (float)(horzExtent - spriteBounds.sprite.bounds.size.x / 2.0f);
    rightBound = (float)(spriteBounds.sprite.bounds.size.x / 2.0f - horzExtent);
    bottomBound = (float)(vertExtent - spriteBounds.sprite.bounds.size.y / 2.0f);
    topBound = (float)(spriteBounds.sprite.bounds.size.y / 2.0f - vertExtent);
 
    camPlayer1.transform.position = new Vector3(Mathf.Clamp(trackPlayer1.transform.position.x, leftBound, rightBound), Mathf.Clamp(trackPlayer1.transform.position.y, bottomBound, topBound), camPlayer1.transform.position.z);
}
if((trackPlayer2 == null))
{
    camPlayer2.transform.position = this.transform.position;
}
else
{
    float vertExtent = camPlayer2.orthographicSize ;
    float horzExtent = vertExtent * Screen.width / Screen.height; //I guess the problem is here... but how do I fix this??
 
    leftBound = (float)(horzExtent - spriteBounds.sprite.bounds.size.x / 2.0f);
    rightBound = (float)(spriteBounds.sprite.bounds.size.x / 2.0f - horzExtent);
    bottomBound = (float)(vertExtent - spriteBounds.sprite.bounds.size.y / 2.0f);
    topBound = (float)(spriteBounds.sprite.bounds.size.y / 2.0f - vertExtent);
 
    camPlayer2.transform.position = new Vector3(Mathf.Clamp(trackPlayer2.transform.position.x, leftBound, rightBound), Mathf.Clamp(trackPlayer2.transform.position.y, topBound, bottomBound), camPlayer2.transform.position.z);
}
if((trackPlayer3 == null))
{
    camPlayer3.transform.position = this.transform.position;
}
else
{
    float vertExtent = camPlayer3.orthographicSize;
    float horzExtent = vertExtent * Screen.width / Screen.height; //I guess the problem is here... but how do I fix this??
 
    leftBound = (float)(horzExtent - spriteBounds.sprite.bounds.size.x / 2.0f);
    rightBound = (float)(spriteBounds.sprite.bounds.size.x / 2.0f - horzExtent);
    bottomBound = (float)(vertExtent - spriteBounds.sprite.bounds.size.y / 2.0f);
    topBound = (float)(spriteBounds.sprite.bounds.size.y / 2.0f - vertExtent);
 
    camPlayer3.transform.position = new Vector3(Mathf.Clamp(trackPlayer3.transform.position.x, leftBound, rightBound), Mathf.Clamp(trackPlayer3.transform.position.y, topBound, bottomBound), camPlayer3.transform.position.z);     
}
if((trackPlayer4 == null))
{
    camPlayer4.transform.position = this.transform.position;
}
else
{
    float vertExtent = camPlayer4.orthographicSize;
    float horzExtent = vertExtent * Screen.width / Screen.height; //I guess the problem is here... but how do I fix this??
 
    leftBound = (float)(horzExtent - spriteBounds.sprite.bounds.size.x / 2.0f);
    rightBound = (float)(spriteBounds.sprite.bounds.size.x / 2.0f - horzExtent);
    bottomBound = (float)(vertExtent - spriteBounds.sprite.bounds.size.y / 2.0f);
    topBound = (float)(spriteBounds.sprite.bounds.size.y / 2.0f - vertExtent);
 
    camPlayer4.transform.position = new Vector3(Mathf.Clamp(trackPlayer4.transform.position.x, leftBound, rightBound), Mathf.Clamp(trackPlayer4.transform.position.y, topBound, bottomBound), camPlayer4.transform.position.z);
}

So I'm pretty sure that I need to be checking against the cameras size and relative position on the screen, but I am lost as to exactly what I need to be doing.