// Tom Plick
// 27 July 2005
// projector.h
// Handle perspective of the board.  Akin to Luna's Camera class (ch. 12),
//     but the Projector always points at the origin, and places 
//     restriction on angles of view.

#pragma once

#include <d3d9.h>
#include <d3dx9.h>

class Projector {
private:	
	// distance from the origin, in screen units
	float distance;


	// angle (in the xy-plane) between the z-axis
	//      and the direction of the user's view.
	// Varying theta changes the location around the board
	//      at which the user "sits".
	// e.g. if theta == -90 degrees, user is at left side of board;
	//      if theta == 90 degrees, user is at right side
	float theta;


	// angle (in the xz-plane) between the y-axis
	//      and the direction of the user's view
	// Varying phi changes the "height" of the user.
	// e.g. if phi == 90 degrees, user is looking at board top-down;
	//      if phi == 0 degrees, user is looking parallel to the board
	float phi;

	// projection matrix
	D3DXMATRIX mat;
	void calculateMatrix();

	void checkBounds();

public:
	Projector();
	void recenter();

	void setDistance(float);
	float getDistance();
	void addDistance(float);


	void setTheta(float);
	float getTheta();
	void addTheta(float);


	void setPhi(float);
	float getPhi();
	void addPhi(float);

	D3DXMATRIX getViewMatrix();
};