#include "camera.h"



void camera_look_at(camera_t &camera, const D3DXVECTOR3 &position, const D3DXVECTOR3 &center, const D3DXVECTOR3 &up)

{

	D3DXMatrixLookAtLH(&camera.view, &position, &center, &up);

}



void camera_perspective(camera_t &camera, float fov, float aspect, float znear, float zfar)

{

	D3DXMatrixPerspectiveFovLH(&camera.projection, fov, aspect, znear, zfar);

}



void camera_update(camera_t &camera)

{

	if( camera.phi < 0.1f )

		camera.phi = 0.1f;



	if( camera.phi > 3.14f / 3.0f )

		camera.phi =  3.14f / 3.0f;



	camera.position.x = camera.target.x + sin(camera.angle) * camera.radius;

	camera.position.z = camera.target.z + cos(camera.angle) * camera.radius;

	camera.position.y = sin(camera.phi) * camera.radius;



	D3DXVECTOR3 up = D3DXVECTOR3(0.0f, 1.0f, 0.0f);

	D3DXMatrixLookAtLH(&camera.view, &camera.position, &camera.target, &up);

	D3DXMatrixPerspectiveFovLH(&camera.projection, camera.fov, camera.aspect, camera.znear, camera.zfar);

}



void camera_rotate(camera_t &camera, float delta)

{

	camera.angle += delta;

	camera_update(camera);

}



void camera_move(camera_t &camera, float dx, float dz)

{

	D3DXVECTOR3 fwd = camera.position - camera.target;

	fwd.y = 0;

	D3DXVECTOR3 side = D3DXVECTOR3(fwd.z, 0.0f, -fwd.x);

	D3DXVec3Normalize(&fwd, &fwd);

	D3DXVec3Normalize(&side, &side);



	camera.position += D3DXVECTOR3(fwd.x * dz, 0.0f, fwd.z * dz);

	camera.target += D3DXVECTOR3(fwd.x * dz, 0.0f, fwd.z * dz);



	camera.position += D3DXVECTOR3(side.x * dx, 0.0f, side.z * dx);

	camera.target += D3DXVECTOR3(side.x * dx, 0.0f, side.z * dx);



	camera_update(camera);

}



void camera_zoom(camera_t &camera, float delta)

{

	camera.radius += delta;

	if(camera.radius < 1.0f)

		camera.radius = 1.0f;

	camera_update(camera);

}