Camera initcam(V3 pos, F32 fov, F32 near, F32 far, F32 yaw, F32 pitch, F32 roll)
{
	Camera	c = {
		.pos = pos,
		.fov = fov,
		.near = near,
		.far = far,
		.yaw = yaw,
		.pitch = pitch,
		.roll = roll,
	};
	return c;
}

MAT4 getfpviewmat(Camera *c)
{
	MAT4	v;
	v = translmat4(MAT4_IDENTITY, invv3(c->pos));
	v = rotatemat4(v, v3(c->pitch, c->yaw, c->roll));
	return v;
}

void getfpvecs(Camera *c, V3 *l, V3 *u, V3 *f)
{
	F32	angle, cp, sp, cy, sy, cr, sr;

	angle = DEG2RAD*c->pitch;
	cp = f32cos(angle);
	sp = f32sin(angle);
	angle = DEG2RAD*c->yaw;
	cy = f32cos(angle);
	sy = f32sin(angle);
	angle = DEG2RAD*c->roll;
	cr = f32cos(angle);
	sr = f32sin(angle);

	*l = v3(cy*cr, -cy*sr, sy);
	*u = v3(sp*sy*cr+cp*sr, -sp*sy*sr+cp*cr, -sp*cy);
	*f = v3(-cp*sy*cr+sp*sr, cp*sy*sr+sp*cr, cp*cy);
}

MAT4 lookat(Camera c, V3 t, V3 wup)
{
	V3	f, r, u;
	MAT4	transl, rotate, res;

	f = normv3(subv3(c.pos, t));
	r = normv3(crossv3(wup, f));
	u = crossv3(f, r);

	transl = translmat4(MAT4_IDENTITY, invv3(c.pos));
	rotate = transpmat4(rotateaxismat4(r, u, f));
	res = mulmat4(rotate, transl);

	return res;
}

MAT4 ortho(F32 l, F32 r, F32 b, F32 t, F32 n, F32 f)
{
	MAT4	res;

	res = MAT4_IDENTITY;
	res.m0.x = 2.0f/(r-l);
	res.m1.y = 2.0f/(t-b);
	res.m2.z = -2.0f/(f-n);
	res.m3.x = -(r+l)/(r-l);
	res.m3.y = -(t+b)/(t-b);
	res.m3.z = -(f+n)/(f-n);

	return res;
}

MAT4 persp(F32 fov, F32 ar, F32 n, F32 f)
{
	F32	r, t;
	MAT4	res;

	r = n*f32tan(fov/2.0f*DEG2RAD);
	t = r/ar;

	res = MAT4_IDENTITY;
	res.m0.x = n/r;
	res.m1.y = n/t;
	res.m2.z = -(f+n)/(f-n);
	res.m2.w = -1.0f;
	res.m3.z = (-2.0f*f*n)/(f-n);
	res.m3.w = 0.0f;

	return res;
}

MAT4 camera_persp(Camera c, F32 ar)
{
	MAT4	res;

	res = persp(c.fov, ar, c.near, c.far);

	return res;
}