/**
* @methodOf lights
*/
function update_light_transform(obj) {
if (obj.type != "LAMP")
throw "Wrong light object";
var light = obj.light;
if (!light)
return;
var quat = m_tsr.get_quat_view(obj.render.world_tsr);
m_util.quat_to_dir(quat, m_util.AXIS_Y, light.direction);
m_vec3.normalize(light.direction, light.direction);
if (light.type == "SUN") {
var prev_angle = Math.acos(m_vec3.dot(light.prev_direction, m_util.VEC3_UNIT));
var new_angle = Math.acos(m_vec3.dot(light.direction, m_util.VEC3_UNIT));
var floor_prev = Math.floor(prev_angle / 0.025);
var floor_new = Math.floor(new_angle / 0.025);
if (floor_prev != floor_new)
light.need_sun_fog_update = true;
else
light.need_sun_fog_update = false;
}
m_vec3.copy(light.direction, light.prev_direction);
}
/**
* Find minimum/maximum extent in direction dir
*/
function find_min_max_extent(exts, dir) {
var dir_n = m_vec3.normalize(dir, m_vec3.create());
var min = exts[0];
var max = exts[0];
for (var i = 1; i < exts.length; i++) {
var proj = m_vec3.dot(exts[i], dir_n);
if (proj < m_vec3.dot(min, dir_n))
min = exts[i];
if (proj > m_vec3.dot(max, dir_n))
max = exts[i];
}
return [min, max];
}
exports.get_frustum_mec = function(corners) {
// left bottom near
var p0 = corners.subarray(0, 3);
// right top near
var p1 = corners.subarray(6, 9);
// left bottom far
var p2 = corners.subarray(12, 15);
// right top far
var p3 = corners.subarray(18, 21);
// basis vector: l
var l = m_vec3.subtract(p1, p0, _vec3_tmp);
m_vec3.normalize(l, l);
// basis vector: m
var normal = m_util.get_plane_normal(p0, p1, p2, _vec3_tmp2);
var m = m_vec3.cross(normal, l, normal);
m_vec3.normalize(m, m);
// transform points coordinates for new 2D Cartesian coordinate system
// q0 - center of the new system (former p0);
// NOTE: using gl_matrix vec3 for simplicity
var q0 = m_vec3.create();
var q1 = m_vec3.create();
m_vec3.subtract(p1, p0, _vec3_tmp3);
q1[0] = m_vec3.dot(_vec3_tmp3, l);
q1[1] = m_vec3.dot(_vec3_tmp3, m);
var q2 = m_vec3.create();
m_vec3.subtract(p2, p0, _vec3_tmp3);
q2[0] = m_vec3.dot(_vec3_tmp3, l);
q2[1] = m_vec3.dot(_vec3_tmp3, m);
var q3 = m_vec3.create();
m_vec3.subtract(p3, p0, _vec3_tmp3);
q3[0] = m_vec3.dot(_vec3_tmp3, l);
q3[1] = m_vec3.dot(_vec3_tmp3, m);
var bs = exports.zero_bounding_sphere();
bs = get_mec_2d([q0, q1, q2, q3], bs);
var center_origin = m_vec3.scale(l, bs.center[0], _vec3_tmp3);
m_vec3.scaleAndAdd(center_origin, m, bs.center[1], center_origin);
m_vec3.add(center_origin, p0, bs.center);
return bs;
}
