-------Draw--------

var view_mat = camera_get_view_mat(cam),
	x_scale = camera_get_view_width/surface_get_width(application_surface),
	y_scale = camera_get_view_height/surface_get_height(application_surface),
	view_x = c_x + camera_get_view_width(cam)*.5 - camera_get_view_width(cam)*.5 * view_mat[0] - camera_get_view_height(cam)*.5 * view_mat[1],
	view_y = c_y + camera_get_view_height(cam)*.5 + camera_get_view_width(cam)*.5 * view_mat[1] - camera_get_view_height(cam)*.5 * view_mat[0];


//Create and populate array of lights
var l_count = instance_number(o_Light),
	l_arr = array_create(l_count * 7 + 1),
	l_i = 1;

l_arr[0] = l_count;

with (o_Light) {
	l_arr[l_i++] = x;
	l_arr[l_i++] = y;
	l_arr[l_i++] = image_blend;
	l_arr[l_i++] = in_rad;
	l_arr[l_i++] = out_rad;
	l_arr[l_i++] = dir;
	l_arr[l_i++] = fov;
}

//Create the light surface and set it as target
if (!surface_exists(light_surf))
	light_surf = surface_create(surface_get_width(application_surface), surface_get_height(application_surface));

gpu_set_blendmode_ext(bm_one, bm_zero);
surface_set_target(light_surf); {
	camera_apply(cam);
	shader_set(sh_LightArray);
	shader_set_uniform_f_array(l_array, l_arr);
	draw_surface_ext(application_surface, view_x, view_y, x_scale, y_scale, 0, c_white, 1);
	shader_reset();
} surface_reset_target();

//Draw light_surf back to app_surf
draw_surface_ext(light_surf, view_x, view_y, x_scale, y_scale, 0, c_white, 1);
gpu_set_blendmode(bm_normal);


-------Shader--------

vec3 get_radiance(float c)
{
	// UNPACK COLOR BITS
	vec3 col;
	col.b = floor(c * 0.0000152587890625);
	float blue_bits = c - col.b * 65536.0;
	col.g = floor(blue_bits * 0.00390625);
	col.r = floor(blue_bits - col.g * 256.0);

	// NORMALIZE 0-255
	return col * 0.00390625;
}

varying vec2 pos; //Pixel position
varying vec2 tex;

uniform float l_array[512];

#define PI 3.1415926538

void main() {

	vec3 albedo = texture2D(gm_BaseTexture, tex).rgb;
	vec3 color = vec3(0.0);

	//Iterate over the lights array
	int num_lights = int(l_array[0]);
	int l_i = 1;
	for (int i=0; i<num_lights; ++i) {

		vec2 l_pos = vec2(l_array[l_i++], l_array[l_i++]);
		vec3 radiance = get_radiance(l_array[l_i++]);
		float l_in_rad = l_array[l_i++];
		float l_out_rad = l_array[l_i++];
		float l_dir = l_array[l_i++];
		float l_fov = l_array[l_i++];


		//Test attenuation
		float dist = length(l_pos.xy - pos.xy) / l_out_rad;
		float new_alpha = 5./(dist*dist*.1 + 1.);

		color += albedo * new_alpha * radiance;
	}

	gl_FragColor = vec4(color, 1.);
}