Shadow.shader.m4

divert(`-1')
define(`forloop', `pushdef(`$1', `$2')_forloop($@)popdef(`$1')')
define(`_forloop',
       `$4`'ifelse($1, `$3', `', `define(`$1', incr($1))$0($@)')')
divert`'dnl
define(`lastindex', `60')dnl
shader_type spatial;

render_mode blend_mul,depth_draw_opaque,cull_disabled,diffuse_burley,specular_schlick_ggx,world_vertex_coords;

uniform float grow;

forloop(`i', `1', lastindex, `dnl
uniform float obj`'i`'_size;
uniform float obj`'i`'_pos;
')

varying vec2 xz;

void vertex() {
	xz = VERTEX.xz;
	VERTEX+=NORMAL*grow;
}

void light() {
	float mult = 1.0;
forloop(`i', `1', lastindex, `dnl
	if (obj`'i`'_size > 0.0 && distance(xz, obj`'i`'_pos) < 0.5) {
		mult = 0.3;
	}
')
	DIFFUSE_LIGHT = vec3(mult, mult, mult);
	SPECULAR_LIGHT = vec3(mult, mult, mult);
}