Merge pull request 'Bug markers look better at longer distances.' (#9) from bug-marker-distance-improvements into main

Reviewed-on: BattyBovine/Bugbot#9

Materials/BugMarker/bug_marker.gdshader

@@ -6,20 +6,23 @@ render_mode blend_mix,depth_test_disabled,cull_disabled,unshaded;
 uniform vec3 colour : source_color = vec3(1.0f);
 uniform sampler2D msdf_icon : filter_linear_mipmap,hint_default_black;
 uniform float shape_thickness : hint_range(0.0f,1.0f,0.01) = 0.95f;
-uniform vec3 line_colour : source_color = vec3(0.0f);
-uniform float line_thickness : hint_range(0.0f,1.0f,0.01) = 0.0f;
+//uniform vec3 line_colour : source_color = vec3(0.0f);
+//uniform float line_thickness : hint_range(0.0f,1.0f,0.01) = 0.0f;
 uniform bool billboard = false;
 
+varying float model_distance;
+
 void vertex() {
 	if (billboard) {
 		MODELVIEW_MATRIX = VIEW_MATRIX * mat4(INV_VIEW_MATRIX[0], INV_VIEW_MATRIX[1], INV_VIEW_MATRIX[2], MODEL_MATRIX[3]);
 		MODELVIEW_MATRIX = MODELVIEW_MATRIX * mat4(vec4(length(MODEL_MATRIX[0].xyz), 0.0, 0.0, 0.0), vec4(0.0, length(MODEL_MATRIX[1].xyz), 0.0, 0.0), vec4(0.0, 0.0, length(MODEL_MATRIX[2].xyz), 0.0), vec4(0.0, 0.0, 0.0, 1.0));
 		MODELVIEW_NORMAL_MATRIX = mat3(MODELVIEW_MATRIX);
 	}
+	model_distance = pow(length(VIEW_MATRIX * MODEL_MATRIX[3]), 0.125f);
 }
 
 void fragment() {
 	vec4 albedo_tex = texture(msdf_icon, UV);
-	if (step(shape_thickness, albedo_tex.r) > 0.5f) { discard; }
-	ALBEDO = (step(shape_thickness-line_thickness, albedo_tex.r) > 0.5f) ? pow(line_colour, vec3(0.4545454545)) : pow(colour.rgb, vec3(0.4545454545));
+	if (step(clamp(shape_thickness / model_distance, 0.0, shape_thickness), albedo_tex.r) > 0.5f) { discard; }
+	ALBEDO = /*(step(shape_thickness-line_thickness, albedo_tex.r) > 0.5f) ? pow(line_colour, vec3(0.4545454545)) : */pow(colour.rgb, vec3(0.4545454545));
 }