add (very) fake halation to the bloom extraction shader

framework/opengl_renderer/src/mm/opengl/render_tasks/bloom_extraction.cpp

@@ -102,6 +102,9 @@ in vec2 _uv;
 
 out vec3 _out_color;
 
+// global config, keep it constant
+const float fake_halation_strenth = 1.0;
+
 void main() {
 	vec3 color = texture(color_tex, _uv).rgb;
 
@@ -114,7 +117,16 @@ void main() {
 		//step(vec3(0.0), color)
 	//);
 
-	_out_color = max(min(color, vec3(0.0)), color - vec3(1.0));
+	const vec3 fake_halation_base = vec3(0.03, 0.01, 0.0) * vec3(fake_halation_strenth);
+	const vec3 fake_halation_extraction_offset = vec3(1.0) - fake_halation_base;
+	const vec3 fake_halation_bloom_fact = vec3(1.0) + fake_halation_base;
+
+	if (fake_halation_strenth <= 0.001) {
+		_out_color = max(min(color, vec3(0.0)), color - vec3(1.0));
+	} else {
+		_out_color = max(min(color, vec3(0.0)), color - fake_halation_extraction_offset) * fake_halation_bloom_fact;
+		//_out_color = max(min(color, vec3(0.0)), color - vec3(0.95, 0.97, 1.0)) * vec3(1.10, 1.05, 1.0);
+	}
 })")
 }