Pixel-Composer/scripts/node_level_selector/node_level.gml

function Node_create_Level(_x, _y) {
	var node = new Node_Level(_x, _y);
	ds_list_add(PANEL_GRAPH.nodes_list, node);
	return node;
}

function Node_Level(_x, _y) : Node_Processor(_x, _y) constructor {
	name = "Level";
	
	uniform_black = shader_get_uniform(sh_level, "black");
	uniform_white = shader_get_uniform(sh_level, "white");
	
	newInput(| 0, NodeValue(0, "Surface in", self, JUNCTION_CONNECT.input, VALUE_TYPE.surface, 0));
	
	newInput(| 1, NodeValue_Float(1, "Black", self, 0));
	inputs[| 1].setDisplay(VALUE_DISPLAY.slider, [ 0, 1, 0.01]);
	
	newInput(| 2, NodeValue_Float(2, "White",   self, 1));
	inputs[| 2].setDisplay(VALUE_DISPLAY.slider, [ 0, 1, 0.01]);
	
	outputs[| 0] = new nodeValue_Output(0, "Surface out", self, VALUE_TYPE.surface, surface_create(1, 1));
	
	function process_data(_outSurf, _data, _output_index) {
		var _black = _data[1];
		var _white = _data[2];
		
		surface_set_target(_outSurf);
		draw_clear_alpha(c_white, 0);
		
		shader_set(sh_level);
			shader_set_uniform_f(uniform_black, _black);
			shader_set_uniform_f(uniform_white, _white);
			
			draw_surface(_data[0], 0, 0);
		shader_reset();
		surface_reset_target();
		
		return _outSurf;
	}
}