Pixel-Composer/scripts/node_edge_detect/node_edge_detect.gml

function Node_Edge_Detect(_x, _y, _group = -1) : Node_Processor(_x, _y, _group) constructor {
	name = "Edge detect";
	
	shader = sh_edge_detect;
	uniform_dim    = shader_get_uniform(shader, "dimension");
	uniform_filter = shader_get_uniform(shader, "filter");
	
	inputs[| 0] = nodeValue(0, "Surface in",	 self, JUNCTION_CONNECT.input, VALUE_TYPE.surface, 0);
	inputs[| 1] = nodeValue(1, "Filter",		 self, JUNCTION_CONNECT.input, VALUE_TYPE.integer, 0)
		.setDisplay(VALUE_DISPLAY.enum_scroll, ["Sobel", "Prewitt", "Laplacian"] );
	
	outputs[| 0] = nodeValue(0, "Surface out", self, JUNCTION_CONNECT.output, VALUE_TYPE.surface, PIXEL_SURFACE);
	
	static process_data = function(_outSurf, _data, _output_index) {
		var ft = _data[1];
		
		surface_set_target(_outSurf);
		draw_clear_alpha(0, 0);
		BLEND_OVER
		
		shader_set(shader);
			shader_set_uniform_f_array(uniform_dim, [surface_get_width(_data[0]), surface_get_height(_data[0])]);
			shader_set_uniform_i(uniform_filter, ft);
			draw_surface_safe(_data[0], 0, 0);
		shader_reset();
		
		BLEND_NORMAL
		surface_reset_target();
		
		return _outSurf;
	}
}