Pixel-Composer/scripts/buffer_functions/buffer_functions.gml

function buffer_get_color(buffer, _x, _y, w, h) {
	buffer_seek(buffer, buffer_seek_start, (w * _y + _x) * 4);
	var c = buffer_read(buffer, buffer_u32);
	
	return c;
}

function buffer_get_string(buffer, text = true) {
	buffer_seek(buffer, buffer_seek_start, 0);
	var len = buffer_get_size(buffer);
    var ss = "";
    
    for (var i = 0; i < len; i++) {
		var _r = buffer_read(buffer, buffer_u8);
		var _s = text? chr(_r) : dec_to_hex(_r, 2);
        ss += _s;
		if(!text && i % 2) ss += " ";
	}
    
    return ss;
}

function buffer_from_string(str) {
	var _b = buffer_create(string_length(str) * 1, buffer_fast, 1);
	for( var i = 1; i <= string_length(str); i++ ) 
		buffer_write(_b, buffer_u8, ord(string_char_at(str, i)));
	return _b;
}

function buffer_from_surface(surface, size = true) {
	static header_length = 24;
	if(!is_surface(surface)) return noone;
	
	var bitSize = surface_format_get_bytes(surface_get_format(surface));
	
	var _b = buffer_create((header_length * size) + surface_get_width(surface) * surface_get_height(surface) * bitSize, buffer_fixed, 1);
	if(size) {
		buffer_write(_b, buffer_text, "PXCS");
		buffer_write(_b, buffer_u16, surface_get_width(surface));
		buffer_write(_b, buffer_u16, surface_get_height(surface));
		buffer_write(_b, buffer_u8, surface_get_format(surface));
	}
	
	buffer_get_surface(_b, surface, header_length * size);
	return _b;
}

function buffer_from_file(path) {
	if(!file_exists(path)) return;
	var _b = buffer_load(path);
	return _b;
}

function buffer_read_at(buffer, position, type) {
	buffer_seek(buffer, buffer_seek_start, position);
	return buffer_read(buffer, type);
}