functions for reading and writing tilemaps from and to buffers

tilemap_get_buffer.gml

/**
 * writes a tilemap to a buffer
 * @param {id.TileMapElement} map the tilemap source
 * @return {id.Buffer}
 */
function buffer_get_tilemap(map) {
	var width = tilemap_get_width(map);
	var height = tilemap_get_height(map);
	var buffer = buffer_create(width * height * buffer_sizeof(buffer_u32), buffer_fixed, 1);
	for (var i = 0; i < width; i++) {
		for (var j = 0; j < height; j++) {
			buffer_write(buffer, buffer_u32, tilemap_get(map, i, j));	
		}
	}
	return buffer;
}

/**
 * writes a tilemap to a buffer
 * @param {id.TileMapElement} map the tilemap destination
 * @param {id.Buffer} buffer the buffer source
 */
function buffer_set_tilemap(map, buffer) {
	var width = tilemap_get_width(map);
	var height = tilemap_get_height(map);
	for (var i = 0; i < width; i++) {
		for (var j = 0; j < height; j++) {
			tilemap_set(map, buffer_read(buffer, buffer_u32), i, j);
		}
	}
}

/**
 * writes a tilemap to a buffer within a specific position and size
 * @param {id.TileMapElement} map the tilemap source
 * @return {id.Buffer}
 */
function buffer_get_tilemap_ext(map, x, y, width, height) {
	var buffer = buffer_create(width * height * buffer_sizeof(buffer_u32), buffer_fixed, 1);
	for (var i = x, il = x + width; i < il; i++) {
		for (var j = y, jl = y + height; j < jl; j++) {
			buffer_write(buffer, buffer_u32, tilemap_get(map, i, j));	
		}
	}
	return buffer;
}

/**
 * writes a tilemap to a buffer in a specific position and size
 * @param {id.TileMapElement} map the tilemap destination
 * @param {id.Buffer} buffer the buffer source
 */
function buffer_set_tilemap_ext(map, buffer, x, y, width, height) {
	for (var i = x, il = x + width; i < il; i++) {
		for (var j = y, jl = y + height; j < jl; j++) {
			tilemap_set(map, buffer_read(buffer, buffer_u32), i, j);
		}
	}
}