function draw_selection_box(ctx, rect_x, rect_y, rect_w, rect_h, scale, translate_x, translate_y) {
	draw_dashes(ctx, rect_x, rect_y, rect_w - 1, 0, scale, translate_x, translate_y); // top
	if (rect_h === 1) {
		draw_dashes(ctx, rect_x, rect_y, 0, 1, scale, translate_x, translate_y); // left
	} else {
		draw_dashes(ctx, rect_x, rect_y + 1, 0, rect_h - 2, scale, translate_x, translate_y); // left
	}
	draw_dashes(ctx, rect_x + rect_w - 1, rect_y, 0, rect_h, scale, translate_x, translate_y); // right
	draw_dashes(ctx, rect_x, rect_y + rect_h - 1, rect_w - 1, 0, scale, translate_x, translate_y); // bottom
	draw_dashes(ctx, rect_x, rect_y + 1, 0, 1, scale, translate_x, translate_y); // top left dangling bit???
}
@param {CanvasRenderingContext2D} ctx
@param {number} rect_x
@param {number} rect_y
@param {number} rect_w
@param {number} rect_h
@param {number} scale
@param {number} translate_x
@param {number} translate_y