Boolean matrix. A two-dimensional array of boolean values, can be used to efficiently store a binary matrix (every matrix element takes only one bit) and query the values using natural cartesian coordinates. Creates a bitmap with the specified size, filled with [code]false[/code]. Creates a bitmap that matches the given image dimensions, every element of the bitmap is set to [code]false[/code] if the alpha value of the image at that position is equal to [code]threshold[/code] or less, and [code]true[/code] in other case. Returns bitmap's value at the specified position. Returns bitmap's dimensions. Returns the amount of bitmap elements that are set to [code]true[/code]. Applies morphological dilation or erosion to the bitmap. If [code]pixels[/code] is positive, dilation is applied to the bitmap. If [code]pixels[/code] is negative, erosion is applied to the bitmap. [code]rect[/code] defines the area where the morphological operation is applied. Pixels located outside the [code]rect[/code] are unaffected by [method grow_mask]. Sets the bitmap's element at the specified position, to the specified value. Sets a rectangular portion of the bitmap to the specified value.