BitMap

Inherits: Resource < Reference < Object

Boolean matrix.

Description

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.

Methods

void	create ( Vector2 size )
void	create_from_image_alpha ( Image image, float threshold=0.1 )
bool	get_bit ( Vector2 position ) const
Vector2	get_size ( ) const
int	get_true_bit_count ( ) const
void	grow_mask ( int pixels, Rect2 rect )
Array	opaque_to_polygons ( Rect2 rect, float epsilon=2.0 ) const
void	set_bit ( Vector2 position, bool bit )
void	set_bit_rect ( Rect2 rect, bool bit )

Method Descriptions

void create ( Vector2 size )

Creates a bitmap with the specified size, filled with false.

void create_from_image_alpha ( Image image, float threshold=0.1 )

Creates a bitmap that matches the given image dimensions, every element of the bitmap is set to false if the alpha value of the image at that position is equal to threshold or less, and true in other case.

bool get_bit ( Vector2 position ) const

Returns bitmap's value at the specified position.

Vector2 get_size ( ) const

Returns bitmap's dimensions.

int get_true_bit_count ( ) const

Returns the amount of bitmap elements that are set to true.

void grow_mask ( int pixels, Rect2 rect )

Applies morphological dilation or erosion to the bitmap. If pixels is positive, dilation is applied to the bitmap. If pixels is negative, erosion is applied to the bitmap. rect defines the area where the morphological operation is applied. Pixels located outside the rect are unaffected by grow_mask.

Array opaque_to_polygons ( Rect2 rect, float epsilon=2.0 ) const

void set_bit ( Vector2 position, bool bit )

Sets the bitmap's element at the specified position, to the specified value.

void set_bit_rect ( Rect2 rect, bool bit )

Sets a rectangular portion of the bitmap to the specified value.