godot-docs/classes/class_bitmap.rst

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.. _class_BitMap:

BitMap
======

**Inherits:** :ref:`Resource<class_Resource>` **<** :ref:`RefCounted<class_RefCounted>` **<** :ref:`Object<class_Object>`

Boolean matrix.

.. rst-class:: classref-introduction-group

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.

.. rst-class:: classref-reftable-group

Methods
-------

.. table::
   :widths: auto

   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Image<class_Image>`                                                        | :ref:`convert_to_image<class_BitMap_method_convert_to_image>`\ (\ ) |const|                                                                                       |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`create<class_BitMap_method_create>`\ (\ size\: :ref:`Vector2i<class_Vector2i>`\ )                                                                           |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`create_from_image_alpha<class_BitMap_method_create_from_image_alpha>`\ (\ image\: :ref:`Image<class_Image>`, threshold\: :ref:`float<class_float>` = 0.1\ ) |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`                                                          | :ref:`get_bit<class_BitMap_method_get_bit>`\ (\ x\: :ref:`int<class_int>`, y\: :ref:`int<class_int>`\ ) |const|                                                   |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`                                                          | :ref:`get_bitv<class_BitMap_method_get_bitv>`\ (\ position\: :ref:`Vector2i<class_Vector2i>`\ ) |const|                                                           |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Vector2i<class_Vector2i>`                                                  | :ref:`get_size<class_BitMap_method_get_size>`\ (\ ) |const|                                                                                                       |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`int<class_int>`                                                            | :ref:`get_true_bit_count<class_BitMap_method_get_true_bit_count>`\ (\ ) |const|                                                                                   |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`grow_mask<class_BitMap_method_grow_mask>`\ (\ pixels\: :ref:`int<class_int>`, rect\: :ref:`Rect2i<class_Rect2i>`\ )                                         |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Array<class_Array>`\[:ref:`PackedVector2Array<class_PackedVector2Array>`\] | :ref:`opaque_to_polygons<class_BitMap_method_opaque_to_polygons>`\ (\ rect\: :ref:`Rect2i<class_Rect2i>`, epsilon\: :ref:`float<class_float>` = 2.0\ ) |const|    |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`resize<class_BitMap_method_resize>`\ (\ new_size\: :ref:`Vector2i<class_Vector2i>`\ )                                                                       |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`set_bit<class_BitMap_method_set_bit>`\ (\ x\: :ref:`int<class_int>`, y\: :ref:`int<class_int>`, bit\: :ref:`bool<class_bool>`\ )                            |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`set_bit_rect<class_BitMap_method_set_bit_rect>`\ (\ rect\: :ref:`Rect2i<class_Rect2i>`, bit\: :ref:`bool<class_bool>`\ )                                    |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | |void|                                                                           | :ref:`set_bitv<class_BitMap_method_set_bitv>`\ (\ position\: :ref:`Vector2i<class_Vector2i>`, bit\: :ref:`bool<class_bool>`\ )                                    |
   +----------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Method Descriptions
-------------------

.. _class_BitMap_method_convert_to_image:

.. rst-class:: classref-method

:ref:`Image<class_Image>` **convert_to_image**\ (\ ) |const| :ref:`🔗<class_BitMap_method_convert_to_image>`

Returns an image of the same size as the bitmap and with an :ref:`Format<enum_Image_Format>` of type :ref:`Image.FORMAT_L8<class_Image_constant_FORMAT_L8>`. ``true`` bits of the bitmap are being converted into white pixels, and ``false`` bits into black.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_create:

.. rst-class:: classref-method

|void| **create**\ (\ size\: :ref:`Vector2i<class_Vector2i>`\ ) :ref:`🔗<class_BitMap_method_create>`

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

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_create_from_image_alpha:

.. rst-class:: classref-method

|void| **create_from_image_alpha**\ (\ image\: :ref:`Image<class_Image>`, threshold\: :ref:`float<class_float>` = 0.1\ ) :ref:`🔗<class_BitMap_method_create_from_image_alpha>`

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.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_get_bit:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **get_bit**\ (\ x\: :ref:`int<class_int>`, y\: :ref:`int<class_int>`\ ) |const| :ref:`🔗<class_BitMap_method_get_bit>`

Returns bitmap's value at the specified position.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_get_bitv:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **get_bitv**\ (\ position\: :ref:`Vector2i<class_Vector2i>`\ ) |const| :ref:`🔗<class_BitMap_method_get_bitv>`

Returns bitmap's value at the specified position.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_get_size:

.. rst-class:: classref-method

:ref:`Vector2i<class_Vector2i>` **get_size**\ (\ ) |const| :ref:`🔗<class_BitMap_method_get_size>`

Returns bitmap's dimensions.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_get_true_bit_count:

.. rst-class:: classref-method

:ref:`int<class_int>` **get_true_bit_count**\ (\ ) |const| :ref:`🔗<class_BitMap_method_get_true_bit_count>`

Returns the number of bitmap elements that are set to ``true``.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_grow_mask:

.. rst-class:: classref-method

|void| **grow_mask**\ (\ pixels\: :ref:`int<class_int>`, rect\: :ref:`Rect2i<class_Rect2i>`\ ) :ref:`🔗<class_BitMap_method_grow_mask>`

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 :ref:`grow_mask()<class_BitMap_method_grow_mask>`.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_opaque_to_polygons:

.. rst-class:: classref-method

:ref:`Array<class_Array>`\[:ref:`PackedVector2Array<class_PackedVector2Array>`\] **opaque_to_polygons**\ (\ rect\: :ref:`Rect2i<class_Rect2i>`, epsilon\: :ref:`float<class_float>` = 2.0\ ) |const| :ref:`🔗<class_BitMap_method_opaque_to_polygons>`

Creates an :ref:`Array<class_Array>` of polygons covering a rectangular portion of the bitmap. It uses a marching squares algorithm, followed by Ramer-Douglas-Peucker (RDP) reduction of the number of vertices. Each polygon is described as a :ref:`PackedVector2Array<class_PackedVector2Array>` of its vertices.

To get polygons covering the whole bitmap, pass:

::

    Rect2(Vector2(), get_size())

\ ``epsilon`` is passed to RDP to control how accurately the polygons cover the bitmap: a lower ``epsilon`` corresponds to more points in the polygons.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_resize:

.. rst-class:: classref-method

|void| **resize**\ (\ new_size\: :ref:`Vector2i<class_Vector2i>`\ ) :ref:`🔗<class_BitMap_method_resize>`

Resizes the image to ``new_size``.

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_set_bit:

.. rst-class:: classref-method

|void| **set_bit**\ (\ x\: :ref:`int<class_int>`, y\: :ref:`int<class_int>`, bit\: :ref:`bool<class_bool>`\ ) :ref:`🔗<class_BitMap_method_set_bit>`

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

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_set_bit_rect:

.. rst-class:: classref-method

|void| **set_bit_rect**\ (\ rect\: :ref:`Rect2i<class_Rect2i>`, bit\: :ref:`bool<class_bool>`\ ) :ref:`🔗<class_BitMap_method_set_bit_rect>`

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

.. rst-class:: classref-item-separator

----

.. _class_BitMap_method_set_bitv:

.. rst-class:: classref-method

|void| **set_bitv**\ (\ position\: :ref:`Vector2i<class_Vector2i>`, bit\: :ref:`bool<class_bool>`\ ) :ref:`🔗<class_BitMap_method_set_bitv>`

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

.. |virtual| replace:: :abbr:`virtual (This method should typically be overridden by the user to have any effect.)`
.. |required| replace:: :abbr:`required (This method is required to be overridden when extending its base class.)`
.. |const| replace:: :abbr:`const (This method has no side effects. It doesn't modify any of the instance's member variables.)`
.. |vararg| replace:: :abbr:`vararg (This method accepts any number of arguments after the ones described here.)`
.. |constructor| replace:: :abbr:`constructor (This method is used to construct a type.)`
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`
.. |operator| replace:: :abbr:`operator (This method describes a valid operator to use with this type as left-hand operand.)`
.. |bitfield| replace:: :abbr:`BitField (This value is an integer composed as a bitmask of the following flags.)`
.. |void| replace:: :abbr:`void (No return value.)`