Module pyboy.api.screen

This class gives access to the frame buffer and other screen parameters of PyBoy.

Expand source code
#
# License: See LICENSE.md file
# GitHub: https://github.com/Baekalfen/PyBoy
#
"""
This class gives access to the frame buffer and other screen parameters of PyBoy.
"""

import numpy as np

from pyboy import utils
from pyboy.logging import get_logger

from .constants import COLS, ROWS

logger = get_logger(__name__)

try:
    from PIL import Image
except ImportError:
    Image = None


class Screen:
    """
    As part of the emulation, we generate a screen buffer in 32-bit RGBA format. This class has several helper methods
    to make it possible to read this buffer out.

    If you're making an AI or bot, it's highly recommended to _not_ use this class for detecting objects on the screen.
    It's much more efficient to use `pyboy.PyBoy.tilemap_background`, `pyboy.PyBoy.tilemap_window`, and `pyboy.PyBoy.get_sprite` instead.
    """
    def __init__(self, mb):
        self.mb = mb

        self.raw_buffer = self.mb.lcd.renderer._screenbuffer
        """
        Provides a raw, unfiltered `bytes` object with the data from the screen. Check
        `Screen.raw_buffer_format` to see which dataformat is used. **The returned type and dataformat are
        subject to change.** The screen buffer is row-major.

        Use this, only if you need to bypass the overhead of `Screen.image` or `Screen.ndarray`.

        Example:
        ```python
        >>> import numpy as np
        >>> rows, cols = pyboy.screen.raw_buffer_dims
        >>> ndarray = np.frombuffer(
        ...     pyboy.screen.raw_buffer,
        ...     dtype=np.uint8,
        ... ).reshape(rows, cols, 4) # Just an example, use pyboy.screen.ndarray instead

        ```

        Returns
        -------
        bytes:
            92160 bytes of screen data in a `bytes` object.
        """
        self.raw_buffer_dims = self.mb.lcd.renderer.buffer_dims
        """
        Returns the dimensions of the raw screen buffer. The screen buffer is row-major.

        Example:
        ```python
        >>> pyboy.screen.raw_buffer_dims
        (144, 160)

        ```

        Returns
        -------
        tuple:
            A two-tuple of the buffer dimensions. E.g. (144, 160).
        """
        self.raw_buffer_format = self.mb.lcd.renderer.color_format
        """
        Returns the color format of the raw screen buffer. **This format is subject to change.**

        Example:
        ```python
        >>> from PIL import Image
        >>> pyboy.screen.raw_buffer_format
        'RGBA'
        >>> image = Image.frombuffer(
        ...    pyboy.screen.raw_buffer_format,
        ...    pyboy.screen.raw_buffer_dims[::-1],
        ...    pyboy.screen.raw_buffer,
        ... ) # Just an example, use pyboy.screen.image instead
        >>> image.save('frame.png')

        ```

        Returns
        -------
        str:
            Color format of the raw screen buffer. E.g. 'RGBA'.
        """
        self.image = None
        """
        Reference to a PIL Image from the screen buffer. **Remember to copy, resize or convert this object** if you
        intend to store it. The backing buffer will update, but it will be the same `PIL.Image` object.

        Convenient for screen captures, but might be a bottleneck, if you use it to train a neural network. In which
        case, read up on the `pyboy.api` features, [Pan Docs](https://gbdev.io/pandocs/) on tiles/sprites,
        and join our Discord channel for more help.

        Example:
        ```python
        >>> image = pyboy.screen.image
        >>> type(image)
        <class 'PIL.Image.Image'>
        >>> image.save('frame.png')

        ```

        Returns
        -------
        PIL.Image:
            RGB image of (160, 144) pixels
        """
        if not Image:
            logger.warning("Cannot generate screen image. Missing dependency \"Pillow\".")
        else:
            self._set_image()

        self.ndarray = np.frombuffer(
            self.mb.lcd.renderer._screenbuffer_raw,
            dtype=np.uint8,
        ).reshape(ROWS, COLS, 4)
        """
        References the screen data in NumPy format. **Remember to copy this object** if you intend to store it.
        The backing buffer will update, but it will be the same `ndarray` object.

        The format is given by `pyboy.api.screen.Screen.raw_buffer_format`. The screen buffer is row-major.

        Example:
        ```python
        >>> pyboy.screen.ndarray.shape
        (144, 160, 4)
        >>> # Display "P" on screen from the PyBoy bootrom
        >>> pyboy.screen.ndarray[66:80,64:72,0]
        array([[255, 255, 255, 255, 255, 255, 255, 255],
               [255,   0,   0,   0,   0,   0, 255, 255],
               [255,   0,   0,   0,   0,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0,   0,   0,   0,   0, 255],
               [255,   0,   0,   0,   0,   0, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255, 255, 255, 255, 255, 255, 255, 255]], dtype=uint8)

        ```

        Returns
        -------
        numpy.ndarray:
            Screendata in `ndarray` of bytes with shape (144, 160, 4)
        """

    def _set_image(self):
        self.image = Image.frombuffer(
            self.mb.lcd.renderer.color_format, self.mb.lcd.renderer.buffer_dims[::-1],
            self.mb.lcd.renderer._screenbuffer_raw
        )

    @property
    def tilemap_position_list(self):
        """
        This function provides the screen (SCX, SCY) and window (WX. WY) position for each horizontal line in the
        screen buffer. These parameters are often used for visual effects, and some games will reset the registers at
        the end of each call to `pyboy.PyBoy.tick()`.

        See `Screen.get_tilemap_position` for more information.

        Example:
        ```python
        >>> pyboy.tick(25)
        True
        >>> swoosh = pyboy.screen.tilemap_position_list[67:78]
        >>> print(*swoosh, sep=newline) # Just to pretty-print it
        [0, 0, -7, 0]
        [1, 0, -7, 0]
        [2, 0, -7, 0]
        [2, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [2, 0, -7, 0]
        [1, 0, -7, 0]
        [0, 0, -7, 0]

        ```

        Returns
        -------
        list:
            Nested list of SCX, SCY, WX and WY for each scanline (144x4). Returns (0, 0, 0, 0) when LCD is off.
        """

        if self.mb.lcd._LCDC.lcd_enable:
            return [[line[0], line[1], line[2], line[3]] for line in self.mb.lcd._scanlineparameters]
        else:
            return [[0, 0, 0, 0] for line in range(144)]

    def get_tilemap_position(self):
        """
        These coordinates define the offset in the tile map from where the top-left corner of the screen is place. Note
        that the tile map defines 256x256 pixels, but the screen can only show 160x144 pixels. When the offset is closer
        to the right or bottom edge than 160x144 pixels, the screen will wrap around and render from the opposite site
        of the tile map.

        For more details, see "7.4 Viewport" in the [report](https://github.com/Baekalfen/PyBoy/raw/master/extras/PyBoy.pdf),
        or the Pan Docs under [LCD Position and Scrolling](https://gbdev.io/pandocs/Scrolling.html).

        Example:
        ```python
        >>> pyboy.screen.get_tilemap_position()
        ((0, 0), (-7, 0))

        ```

        Returns
        -------
        tuple:
            Returns the tuple of registers ((SCX, SCY), (WX - 7, WY))
        """
        return (self.mb.lcd.getviewport(), self.mb.lcd.getwindowpos())

Classes

class Screen (mb)

As part of the emulation, we generate a screen buffer in 32-bit RGBA format. This class has several helper methods to make it possible to read this buffer out.

If you're making an AI or bot, it's highly recommended to not use this class for detecting objects on the screen. It's much more efficient to use PyBoy.tilemap_background, PyBoy.tilemap_window, and PyBoy.get_sprite() instead.

Expand source code
class Screen:
    """
    As part of the emulation, we generate a screen buffer in 32-bit RGBA format. This class has several helper methods
    to make it possible to read this buffer out.

    If you're making an AI or bot, it's highly recommended to _not_ use this class for detecting objects on the screen.
    It's much more efficient to use `pyboy.PyBoy.tilemap_background`, `pyboy.PyBoy.tilemap_window`, and `pyboy.PyBoy.get_sprite` instead.
    """
    def __init__(self, mb):
        self.mb = mb

        self.raw_buffer = self.mb.lcd.renderer._screenbuffer
        """
        Provides a raw, unfiltered `bytes` object with the data from the screen. Check
        `Screen.raw_buffer_format` to see which dataformat is used. **The returned type and dataformat are
        subject to change.** The screen buffer is row-major.

        Use this, only if you need to bypass the overhead of `Screen.image` or `Screen.ndarray`.

        Example:
        ```python
        >>> import numpy as np
        >>> rows, cols = pyboy.screen.raw_buffer_dims
        >>> ndarray = np.frombuffer(
        ...     pyboy.screen.raw_buffer,
        ...     dtype=np.uint8,
        ... ).reshape(rows, cols, 4) # Just an example, use pyboy.screen.ndarray instead

        ```

        Returns
        -------
        bytes:
            92160 bytes of screen data in a `bytes` object.
        """
        self.raw_buffer_dims = self.mb.lcd.renderer.buffer_dims
        """
        Returns the dimensions of the raw screen buffer. The screen buffer is row-major.

        Example:
        ```python
        >>> pyboy.screen.raw_buffer_dims
        (144, 160)

        ```

        Returns
        -------
        tuple:
            A two-tuple of the buffer dimensions. E.g. (144, 160).
        """
        self.raw_buffer_format = self.mb.lcd.renderer.color_format
        """
        Returns the color format of the raw screen buffer. **This format is subject to change.**

        Example:
        ```python
        >>> from PIL import Image
        >>> pyboy.screen.raw_buffer_format
        'RGBA'
        >>> image = Image.frombuffer(
        ...    pyboy.screen.raw_buffer_format,
        ...    pyboy.screen.raw_buffer_dims[::-1],
        ...    pyboy.screen.raw_buffer,
        ... ) # Just an example, use pyboy.screen.image instead
        >>> image.save('frame.png')

        ```

        Returns
        -------
        str:
            Color format of the raw screen buffer. E.g. 'RGBA'.
        """
        self.image = None
        """
        Reference to a PIL Image from the screen buffer. **Remember to copy, resize or convert this object** if you
        intend to store it. The backing buffer will update, but it will be the same `PIL.Image` object.

        Convenient for screen captures, but might be a bottleneck, if you use it to train a neural network. In which
        case, read up on the `pyboy.api` features, [Pan Docs](https://gbdev.io/pandocs/) on tiles/sprites,
        and join our Discord channel for more help.

        Example:
        ```python
        >>> image = pyboy.screen.image
        >>> type(image)
        <class 'PIL.Image.Image'>
        >>> image.save('frame.png')

        ```

        Returns
        -------
        PIL.Image:
            RGB image of (160, 144) pixels
        """
        if not Image:
            logger.warning("Cannot generate screen image. Missing dependency \"Pillow\".")
        else:
            self._set_image()

        self.ndarray = np.frombuffer(
            self.mb.lcd.renderer._screenbuffer_raw,
            dtype=np.uint8,
        ).reshape(ROWS, COLS, 4)
        """
        References the screen data in NumPy format. **Remember to copy this object** if you intend to store it.
        The backing buffer will update, but it will be the same `ndarray` object.

        The format is given by `pyboy.api.screen.Screen.raw_buffer_format`. The screen buffer is row-major.

        Example:
        ```python
        >>> pyboy.screen.ndarray.shape
        (144, 160, 4)
        >>> # Display "P" on screen from the PyBoy bootrom
        >>> pyboy.screen.ndarray[66:80,64:72,0]
        array([[255, 255, 255, 255, 255, 255, 255, 255],
               [255,   0,   0,   0,   0,   0, 255, 255],
               [255,   0,   0,   0,   0,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0, 255, 255,   0,   0, 255],
               [255,   0,   0,   0,   0,   0,   0, 255],
               [255,   0,   0,   0,   0,   0, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255,   0,   0, 255, 255, 255, 255, 255],
               [255, 255, 255, 255, 255, 255, 255, 255]], dtype=uint8)

        ```

        Returns
        -------
        numpy.ndarray:
            Screendata in `ndarray` of bytes with shape (144, 160, 4)
        """

    def _set_image(self):
        self.image = Image.frombuffer(
            self.mb.lcd.renderer.color_format, self.mb.lcd.renderer.buffer_dims[::-1],
            self.mb.lcd.renderer._screenbuffer_raw
        )

    @property
    def tilemap_position_list(self):
        """
        This function provides the screen (SCX, SCY) and window (WX. WY) position for each horizontal line in the
        screen buffer. These parameters are often used for visual effects, and some games will reset the registers at
        the end of each call to `pyboy.PyBoy.tick()`.

        See `Screen.get_tilemap_position` for more information.

        Example:
        ```python
        >>> pyboy.tick(25)
        True
        >>> swoosh = pyboy.screen.tilemap_position_list[67:78]
        >>> print(*swoosh, sep=newline) # Just to pretty-print it
        [0, 0, -7, 0]
        [1, 0, -7, 0]
        [2, 0, -7, 0]
        [2, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [3, 0, -7, 0]
        [2, 0, -7, 0]
        [1, 0, -7, 0]
        [0, 0, -7, 0]

        ```

        Returns
        -------
        list:
            Nested list of SCX, SCY, WX and WY for each scanline (144x4). Returns (0, 0, 0, 0) when LCD is off.
        """

        if self.mb.lcd._LCDC.lcd_enable:
            return [[line[0], line[1], line[2], line[3]] for line in self.mb.lcd._scanlineparameters]
        else:
            return [[0, 0, 0, 0] for line in range(144)]

    def get_tilemap_position(self):
        """
        These coordinates define the offset in the tile map from where the top-left corner of the screen is place. Note
        that the tile map defines 256x256 pixels, but the screen can only show 160x144 pixels. When the offset is closer
        to the right or bottom edge than 160x144 pixels, the screen will wrap around and render from the opposite site
        of the tile map.

        For more details, see "7.4 Viewport" in the [report](https://github.com/Baekalfen/PyBoy/raw/master/extras/PyBoy.pdf),
        or the Pan Docs under [LCD Position and Scrolling](https://gbdev.io/pandocs/Scrolling.html).

        Example:
        ```python
        >>> pyboy.screen.get_tilemap_position()
        ((0, 0), (-7, 0))

        ```

        Returns
        -------
        tuple:
            Returns the tuple of registers ((SCX, SCY), (WX - 7, WY))
        """
        return (self.mb.lcd.getviewport(), self.mb.lcd.getwindowpos())

Instance variables

var tilemap_position_list

This function provides the screen (SCX, SCY) and window (WX. WY) position for each horizontal line in the screen buffer. These parameters are often used for visual effects, and some games will reset the registers at the end of each call to PyBoy.tick().

See Screen.get_tilemap_position() for more information.

Example:

>>> pyboy.tick(25)
True
>>> swoosh = pyboy.screen.tilemap_position_list[67:78]
>>> print(*swoosh, sep=newline) # Just to pretty-print it
[0, 0, -7, 0]
[1, 0, -7, 0]
[2, 0, -7, 0]
[2, 0, -7, 0]
[3, 0, -7, 0]
[3, 0, -7, 0]
[3, 0, -7, 0]
[3, 0, -7, 0]
[2, 0, -7, 0]
[1, 0, -7, 0]
[0, 0, -7, 0]

Returns

list:
Nested list of SCX, SCY, WX and WY for each scanline (144x4). Returns (0, 0, 0, 0) when LCD is off.
Expand source code
@property
def tilemap_position_list(self):
    """
    This function provides the screen (SCX, SCY) and window (WX. WY) position for each horizontal line in the
    screen buffer. These parameters are often used for visual effects, and some games will reset the registers at
    the end of each call to `pyboy.PyBoy.tick()`.

    See `Screen.get_tilemap_position` for more information.

    Example:
    ```python
    >>> pyboy.tick(25)
    True
    >>> swoosh = pyboy.screen.tilemap_position_list[67:78]
    >>> print(*swoosh, sep=newline) # Just to pretty-print it
    [0, 0, -7, 0]
    [1, 0, -7, 0]
    [2, 0, -7, 0]
    [2, 0, -7, 0]
    [3, 0, -7, 0]
    [3, 0, -7, 0]
    [3, 0, -7, 0]
    [3, 0, -7, 0]
    [2, 0, -7, 0]
    [1, 0, -7, 0]
    [0, 0, -7, 0]

    ```

    Returns
    -------
    list:
        Nested list of SCX, SCY, WX and WY for each scanline (144x4). Returns (0, 0, 0, 0) when LCD is off.
    """

    if self.mb.lcd._LCDC.lcd_enable:
        return [[line[0], line[1], line[2], line[3]] for line in self.mb.lcd._scanlineparameters]
    else:
        return [[0, 0, 0, 0] for line in range(144)]
var raw_buffer

Provides a raw, unfiltered bytes object with the data from the screen. Check Screen.raw_buffer_format to see which dataformat is used. The returned type and dataformat are subject to change. The screen buffer is row-major.

Use this, only if you need to bypass the overhead of Screen.image or Screen.ndarray.

Example:

>>> import numpy as np
>>> rows, cols = pyboy.screen.raw_buffer_dims
>>> ndarray = np.frombuffer(
...     pyboy.screen.raw_buffer,
...     dtype=np.uint8,
... ).reshape(rows, cols, 4) # Just an example, use pyboy.screen.ndarray instead

Returns

bytes:
92160 bytes of screen data in a bytes object.
var raw_buffer_dims

Returns the dimensions of the raw screen buffer. The screen buffer is row-major.

Example:

>>> pyboy.screen.raw_buffer_dims
(144, 160)

Returns

tuple:
A two-tuple of the buffer dimensions. E.g. (144, 160).
var raw_buffer_format

Returns the color format of the raw screen buffer. This format is subject to change.

Example:

>>> from PIL import Image
>>> pyboy.screen.raw_buffer_format
'RGBA'
>>> image = Image.frombuffer(
...    pyboy.screen.raw_buffer_format,
...    pyboy.screen.raw_buffer_dims[::-1],
...    pyboy.screen.raw_buffer,
... ) # Just an example, use pyboy.screen.image instead
>>> image.save('frame.png')

Returns

str:
Color format of the raw screen buffer. E.g. 'RGBA'.
var image

Reference to a PIL Image from the screen buffer. Remember to copy, resize or convert this object if you intend to store it. The backing buffer will update, but it will be the same PIL.Image object.

Convenient for screen captures, but might be a bottleneck, if you use it to train a neural network. In which case, read up on the pyboy.api features, Pan Docs on tiles/sprites, and join our Discord channel for more help.

Example:

>>> image = pyboy.screen.image
>>> type(image)
<class 'PIL.Image.Image'>
>>> image.save('frame.png')

Returns

PIL.Image:
RGB image of (160, 144) pixels
var ndarray

References the screen data in NumPy format. Remember to copy this object if you intend to store it. The backing buffer will update, but it will be the same ndarray object.

The format is given by Screen.raw_buffer_format. The screen buffer is row-major.

Example:

>>> pyboy.screen.ndarray.shape
(144, 160, 4)
>>> # Display "P" on screen from the PyBoy bootrom
>>> pyboy.screen.ndarray[66:80,64:72,0]
array([[255, 255, 255, 255, 255, 255, 255, 255],
       [255,   0,   0,   0,   0,   0, 255, 255],
       [255,   0,   0,   0,   0,   0,   0, 255],
       [255,   0,   0, 255, 255,   0,   0, 255],
       [255,   0,   0, 255, 255,   0,   0, 255],
       [255,   0,   0, 255, 255,   0,   0, 255],
       [255,   0,   0,   0,   0,   0,   0, 255],
       [255,   0,   0,   0,   0,   0, 255, 255],
       [255,   0,   0, 255, 255, 255, 255, 255],
       [255,   0,   0, 255, 255, 255, 255, 255],
       [255,   0,   0, 255, 255, 255, 255, 255],
       [255,   0,   0, 255, 255, 255, 255, 255],
       [255,   0,   0, 255, 255, 255, 255, 255],
       [255, 255, 255, 255, 255, 255, 255, 255]], dtype=uint8)

Returns

numpy.ndarray:
Screendata in ndarray of bytes with shape (144, 160, 4)

Methods

def get_tilemap_position(self)

These coordinates define the offset in the tile map from where the top-left corner of the screen is place. Note that the tile map defines 256x256 pixels, but the screen can only show 160x144 pixels. When the offset is closer to the right or bottom edge than 160x144 pixels, the screen will wrap around and render from the opposite site of the tile map.

For more details, see "7.4 Viewport" in the report, or the Pan Docs under LCD Position and Scrolling.

Example:

>>> pyboy.screen.get_tilemap_position()
((0, 0), (-7, 0))

Returns

tuple:
Returns the tuple of registers ((SCX, SCY), (WX - 7, WY))
Expand source code
def get_tilemap_position(self):
    """
    These coordinates define the offset in the tile map from where the top-left corner of the screen is place. Note
    that the tile map defines 256x256 pixels, but the screen can only show 160x144 pixels. When the offset is closer
    to the right or bottom edge than 160x144 pixels, the screen will wrap around and render from the opposite site
    of the tile map.

    For more details, see "7.4 Viewport" in the [report](https://github.com/Baekalfen/PyBoy/raw/master/extras/PyBoy.pdf),
    or the Pan Docs under [LCD Position and Scrolling](https://gbdev.io/pandocs/Scrolling.html).

    Example:
    ```python
    >>> pyboy.screen.get_tilemap_position()
    ((0, 0), (-7, 0))

    ```

    Returns
    -------
    tuple:
        Returns the tuple of registers ((SCX, SCY), (WX - 7, WY))
    """
    return (self.mb.lcd.getviewport(), self.mb.lcd.getwindowpos())