adding docstrings and copyright.

Author: FoamyGuy

bitmaptools/__init__.py

@@ -1,3 +1,10 @@
+# SPDX-FileCopyrightText: 2025 Tim Cocks
+#
+# SPDX-License-Identifier: MIT
+"""
+Collection of bitmap manipulation tools
+"""
+
 import math
 import struct
 from typing import Optional, Tuple, BinaryIO
@@ -7,12 +14,32 @@
 
 # pylint: disable=invalid-name, too-many-arguments, too-many-locals, too-many-branches, too-many-statements
 def fill_region(dest_bitmap: Bitmap, x1: int, y1: int, x2: int, y2: int, value: int):
+    """Draws the color value into the destination bitmap within the
+    rectangular region bounded by (x1,y1) and (x2,y2), exclusive.
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param int x1: x-pixel position of the first corner of the rectangular fill region
+    :param int y1: y-pixel position of the first corner of the rectangular fill region
+    :param int x2: x-pixel position of the second corner of the rectangular fill region (exclusive)
+    :param int y2: y-pixel position of the second corner of the rectangular fill region (exclusive)
+    :param int value: Bitmap palette index that will be written into the rectangular
+           fill region in the destination bitmap"""
+
     for y in range(y1, y2):
         for x in range(x1, x2):
             dest_bitmap[x, y] = value
 
 
 def draw_line(dest_bitmap: Bitmap, x1: int, y1: int, x2: int, y2: int, value: int):
+    """Draws a line into a bitmap specified two endpoints (x1,y1) and (x2,y2).
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param int x1: x-pixel position of the line's first endpoint
+    :param int y1: y-pixel position of the line's first endpoint
+    :param int x2: x-pixel position of the line's second endpoint
+    :param int y2: y-pixel position of the line's second endpoint
+    :param int value: Bitmap palette index that will be written into the
+        line in the destination bitmap"""
     dx = abs(x2 - x1)
     sx = 1 if x1 < x2 else -1
     dy = -abs(y2 - y1)
@@ -33,6 +60,15 @@ def draw_line(dest_bitmap: Bitmap, x1: int, y1: int, x2: int, y2: int, value: in
 
 
 def draw_circle(dest_bitmap: Bitmap, x: int, y: int, radius: int, value: int):
+    """Draws a circle into a bitmap specified using a center (x0,y0) and radius r.
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param int x: x-pixel position of the circle's center
+    :param int y: y-pixel position of the circle's center
+    :param int radius: circle's radius
+    :param int value: Bitmap palette index that will be written into the
+           circle in the destination bitmap"""
+
     x = max(0, min(x, dest_bitmap.width - 1))
     y = max(0, min(y, dest_bitmap.height - 1))
 
@@ -66,6 +102,15 @@ def draw_polygon(
     value: int,
     close: bool = True,
 ):
+    """Draw a polygon connecting points on provided bitmap with provided value
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param ReadableBuffer xs: x-pixel position of the polygon's vertices
+    :param ReadableBuffer ys: y-pixel position of the polygon's vertices
+    :param int value: Bitmap palette index that will be written into the
+           line in the destination bitmap
+    :param bool close: (Optional) Whether to connect first and last point. (True)
+    """
     if len(xs) != len(ys):
         raise ValueError("Length of xs and ys must be equal.")
 
@@ -107,7 +152,33 @@ def blit(
     skip_source_index: int | None = None,
     skip_dest_index: int | None = None,
 ):
-    """Inserts the source_bitmap region defined by rectangular boundaries"""
+    """Inserts the source_bitmap region defined by rectangular boundaries
+    (x1,y1) and (x2,y2) into the bitmap at the specified (x,y) location.
+
+    :param bitmap dest_bitmap: Destination bitmap that the area will
+     be copied into.
+    :param bitmap source_bitmap: Source bitmap that contains the graphical
+     region to be copied
+    :param int x: Horizontal pixel location in bitmap where source_bitmap
+                  upper-left corner will be placed
+    :param int y: Vertical pixel location in bitmap where source_bitmap upper-left
+                  corner will be placed
+    :param int x1: Minimum x-value for rectangular bounding box to be
+     copied from the source bitmap
+    :param int y1: Minimum y-value for rectangular bounding box to be
+     copied from the source bitmap
+    :param int x2: Maximum x-value (exclusive) for rectangular
+     bounding box to be copied from the source bitmap.
+     If unspecified or `None`, the source bitmap width is used.
+    :param int y2: Maximum y-value (exclusive) for rectangular
+     bounding box to be copied from the source bitmap.
+     If unspecified or `None`, the source bitmap height is used.
+    :param int skip_source_index: bitmap palette index in the source that
+     will not be copied, set to None to copy all pixels
+    :param int skip_dest_index: bitmap palette index in the
+     destination bitmap that will not get overwritten by the
+     pixels from the source"""
+
     # pylint: disable=invalid-name
     if x2 is None:
         x2 = source_bitmap.width
@@ -167,6 +238,37 @@ def rotozoom(
     scale: Optional[float] = None,
     skip_index: Optional[int] = None,
 ):
+    """Inserts the source bitmap region into the destination bitmap with rotation
+    (angle), scale and clipping (both on source and destination bitmaps).
+
+    :param bitmap dest_bitmap: Destination bitmap that will be copied into
+    :param bitmap source_bitmap: Source bitmap that contains the graphical region to be copied
+    :param int ox: Horizontal pixel location in destination bitmap where source bitmap
+           point (px,py) is placed. Defaults to None which causes it to use the horizontal
+           midway point of the destination bitmap.
+    :param int oy: Vertical pixel location in destination bitmap where source bitmap
+           point (px,py) is placed. Defaults to None which causes it to use the vertical
+           midway point of the destination bitmap.
+    :param Tuple[int,int] dest_clip0: First corner of rectangular destination clipping
+           region that constrains region of writing into destination bitmap
+    :param Tuple[int,int] dest_clip1: Second corner of rectangular destination clipping
+           region that constrains region of writing into destination bitmap
+    :param int px: Horizontal pixel location in source bitmap that is placed into the
+           destination bitmap at (ox,oy). Defaults to None which causes it to use the
+           horizontal midway point in the source bitmap.
+    :param int py: Vertical pixel location in source bitmap that is placed into the
+           destination bitmap at (ox,oy). Defaults to None which causes it to use the
+           vertical midway point in the source bitmap.
+    :param Tuple[int,int] source_clip0: First corner of rectangular source clipping
+           region that constrains region of reading from the source bitmap
+    :param Tuple[int,int] source_clip1: Second corner of rectangular source clipping
+           region that constrains region of reading from the source bitmap
+    :param float angle: Angle of rotation, in radians (positive is clockwise direction).
+           Defaults to None which gets treated as 0.0 radians or no rotation.
+    :param float scale: Scaling factor. Defaults to None which gets treated as 1.0 or same
+           as original source size.
+    :param int skip_index: Bitmap palette index in the source that will not be copied,
+           set to None to copy all pixels"""
     if ox is None:
         ox = dest_bitmap.width // 2
     if oy is None:
@@ -277,6 +379,35 @@ def arrayblit(
     y2: Optional[int] = None,
     skip_index: Optional[int] = None,
 ):
+    """Inserts pixels from ``data`` into the rectangle
+     of width×height pixels with the upper left corner at ``(x,y)``
+
+    The values from ``data`` are taken modulo the number of color values
+    available in the destination bitmap.
+
+    If x1 or y1 are not specified, they are taken as 0.  If x2 or y2
+    are not specified, or are given as None, they are taken as the width
+    and height of the image.
+
+    The coordinates affected by the blit are
+    ``x1 <= x < x2`` and ``y1 <= y < y2``.
+
+    ``data`` must contain at least as many elements as required.  If it
+    contains excess elements, they are ignored.
+
+    The blit takes place by rows, so the first elements of ``data`` go
+    to the first row, the next elements to the next row, and so on.
+
+    :param displayio.Bitmap bitmap: A writable bitmap
+    :param ReadableBuffer data: Buffer containing the source pixel values
+    :param int x1: The left corner of the area to blit into (inclusive)
+    :param int y1: The top corner of the area to blit into (inclusive)
+    :param int x2: The right of the area to blit into (exclusive)
+    :param int y2: The bottom corner of the area to blit into (exclusive)
+    :param int skip_index: Bitmap palette index in the source
+     that will not be copied, set to None to copy all pixels
+
+    """
     if x2 is None:
         x2 = bitmap.width
     if y2 is None:
@@ -300,6 +431,34 @@ def readinto(
     swap_bytes: bool = False,
     reverse_rows: bool = False,
 ):
+    """Reads from a binary file into a bitmap.
+
+    The file must be positioned so that it consists of ``bitmap.height``
+    rows of pixel data, where each row is the smallest multiple
+    of ``element_size`` bytes that can hold ``bitmap.width`` pixels.
+
+    The bytes in an element can be optionally swapped, and the pixels
+    in an element can be reversed.  Also, therow loading direction can
+     be reversed, which may be requires for loading certain bitmap files.
+
+    This function doesn't parse image headers, but is useful to
+    speed up loading of uncompressed image formats such as PCF glyph data.
+
+    :param displayio.Bitmap bitmap: A writable bitmap
+    :param typing.BinaryIO file: A file opened in binary mode
+    :param int bits_per_pixel: Number of bits per pixel.
+     Values 1, 2, 4, 8, 16, 24, and 32 are supported;
+    :param int element_size: Number of bytes per element.
+     Values of 1, 2, and 4 are supported, except that 24
+     ``bits_per_pixel`` requires 1 byte per element.
+    :param bool reverse_pixels_in_element: If set, the first pixel in a
+      word is taken from the Most Significant Bits; otherwise,
+      it is taken from the Least Significant Bits.
+    :param bool swap_bytes_in_element: If the ``element_size`` is not 1,
+     then reverse the byte order of each element read.
+    :param bool reverse_rows: Reverse the direction of the row loading
+     (required for some bitmap images).
+    """
     width = bitmap.width
     height = bitmap.height
     bits_per_value = bitmap._bits_per_value
@@ -370,6 +529,10 @@ def readinto(
 
 
 class BlendMode:
+    """
+    Options for modes to use by alphablend() function.
+    """
+
     Normal = "bitmaptools.BlendMode.Normal"
     Screen = "bitmaptools.BlendMode.Screen"
 
@@ -385,11 +548,28 @@ def alphablend(
     skip_source1_index: Optional[int] = None,
     skip_source2_index: Optional[int] = None,
 ):
-    """
-    colorspace should be one of: 'L8', 'RGB565', 'RGB565_SWAPPED', 'BGR565_SWAPPED'.
-
-    blendmode must be one of the BlendMode constants
-    """
+    """Alpha blend the two source bitmaps into the destination.
+
+    It is permitted for the destination bitmap to be one of the two
+    source bitmaps.
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param bitmap source_bitmap_1: The first source bitmap
+    :param bitmap source_bitmap_2: The second source bitmap
+    :param float factor1: The proportion of bitmap 1 to mix in
+    :param float factor2: The proportion of bitmap 2 to mix in.
+      If specified as `None`, ``1-factor1`` is used.  Usually the proportions should sum to 1.
+    :param displayio.Colorspace colorspace: The colorspace of the bitmaps.
+      They must all have the same colorspace.  Only the following colorspaces are permitted:
+      ``L8``, ``RGB565``, ``RGB565_SWAPPED``, ``BGR565`` and ``BGR565_SWAPPED``.
+    :param bitmaptools.BlendMode blendmode: The blend mode to use. Default is Normal.
+    :param int skip_source1_index: Bitmap palette or luminance index in
+      source_bitmap_1 that will not be blended, set to None to blend all pixels
+    :param int skip_source2_index: Bitmap palette or luminance index in
+      source_bitmap_2 that will not be blended, set to None to blend all pixels
+
+    For the L8 colorspace, the bitmaps must have a bits-per-value of 8.
+    For the RGB colorspaces, they must have a bits-per-value of 16."""
 
     def clamp(val, minval, maxval):
         return max(minval, min(maxval, val))
@@ -492,6 +672,10 @@ def clamp(val, minval, maxval):
 
 
 class DitherAlgorithm:
+    """
+    Options for algorithm to use by dither() function.
+    """
+
     Atkinson = "bitmaptools.DitherAlgorithm.Atkinson"
     FloydStenberg = "bitmaptools.DitherAlgorithm.FloydStenberg"
 
@@ -522,6 +706,16 @@ class DitherAlgorithm:
 
 
 def dither(dest_bitmap, source_bitmap, colorspace, algorithm=DitherAlgorithm.Atkinson):
+    """Convert the input image into a 2-level output image using the given dither algorithm.
+
+    :param bitmap dest_bitmap: Destination bitmap.  It must have
+      a value_count of 2 or 65536.  The stored values are 0 and the maximum pixel value.
+    :param bitmap source_bitmap: Source bitmap that contains the
+      graphical region to be dithered.  It must have a value_count of 65536.
+    :param colorspace: The colorspace of the image.  The supported colorspaces
+      are ``RGB565``, ``BGR565``, ``RGB565_SWAPPED``, and ``BGR565_SWAPPED``
+    :param algorithm: The dither algorithm to use, one of the `DitherAlgorithm` values.
+    """
     SWAP_BYTES = 1 << 0
     SWAP_RB = 1 << 1
     height, width = dest_bitmap.width, dest_bitmap.height
@@ -667,6 +861,17 @@ def boundary_fill(
     fill_color_value: int,
     replaced_color_value: Optional[int] = None,
 ):
+    """Draws the color value into the destination bitmap enclosed
+    area of pixels of the background_value color. Like "Paint Bucket"
+    fill tool.
+
+    :param bitmap dest_bitmap: Destination bitmap that will be written into
+    :param int x: x-pixel position of the first pixel to check and fill if needed
+    :param int y: y-pixel position of the first pixel to check and fill if needed
+    :param int fill_color_value: Bitmap palette index that will be written into the
+           enclosed area in the destination bitmap
+    :param int replaced_color_value: Bitmap palette index that will filled with the
+           value color in the enclosed area in the destination bitmap"""
     if fill_color_value == replaced_color_value:
         return
     if replaced_color_value == -1: