"""
Functions used to support drawing. No Pyglet/OpenGL here.
"""
import math
from typing import Tuple, Union, cast
from arcade import Color
from arcade import RGBA, RGB
[docs]def get_points_for_thick_line(start_x: float, start_y: float,
end_x: float, end_y: float,
line_width: float):
"""
Function used internally for Arcade. OpenGL draws triangles only, so a thick
line must be two triangles that make up a rectangle. This calculates and returns
those points.
"""
vector_x = start_x - end_x
vector_y = start_y - end_y
perpendicular_x = vector_y
perpendicular_y = -vector_x
length = math.sqrt(vector_x * vector_x + vector_y * vector_y)
if length == 0:
normal_x = 1.0
normal_y = 1.0
else:
normal_x = perpendicular_x / length
normal_y = perpendicular_y / length
r1_x = start_x + normal_x * line_width / 2
r1_y = start_y + normal_y * line_width / 2
r2_x = start_x - normal_x * line_width / 2
r2_y = start_y - normal_y * line_width / 2
r3_x = end_x + normal_x * line_width / 2
r3_y = end_y + normal_y * line_width / 2
r4_x = end_x - normal_x * line_width / 2
r4_y = end_y - normal_y * line_width / 2
return (r1_x, r1_y), (r2_x, r2_y), (r4_x, r4_y), (r3_x, r3_y)
[docs]def get_four_byte_color(color: Color) -> RGBA:
"""
Converts a color to RGBA. If the color is already
RGBA the original color value will be returned.
If the alpha channel is not present a 255 value will be added.
This function is useful when a mix of RGB and RGBA
values are used and you need to enforce RGBA.
Examples::
>>> arcade.get_four_byte_color((255, 255, 255))
(255, 255, 255, 255)
:param Color color: Three or four byte tuple
:returns: return: Four byte RGBA tuple
"""
if len(color) == 4:
return cast(RGBA, color)
elif len(color) == 3:
return color[0], color[1], color[2], 255
else:
raise ValueError(f"This isn't a 3 or 4 byte color: {color}")
[docs]def get_four_float_color(color: Color) -> Tuple[float, float, float, float]:
"""
Converts an RGB or RGBA byte color to a floating point RGBA color.
Basically we divide each component by 255.
Float based colors are often used with OpenGL.
Examples::
>>> arcade.get_four_float_color((255, 127, 0))
(1.0, 0.4980392156862745, 0.0, 1.0)
>>> arcade.get_four_float_color((255, 255, 255, 127))
(1.0, 1.0, 1.0, 0.4980392156862745)
:param Color color: Three or four byte tuple
:return: Four floats as a RGBA tuple
"""
if len(color) == 4:
return color[0] / 255, color[1] / 255, color[2] / 255, color[3] / 255 # type: ignore
elif len(color) == 3:
return color[0] / 255, color[1] / 255, color[2] / 255, 1.0
else:
raise ValueError("This isn't a 3 or 4 byte color")
[docs]def get_three_float_color(color: Color) -> Tuple[float, float, float]:
"""
Converts an RGB or RGBA byte color to a floating point RGB color.
Basically we divide each component by 255.
Float based colors are often used with OpenGL.
Examples:
>>> arcade.get_three_float_color(arcade.color.RED)
(1.0, 0.0, 0.0)
>>> arcade.get_three_float_color((255, 255, 255, 255))
(1.0, 1.0, 1.0)
:param Color color: Three or four byte tuple
:return: Three floats as a RGB tuple
"""
if len(color) in (3, 4):
return color[0] / 255, color[1] / 255, color[2] / 255 # type: ignore
else:
raise ValueError("This isn't a 3 or 4 byte color")
[docs]def make_transparent_color(color: Color, transparency: float):
"""
Given a RGB color, along with an alpha, returns an RGBA color tuple:
``(R, G, B, transparency)``.
Example::
>>> arcade.make_transparent_color((255, 255, 255), 127)
(255, 255, 255, 127)
:param Color color: Three or four byte RGBA color
:param float transparency: Transparency
"""
return color[0], color[1], color[2], transparency
[docs]def uint24_to_three_byte_color(color: int) -> RGB:
"""
Given an int between 0 and 16777215, return a RGB color tuple.
Example::
>>> arcade.uint24_to_three_byte_color(16777215)
(255, 255, 255)
:param int color: 3 byte int
"""
return (color & (255 << 16)) >> 16, (color & (255 << 8)) >> 8, color & 255
[docs]def uint32_to_four_byte_color(color: int) -> RGBA:
"""
Given an int between 0 and 4294967295, return a RGBA color tuple.
Example::
>>> arcade.uint32_to_four_byte_color(4294967295)
(255, 255, 255, 255)
:param int color: 4 byte int
"""
return (color & (255 << 24)) >> 24, (color & (255 << 16)) >> 16, (color & (255 << 8)) >> 8, color & 255
[docs]def color_from_hex_string(code: str) -> RGBA:
"""
Make a color from a hex code (3, 4, 6 or 8 characters of hex, normally with a hashtag).
Supports most formats used in CSS. Returns an RGBA color.
Examples::
>>> arcade.color_from_hex_string("#ff00ff")
(255, 0, 255, 255)
>>> arcade.color_from_hex_string("#ff00ff00")
(255, 0, 255, 0)
>>> arcade.color_from_hex_string("#fff")
(255, 255, 255, 255)
"""
code = code.lstrip("#")
if len(code) <= 4:
code = "".join(i * 2 for i in code)
if len(code) == 6:
# full opacity if no alpha specified
return int(code[:2], 16), int(code[2:4], 16), int(code[4:6], 16), 255
elif len(code) == 8:
return int(code[:2], 16), int(code[2:4], 16), int(code[4:6], 16), int(code[6:8], 16)
raise ValueError(f"Improperly formatted color: '{code}'")
[docs]def float_to_byte_color(
color: Union[Tuple[float, float, float, float], Tuple[float, float, float]],
) -> Color:
"""
Converts a float colors to a byte color.
This works for 3 of 4-component colors.
Example::
>>> arcade.float_to_byte_color((1.0, 0.5, 0.25, 1.0))
(255, 127, 63, 255)
>>> arcade.float_to_byte_color((1.0, 0.5, 0.25))
(255, 127, 63)
"""
if len(color) == 3:
return int(color[0] * 255), int(color[1] * 255), int(color[2] * 255)
elif len(color) == 4:
color = cast(Tuple[float, float, float, float], color)
return int(color[0] * 255), int(color[1] * 255), int(color[2] * 255), int(color[3] * 255)
else:
raise ValueError(f"color needs to have 3 or 4 components, not {color}")