"""
Functions used to support drawing. No Pyglet/OpenGL here.
"""
import math
from typing import List, Tuple, cast
from arcade import Color
from arcade import RGBA
[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 think
line must be two triangles that make up a rectangle. This calculates 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
points = (r1_x, r1_y), (r2_x, r2_y), (r4_x, r4_y), (r3_x, r3_y)
return points
[docs]def get_four_byte_color(color: Color) -> RGBA:
"""
Given a RGB list, it will return RGBA.
Given a RGBA list, it will return the same RGBA.
: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("This isn't a 3 or 4 byte color")
[docs]def get_four_float_color(color: Color) -> Tuple[float, float, float, float]:
"""
Given a 3 or 4 RGB/RGBA color where each color goes 0-255, this
returns a RGBA tuple where each item is a scaled float from 0 to 1.
: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 make_transparent_color(color: Color, transparency: float):
"""
Given a RGB color, along with an alpha, returns a RGBA color tuple.
:param Color color: Three or four byte RGBA color
:param float transparency: Transparency
"""
return color[0], color[1], color[2], transparency
[docs]def rotate_point(x: float, y: float, cx: float, cy: float,
angle_degrees: float) -> List[float]:
"""
Rotate a point around a center.
:param x: x value of the point you want to rotate
:param y: y value of the point you want to rotate
:param cx: x value of the center point you want to rotate around
:param cy: y value of the center point you want to rotate around
:param angle_degrees: Angle, in degrees, to rotate
:return: Return rotated (x, y) pair
:rtype: (float, float)
"""
temp_x = x - cx
temp_y = y - cy
# now apply rotation
angle_radians = math.radians(angle_degrees)
cos_angle = math.cos(angle_radians)
sin_angle = math.sin(angle_radians)
rotated_x = temp_x * cos_angle - temp_y * sin_angle
rotated_y = temp_x * sin_angle + temp_y * cos_angle
# translate back
rounding_precision = 2
x = round(rotated_x + cx, rounding_precision)
y = round(rotated_y + cy, rounding_precision)
return [x, y]
[docs]def calculate_points(image):
"""
Given an image, this returns points that make up a hit box around it. Attempts
to trim out transparent pixels.
:param Image image:
:Returns: List of points
"""
left_border = 0
good = True
while good and left_border < image.width:
for row in range(image.height):
pos = (left_border, row)
pixel = image.getpixel(pos)
if type(pixel) is int or len(pixel) != 4:
raise TypeError("Error, calculate_points called on image not in RGBA format")
else:
if pixel[3] != 0:
good = False
break
if good:
left_border += 1
right_border = image.width - 1
good = True
while good and right_border > 0:
for row in range(image.height):
pos = (right_border, row)
pixel = image.getpixel(pos)
if pixel[3] != 0:
good = False
break
if good:
right_border -= 1
top_border = 0
good = True
while good and top_border < image.height:
for column in range(image.width):
pos = (column, top_border)
pixel = image.getpixel(pos)
if pixel[3] != 0:
good = False
break
if good:
top_border += 1
bottom_border = image.height - 1
good = True
while good and bottom_border > 0:
for column in range(image.width):
pos = (column, bottom_border)
pixel = image.getpixel(pos)
if pixel[3] != 0:
good = False
break
if good:
bottom_border -= 1
def _check_corner_offset(start_x, start_y, x_direction, y_direction):
bad = False
offset = 0
while not bad:
y = start_y + (offset * y_direction)
x = start_x
for count in range(offset + 1):
my_pixel = image.getpixel((x, y))
# print(f"({x}, {y}) = {pixel} | ", end="")
if my_pixel[3] != 0:
bad = True
break
y -= y_direction
x += x_direction
# print(f" - {bad}")
offset += 1
# print(f"offset: {offset}")
return offset
def _r(point, height, width):
return point[0] - width / 2, (height - point[1]) - height / 2
top_left_corner_offset = _check_corner_offset(left_border, top_border, 1, 1)
top_right_corner_offset = _check_corner_offset(right_border, top_border, -1, 1)
bottom_left_corner_offset = _check_corner_offset(left_border, bottom_border, 1, -1)
bottom_right_corner_offset = _check_corner_offset(right_border, bottom_border, -1, -1)
p1 = left_border + top_left_corner_offset, top_border
p2 = right_border - top_right_corner_offset, top_border
p3 = right_border, top_border + top_right_corner_offset
p4 = right_border, bottom_border - bottom_right_corner_offset
p5 = right_border - bottom_right_corner_offset, bottom_border
p6 = left_border + bottom_left_corner_offset, bottom_border
p7 = left_border, bottom_border - bottom_left_corner_offset
p8 = left_border, top_border + top_left_corner_offset
result = []
h = image.height
w = image.width
result.append(_r(p1, h, w))
if top_left_corner_offset:
result.append(_r(p2, h, w))
result.append(_r(p3, h, w))
if top_right_corner_offset:
result.append(_r(p4, h, w))
result.append(_r(p5, h, w))
if bottom_right_corner_offset:
result.append(_r(p6, h, w))
result.append(_r(p7, h, w))
if bottom_left_corner_offset:
result.append(_r(p8, h, w))
# Remove duplicates
result = list(dict.fromkeys(result))
return result