```"""
Functions used to support drawing. No Pyglet/OpenGL here.
"""

import math

import pymunkoptions
pymunkoptions.options["debug"] = False
import pymunk

from PIL import Image

from pymunk import autogeometry

from typing import List, Tuple, cast

[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
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_hit_box_points_simple(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

# If the image is empty, return an empty set
if bottom_border == 0:
return []

def _check_corner_offset(start_x, start_y, x_direction, y_direction):

offset = 0
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:
break
y -= y_direction
x += x_direction
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 + 1) - top_right_corner_offset, top_border
p3 = (right_border + 1), top_border + top_right_corner_offset
p4 = (right_border + 1), (bottom_border + 1) - bottom_right_corner_offset
p5 = (right_border + 1) - bottom_right_corner_offset, (bottom_border + 1)
p6 = left_border + bottom_left_corner_offset, (bottom_border + 1)
p7 = left_border, (bottom_border + 1) - bottom_left_corner_offset
p8 = left_border, top_border + top_left_corner_offset

result = []

h = image.height
w = image.width

result.append(_r(p7, h, w))
if bottom_left_corner_offset:
result.append(_r(p6, h, w))

result.append(_r(p5, h, w))
if bottom_right_corner_offset:
result.append(_r(p4, h, w))

result.append(_r(p3, h, w))
if top_right_corner_offset:
result.append(_r(p2, h, w))

result.append(_r(p1, h, w))
if top_left_corner_offset:
result.append(_r(p8, h, w))

# Remove duplicates
result = tuple(dict.fromkeys(result))

return result

[docs]def calculate_hit_box_points_detailed(image: Image, hit_box_detail: float = 4.5):
"""
Given an image, this returns points that make up a hit box around it. Attempts
to trim out transparent pixels.

:param Image image: Image get hit box from.
:param int hit_box_detail: How detailed to make the hit box. There's a
trade-off in number of points vs. accuracy.

:Returns: List of points

"""

def sample_func(sample_point):
""" Method used to sample image. """
if sample_point[0] < 0 \
or sample_point[1] < 0 \
or sample_point[0] >= image.width \
or sample_point[1] >= image.height:
return 0

point_tuple = sample_point[0], sample_point[1]
color = image.getpixel(point_tuple)
if color[3] > 0:
return 255
else:
return 0

# Do a quick check if it is a full tile
p1 = 0, 0
p2 = 0, image.height - 1
p3 = image.width - 1, image.height - 1
p4 = image.width - 1, 0

if sample_func(p1) and sample_func(p2) and sample_func(p3) and sample_func(p4):
# Do a quick check if it is a full tile
p1 = (-image.width / 2, -image.height / 2)
p2 = (image.width / 2, -image.height / 2)
p3 = (image.width / 2, image.height / 2)
p4 = (-image.width / 2, image.height / 2)

return p1, p2, p3, p4

# Get the bounding box
logo_bb = pymunk.BB(-1, -1, image.width, image.height)

# Set of lines that trace the image
line_set = pymunk.autogeometry.PolylineSet()

# Collect the line segments
def _segment_func(v0, v1):
line_set.collect_segment(v0, v1)

# How often to sample?
downres = 1
horizontal_samples = int(image.width / downres)
vertical_samples = int(image.height / downres)

# Run the trace
pymunk.autogeometry.march_soft(
logo_bb,
horizontal_samples, vertical_samples,
99,
_segment_func,
sample_func)

# Select which line set to use
if len(line_set) == 0:
return []

selected_line_set = line_set[0]
selected_range = None
if len(line_set) > 1:
# We have more than one line set. Try and find one that covers most of
# the sprite.
for line in line_set:
min_x = None
min_y = None
max_x = None
max_y = None
for point in line:
if min_x is None or point.x < min_x:
min_x = point.x
if max_x is None or point.x > max_x:
max_x = point.x
if min_y is None or point.y < min_y:
min_y = point.y
if max_y is None or point.y > max_y:
max_y = point.y

if min_x is None or max_x is None or min_y is None or max_y is None:
raise ValueError("No points in bounding box.")

my_range = max_x - min_x + max_y + min_y
if selected_range is None or my_range > selected_range:
selected_range = my_range
selected_line_set = line

# Reduce number of vertices
# original_points = len(selected_line_set)
selected_line_set = pymunk.autogeometry.simplify_curves(selected_line_set,
hit_box_detail)
# downsampled_points = len(selected_line_set)

# Convert to normal points, offset fo 0,0 is center, flip the y
hh = image.height / 2
hw = image.width / 2
points = []
for vec2 in selected_line_set:
point = round(vec2.x - hw), round(image.height - (vec2.y - hh) - image.height)
points.append(point)

if len(points) > 1 and points[0] == points[-1]:
points.pop()

# print(f"{sprite.texture.name} Line-sets={len(line_set)}, Original points={original_points}, Downsampled points={downsampled_points}")
return points
```