"""
Copyright 2023 Ethan Christensen
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
from ..bruhutil import Buffer
from .base_effect import BaseEffect
from .settings import DrawLinesSettings
[docs]
class Line:
"""
A line segment defined by two endpoints.
"""
[docs]
def __init__(self, start_point: tuple[int], end_point: tuple[int]):
"""
Initializes a Line with start and end points (doubled for sub-cell rendering).
Args:
start_point (tuple[int]): Start point as (x, y).
end_point (tuple[int]): End point as (x, y).
"""
if start_point and end_point:
self.start_point = (start_point[0] * 2, start_point[1] * 2)
self.end_point = (end_point[0] * 2, end_point[1] * 2)
else:
self.start_point = None
self.end_point = None
[docs]
def update_points(self, start_point: tuple[int], end_point: tuple[int]):
"""
Updates the line's start and end points.
Args:
start_point (tuple[int]): New start point as (x, y).
end_point (tuple[int]): New end point as (x, y).
"""
self.start_point = (start_point[0], start_point[1])
self.end_point = (end_point[0], end_point[1])
[docs]
def get_points(self):
"""
Returns the start and end points of the line.
Returns:
tuple[tuple[int], tuple[int]]: The start and end points.
"""
return self.start_point, self.end_point
[docs]
class DrawLinesEffect(BaseEffect):
"""
Effect for drawing Bresenham line segments onto the buffer.
"""
[docs]
def __init__(
self, buffer: Buffer, background: str, settings: DrawLinesSettings = None
):
"""
Initializes the DrawLinesEffect.
Args:
buffer (Buffer): Effect buffer to push updates to.
background (str): Character or string to use as the background.
settings (DrawLinesSettings, optional): Configuration for the effect. Defaults to None.
"""
super(DrawLinesEffect, self).__init__(buffer, background)
s = settings or DrawLinesSettings()
self.lines = []
self.char = s.char
self.thin = s.thin
[docs]
def add_line(self, start_point: tuple[int], end_point: tuple[int]):
"""
Adds a line segment to be rendered.
Args:
start_point (tuple[int]): Start point as (x, y).
end_point (tuple[int]): End point as (x, y).
"""
self.lines.append(Line(start_point, end_point))
[docs]
def render_frame(self, frame_number: int):
"""
Renders all lines on frame 0.
Args:
frame_number (int): The current frame number.
"""
if frame_number == 0 and len(self.lines) > 0:
for y in range(self.buffer.height()):
self.buffer.put_at(0, y, self.background * self.buffer.width())
for line in self.lines:
if (
(line.start_point[0] < 0 and line.end_point[0]) < 0
or (
line.start_point[0] >= self.buffer.width() * 2
and line.end_point[0] > self.buffer.width() * 2
)
or (line.start_point[1] < 0 and line.end_point[1] < 0)
or (
line.start_point[1] >= self.buffer.height() * 2
and line.end_point[1] >= self.buffer.height() * 2
)
):
return
line_chars = " ''^.|/7.\\|Ywbd#"
dx = abs(line.end_point[0] - line.start_point[0])
dy = abs(line.end_point[1] - line.start_point[1])
cx = -1 if line.start_point[0] > line.end_point[0] else 1
cy = -1 if line.start_point[1] > line.end_point[1] else 1
def get_start(x, y):
c = self.buffer.get_char(x, y)
if c is not None:
return line_chars.find(c)
return 0
def x_draw(ix, iy):
err = dx
px = ix - 2
py = iy - 2
next_char = 0
while ix != line.end_point[0]:
if ix < px or ix - px >= 2 or iy < py or iy - py >= 2:
px = ix & ~1
py = iy & ~1
next_char = get_start(px // 2, py // 2)
next_char |= 2 ** abs(ix % 2) * 4 ** (iy % 2)
err -= 2 * dy
if err < 0:
iy += cy
err += 2 * dx
ix += cx
if self.char is None:
self.buffer.put_char(
px // 2, py // 2, line_chars[next_char]
)
else:
self.buffer.put_char(px // 2, py // 2, self.char)
def y_draw(ix, iy):
err = dy
px = ix - 2
py = iy - 2
next_char = 0
while iy != line.end_point[1]:
if ix < px or ix - px >= 2 or iy < py or iy - py >= 2:
px = ix & ~1
py = iy & ~1
next_char = get_start(px // 2, py // 2)
next_char |= 2 ** abs(ix % 2) * 4 ** (iy % 2)
err -= 2 * dx
if err < 0:
ix += cx
err += 2 * dy
iy += cy
if self.char is None:
self.buffer.put_char(
px // 2, py // 2, line_chars[next_char]
)
else:
self.buffer.put_char(px // 2, py // 2, self.char)
if dy == 0 and self.thin and self.char is None:
pass
elif dx > dy:
x_draw(line.start_point[0], line.start_point[1] + 1)
else:
y_draw(line.start_point[0] + 1, line.start_point[1])