File size: 8,440 Bytes
9f85448 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 | from __future__ import annotations
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
import cv2
import numpy as np
PALETTE: tuple[tuple[int, int, int], ...] = (
(60, 60, 255),
(60, 220, 255),
(90, 230, 90),
(255, 190, 60),
(255, 110, 200),
(255, 255, 255),
)
COLOR_NAMES: tuple[str, ...] = (
"red", "yellow", "green", "blue", "pink", "white",
)
@dataclass
class Stroke:
"""One drawn stroke."""
color: tuple[int, int, int]
thickness: int
points: list[tuple[int, int]] = field(default_factory=list)
class Canvas:
"""Vector drawing canvas."""
MAX_JUMP = 0.12
def __init__(self, width: int, height: int, output_dir: str | Path = "output") -> None:
self.width = width
self.height = height
self.output_dir = Path(output_dir)
self.strokes: list[Stroke] = []
self._active: Stroke | None = None
self.color: tuple[int, int, int] = PALETTE[0]
self.thickness: int = 6
self._layer = np.zeros((height, width, 3), dtype=np.uint8)
self._mask = np.zeros((height, width), dtype=np.uint8)
self._bounds: list[int] | None = None
self.revision = 0
def begin(self) -> None:
"""Start a new stroke."""
if self._active is None:
self._active = Stroke(color=self.color, thickness=self.thickness)
self.strokes.append(self._active)
def add_point(self, point) -> None:
"""Append point to stroke."""
if self._active is None:
self.begin()
assert self._active is not None
x, y = int(round(float(point[0]))), int(round(float(point[1])))
x = max(0, min(self.width - 1, x))
y = max(0, min(self.height - 1, y))
pts = self._active.points
if pts and pts[-1] == (x, y):
return
if pts:
jump = np.hypot(x - pts[-1][0], y - pts[-1][1])
if jump > self.MAX_JUMP * np.hypot(self.width, self.height):
self.end()
self.begin()
pts = self._active.points
pts.append((x, y))
if len(pts) >= 2:
self._draw_segment(pts[-2], pts[-1], self._active)
else:
self._draw_dot((x, y), self._active)
def end(self) -> None:
"""Finish current stroke."""
if self._active is not None and len(self._active.points) < 2:
if len(self._active.points) == 0:
self.strokes.remove(self._active)
self._rebuild()
self._active = None
def _grow_bounds(self, points, radius: int) -> None:
"""Extend content bounding box."""
xs = [p[0] for p in points]
ys = [p[1] for p in points]
x0, y0 = min(xs) - radius, min(ys) - radius
x1, y1 = max(xs) + radius, max(ys) + radius
if self._bounds is None:
self._bounds = [x0, y0, x1, y1]
else:
b = self._bounds
b[0], b[1] = min(b[0], x0), min(b[1], y0)
b[2], b[3] = max(b[2], x1), max(b[3], y1)
def _draw_segment(self, a, b, stroke: Stroke) -> None:
"""Draw one line segment."""
cv2.line(self._layer, a, b, stroke.color, stroke.thickness, cv2.LINE_AA)
cv2.line(self._mask, a, b, 255, stroke.thickness, cv2.LINE_AA)
self._grow_bounds((a, b), stroke.thickness // 2 + 2)
self.revision += 1
def _draw_dot(self, p, stroke: Stroke) -> None:
"""Draw one dot."""
r = max(1, stroke.thickness // 2)
cv2.circle(self._layer, p, r, stroke.color, -1, cv2.LINE_AA)
cv2.circle(self._mask, p, r, 255, -1, cv2.LINE_AA)
self._grow_bounds((p,), r + 2)
self.revision += 1
def _rebuild(self) -> None:
"""Redraw all strokes."""
self._layer[:] = 0
self._mask[:] = 0
self._bounds = None
self.revision += 1
for s in self.strokes:
if len(s.points) == 1:
self._draw_dot(s.points[0], s)
for a, b in zip(s.points, s.points[1:]):
self._draw_segment(a, b, s)
def undo(self) -> None:
"""Remove last stroke."""
if self.strokes:
self.strokes.pop()
self._active = None
self._rebuild()
def clear(self) -> None:
"""Erase whole canvas."""
self.strokes.clear()
self._active = None
self._rebuild()
def scale_content(self, factor: float) -> None:
"""Scale drawing about center."""
if not self.strokes or abs(factor - 1.0) < 1e-3:
return
cx, cy = self.width * 0.5, self.height * 0.5
for s in self.strokes:
s.points = [
(
int(round(cx + (x - cx) * factor)),
int(round(cy + (y - cy) * factor)),
)
for x, y in s.points
]
s.thickness = int(max(1, min(48, round(s.thickness * factor))))
self._active = None
self._rebuild()
def content_span(self) -> float:
"""Drawing diagonal length."""
box = self.content_bbox(padding=0)
if box is None:
return 0.0
x0, y0, x1, y1 = box
return float(np.hypot(x1 - x0, y1 - y0))
def set_color(self, index: int) -> None:
"""Select palette color."""
self.color = PALETTE[index % len(PALETTE)]
def set_thickness(self, value: int) -> None:
"""Set stroke thickness."""
self.thickness = int(max(1, min(48, value)))
@property
def is_empty(self) -> bool:
"""No strokes drawn."""
return not any(s.points for s in self.strokes)
@property
def layer(self) -> np.ndarray:
"""Color drawing layer."""
return self._layer
@property
def mask(self) -> np.ndarray:
"""Drawing alpha mask."""
return self._mask
def composite_over(self, frame: np.ndarray, opacity: float = 1.0) -> np.ndarray:
"""Blend drawing onto frame."""
out = frame.copy()
box = self.content_bbox(padding=2)
if box is None:
return out
x0, y0, x1, y1 = box
roi = out[y0:y1, x0:x1]
layer = self._layer[y0:y1, x0:x1]
mask = self._mask[y0:y1, x0:x1]
if opacity < 1.0:
mask = (mask.astype(np.float32) * opacity).astype(np.uint8)
a = cv2.cvtColor(mask, cv2.COLOR_GRAY2BGR)
inv = cv2.bitwise_not(a)
blended = cv2.add(
cv2.multiply(roi, inv, scale=1 / 255.0),
cv2.multiply(layer, a, scale=1 / 255.0),
)
out[y0:y1, x0:x1] = blended
return out
def to_bgra(self) -> np.ndarray:
"""Drawing with transparent background."""
bgra = np.dstack([self._layer, self._mask])
return bgra
def content_bbox(self, padding: int = 24) -> tuple[int, int, int, int] | None:
"""Bounding box of drawing."""
if self._bounds is None:
return None
bx0, by0, bx1, by1 = self._bounds
x0 = max(0, bx0 - padding)
y0 = max(0, by0 - padding)
x1 = min(self.width, bx1 + padding + 1)
y1 = min(self.height, by1 + padding + 1)
if x1 <= x0 or y1 <= y0:
return None
return x0, y0, x1, y1
def cropped_bgra(self, padding: int = 24) -> np.ndarray | None:
"""Cropped transparent drawing."""
box = self.content_bbox(padding)
if box is None:
return None
x0, y0, x1, y1 = box
return self.to_bgra()[y0:y1, x0:x1]
def save(self, tag: str = "") -> list[Path]:
"""Save canvas as PNGs."""
self.output_dir.mkdir(parents=True, exist_ok=True)
stamp = datetime.now().strftime("%Y%m%d_%H%M%S")
suffix = f"_{tag}" if tag else ""
saved: list[Path] = []
transparent = self.output_dir / f"drawing_{stamp}{suffix}.png"
cv2.imwrite(str(transparent), self.to_bgra())
saved.append(transparent)
white = np.full((self.height, self.width, 3), 255, dtype=np.uint8)
alpha = (self._mask.astype(np.float32) / 255.0)[:, :, None]
flat = (white * (1.0 - alpha) + self._layer * alpha).astype(np.uint8)
on_white = self.output_dir / f"drawing_{stamp}{suffix}_white.png"
cv2.imwrite(str(on_white), flat)
saved.append(on_white)
return saved
|