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Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/GimpGradientFile.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/GimpGradientFile.py | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/GimpGradientFile.py b/.venv/lib/python3.12/site-packages/PIL/GimpGradientFile.py new file mode 100644 index 00000000..220eac57 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/GimpGradientFile.py @@ -0,0 +1,149 @@ +# +# Python Imaging Library +# $Id$ +# +# stuff to read (and render) GIMP gradient files +# +# History: +# 97-08-23 fl Created +# +# Copyright (c) Secret Labs AB 1997. +# Copyright (c) Fredrik Lundh 1997. +# +# See the README file for information on usage and redistribution. +# + +""" +Stuff to translate curve segments to palette values (derived from +the corresponding code in GIMP, written by Federico Mena Quintero. +See the GIMP distribution for more information.) +""" +from __future__ import annotations + +from math import log, pi, sin, sqrt +from typing import IO, Callable + +from ._binary import o8 + +EPSILON = 1e-10 +"""""" # Enable auto-doc for data member + + +def linear(middle: float, pos: float) -> float: + if pos <= middle: + if middle < EPSILON: + return 0.0 + else: + return 0.5 * pos / middle + else: + pos = pos - middle + middle = 1.0 - middle + if middle < EPSILON: + return 1.0 + else: + return 0.5 + 0.5 * pos / middle + + +def curved(middle: float, pos: float) -> float: + return pos ** (log(0.5) / log(max(middle, EPSILON))) + + +def sine(middle: float, pos: float) -> float: + return (sin((-pi / 2.0) + pi * linear(middle, pos)) + 1.0) / 2.0 + + +def sphere_increasing(middle: float, pos: float) -> float: + return sqrt(1.0 - (linear(middle, pos) - 1.0) ** 2) + + +def sphere_decreasing(middle: float, pos: float) -> float: + return 1.0 - sqrt(1.0 - linear(middle, pos) ** 2) + + +SEGMENTS = [linear, curved, sine, sphere_increasing, sphere_decreasing] +"""""" # Enable auto-doc for data member + + +class GradientFile: + gradient: ( + list[ + tuple[ + float, + float, + float, + list[float], + list[float], + Callable[[float, float], float], + ] + ] + | None + ) = None + + def getpalette(self, entries: int = 256) -> tuple[bytes, str]: + assert self.gradient is not None + palette = [] + + ix = 0 + x0, x1, xm, rgb0, rgb1, segment = self.gradient[ix] + + for i in range(entries): + x = i / (entries - 1) + + while x1 < x: + ix += 1 + x0, x1, xm, rgb0, rgb1, segment = self.gradient[ix] + + w = x1 - x0 + + if w < EPSILON: + scale = segment(0.5, 0.5) + else: + scale = segment((xm - x0) / w, (x - x0) / w) + + # expand to RGBA + r = o8(int(255 * ((rgb1[0] - rgb0[0]) * scale + rgb0[0]) + 0.5)) + g = o8(int(255 * ((rgb1[1] - rgb0[1]) * scale + rgb0[1]) + 0.5)) + b = o8(int(255 * ((rgb1[2] - rgb0[2]) * scale + rgb0[2]) + 0.5)) + a = o8(int(255 * ((rgb1[3] - rgb0[3]) * scale + rgb0[3]) + 0.5)) + + # add to palette + palette.append(r + g + b + a) + + return b"".join(palette), "RGBA" + + +class GimpGradientFile(GradientFile): + """File handler for GIMP's gradient format.""" + + def __init__(self, fp: IO[bytes]) -> None: + if fp.readline()[:13] != b"GIMP Gradient": + msg = "not a GIMP gradient file" + raise SyntaxError(msg) + + line = fp.readline() + + # GIMP 1.2 gradient files don't contain a name, but GIMP 1.3 files do + if line.startswith(b"Name: "): + line = fp.readline().strip() + + count = int(line) + + self.gradient = [] + + for i in range(count): + s = fp.readline().split() + w = [float(x) for x in s[:11]] + + x0, x1 = w[0], w[2] + xm = w[1] + rgb0 = w[3:7] + rgb1 = w[7:11] + + segment = SEGMENTS[int(s[11])] + cspace = int(s[12]) + + if cspace != 0: + msg = "cannot handle HSV colour space" + raise OSError(msg) + + self.gradient.append((x0, x1, xm, rgb0, rgb1, segment)) |