From 5d86cfd98437eaa2b84b07ba19d51d50d64bc53f Mon Sep 17 00:00:00 2001
From: Walter Purcaro <vuolter@users.noreply.github.com>
Date: Tue, 12 May 2015 14:07:48 +0200
Subject: Missing optional lib
---
lib/Python/Lib/PIL/GimpGradientFile.py | 137 +++++++++++++++++++++++++++++++++
1 file changed, 137 insertions(+)
create mode 100644 lib/Python/Lib/PIL/GimpGradientFile.py
(limited to 'lib/Python/Lib/PIL/GimpGradientFile.py')
diff --git a/lib/Python/Lib/PIL/GimpGradientFile.py b/lib/Python/Lib/PIL/GimpGradientFile.py
new file mode 100644
index 000000000..696f425f1
--- /dev/null
+++ b/lib/Python/Lib/PIL/GimpGradientFile.py
@@ -0,0 +1,137 @@
+#
+# 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.
+#
+
+from math import pi, log, sin, sqrt
+from PIL._binary import o8
+
+# --------------------------------------------------------------------
+# 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.)
+#
+
+EPSILON = 1e-10
+
+
+def linear(middle, pos):
+ 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, pos):
+ return pos ** (log(0.5) / log(max(middle, EPSILON)))
+
+
+def sine(middle, pos):
+ return (sin((-pi / 2.0) + pi * linear(middle, pos)) + 1.0) / 2.0
+
+
+def sphere_increasing(middle, pos):
+ return sqrt(1.0 - (linear(middle, pos) - 1.0) ** 2)
+
+
+def sphere_decreasing(middle, pos):
+ return 1.0 - sqrt(1.0 - linear(middle, pos) ** 2)
+
+SEGMENTS = [linear, curved, sine, sphere_increasing, sphere_decreasing]
+
+
+class GradientFile:
+
+ gradient = None
+
+ def getpalette(self, entries=256):
+
+ palette = []
+
+ ix = 0
+ x0, x1, xm, rgb0, rgb1, segment = self.gradient[ix]
+
+ for i in range(entries):
+
+ x = i / float(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"
+
+
+##
+# File handler for GIMP's gradient format.
+
+class GimpGradientFile(GradientFile):
+
+ def __init__(self, fp):
+
+ if fp.readline()[:13] != b"GIMP Gradient":
+ raise SyntaxError("not a GIMP gradient file")
+
+ 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)
+
+ 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:
+ raise IOError("cannot handle HSV colour space")
+
+ gradient.append((x0, x1, xm, rgb0, rgb1, segment))
+
+ self.gradient = gradient
--
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