wxWidgets/wxPython/wx/lib/imageutils.py
Robin Dunn fd363e1abc Added stepColour utility function
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44260 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2007-01-19 19:51:08 +00:00

92 lines
2.5 KiB
Python

#----------------------------------------------------------------------
# Name: wxPython.lib.imageutils
# Purpose: A collection of functions for simple image manipulations
#
# Author: Robb Shecter
#
# Created: 7-Nov-2002
# RCS-ID: $Id$
# Copyright: (c) 2002 by
# Licence: wxWindows license
#----------------------------------------------------------------------
import wx
def grayOut(anImage):
"""
Convert the given image (in place) to a grayed-out
version, appropriate for a 'disabled' appearance.
"""
factor = 0.7 # 0 < f < 1. Higher is grayer.
if anImage.HasMask():
maskColor = (anImage.GetMaskRed(), anImage.GetMaskGreen(), anImage.GetMaskBlue())
else:
maskColor = None
data = map(ord, list(anImage.GetData()))
for i in range(0, len(data), 3):
pixel = (data[i], data[i+1], data[i+2])
pixel = makeGray(pixel, factor, maskColor)
for x in range(3):
data[i+x] = pixel[x]
anImage.SetData(''.join(map(chr, data)))
def makeGray((r,g,b), factor, maskColor):
"""
Make a pixel grayed-out. If the pixel
matches the maskColor, it won't be
changed.
"""
if (r,g,b) != maskColor:
return map(lambda x: int((230 - x) * factor) + x, (r,g,b))
else:
return (r,g,b)
def stepColour(c, step):
"""
stepColour is a utility function that simply darkens or lightens a
color, based on the specified step value. A step of 0 is
completely black and a step of 200 is totally white, and 100
results in the same color as was passed in.
"""
def _blendColour(fg, bg, dstep):
result = bg + (dstep * (fg - bg))
if result < 0:
result = 0
if result > 255:
result = 255
return result
if step == 100:
return c
r = c.Red()
g = c.Green()
b = c.Blue()
# step is 0..200 where 0 is completely black
# and 200 is completely white and 100 is the same
# convert that to a range of -1.0 .. 1.0
step = min(step, 200)
step = max(step, 0)
dstep = (step - 100.0)/100.0
if step > 100:
# blend with white
bg = 255.0
dstep = 1.0 - dstep # 0 = transparent fg; 1 = opaque fg
else:
# blend with black
bg = 0.0
dstep = 1.0 + dstep; # 0 = transparent fg; 1 = opaque fg
r = _blendColour(r, bg, dstep)
g = _blendColour(g, bg, dstep)
b = _blendColour(b, bg, dstep)
return wx.Colour(int(r), int(g), int(b))