I'm not a color or gif expert. But this works:
# see http://www.cocoabuilder.com/archive/cocoa/104713-nsimagergbcolortable-crash.html
newPage(100, 100)
linearGradient(
(0, 0), # startPoint
(100, 100), # endPoint
[(1, 0, 0), (0, 0, 1), (0, 1, 0)], # colors
[0, .2, 1] # locations
)
rect(0, 0, 100, 100)
fill(1, 0, 0)
rect(20, 20, 20, 20)
fill(0, 1, 0)
rect(100-40, 20, 20, 20)
fill(0, 0, 1)
rect(100-40, 100-40, 20, 20)
fill(0, 1, 1)
rect(20, 100-40, 20, 20)
import struct
table = b""
for i in range(256):
r = struct.pack(">B", 30)
g = struct.pack(">B", i)
b = struct.pack(">B", 255)
#a = struct.pack(">B", 254) # use if imageGIFDitherTransparency is True
table += r + g + b # + a
# table must have a size of 768
# or 1024 when imageGIFDitherTransparency is True
print(len(table))
test = '~/Desktop/testGif.gif'
saveImage(test, imageGIFRGBColorTable=table)
newPage(100, 100)
image(test, (0, 0))
