Explain how. Explain why.
Primitive:
proc make_color_dot color {
return \x47\x49\x46\x38\x37\x61\x01\x00\x01\x00\x91\x00$color\xff\xff\xff\xff\xff\xff\xff\xff\xff\x2c\x00\x00\x00\x00\x01\x00\x01\x00\x00\x02\x02\x44\x01\x00\x3b\x00
}
proc write_color_dot {color filename} {
set fp [open $filename w]
puts -nonewline $fp [make_color_dot $color]
close $fp
}
write_color_dot \x00\x00\xff\x00 /tmp/gif/green.gif
[Write up Tk example for simply putting color on PhotoImage.]
Pythonic expression of same:
template = [71, 73, 70, 56, 57, 97, 1, 0, 1, 0, 128, 0, 0, 255, 255,
255,
0, 0, 0, 33, 249, 4, 1, 0, 0, 0, 0, 44, 0, 0, 0, 0, 1,
0, 1,
0, 0, 2, 2, 68, 1, 0, 59]
if color:
rgb = [63, 127, 255] # will be calculated later
template[13:16] = rgb
template[22] = 0 # remove transparency Modern Web programming deprecates spacer gif-s in favor of CSS positioning.