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#!/bin/sh -- # A comment mentioning perl
eval 'exec perl -S $0 ${1+"$@"}'
if 0;
# ranfb.pl: example -rawfb setup program.
# E.g. x11vnc -rawfb setup:./ranfb.pl
# can supply WxH or W H on cmd line:
if ($ARGV[0] =~ /^(\d+)x(\d+)$/) {
$W = $1;
$H = $2;
} else {
$W = shift;
$H = shift;
}
$W = 480 unless $W;
$H = 360 unless $H;
$fb = "/tmp/ranfb.$$";
open(FB, ">$fb") || die "$!";
$ones = "\377" x ($W * 4);
for ($y = 0; $y < $H; $y++) {
print FB $ones;
}
if (fork) {
print "map:$fb\@${W}x${H}x32\n";
exit 0;
}
srand();
while (1) {
showpic();
if (! kill 0, $ENV{X11VNC_PID}) {
print STDERR "PID $ENV{X11VNC_PID} gone\n";
unlink($fb);
exit;
}
}
sub showpic {
# 0 < x,y < 1; R1, R2, ... B4 random & scaled so R,G,B < 255:
# R(x,y) = R1 + R2 * x + R3 * y + R4 * x * y
# G(x,y) = G1 + G2 * x + G3 * y + G4 * x * y
# B(x,y) = B1 + B2 * x + B3 * y + B4 * x * y
$minfac = 0.25;
foreach $c ('R', 'G', 'B') {
$a1 = rand() * $minfac;
$a2 = rand();
$a3 = rand();
$a4 = rand();
$at = $a1 + $a2 + $a3 + $a4;
$a1 = 255 * ($a1/$at);
$a2 = 255 * ($a2/$at);
$a3 = 255 * ($a3/$at);
$a4 = 255 * ($a4/$at);
# invert axes randomly
$ax = 0; $ax = 1 if rand() < 0.5;
$ay = 0; $ay = 1 if rand() < 0.5;
eval "\$${c}1 = \$a1";
eval "\$${c}2 = \$a2";
eval "\$${c}3 = \$a3";
eval "\$${c}4 = \$a4";
eval "\$${c}x = \$ax";
eval "\$${c}y = \$ay";
}
for ($i = 0; $i < 256; $i++) {
$p[$i] = pack("c", $i);
}
$Winv = 1.0/$W;
$Hinv = 1.0/$H;
$str = '';
for ($y = 0; $y < $H; $y++) {
$yr = $yg = $yb = $y;
$yr = $H - $yr if $Ry;
$yg = $H - $yg if $Gy;
$yb = $H - $yb if $By;
$yr = $yr * $Hinv;
$yg = $yg * $Hinv;
$yb = $yb * $Hinv;
$Y[3*$y+0] = $yr;
$Y[3*$y+1] = $yg;
$Y[3*$y+2] = $yb;
}
for ($x = 0; $x < $W; $x++) {
$xr = $xg = $xb = $x;
$xr = $W - $xr if $Rx;
$xg = $W - $xg if $Gx;
$xb = $W - $xb if $Bx;
$xr = $xr * $Winv;
$xg = $xg * $Winv;
$xb = $xb * $Winv;
$X[3*$x+0] = $xr;
$X[3*$x+1] = $xg;
$X[3*$x+2] = $xb;
}
for ($y = 0; $y < $H; $y++) {
#$yr = $yg = $yb = $y;
#$yr = $H - $yr if $Ry;
#$yg = $H - $yg if $Gy;
#$yb = $H - $yb if $By;
#$yr = $yr * $Hinv;
#$yg = $yg * $Hinv;
#$yb = $yb * $Hinv;
$yr = $Y[3*$y+0];
$yg = $Y[3*$y+1];
$yb = $Y[3*$y+2];
$RY1 = $R1 + $yr * $R3;
$GY1 = $G1 + $yg * $G3;
$BY1 = $B1 + $yb * $B3;
$RY2 = $R2 + $yr * $R4;
$GY2 = $G2 + $yg * $G4;
$BY2 = $B2 + $yb * $B4;
for ($x = 0; $x < $W; $x++) {
#$xr = $xg = $xb = $x;
#$xr = $W - $xr if $Rx;
#$xg = $W - $xg if $Gx;
#$xb = $W - $xb if $Bx;
#$xr = $xr * $Winv;
#$xg = $xg * $Winv;
#$xb = $xb * $Winv;
$n = 3 * $x;
#$v = int($R1 + $xr*$R2 + $yr*$R3 + $xr*$yr*$R4);
$v = int($RY1 + $X[$n]*$RY2);
$str .= $p[$v];
#$v = int($G1 + $xg*$G2 + $yg*$G3 + $xg*$yg*$G4);
$v = int($GY1 + $X[$n+1]*$GY2);
$str .= $p[$v];
#$v = int($B1 + $xb*$B2 + $yb*$B3 + $xb*$yb*$B4);
$v = int($BY1 + $X[$n+2]*$BY2);
$str .= $p[$v];
$str .= "\0";
}
}
seek(FB, 0, 0);
print FB $str;
}
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