x11vnc: add rawfb setup example misc/ranfb.pl

1 files changed, 157 insertions, 0 deletions

diff --git a/x11vnc/misc/ranfb.pl b/x11vnc/misc/ranfb.pl
new file mode 100755
index 0000000..d6aa49d
--- /dev/null
+++ b/x11vnc/misc/ranfb.pl
@@ -0,0 +1,157 @@
+  #!/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;
+}