PDL_SIMPLE_DEVICE in env replaces driver guessing

Changes

@@ -3,6 +3,7 @@
 - each driver module now publishes which $P:G:S::API_VERSION it conforms to
 - PGS::register takes hashref instead of magic var in driver namespace
 - loading driver module not eval-ed
+- PDL_SIMPLE_DEVICE in env replaces driver guessing
 
 1.010 2024-03-24
 - fix PGPLOT to read devices correctly

lib/PDL/Graphics/Simple.pm

@@ -399,10 +399,6 @@ or "interactive" - though only the leading character is checked.  If
 you don't specify either C<type> or C<output> (below), the default is
 "interactive". If you specify only C<output>, the default is "file".
 
-For PGPLOT, if the type is "interactive", the environment variable
-C<PGPLOT_DEV> is set (eg C</NULL>), that will be used as the output
-device.
-
 =item output
 
 This should be a window number or name for interactive plots, or a
@@ -1504,6 +1500,19 @@ legend (if present).  The C<with> option will be one of C<points>,
 C<lines>, C<bins>, C<errorbars>, C<limitbars>, C<circles>
 C<image>, or C<labels>.
 
+=head1 ENVIRONMENT
+
+Setting some environment variables affects operation of the module:
+
+=head2 PDL_SIMPLE_ENGINE
+
+See L</new>.
+
+=head2 PDL_SIMPLE_DEVICE
+
+If this is a meaningful thing for the given engine, this value will be
+used instead of the driver module guessing.
+
 =head1 TO-DO
 
 Deal with legend generation.  In particular: adding legends with multi-call

lib/PDL/Graphics/Simple/Gnuplot.pm

@@ -83,10 +83,14 @@ sub check {
     $mod->{valid_terms} = $gpw->{valid_terms};
 
     my $okterm = undef;
-    for my $term (@disp_terms) {
-	if ($mod->{valid_terms}{$term}) {
-	    $okterm = $term;
-	    last;
+    if ($ENV{PDL_SIMPLE_DEVICE}) {
+	$okterm = 1;
+    } else {
+	for my $term (@disp_terms) {
+	    if ($mod->{valid_terms}{$term}) {
+		$okterm = $term;
+		last;
+	    }
 	}
     }
 
@@ -136,7 +140,7 @@ sub new {
     # Do different things for interactive and file types
     if($opt->{type} =~ m/^i/i) {
 	push(@params, title=>$opt->{output}) if defined $opt->{output};
-	# Interactive - try known terminals
+	# Interactive - try known terminals unless PDL_SIMPLE_DEVICE given
 	push @params, font=>"=16", dashed=>1;
 	if (my $try = $mod->{itype}) {
 	    $gpw = gpwin($mod->{itype}, @params,
@@ -145,11 +149,17 @@ sub new {
             no warnings 'once';
 	    print $PDL::Graphics::Gnuplot::last_plotcmd;
 	} else {
-	    attempt:for my $try( @disp_terms ) {
-		eval { $gpw = gpwin($try, @params,
+	    if (my $try = $ENV{PDL_SIMPLE_DEVICE}) {
+		$gpw = gpwin($try, @params,
 		    ($disp_opts->{$try} // {})->{persist} ? (persist=>0) : ()
-		); };
-		last attempt if($gpw);
+		);
+	    } else {
+		attempt:for my $try( @disp_terms ) {
+		    eval { $gpw = gpwin($try, @params,
+			($disp_opts->{$try} // {})->{persist} ? (persist=>0) : ()
+		    ); };
+		    last attempt if($gpw);
+		}
 	    }
 	    die "Couldn't start a gnuplot interactive window" unless($gpw);
 	    $mod->{itype} = $gpw->{terminal};

lib/PDL/Graphics/Simple/PGPLOT.pm

@@ -56,8 +56,9 @@ sub check {
     return 0;
   }
   delete $mod->{disp_dev};
-  if ($ENV{PGPLOT_DEV}) {
-    $mod->{disp_dev} = $ENV{PGPLOT_DEV};
+  if ($ENV{PDL_SIMPLE_DEVICE} || $ENV{PGPLOT_DEV}) {
+    $mod->{disp_dev} = $ENV{PDL_SIMPLE_DEVICE} || $ENV{PGPLOT_DEV};
+    $mod->{disp_dev} =~ s#^/+##;
   } else {
     TRY:for my $try(qw/XWINDOW XSERVE CGW GW/){
       if($mod->{devices}->{$try}) { 
@@ -113,7 +114,7 @@ sub new {
     my $dev;
 
     if( $opt->{type} =~ m/^i/i) {
-	$dev = ( defined($opt->{output}) ? $opt->{output} : "" ) . ($ENV{PGPLOT_DEV} || "/$mod->{disp_dev}");
+	$dev = ( defined($opt->{output}) ? $opt->{output} : "" ) . "/$mod->{disp_dev}";
     } else {
 	my $ext;
 

lib/PDL/Graphics/Simple/PLplot.pm

@@ -61,7 +61,7 @@ sub check {
     my $plgDevs = plgDevs();
     $mod->{devices} = {map +($_=>1), keys %$plgDevs};
 
-    if ( my ($good_dev) = grep $mod->{devices}{$_}, @DEVICES ) {
+    if ( my ($good_dev) = $ENV{PDL_SIMPLE_DEVICE} || grep $mod->{devices}{$_}, @DEVICES ) {
 	$mod->{disp_dev} = $good_dev;
     } else {
 	$mod->{ok} = 0;
@@ -246,7 +246,6 @@ our $plplot_methods = {
 
 	plshades( $data->[2], $xmin, $xmax, $ymin, $ymax, $clevel, $fill_width, $cont_color, $cont_width, 0, 0, \&pltr2, $grid );
 	plFreeGrid($grid);
-	plflush();
 
 	if($ipo->{wedge}) {
 	    # Work around PLplot justify bug
@@ -382,6 +381,7 @@ sub plot {
 	} else {
 	    $me->{obj}->xyplot(@data,PLOTTYPE=>$plpm,%plplot_opts);
 	}
+	plflush();
     }
 
     $me->{obj}->close if $me->{opt}->{type} =~ m/^f/i and !defined($me->{opt}->{multi});