if PDL_SIMPLE_ENGINE in ENV, use ONLY that if engine unspecified

Changes

@@ -1,4 +1,5 @@
 - P{GPLOT,Lplot} to read devices using proper API not subprocesses
+- if PDL_SIMPLE_ENGINE in ENV, use ONLY that if engine unspecified
 
 1.010 2024-03-24
 - fix PGPLOT to read devices correctly
@@ -27,8 +28,11 @@
 1.003 2013-03-20
 - Fix tests for smoker compatibility
 
-1.002
+1.002 2013-03-20
+- window name, default to inches
+
+1.001 2013-03-20
 - Include Prima support
 
-1.001 2013-03-19
+1.000 2013-03-14
 - initial CPAN release

lib/PDL/Graphics/Simple.pm

@@ -125,10 +125,25 @@ object.
 
 The non-object interface will keep using the last plot engine you used
 successfully.  On first start, you can specify an engine with the
-environment variable PDL_SIMPLE_ENGINE.  If that one isn't working, or
+environment variable C<PDL_SIMPLE_ENGINE>. As of 1.011, only that will be tried, but
 if you didn't specify one, all known engines are tried in alphabetical
 order until one works.
 
+The value of C<PDL_SIMPLE_ENGINE> should be the "shortname" of the
+engine, currently:
+
+=over
+
+=item C<gnuplot>
+
+=item C<plplot>
+
+=item C<pgplot>
+
+=item C<prima>
+
+=back
+
 =over 3
 
 =item * Load module and create line plots
@@ -364,9 +379,9 @@ If specified, this must be one of the supported plotting engines.  You
 can use a module name or the shortened name.  If you don't give one,
 the constructor will try the last one you used, or else scan through
 existing modules and pick one that seems to work.  It will first check
-the environment variable PDL_SIMPLE_ENGINE, then search through all
-the known engines in alphabetical order until it finds one that seems
-to work on your system.
+the environment variable C<PDL_SIMPLE_ENGINE>, and as of 1.011, only that will be tried, but
+if you didn't specify one, all known engines are tried in alphabetical
+order until one works.
 
 =item size
 
@@ -430,37 +445,36 @@ sub new {
     ##############################
     # Pick out a working plot engine...
 
-    unless($opt->{engine}) {
+    unless ($opt->{engine}) {
 	# find the first working subclass...
-	unless($last_successful_type) {
+	unless ($last_successful_type) {
 
 	    my @try = ();
-
-	    if($ENV{'PDL_SIMPLE_ENGINE'}) {
+	    if ($ENV{'PDL_SIMPLE_ENGINE'}) {
 		push(@try, $ENV{'PDL_SIMPLE_ENGINE'});
+	    } else {
+		push(@try, sort keys %$mods);
 	    }
 
-	    push(@try, sort keys %$mods);
-
 	    attempt: for my $engine( @try ) {
 		print "Trying $engine ($mods->{$engine}->{engine})...";
 		my $s;
 		my $a = eval { $mods->{$engine}{module}->can('check')->() };
-		if($@) {
+		if ($@) {
 		    chomp $@;
 		    $s = "$@";
 		} else {
 		    $s = ($a ? "ok" : "nope");
 		}
 		print $s."\n";
-		if($a) {
+		if ($a) {
 		    $last_successful_type = $engine;
 		    last attempt;
 		}
 	    }
-	      unless( $last_successful_type ) {
-		  barf "Sorry, all known plotting engines failed.  Install one and try again.\n";
-	      }
+	    unless ( $last_successful_type ) {
+		barf "Sorry, all known plotting engines failed.  Install one and try again.\n";
+	    }
 	}
 	$opt->{engine} = $last_successful_type;
     }

t/simple.t

@@ -6,7 +6,7 @@ use File::Temp q/tempfile/;
 use PDL;
 
 my $tests_per_engine = 17;
-my @engines = qw/plplot gnuplot pgplot prima/;
+my @engines = $ENV{PDL_SIMPLE_ENGINE} || qw/plplot gnuplot pgplot prima/;
 my $smoker = ($ENV{'PERL_MM_USE_DEFAULT'} or $ENV{'AUTOMATED_TESTING'});
 $ENV{PGPLOT_DEV} ||= '/NULL' if $smoker;