support many-returns ops in Python

add various %apply rules to move values returned via args into the result

ChangeLog

@@ -2,6 +2,7 @@
 - version bump
 - added vips_foreign_find_save_options()/vips_foreign_find_load_options()
 - delayed write to foreign via a "w" image was not working
+- support operations with many returns in Python
 
 20/8/11 started 7.27.0
 - version bump for new dev cycle

TODO

@@ -1,8 +1,5 @@
-- swig is not wrapping ops which return more than one arg by reference
-  correctly .. eg. im_correl()
-
-
-
+- swig is not wrapping im_project() correctly ... returns an extra VImage via
+  a param
 
 - fft with odd width or height is broken ... DC ends up in the wring place
 

libvipsCC/VImage.cc

@@ -444,14 +444,6 @@ void VImage::initdesc( int x, int y, int b,
 		verror();
 }
 
-// used to test SWIG wrappers with output args
-double VImage::test_member( double a, double b, double *c, double *d )
-{
-	*c = a + b;
-	*d = a - b;
-	return a * b;
-}
-
 // Create a Vargv from a name
 Vargv::Vargv( const char *name )
 {

libvipsCC/include/vips/VImage.h

@@ -288,9 +288,6 @@ public:
 	void initdesc( int, int, int, TBandFmt, TCoding, TType, 
 		float = 1.0, float = 1.0, int = 0, int = 0 ) throw( VError );
 
-	// test member for SWIG output args
-	double test_member( double a, double b, double *c, double *d );
-
 	/* Insert automatically generated headers.
 	 */
 #include "vipsc++.h"

swig/vipsCC/VImage.i

@@ -75,13 +75,53 @@ struct VBuffer {
   $1.size = buffer_len;
 }
 
+/* Functions which return extra values though their parameters need special
+ * typemaps.
+ */
+
+// double maxpos_avg( double& maxpos_avg_y, double& maxpos_avg_out )
+%apply double *OUTPUT { double & maxpos_avg_y };
+%apply double *OUTPUT { double & maxpos_avg_out };
+
+// VImage system_image( char* system_image_in_format, char* system_image_out_format, char* system_image_command, char*& system_image_log ) 
+%cstring_output_allocate(char **system_image_log, g_free(*$1));
+
+// VImage segment( int& segment_segments ) 
+%apply int *OUTPUT { int & segment_segments };
+
+// VImage project( VImage& project_vout ) throw( VError );
+// nope ... not sure how to handle this one
+//%apply VImage *OUTPUT { VImage & project_vout };
+
+// VImage label_regions( int& label_regions_segments ) 
+%apply int *OUTPUT { int & label_regions_segments };
+
+// double correl( VImage correl_sec, int correl_xref, int correl_yref, int correl_xsec, int correl_ysec, int correl_hwindowsize, int correl_hsearchsize, int& correl_x, int& correl_y ) 
+%apply int *OUTPUT { int & correl_x };
+%apply int *OUTPUT { int & correl_y };
+
+// int _find_lroverlap( VImage _find_lroverlap_sec, int _find_lroverlap_bandno, int _find_lroverlap_xr, int _find_lroverlap_yr, int _find_lroverlap_xs, int _find_lroverlap_ys, int _find_lroverlap_halfcorrelation, int _find_lroverlap_halfarea, int& _find_lroverlap_dy0, double& _find_lroverlap_scale1, double& _find_lroverlap_angle1, double& _find_lroverlap_dx1, double& _find_lroverlap_dy1 ) 
+%apply int *OUTPUT { int & _find_lroverlap_dy0 };
+%apply double *OUTPUT { double & _find_lroverlap_scale1 };
+%apply double *OUTPUT { double & _find_lroverlap_angle1 };
+%apply double *OUTPUT { double & _find_lroverlap_dx1 };
+%apply double *OUTPUT { double & _find_lroverlap_dy1 };
+
+// int _find_tboverlap( VImage _find_tboverlap_sec, int _find_tboverlap_bandno, int _find_tboverlap_xr, int _find_tboverlap_yr, int _find_tboverlap_xs, int _find_tboverlap_ys, int _find_tboverlap_halfcorrelation, int _find_tboverlap_halfarea, int& _find_tboverlap_dy0, double& _find_tboverlap_scale1, double& _find_tboverlap_angle1, double& _find_tboverlap_dx1, double& _find_tboverlap_dy1 ) 
+%apply int *OUTPUT { int & _find_tboverlap_dy0 };
+%apply double *OUTPUT { double & _find_tboverlap_scale1 };
+%apply double *OUTPUT { double & _find_tboverlap_angle1 };
+%apply double *OUTPUT { double & _find_tboverlap_dx1 };
+%apply double *OUTPUT { double & _find_tboverlap_dy1 };
+
+// double maxpos_subpel( double& maxpos_subpel_y ) 
+%apply double *OUTPUT { double & maxpos_subpel_y };
+
 /* Need the expanded VImage.h in this directory, rather than the usual
  * vips/VImage.h. SWIG b0rks on #include inside class definitions.
  */
 %include VImage.h
 
-
-
 %extend vips::VImage {
 public:
   VBuffer tobuffer () throw (VError)

swig/vipsCC/test.py

@@ -1,4 +0,0 @@
-from vipsCC import * 
-
-a = VImage.VImage("/home/john/pics/shark.jpg")
-print a.maxpos_avg()