[Plplot-cvs] SF.net SVN: plplot:[12652] trunk/src/plvect.c

[<and...@us...>]

Revision: 12652
          http://sourceforge.net/p/plplot/code/12652
Author:   andrewross
Date:     2013-11-05 13:47:05 +0000 (Tue, 05 Nov 2013)
Log Message:
-----------
Apply modified version of patch from Phil Rosenberg so that global coordinate transformations are applied to vector plots. 

Also fix bug in autoscaling of vectors for the case where vectors were all parallel to one of the coordinate axes.

Modified Paths:
--------------
    trunk/src/plvect.c

Modified: trunk/src/plvect.c
===================================================================
--- trunk/src/plvect.c	2013-11-05 11:31:45 UTC (rev 12651)
+++ trunk/src/plvect.c	2013-11-05 13:47:05 UTC (rev 12652)
@@ -68,6 +68,7 @@
 plP_plotvect( PLFLT x, PLFLT y, PLFLT u, PLFLT v, PLFLT scale )
 {
     PLFLT uu, vv, px0, py0, dpx, dpy;
+    PLFLT xt, yt;
     // Unnecessarily initialize a_y to quiet a -O1 -Wuninitialized warning
     // which is a false alarm.  (If something goes wrong with the
     // a_x malloc below any further use of a_y does not occur.)
@@ -86,13 +87,16 @@
         plexit( "plP_plotvect: Insufficient memory" );
     }
 
-    px0 = plP_wcpcx( x );
-    py0 = plP_wcpcy( y );
+    TRANSFORM( x, y, &xt, &yt );
+    px0 = plP_wcpcx( xt );
+    py0 = plP_wcpcy( yt );
 
     pldebug( "plP_plotvect", "%f %f %d %d\n", x, y, px0, py0 );
 
-    dpx = plP_wcpcx( x + 0.5 * uu ) - px0;
-    dpy = plP_wcpcy( y + 0.5 * vv ) - py0;
+    TRANSFORM( x + 0.5 * uu, y + 0.5 * vv, &xt, &yt );
+    //printf("plvect: %f %f %f %f %f %f %f\n",scale, x,0.5*uu, y,0.5*vv, xt, yt);
+    dpx = plP_wcpcx( xt ) - px0;
+    dpy = plP_wcpcy( yt ) - py0;
 
     // transform arrow -> a
 
@@ -187,10 +191,7 @@
                 vmax = ( v[i][j] > vmax ) ? v[i][j] : vmax;
             }
         }
-        umax   = umax / dxmin;
-        vmax   = vmax / dymin;
-        lscale = ( umax < vmax ) ? umax : vmax;
-        lscale = 1.5 / lscale;
+        lscale = 1.5*MIN(dxmin / umax, dymin / vmax);
         if ( scale < 0.0 )
         {
             scale = -scale * lscale;

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