Add a second label to the Y axis if there is only going to be one -- Jason A. Smith...

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2@795 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/program/src/rrd_graph.c b/program/src/rrd_graph.c
index a71a174a5001cc931a0013fed39a93e6d8302bc4..f8a52e0ce1319f3488fdc27a54607fe72b8f4fbc 100644 (file)
--- a/program/src/rrd_graph.c
+++ b/program/src/rrd_graph.c
@@ -1612,6 +1612,7 @@ int draw_horizontal_grid(image_desc_t *im)
     int      i;
     double   scaledstep;
     char     graph_label[100];
+    int      nlabels=0;
     double X0=im->xorigin;
     double X1=im->xorigin+im->xsize;
    
@@ -1622,9 +1623,13 @@ int draw_horizontal_grid(image_desc_t *im)
     MaxY = scaledstep*(double)egrid;
     for (i = sgrid; i <= egrid; i++){
        double Y0=ytr(im,im->ygrid_scale.gridstep*i);
+       double YN=ytr(im,im->ygrid_scale.gridstep*(i+1));
        if ( Y0 >= im->yorigin-im->ysize
                 && Y0 <= im->yorigin){       
-           if(i % im->ygrid_scale.labfact == 0){               
+           /* Make sure at least 2 grid labels are shown, even if it doesn't agree
+              with the chosen settings. Add a label if required by settings, or if
+              there is only one label so far and the next grid line is out of bounds. */
+           if(i % im->ygrid_scale.labfact == 0 || ( nlabels==1 && (YN < im->yorigin-im->ysize || YN > im->yorigin) )){         
                if (im->symbol == ' ') {
                    if(im->extra_flags & ALTYGRID) {
                        sprintf(graph_label,im->ygrid_scale.labfmt,scaledstep*(double)i);
@@ -1647,6 +1652,7 @@ int draw_horizontal_grid(image_desc_t *im)
                        }
                     }
                }
+               nlabels++;
 
               gfx_new_text ( im->canvas,
                              X0-im->text_prop[TEXT_PROP_AXIS].size, Y0,