Modification of rrd_graph.c/h so it uses dashes for gridlines much like

rrdtool 1.0 Avoids drawing minor vertical gridlines where a major gridline
is to avoid artifacts from having the grey line beneath the red one. Patches
src/rrd_graph.c and src/rrd_graph.h
--  Peter Speck <speck@ruc.dk

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@127 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index 135a8a0..9b46311 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -1569,16 +1569,18 @@ int draw_horizontal_grid(image_desc_t *im)
                              im->text_prop[TEXT_PROP_AXIS].size,
                              im->tabwidth, 0.0, GFX_H_RIGHT, GFX_V_CENTER,
                              graph_label );
-              gfx_new_line ( im->canvas,
+              gfx_new_dashed_line ( im->canvas,
                              X0-2,Y0,
                              X1+2,Y0,
-                             MGRIDWIDTH, im->graph_col[GRC_MGRID] );          
+                             MGRIDWIDTH, im->graph_col[GRC_MGRID],
+                             im->grid_dash_on, im->grid_dash_off);            
               
            } else {            
-              gfx_new_line ( im->canvas,
+              gfx_new_dashed_line ( im->canvas,
                              X0-1,Y0,
                              X1+1,Y0,
-                             GRIDWIDTH, im->graph_col[GRC_GRID] );            
+                             GRIDWIDTH, im->graph_col[GRC_GRID],
+                             im->grid_dash_on, im->grid_dash_off);            
               
            }       
        }       
@@ -1629,10 +1631,11 @@ horizontal_log_grid(image_desc_t   *im)
        while(yloglab[minoridx][++i] > 0){          
           Y0 = ytr(im,value * yloglab[minoridx][i]);
           if (Y0 <= im->yorigin - im->ysize) break;
-          gfx_new_line ( im->canvas,
+          gfx_new_dashed_line ( im->canvas,
                          X0-1,Y0,
                          X1+1,Y0,
-                         GRIDWIDTH, im->graph_col[GRC_GRID] );
+                         GRIDWIDTH, im->graph_col[GRC_GRID],
+                         im->grid_dash_on, im->grid_dash_off);
        }
     }
 
@@ -1646,10 +1649,11 @@ horizontal_log_grid(image_desc_t   *im)
        while(yloglab[majoridx][++i] > 0){          
           Y0 = ytr(im,value * yloglab[majoridx][i]);    
           if (Y0 <= im->yorigin - im->ysize) break;
-          gfx_new_line ( im->canvas,
+          gfx_new_dashed_line ( im->canvas,
                          X0-2,Y0,
                          X1+2,Y0,
-                         MGRIDWIDTH, im->graph_col[GRC_MGRID] );
+                         MGRIDWIDTH, im->graph_col[GRC_MGRID],
+                         im->grid_dash_on, im->grid_dash_off);
           
           sprintf(graph_label,"%3.0e",value * yloglab[majoridx][i]);
           gfx_new_text ( im->canvas,
@@ -1670,7 +1674,7 @@ vertical_grid(
     image_desc_t   *im )
 {   
     int xlab_sel;              /* which sort of label and grid ? */
-    time_t ti, tilab;
+    time_t ti, tilab, timajor;
     long factor;
     char graph_label[100];
     double X0,Y0,Y1; /* points for filled graph and more*/
@@ -1703,14 +1707,24 @@ vertical_grid(
     /* paint the minor grid */
     for(ti = find_first_time(im->start,
                            im->xlab_user.gridtm,
-                           im->xlab_user.gridst);
+                           im->xlab_user.gridst),
+        timajor = find_first_time(im->start,
+                           im->xlab_user.mgridtm,
+                           im->xlab_user.mgridst);
        ti < im->end; 
        ti = find_next_time(ti,im->xlab_user.gridtm,im->xlab_user.gridst)
        ){
        /* are we inside the graph ? */
        if (ti < im->start || ti > im->end) continue;
+       while (timajor < ti) {
+           timajor = find_next_time(timajor,
+                   im->xlab_user.mgridtm, im->xlab_user.mgridst);
+       }
+       if (ti == timajor) continue; /* skip as falls on major grid line */
        X0 = xtr(im,ti);       
-       gfx_new_line(im->canvas,X0,Y0+1, X0,Y1-1,GRIDWIDTH, im->graph_col[GRC_GRID]);
+       gfx_new_dashed_line(im->canvas,X0,Y0+1, X0,Y1-1,GRIDWIDTH,
+          im->graph_col[GRC_GRID],
+          im->grid_dash_on, im->grid_dash_off);
        
     }
 
@@ -1724,7 +1738,9 @@ vertical_grid(
        /* are we inside the graph ? */
        if (ti < im->start || ti > im->end) continue;
        X0 = xtr(im,ti);
-       gfx_new_line(im->canvas,X0,Y0+2, X0,Y1-2,MGRIDWIDTH, im->graph_col[GRC_MGRID]);
+       gfx_new_dashed_line(im->canvas,X0,Y0+3, X0,Y1-2,MGRIDWIDTH,
+          im->graph_col[GRC_MGRID],
+          im->grid_dash_on, im->grid_dash_off);
        
     }
     /* paint the labels below the graph */
@@ -2605,6 +2621,8 @@ rrd_graph_init(image_desc_t *im)
     im->gdes_c = 0;
     im->gdes = NULL;
     im->canvas = gfx_new_canvas();
+    im->grid_dash_on = 1;
+    im->grid_dash_off = 1;
 
     for(i=0;i<DIM(graph_col);i++)
         im->graph_col[i]=graph_col[i];

diff --git a/src/rrd_graph.h b/src/rrd_graph.h
index 6fac38d..e61d6b0 100644 (file)
--- a/src/rrd_graph.h
+++ b/src/rrd_graph.h
@@ -129,6 +129,7 @@ typedef struct image_desc_t {
     char           title[200];     /* title for graph */
     int            draw_x_grid;      /* no x-grid at all */
     int            draw_y_grid;      /* no x-grid at all */
+    double         grid_dash_on, grid_dash_off;
     xlab_t         xlab_user;      /* user defined labeling for xaxis */
     char           xlab_form[200]; /* format for the label on the xaxis */