SVG: Fix Y axis scale graduations for small values

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>

diff --git a/svg_stats.c b/svg_stats.c
index 426d286a0d047a9a9a62a182bbeadd448230d4b6..ce57c0a5c023f4c3878d108d59565d1c798ac838 100644 (file)
--- a/svg_stats.c
+++ b/svg_stats.c
@@ -251,17 +251,28 @@ void lnappend(unsigned long timetag, double value, char **out, int *outsize, int
  * IN:
  * @lmax       Max value reached for this graph.
  *
+ * OUT:
+ * @dp         Number of decimal places for Y graduations.
+ *
  * RETURNS:
  * Value between two horizontal lines.
  ***************************************************************************
  */
-long int ygrid(double lmax)
+double ygrid(double lmax, int *dp)
 {
        char val[32];
        int l, i, e = 1;
-       long n;
-       
+       long n = 0;
+
+       *dp = 0;
+       if (lmax == 0) {
+               lmax = 1;
+       }
        n = (long) (lmax / SVG_H_GRIDNR);
+       if (!n) {
+               *dp = 2;
+               return (lmax / SVG_H_GRIDNR);
+       }
        snprintf(val, 32, "%ld", n);
        val[31] = '\0';
        l = strlen(val);
@@ -270,7 +281,7 @@ long int ygrid(double lmax)
        for (i = 1; i < l; i++) {
                e = e * 10;
        }
-       return ((long) ((n / e)) * e);
+       return ((double) (((long) (n / e)) * e));
 }
 
 /*
@@ -320,9 +331,9 @@ __print_funct_t svg_print_pcsw_stats(struct activity *a, int curr, int action, s
        static char **out;
        char *out_p;
        static int *outsize;
-       int i, j;
+       int i, j, dp;
        long int k;
-       double lmax, xfactor, yfactor;
+       double lmax, xfactor, yfactor, ypos;
        char cur_time[32];
 
        if (action & F_BEGIN) {
@@ -402,18 +413,24 @@ __print_funct_t svg_print_pcsw_stats(struct activity *a, int curr, int action, s
                               SVG_M_XSIZE, SVG_M_YSIZE + SVG_G_YSIZE + i * SVG_T_YSIZE);
                        
                        /* Grid */
-                       k = ygrid(*(spmax + i));
+                       ypos = ygrid(*(spmax + i), &dp);
                        yfactor = (double) -SVG_G_YSIZE / lmax;
-                       for (j = 1; j <= SVG_H_GRIDNR; j++) {
-                               printf("<polyline points=\"0,%ld %d,%ld\" vector-effect=\"non-scaling-stroke\" "
+                       j = 1;
+                       do {
+                               printf("<polyline points=\"0,%.2f %d,%.2f\" vector-effect=\"non-scaling-stroke\" "
                                       "stroke=\"#202020\" transform=\"scale(1,%f)\"/>\n",
-                                      k * j, SVG_G_XSIZE, k * j, yfactor);
+                                      ypos * j, SVG_G_XSIZE, ypos * j, yfactor);
+                               j++;
                        }
-                       for (j = 0; j <= SVG_H_GRIDNR; j++) {
+                       while (ypos * j <= *(spmax + i));
+                       j = 0;
+                       do {
                                printf("<text x=\"0\" y=\"%ld\" style=\"fill: white; stroke: none; font-size: 12px; "
-                                      "text-anchor: end\">%ld.</text>\n",
-                                      (long) (k * j * yfactor), k * j);
+                                      "text-anchor: end\">%.*f.</text>\n",
+                                      (long) (ypos * j * yfactor), dp, ypos * j);
+                               j++;
                        }
+                       while (ypos * j <= *(spmax + i));
 
                        k = xgrid(svg_p->record_hdr->ust_time, record_hdr->ust_time);
                        xfactor = (double) SVG_G_XSIZE / (record_hdr->ust_time - svg_p->record_hdr->ust_time);