#include <stdio.h>
#include <math.h>
-#include <malloc.h>
+#include <stdlib.h>
#include <string.h>
-/*
+/*
* adapted from Paul Heckbert's algorithm on p 657-659 of
* Andrew S. Glassner's book, "Graphics Gems"
* ISBN 0-12-286166-3
return 10.0 * pow(10.0, exp);
}
-static void shorten(struct tickmark *tm, int nticks)
+static void shorten(struct tickmark *tm, int nticks, int *power_of_ten,
+ int use_KMG_symbols, int base_offset)
{
- int i, l, minshorten, can_shorten_by;
+ const char shorten_chr[] = { 0, 'K', 'M', 'G', 'P', 'E', 0 };
+ int i, l, minshorten, shorten_idx = 0;
char *str;
- char shorten_char = '?';
minshorten = 100;
for (i = 0; i < nticks; i++) {
str = tm[i].string;
l = strlen(str);
+ if (strcmp(str, "0") == 0)
+ continue;
if (l > 9 && strcmp(&str[l - 9], "000000000") == 0) {
- can_shorten_by = 9;
- shorten_char = 'G';
+ *power_of_ten = 9;
+ shorten_idx = 3;
} else if (6 < minshorten && l > 6 &&
strcmp(&str[l - 6], "000000") == 0) {
- can_shorten_by = 6;
- shorten_char = 'M';
+ *power_of_ten = 6;
+ shorten_idx = 2;
} else if (l > 3 && strcmp(&str[l - 3], "000") == 0) {
- can_shorten_by = 3;
- shorten_char = 'K';
+ *power_of_ten = 3;
+ shorten_idx = 1;
} else {
- can_shorten_by = 0;
+ *power_of_ten = 0;
}
- if (can_shorten_by < minshorten)
- minshorten = can_shorten_by;
+ if (*power_of_ten < minshorten)
+ minshorten = *power_of_ten;
}
if (minshorten == 0)
return;
+ if (!use_KMG_symbols)
+ shorten_idx = 0;
+ else if (base_offset)
+ shorten_idx += base_offset;
for (i = 0; i < nticks; i++) {
str = tm[i].string;
l = strlen(str);
- str[l - minshorten] = shorten_char;
- str[l - minshorten + 1] = '\0';
+ str[l - minshorten] = shorten_chr[shorten_idx];
+ if (shorten_idx)
+ str[l - minshorten + 1] = '\0';
}
}
-int calc_tickmarks(double min, double max, int nticks, struct tickmark **tm)
+int calc_tickmarks(double min, double max, int nticks, struct tickmark **tm,
+ int *power_of_ten, int use_KMG_symbols, int base_offset)
{
char str[100];
int nfrac;
sprintf((*tm)[i].string, str, x);
i++;
}
- shorten(*tm, i);
+ shorten(*tm, i, power_of_ten, use_KMG_symbols, base_offset);
return i;
}
printf("Testing range %g - %g\n", x, y);
nticks = calc_tickmarks(x, y, 10, &tm);
- for (i = 0; i < nticks; i++) {
+ for (i = 0; i < nticks; i++)
printf(" (%s) %g\n", tm[i].string, tm[i].value);
- }
+
printf("\n\n");
free(tm);
}
int main(int argc, char *argv[])
{
- test_range(0.0005, 0.008);
- test_range(0.5, 0.8);
- test_range(5.5, 8.8);
- test_range(50.5, 80.8);
- test_range(-20, 20.8);
- test_range(-30, 700.8);
+ test_range(0.0005, 0.008);
+ test_range(0.5, 0.8);
+ test_range(5.5, 8.8);
+ test_range(50.5, 80.8);
+ test_range(-20, 20.8);
+ test_range(-30, 700.8);
}
#endif