46 lines
916 B
C
46 lines
916 B
C
/* Simple backend for a Logo like tortoise drawer. */
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
|
|
static const int WIDTH = 10;
|
|
static const int HEIGHT = 10;
|
|
|
|
static FILE*
|
|
start_gnuplot() {
|
|
FILE* output;
|
|
int pipes[2];
|
|
pid_t pid;
|
|
|
|
pipe(pipes);
|
|
pid = fork();
|
|
|
|
if (!pid) {
|
|
dup2 (pipes[0], STDIN_FILENO);
|
|
execlp ("gnuplot", NULL);
|
|
return; /* Not reached. */
|
|
}
|
|
|
|
output = fdopen(pipes[1], "w");
|
|
|
|
fprintf (output, "set multiplot\n");
|
|
fprintf (output, "set parametric\n");
|
|
fprintf (output, "set xrange [-%d:%d]\n", WIDTH, WIDTH);
|
|
fprintf (output, "set yrange [-%d:%d]\n", HEIGHT, HEIGHT);
|
|
fprintf (output, "set size ratio -1\n");
|
|
fprintf (output, "unset xtics\n");
|
|
fprintf (output, "unset ytics\n");
|
|
fflush (output);
|
|
|
|
return output;
|
|
}
|
|
|
|
static FILE* global_output;
|
|
|
|
int main(int argc, char *argv[]) {
|
|
global_output = start_gnuplot();
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|