research/2008-displacement/xy2d.c

#include <stdio.h>

#define N 128

#if 1
#define X1 -.1
#define X2 .4
#define Y1 -.05
#define Y2 .45
#endif

int tab[N][N];

int main(void)
{
    float fx, fy;
    int x, y;

    for(;;)
    {
        if(fscanf(stdin, "%g %g\n", &fx, &fy) != 2)
            break;

        x = (N - 0.000001) * (fx - X1) / (X2 - X1);
        y = (N - 0.000001) * (fy - Y1) / (Y2 - Y1);
        if(x < 0 || y < 0 || x >= N || y >= N)
            continue;

        tab[x][y]++;
    }

    for(y = 0; y < N; y++)
    {
        for(x = 0; x < N; x++)
            printf("%g %g %i\n", (float)x * (X2 - X1) / (N - 1) + X1,
                          (float)y * (Y2 - Y1) / (N - 1) + Y1, tab[x][y]);
        printf("\n");
    }

    return 0;
}