C - simple packed bit display example

/*Packed pixels example 8x8 1-bit -- striped in y axis */
/*(4x4)
1111
2222
4444
8888
*/
#include <stdio.h>
const int pixmap[]={0x1,0x2,0x4,0x8,0x10,0x20,0x40,0x80};
unsigned char xy[]={0xFF,0x81,0x89,0xFF,0xFF,0x89,0xC81,0xFF};

void display(void)
{
    for (int j = 0; j<8;j++)
    {
        for (int i = 0; i<8;i++)
        {
            if (xy[i] & pixmap[j])
                printf("*");
            else
                printf(" ");
        }
        printf("\n");
    }
}

unsigned char set_pix(int x, int y, unsigned char val)
{
    int mask = pixmap[y & 7];
    val <<= ((y & 7));
    xy[x] &= ~mask;
    xy[x] |= (val & mask);
}

unsigned char get_pix(int x, int y)
{
    int mask = pixmap[y & 7];
    return (xy[x] & mask)>>(y & 7);
}

int main()
{
    display();
    set_pix(0, 5, 0xF0);
    display();
    printf("%d", get_pix(0,5));
    return 0;
}
/*********************************************************************************/
/*********************************************************************************/
/*********************************************************************************/
/*Packed pixels example 8x8 1-bit -- striped in x axis */
/* (4x4)
1248
1248
1248
1248
*/
#include <stdio.h>
const int pixmap[]={0x1,0x2,0x4,0x8,0x10,0x20,0x40,0x80};
unsigned char xy[]={0xFF,0x81,0x89,0xFF,0xFF,0x89,0xC81,0xFF};

void display(void)
{
    for (int j = 0; j<8;j++)
    {
        for (int i = 0; i<8;i++)
        {
            if (xy[j] & pixmap[i])
                printf("*");
            else
                printf(" ");
        }
        printf("\n");
    }
}
unsigned char set_pix(int x, int y, unsigned char val)
{
    int mask = pixmap[x & 7];
    val <<= ((x & 7));
    xy[y] &= ~mask;
    xy[y] |= (val & mask);
}
unsigned char get_pix(int x, int y)
{
    int mask = pixmap[x & 7];
    return (xy[y] & mask)>>(x & 7);
}
int main()
{
    display();
    set_pix(5, 0, 0xF0);
    display();
    printf("%d", get_pix(5,0));
    return 0;
}