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#import <stdio.h>
#import <nextdev/video.h>
#import <sys/file.h>
#import <sys/ioctl.h>
#import <objc/objc.h>
#import <sys/signal.h>
/* snake.c -- divide the screen up into squares, and play puzzle with 'em
*
* 5/92, CWS -- Added support for signal trapping. Cleaned up the code.
* This now runs forever until the user kills it.
*/
#define PC_WIDTH 64
#define PC_HEIGHT 64
#define X_TILES (VIDEO_W/PC_WIDTH)
#define Y_TILES (VIDEO_H/PC_HEIGHT)
// some pseudo-constants, will change from display to display
unsigned char *old_screen = NULL, *vid_base = NULL;
long num_bytes = (VIDEO_MW * VIDEO_H / NPPB), bytes_per_row = (VIDEO_MW/NPPB);
// various small utility routines for moving memory around
long coordtoindex(x,y)
long x, y;
{
return (y*bytes_per_row + x);
}
void get_piece(x, y, piece, source)
long x,y;
unsigned char *piece, *source;
{
long i,j;
for(j=0;j<PC_HEIGHT;j++){
for(i=0;i<(PC_WIDTH/4);i++){
piece[coordtoindex(i,j)]=
source[coordtoindex(((x*(PC_WIDTH/4))+i),((y*PC_HEIGHT)+j))];
}
}
}
void place_piece(x,y,piece,dest)
long x,y;
unsigned char *piece, *dest;
{
long i,j;
for(j=0;j<PC_HEIGHT;j++){
for(i=0;i<(PC_WIDTH/4);i++){
dest[coordtoindex(((x*(PC_WIDTH/4))+i),((y*PC_HEIGHT)+j))]=
piece[coordtoindex(i,j)];
}
}
}
void erase_piece(x,y,dest)
long x,y;
unsigned char *dest;
{
long i,j;
for(j=0;j<PC_HEIGHT;j++){
for(i=0;i<(PC_WIDTH/4);i++){
dest[coordtoindex(((x*(PC_WIDTH/4))+i),((y*PC_HEIGHT)+j))]=255;
}
}
}
// general signal handler; simply restores screen memory and exits.
void handle(sig)
int sig;
{
bcopy(old_screen, vid_base, num_bytes * sizeof(unsigned char));
free(old_screen);
fprintf(stdout, "\nCaught signal %d...\n", sig);
exit(0);
}
// handle SIGTSTP; restores screen memory, then calls SIGSTOP
void pause(sig)
int sig;
{
bcopy(old_screen, vid_base, num_bytes * sizeof(unsigned char));
raise(SIGSTOP);
}
main() {
int fd, i, j, k;
unsigned char *piece_to_move;
short direction, oldDirection, steps;
long curx, cury;
long newx, newy;
BOOL valid;
// do the signal trapping stuff
if (signal(SIGINT, &handle)) {
fprintf(stdout, "Couldn't establish new error handler for SIGINT.\n");
exit(2);
}
if (signal(SIGTERM, &handle)) {
fprintf(stdout, "Couldn't establish new error handler for SIGTERM.\n");
exit(2);
}
if (signal(SIGTSTP, &pause)) {
fprintf(stdout, "Couldn't establish new errorhandler for SIGTSTP.\n");
exit(2);
}
// open the /dev/vid0, and get the address of screen memory
fd = open("/dev/vid0", O_RDWR, NULL);
if (fd <= 0) {
fprintf(stdout,"open result:%d\n", errno);
exit(1);
}
if (ioctl(fd, DKIOCGADDR, &vid_base) < 0) {
fprintf(stdout, "ioctl errno: %d\n", errno);
exit(1);
}
old_screen=(unsigned char *) malloc(num_bytes * sizeof(unsigned char));
bcopy(vid_base, old_screen, num_bytes);
piece_to_move=(unsigned char *)
malloc(PC_HEIGHT*(PC_WIDTH/4)*sizeof(unsigned char));
srand(getpid()*time(0));
curx=0; cury=0;
get_piece(curx,cury,piece_to_move, vid_base);
for (;;){
erase_piece(curx, cury, vid_base);
valid=NO;
steps=(4.0*(float) (random()/(float) (pow(2,31)-1)));
while(!valid){
direction=(2.0*(float) (random()/(float) (pow(2,31)-1)));
if(direction!=oldDirection) valid=YES;
}
while(steps){
switch(direction){
case 0: // left
newx=curx-1;
newy=cury;
break;
case 1: // right
newx=curx+1;
newy=cury;
break;
case 2: // up
newx=curx;
newy=cury-1;
break;
case 3: // down
newx=curx;
newy=cury+1;
break;
}
if((newx<X_TILES) && (newx>=0) && (newy<Y_TILES) && (newy>=0)) {
get_piece(newx, newy, piece_to_move, vid_base);
place_piece(curx, cury, piece_to_move, vid_base);
erase_piece(newx, newy, vid_base);
curx=newx;
cury=newy;
} else break;
steps--;
}
oldDirection=direction;
}
// do this if/when done with the loop above; useful for a limited number of
// repeats of the drawing algorhithim
sleep(5);
bcopy(old_screen, vid_base, num_bytes);
free(old_screen);
close(fd);
exit(0);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.