add pseudo-working anaconda program and intersect() function

This commit is contained in:
randomuser 2021-10-17 20:56:06 -05:00
parent 1e8c7be1a4
commit 8a6d333cd2
1 changed files with 156 additions and 0 deletions

156
c/anaconda.c Normal file
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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <X11/Xlib.h>
typedef struct point {
double x;
double y;
struct point *next;
} point;
typedef struct anaconda {
int score;
double rot;
struct point *chain;
} anaconda;
Display *d;
Window w;
XEvent e;
int s;
GC gc;
void xinit(void) {
d = XOpenDisplay(NULL);
s = DefaultScreen(d);
w = XCreateSimpleWindow(d, RootWindow(d, s), 10, 10, 100, 100, 1,
BlackPixel(d, s), WhitePixel(d, s));
XSelectInput(d, w, ExposureMask | KeyPressMask | PointerMotionMask);
XMapWindow(d, w);
gc = XCreateGC(d, w, 0, NULL);
}
/* thanks to
* https://stackoverflow.com/questions/3838329/how-can-i-check-if-two-segments-intersect/9997374#9997374
* for functions ccw and intersect
*/
int ccw(point *a, point *b, point *c) {
return (c->y - a->y) * (b->x - a->x) >
(b->y - a->y) * (c->x - a->x);
}
int intersect(point *a, point *b, point *c, point *d) {
return (ccw(a, c, d) != ccw(b, c, d)) && (ccw(a, b, c) != ccw(a, b, d));
}
point *mkPoint(double x, double y) {
point *ret = malloc(sizeof ret);
ret->x = x;
ret->y = y;
ret->next = NULL;
return ret;
}
point *rotate(point *p, double rot) {
double rad = rot * M_PI/180;
return mkPoint(
p->x * cos(rad) - p->y * sin(rad),
p->x * sin(rad) + p->y * cos(rad)
);
}
void appendPoint(point *dest, point *origin) {
while(dest->next) dest = dest->next;
dest->next = origin;
}
void updateAnaconda(anaconda *anaconda) {
point *prev = anaconda->chain;
point *temp = rotate(mkPoint(10, 0), anaconda->rot);
point *new = mkPoint(
prev->x + temp->x,
prev->y + temp->y
);
new->next = prev;
anaconda->chain = new;
free(temp);
point *traverser = new;
while(1) {
if(traverser->next) {
if(traverser->next->next) {
traverser = traverser->next;
} else break;
} else break;
}
free(traverser->next);
traverser->next = NULL;
}
point *generateChain(int length) {
point *ret = mkPoint(100, 100);
point *head = ret;
for(int i = 1; i < length - 1; i++) {
ret->next = mkPoint(
10 * i + 100,
5 * i + 100
);
ret = ret->next;
}
return head;
}
anaconda *mkAnaconda(point *point, double rot) {
anaconda *ret = malloc(sizeof ret);
ret->chain = point;
ret->rot = rot;
ret->score = 0;
return ret;
}
int main(void) {
anaconda *anaconda = mkAnaconda(generateChain(10), 0);
xinit();
while(1) {
updateAnaconda(anaconda);
XClearWindow(d, w);
point *ptr = anaconda->chain;
while(ptr->next) {
XDrawLine(d, w, gc, ptr->x, ptr->y, ptr->next->x, ptr->next->y);
ptr = ptr->next;
}
while(XPending(d)) {
XNextEvent(d, &e);
switch(e.type) {
case KeyPress:
switch(e.xkey.keycode) {
case 113: /* left arrow key */
anaconda->rot += 10;
break;
case 114: /* right arrow key */
anaconda->rot -= 10;
break;
}
break;
}
}
usleep(100000);
}
return 0;
}