added a loop

This commit is contained in:
davidovski 2021-12-05 21:30:29 +00:00
commit d451c04331
2 changed files with 134 additions and 0 deletions

14
Makefile Normal file
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PROG=rope
CC=gcc
FLAGS=-lm -lraylib
.DEFAULT_GOAL := build
install: ${PROG}
cp ${PROG} ~/.local/bin/
build: ${PROG}.c
${CC} ${PROG}.c -o ${PROG} ${FLAGS}
clean: ${PROG}
rm ${PROG}

120
rope.c Executable file
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#include <raylib.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
const int radius = 8;
const int size[] = {800, 450};
const float t = 0.2;
const int distance = 64;
int holding = -1;
typedef struct point {
Vector2 pos;
Vector2 vel;
int next;
} Point;
Point points[64];
int populatePoints() {
int count = sizeof(points) / sizeof(Point);
for (int i = 0; i < count; i++) {
points[i] = (Point){rand() % size[0], rand() % size[1], (i+1) % count};
}
}
float magnitude(Vector2 a) {
return sqrt(a.x*a.x + a.y*a.y);
}
int distanceSquared(Vector2 a, Vector2 b) {
int dx = (a.x - b.x);
int dy = (a.y - b.y);
return dx*dx + dy*dy;
}
Vector2 add(Vector2 a, Vector2 b) {
return (Vector2){a.x + b.x, a.y + b.y};
}
Vector2 mul(Vector2 a, float v) {
return (Vector2){a.x * v, a.y * v};
}
Vector2 normalize(Vector2 a) {
float m = magnitude(a);
return (Vector2){a.x / m, a.y / m};
}
int physics(Point *p, Point *n) {
Vector2 d = (Vector2){(n->pos.x - p->pos.x), (n->pos.y - p->pos.y)};
Vector2 f = mul(normalize(d), t * (magnitude(d) - distance));
p->vel.x += f.x;
p->vel.y += f.y;
}
int draw(void) {
Vector2 mouse = (Vector2){GetMouseX(), GetMouseY()};
BeginDrawing();
ClearBackground(LIGHTGRAY);
int count = sizeof(points) / sizeof(Point);
if (holding > -1) {
Point *p = &points[holding];
p->pos = mouse;
}
for (int i = 0; i < count; i++) {
Point *p = &points[i];
Point *n = &points[(i+1)% count];
Point *m = &points[(i-1)% count];
p->vel.x = 0;
p->vel.y = 0;
physics(p, n);
physics(p, m);
p->pos.x += p->vel.x;
p->pos.y += p->vel.y;
if (IsMouseButtonDown(0)) {
if (distanceSquared(p->pos, mouse) < radius*radius) {
holding = i;
}
} else {
holding = -1;
}
DrawCircle(p->pos.x, p->pos.y, radius, DARKGRAY);
DrawLineEx(p->pos, n->pos, radius / 2, DARKGRAY);
}
EndDrawing();
}
int main(void) {
InitWindow(size[0], size[1], "Rope");
SetTargetFPS(60);
populatePoints();
while (!WindowShouldClose()) {
draw();
}
CloseWindow();
return 0;
}