2d/softbody/softbody_1/snippet2.cpp


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16


struct Spring {
    float mass = 1.f;       // Mass of the weight on the end of the spring
    float k = 4;            // Spring Constant, in N / m
    float c = 1;            // Viscous damping constant, in N / m/s
    float force = 0.f;
    float velocity = 0.f;
    float position = 0.f;
};

void updateSpring(Spring* spring, float dtSeconds) {
    spring->force = spring->c * spring->velocity + spring->k * spring->position;
    float acceleration = spring->force / spring->mass;  // F = ma
    spring->velocity = spring->velocity + acceleration * dtSeconds;
    spring->position = spring->position + spring->velocity * dtSeconds;
}