diff --git a/main.c b/main.c index 4f86f8c..406087b 100644 --- a/main.c +++ b/main.c @@ -1,6 +1,7 @@ #define _POSIX_C_SOURCE 200809L #include "objects.h" +#include "vec_util.h" #include #include #include @@ -12,6 +13,7 @@ #include static const long TIMESTEP = 1000000; +static const long simx = 2; int center_x_text(const char *text, int width, int size) { return (width - MeasureText(text, size)) / 2; @@ -27,6 +29,9 @@ Vector2 body_collision(mass_body_t *a, mass_body_t *b) { if (len > a->radius + b->radius) { return NULL_VEC2; } + if (len == 0) { + return (Vector2){1, 0}; + } Vector2 result = vec2_normalize(diff); return result; } @@ -56,19 +61,33 @@ Vector2 edge_collision(mass_body_t *b) { void collide(mass_body_t *a, mass_body_t *b, const Vector2 *normal, float resitution) { + float inverse_a = 1.0f / a->mass; + float inverse_b = 1.0f / b->mass; + float inverse_total = inverse_a + inverse_b; + float overlap = + a->radius + b->radius - vec2_len(vec2_diff(&a->position, &b->position)); + Vector2 correction = vec2_scale(normal, overlap / inverse_total); + Vector2 a_move = vec2_scale(&correction, inverse_a); + Vector2 b_move = vec2_scale(&correction, inverse_b); + a->position = vec2_sum(&a->position, &a_move); + b->position = vec2_diff(&b->position, &b_move); + Vector2 relative = vec2_diff(&b->speed, &a->speed); float v_normal = vec2_dot(&relative, normal); + if (v_normal <= 0) { + return; + } float factor = -(1 + resitution); float j = factor * v_normal; - j /= (1.0 / a->mass) + (1.0 / b->mass); + j /= inverse_total; Vector2 final = vec2_scale(normal, j); - Vector2 a_diff = vec2_scale(&final, 1.0 / a->mass); + Vector2 a_diff = vec2_scale(&final, inverse_a); a->speed = vec2_diff(&a->speed, &a_diff); - Vector2 b_diff = vec2_scale(&final, 1.0 / b->mass); + Vector2 b_diff = vec2_scale(&final, inverse_b); b->speed = vec2_sum(&b->speed, &b_diff); } @@ -97,12 +116,14 @@ void *physics(void *args) { mass_body_t body_1; mass_body_t body_2; Vector2 collision; + Vector2 scaled_speed; struct timespec ot, ct; while (true) { clock_gettime(CLOCK_MONOTONIC, &ct); for (unsigned int i = 0; i < uni->num_bodies; i++) { body_1 = uni->bodies[i]; - body_1.position = vec2_sum(&body_1.position, &body_1.speed); + scaled_speed = vec2_scale(&body_1.speed, 1.0 / simx); + body_1.position = vec2_sum(&body_1.position, &scaled_speed); if (i < uni->num_bodies - 1) { for (unsigned int y = i + 1; y < uni->num_bodies; y++) { body_2 = uni->bodies[y]; @@ -122,7 +143,7 @@ void *physics(void *args) { ot = ct; clock_gettime(CLOCK_MONOTONIC, &ct); long long elapsed = timespec_diff_ns(ct, ot); - long long remaining = TIMESTEP - elapsed; + long long remaining = TIMESTEP / simx - elapsed; if (remaining > 0) { long long sleep_time = remaining * 9 / 10; @@ -133,7 +154,7 @@ void *physics(void *args) { do { clock_gettime(CLOCK_MONOTONIC, &ct); - } while (timespec_diff_ns(ct, ot) < TIMESTEP); + } while (timespec_diff_ns(ct, ot) < TIMESTEP / simx); } } @@ -142,12 +163,14 @@ int main(void) { const char *welcome_text = "Welcome to Fucked Physics!"; universe_t universe = {0, NULL}; universe.bodies = malloc(1024 * sizeof(mass_body_t)); - for(int i=0;i<100;i++){ - if(i>500){ - universe.bodies[i] = (mass_body_t){100/(25+50/(i+1)), 50+50/(i+1), {i*10, i*200%500}, {0.1, 0.5+i*0.01}}; - }else{ - universe.bodies[i] = (mass_body_t){100/(25+50/(i+1)), 25+50/(i+1), {-i*10, -i*300%500}, {-0.1, 0.8-i*0.005}}; - } + for (int i = 0; i < 100; i++) { + float radius = 12.0f + 8.0f / (i + 1); + universe.bodies[i] = (mass_body_t){ + radius, + radius, + {-360.0f + 80.0f * (i % 10), -202.5f + 45.0f * (i / 10)}, + {-0.1f, 0.8f - i * 0.005f}, + }; } universe.num_bodies = 100; SetConfigFlags(FLAG_WINDOW_RESIZABLE);