33 lines
1.2 KiB
C
33 lines
1.2 KiB
C
#include "magnetism.h"
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#include "consts.h"
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#include "vec_utils.h"
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#include <math.h>
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#define EPSILON 8.85418782E-12
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void magnetism(universe_t* uni){
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for (unsigned int i = 0; i < uni->num_bodies; i++) {
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mass_body_t *body_1 = &uni->bodies[i];
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for (unsigned int y = i + 1; y < uni->num_bodies; y++) {
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mass_body_t *body_2 = &uni->bodies[y];
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if (body_1->charge == 0 || body_2->charge == 0) {
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continue;
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}
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Vector2 diff = vec2_diff(body_2->position, body_1->position);
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float distance_squared = vec2_dot(diff, diff);
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if (distance_squared == 0) {
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continue;
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}
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// Charges are in coulombs; convert acceleration to Earth radii/s^2.
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float factor = PHYSICS_TIMESTEP * body_1->charge * body_2->charge /
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(4 * PI * EPSILON * EARTH_MASS * DISTANCE_UNIT_METERS *
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DISTANCE_UNIT_METERS * DISTANCE_UNIT_METERS * distance_squared);
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Vector2 impulse = vec2_scale(vec2_normalize(diff), factor);
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body_1->speed = vec2_diff(body_1->speed,
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vec2_scale(impulse, 1 / body_1->mass));
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body_2->speed = vec2_sum(body_2->speed,
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vec2_scale(impulse, 1 / body_2->mass));
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}
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}
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}
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