JacksEscape/Physics_Move.c

80 lines
2.0 KiB
C

#include "Physics_Component.h"
#include "Entity.h"
#include "Types.h"
#include "util/tree.h"
#include <stdlib.h>
static const double EPS = 1e-6;
static inline double dabs(double x) {
return x < 0 ? -x : x;
}
void _physics_MoveX(System_Physics *sys, Entity *e, Duration deltaTime) {
double delta = e->position->velocity.x * duration_Seconds(deltaTime);
if (dabs(delta) < EPS)
return;
for (tree_Node *i = tree_FirstNode(sys->hit);
i != NULL;
i = tree_Node_Next(i)) {
Component_Hitbox *tohit = *((Component_Hitbox **)i->data);
if (!tohit->fixed)
continue;
if (box2_Intersects(tohit->box, box2_OffsetX(e->hitbox->box, delta), NULL)) {
if (delta > 0) {
// Moves right, hits left edge
double maxdelta = tohit->box.lefttop.x - e->hitbox->box.lefttop.x - e->hitbox->box.size.x;
delta = maxdelta - EPS;
} else {
// Moves left, hits right edge
double maxdelta = tohit->box.lefttop.x - e->hitbox->box.lefttop.x + tohit->box.size.x;
delta = maxdelta + EPS;
}
}
if (dabs(delta) < EPS)
break;
}
if (dabs(delta) > EPS)
e->position->position.x += delta;
}
void _physics_MoveY(System_Physics *sys, Entity *e, Duration deltaTime) {
double delta = e->position->velocity.y * duration_Seconds(deltaTime);
if (dabs(delta) < EPS)
return;
for (tree_Node *i = tree_FirstNode(sys->hit);
i != NULL;
i = tree_Node_Next(i)) {
Component_Hitbox *tohit = *((Component_Hitbox **)i->data);
if (!tohit->fixed)
continue;
if (box2_Intersects(tohit->box, box2_OffsetY(e->hitbox->box, delta), NULL)) {
if (delta > 0) {
// Moves down, hits top edge
double maxdelta = tohit->box.lefttop.y - e->hitbox->box.lefttop.y - e->hitbox->box.size.y;
delta = maxdelta - EPS;
} else {
// Moves up, hits bottom edge
double maxdelta = tohit->box.lefttop.y - e->hitbox->box.lefttop.y + tohit->box.size.y;
delta = maxdelta + EPS;
}
}
if (dabs(delta) < EPS)
break;
}
if (dabs(delta) > EPS)
e->position->position.y += delta;
}