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SqaureGame
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Implement AABB SAT

master
En Yi 2020-01-31 15:51:47 +08:00
parent eaef3aa213
commit a60713a723
1 changed files with 36 additions and 48 deletions
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84
obj/kinematics.c
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@ -1,4 +1,5 @@
#include "header.h"
#include <math.h>
extern struct kinematic_obj_node *kinematic_HEAD;
struct kinematic_obj init_kinematic_obj(int width, int height){
@ -27,69 +28,56 @@ void move(struct kinematic_obj *obj, Vector2 acceleration){
Rectangle collide_rect;
struct kinematic_obj_node *current;
// Simplistic Collision Handling for AABB, Could add coeff of restitution?
// TODO: Implement the slightly better method of collision from:
// https://hopefultoad.blogspot.com/2017/09/2d-aabb-collision-detection-and-response.html
// Self implement AABB SAT from Metanet
// Also think about what happens if the square is completely inside the shape
// Then extend to multiple object
// Might need to check distance
// TODO: extend to multiple object collision, Might need to check distance
// Move the object and apply hitbox reduction
obj->velocity.x += acceleration.x * delta;
obj->pos.x += obj->velocity.x * delta;
obj->rect.x = obj->pos.x + obj->dim_reduction[0];
obj->rect.width = obj->ori_width - obj->dim_reduction[0] - obj->dim_reduction[2];
current = kinematic_HEAD;
while(current != NULL){
if(current->obj != obj){
if (CheckCollisionRecs(obj->rect, current->obj->rect)){
collide_rect = GetCollisionRec(obj->rect, current->obj->rect);
if(collide_rect.width < collide_rect.height){
if (!place_meeting(obj, (Vector2){-collide_rect.width,0})){
obj->rect.x -= collide_rect.width;
obj->pos.x -= collide_rect.width;
}else{
obj->rect.x += collide_rect.width;
obj->pos.x += collide_rect.width;
}
obj->velocity.x = 0;
}else{
if (!place_meeting(obj, (Vector2){0,-collide_rect.height})){
obj->rect.y -= collide_rect.height;
obj->pos.y -= collide_rect.height;
}else{
obj->rect.y += collide_rect.height;
obj->pos.y += collide_rect.height;
}
obj->velocity.y = 0;
}
}
}
current = current->next;
}
// Repeat for y
obj->velocity.y += acceleration.y * delta;
obj->pos.y += obj->velocity.y * delta;
obj->rect.y = obj->pos.y + obj->dim_reduction[1];
obj->rect.height = obj->ori_height - obj->dim_reduction[1] - obj->dim_reduction[3];
current = kinematic_HEAD;
while(current != NULL){
if(current->obj != obj){
if (CheckCollisionRecs(obj->rect, current->obj->rect)){
collide_rect = GetCollisionRec(obj->rect, current->obj->rect);
if(collide_rect.width < collide_rect.height){
obj->rect.x -= sign(obj->velocity.x) * collide_rect.width;
obj->pos.x -= sign(obj->velocity.x) * collide_rect.width;
obj->velocity.x = 0;
}else{
obj->rect.y -= sign(obj->velocity.y) * collide_rect.height;
obj->pos.y -= sign(obj->velocity.y) * collide_rect.height;
obj->velocity.y = 0;
// SAT: If any projected axis is non overlapping, exit
if (obj->rect.x + obj->rect.width < current->obj->rect.x) goto iter;
if (current->obj->rect.x + current->obj->rect.width < obj->rect.x) goto iter;
if (obj->rect.y + obj->rect.height < current->obj->rect.y) goto iter;
if (current->obj->rect.y + current->obj->rect.height < obj->rect.y) goto iter;
// Move in the direction of the shorter movement
double hmove, vmove;
hmove = (current->obj->rect.width + obj->rect.width) / 2 - fabs(current->obj->rect.x - obj->rect.x + (current->obj->rect.width - obj->rect.width) / 2);
vmove = (current->obj->rect.height + obj->rect.height) / 2 - fabs(current->obj->rect.y - obj->rect.y + (current->obj->rect.height - obj->rect.height) / 2);
if (hmove < vmove){
if (obj->rect.x + obj->rect.width / 2 < current->obj->rect.x + current->obj->rect.width / 2){
obj->rect.x -= hmove;
obj->pos.x -= hmove;
}
else{
obj->rect.x += hmove;
obj->pos.x += hmove;
}
obj->velocity.x = 0;
}else{
if (obj->rect.y + obj->rect.height / 2 < current->obj->rect.y + current->obj->rect.height / 2){
obj->rect.y -= vmove;
obj->pos.y -= vmove;
}
else{
obj->rect.y += vmove;
obj->pos.y += vmove;
}
obj->velocity.y = 0;
}
}
current = current->next;
iter: current = current->next;
}
};