Chain.cpp

#include "Chain.h"
#include "config.h"
#include "util.h"
#include <algorithm>
#include <vector>

extern std::vector<Player*> allPlayers;
extern std::vector<GameObject*> allRenderObjects;

extern GameObject* referenceChain;

Chain::Chain(int player, glm::vec3 origin, glm::vec3 velocity)
        : GameObject(*referenceChain){
    owner = player;
    mModel.position = origin;
    vel = velocity;
    prev = NULL;
    next = NULL;
    hook = NULL;
    pulling = false;
    mModel.rotation.y = glm::atan(vel.x, vel.z) + CHAIN_BASE_ROTATION;
    mModel.scaling = glm::vec3(CHAIN_SCALING, CHAIN_SCALING, CHAIN_SCALING);
    allRenderObjects.push_back(this);
}

Chain::Chain(int player, glm::vec3 origin, glm::vec3 velocity, Chain* next, bool grapple)
        : Chain(player, origin, velocity){
    grappling = grapple;
    this->next = next;
    next->prev = this;
}

Chain::Chain(int player, glm::vec3 origin, glm::vec3 velocity, Hook*  hook, bool grapple)
        : Chain(player, origin, velocity){
    grappling = grapple;
    this->hook = hook;
    hook->prev = this;
}

void Chain::kill(){
    // invalidate pointers
    if(next != NULL) {
        next->prev = prev;
    } else {
        hook->prev = prev;
    }
    if(prev != NULL) {
        prev->next = next;
    }

    allRenderObjects.erase(std::remove(allRenderObjects.begin(), allRenderObjects.end(), this), allRenderObjects.end());
    delete this;
}

void Chain::pull(){
    pulling = true;
    if(next != NULL) {
        next->pull();
    } else {
        hook->pull();
    }
}


void Chain::update(){
    glm::vec3 follow;

    if(pulling) {
        if(grappling) {
            // TODO : what happens here
        } else {
            // pull
            Chain* p = prev;
            do {
                if (p != NULL) {
                    follow = p->mModel.position;
                    p = p->prev;
                } else {
                    follow = allPlayers[owner]->hookpoint;
                }
            } while(glm::length(follow - mModel.position) == 0);

            if (p == NULL) {
                mModel.position += glm::normalize(follow - mModel.position) * CHAIN_PULL;
            } else {
                mModel.position = moveTowards(mModel.position, follow, CHAIN_BASE_PULL);
            }
        }
        // update chain lasst because we are pulling
        this->updateChainLinks();
    } else {
        // update chain first because we are pushing
        this->updateChainLinks();

        // push
        if(next != NULL) {
            follow = next->mModel.position;
        } else {
            follow = hook->mModel.position;
        }

        mModel.position = moveTowards(mModel.position, follow, CHAIN_BASE_PUSH);
    }
    glm::vec3 ne = (next != 0) ? next->mModel.position : hook->mModel.position;
    glm::vec3 pr = (prev != 0) ? prev->mModel.position : allPlayers[owner]->hookpoint;
    glm::vec3 dif = ne-pr;
    mModel.rotation.y = glm::atan(dif.x, dif.z) + CHAIN_BASE_ROTATION + glm::pi<float>();
}

void Chain::updateChainLinks(){
    if(next != NULL) {
        next->update();
    } else {
        hook->update();
    }
}