[SDL] Object manager (WIP)

#include <stdio.h>
#include <stdlib.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include "structdata.h"


// List contains, type, sprite_index, hp, x, y, next object pointer.

int countObjects(ObjectList* base)
{
    return base->length;
}

ObjectList* createObjectList()
{
    ObjectList* olist = NULL;
    olist = malloc(sizeof(ObjectList));
    olist->length = 0;
    olist->objs = malloc(sizeof(ObjectNode));
    olist->objs->next = NULL;

    return olist;
}

void addObject(ObjectList* base, Object* value)
{
    ObjectNode* current = base->objs;
    while(current->obj != NULL && current->next != NULL)
    {
        current = current->next;
    }
    current->next = NULL;
    current->next = malloc(sizeof(ObjectNode));
    current->next->obj = value;
    current->next->next = NULL;
    base->length++;
}

Object* getObjectAt(ObjectList* base, int index)
{
    register int i = 0;
    ObjectNode *tmp = NULL;
    ObjectNode *current = base->objs;
    while( (current->obj != NULL && current->next != NULL) && (i < index-1))
    {
        i++;
        current = current->next;
    }
    return current->obj;
}

Object* findObjectByType(ObjectList* base, int type, int index)
{
    register int i = 0;
    ObjectNode* current = base->objs;
    while(current->obj != NULL && current->next != NULL)
    {
        if(current->obj->type == type)
        {
            if(i == index)
            {
                return current->obj;
            }
            else
            {
                i++;
            }
        }
        current = current->next;
    }
    return NULL;
}

void removeObject_ptr(ObjectList* base, ObjectNode* obj)
{
    if(obj == base->objs)
    {
        ObjectNode** oBase = obj;
        if(*oBase == NULL)
        {
            return -1;
        }
        ObjectNode *next_object = (*oBase)->next;
        free(*oBase);
        *oBase = next_object;
    }

    ObjectNode *tmp = NULL;
    ObjectNode *current = obj;
    tmp = current->next;
    current->next = tmp->next;
    free(tmp);
    base->length--;
}

void removeObjectAt(ObjectList* base, int index)
{
    if(index == 0)
    {
        ObjectNode** oBase = base->objs;
        if(*oBase == NULL)
        {
            return -1;
        }
        ObjectNode *next_object = (*oBase)->next;
        free(*oBase);
        *oBase = next_object;
    }
    int ret = -1;
    register int i = 0;
    ObjectNode *tmp = NULL;
    ObjectNode *current = base->objs;
    while(current != NULL && (i < index-1))
    {
        i++;
        current = current->next;
    }
    if(i < index-1)
    {
        puts("[ObjectManager: Fatal Error] Invalid node index.");
        return -1;
    }
    tmp = current->next;
    current->next = tmp->next;
    free(tmp);
    base->length--;
}