MainTree/core/src-c/entity_lookup.c

#include <entity.h>
#include <state.h>
#include <stdlib.h>

MtEntity * mt_create_entity(void *state_voidptr, u32_t identifier)
{
    MtState *state = state_voidptr;
    MtEntityListL1 *level1 = state->entity_registry.lookup.sublists[identifier >> 24];
    if(level1 == NULL)
    {
        state->entity_registry.lookup.sublists[identifier >> 24] = calloc(sizeof(MtEntityListL1), 1);
        level1 = state->entity_registry.lookup.sublists[identifier >> 24];
    }

    MtEntityListL2 *level2 = level1->sublists[(identifier >> 16) & 0xff];
    if(level2 == NULL)
    {
        level1->sublists[(identifier >> 16) & 0xff] = calloc(sizeof(MtEntityListL2), 1);
        level2 = level1->sublists[(identifier >> 16) & 0xff];
    }

    MtEntityListL3 *level3 = level2->sublists[(identifier >> 8) & 0xff];
    if(level3 == NULL)
    {
        level2->sublists[(identifier >> 8) & 0xff] = calloc(sizeof(MtEntityListL3), 1);
        level3 = level2->sublists[(identifier >> 8) & 0xff];
    }

    MtEntity *entity = level3->entities[identifier & 0xff];
    if(entity == NULL)
    {
        entity = mt_allocate_entity_pool_slot(&state->entity_registry.pool);
        entity->parent_state = state;
        level3->entities[identifier & 0xff] = entity;
    }
    return entity;
}

MtEntity * mt_get_entity(void *state_voidptr, u32_t identifier)
{
    MtState *state = state_voidptr;
    MtEntityListL1 *level1 = state->entity_registry.lookup.sublists[identifier >> 24];
    if(level1 == NULL)
        return NULL;

    MtEntityListL2 *level2 = level1->sublists[(identifier >> 16) & 0xff];
    if(level2 == NULL)
        return NULL;

    MtEntityListL3 *level3 = level2->sublists[(identifier >> 8) & 0xff];
    if(level3 == NULL)
        return NULL;

    MtEntity *entity = level3->entities[identifier & 0xff];
    if(entity == NULL)
        return NULL;

    return entity;
}