[Pokeemerald] [TUTORIAL] Replacing Overworlds and adding Unique Palettes

vxo · Oct 31, 2019

Replacing Overworlds and adding Unique Palettes

Part I: Adding Dynamic Overworld Palette System

Source: https://github.com/pret/pokeemerald/wiki/Dynamic-overworld-palette-system

Notice: The current implementation breaks the reflection palette system, though for ease of adding new overworlds that should be adapted so it is dynamic as well, rather than requiring explicit reflection palettes.
Notice: Depending on your version of Pokeemerald, the function sub_808E894() has been decompiled, so it could be called LoadEventObjectPalette()
Notice: Where it states + or -, add or delete the entire line

Spoiler:

src/overworld.c

~~---------------------------------------------------------~~
sub_8086988()

Code:

static void sub_8086988(u32 a1)
{
    ResetTasks();
    ResetSpriteData();    ResetPaletteFade();
    ScanlineEffect_Clear();
    ResetAllPicSprites();
    ResetCameraUpdateInfo();
    InstallCameraPanAheadCallback();
+   FreeAllSpritePalettes();
-   if (!a1)
-       InitEventObjectPalettes(0);
-   else
-       InitEventObjectPalettes(1);

    FieldEffectActiveListClear();
    sub_80AAFA4();
    sub_80AEE84();
    if (!a1)
        SetUpFieldTasks();
    mapheader_run_script_with_tag_x5();
    sub_81BE6B8();
}

src/event_object_movement.c

~~---------------------------------------------------------~~
TrySetupEventObjectSprite()

Code:

static u8 TrySetupEventObjectSprite(struct EventObjectTemplate *eventObjectTemplate, struct SpriteTemplate *spriteTemplate, u8 mapNum, u8 mapGroup, s16 cameraX, s16 cameraY)
{
    struct EventObject *eventObject;
    const struct EventObjectGraphicsInfo *graphicsInfo;
    struct Sprite *sprite;
    u8 eventObjectId;
-   u8 paletteSlot;
    u8 spriteId;

    eventObjectId = InitEventObjectStateFromTemplate(eventObjectTemplate, mapNum, mapGroup);
    if (eventObjectId == NUM_EVENT_OBJECTS)
        return NUM_EVENT_OBJECTS;

    eventObject = &gEventObjects[eventObjectId];
    graphicsInfo = GetEventObjectGraphicsInfo(eventObject->graphicsId);
+   if (spriteTemplate->paletteTag != 0xffff)
+   {
+       sub_808E894(spriteTemplate->paletteTag);
+   }
-   paletteSlot = graphicsInfo->paletteSlot;
-   if (paletteSlot == 0)
-   {
-       LoadPlayerObjectReflectionPalette(graphicsInfo->paletteTag1, 0);
-   }
-   else if (paletteSlot == 10)
-   {
-       LoadSpecialObjectReflectionPalette(graphicsInfo->paletteTag1, 10);
-   }
-   else if (paletteSlot >= 16)
-   {
-       paletteSlot -= 16;
-       sub_808EAB0(graphicsInfo->paletteTag1, paletteSlot);
-   }
    if (eventObject->movementType == 0x4c)
    {
        eventObject->invisible = TRUE;
    }
-   *(u16 *)&spriteTemplate->paletteTag = 0xFFFF;
    spriteId = CreateSprite(spriteTemplate, 0, 0, 0);
    if (spriteId == MAX_SPRITES)
    {
        gEventObjects[eventObjectId].active = FALSE;
        return NUM_EVENT_OBJECTS;
    }
    sprite = &gSprites[spriteId];
    sub_8092FF0(eventObject->currentCoords.x + cameraX, eventObject->currentCoords.y + cameraY, &sprite->pos1.x, &sprite->pos1.y);
    sprite->centerToCornerVecX = -(graphicsInfo->width >> 1);
    sprite->centerToCornerVecY = -(graphicsInfo->height >> 1);
    sprite->pos1.x += 8;
    sprite->pos1.y += 16 + sprite->centerToCornerVecY;
-   sprite->oam.paletteNum = paletteSlot;
    sprite->coordOffsetEnabled = TRUE;
    sprite->data[0] = eventObjectId;
    eventObject->spriteId = spriteId;
    eventObject->inanimate = graphicsInfo->inanimate;
    if (!eventObject->inanimate)
    {
        StartSpriteAnim(sprite, GetFaceDirectionAnimNum(eventObject->facingDirection));
    }
    SetObjectSubpriorityByZCoord(eventObject->previousElevation, sprite, 1);
    UpdateEventObjectVisibility(eventObject, sprite);
    return eventObjectId;
}

RemoveEventObjectInternal()

Code:

static void RemoveEventObjectInternal(struct EventObject *eventObject)
{
+   u8 paletteNum;

    struct SpriteFrameImage image;
    image.size = GetEventObjectGraphicsInfo(eventObject->graphicsId)->size;
    gSprites[eventObject->spriteId].images = ℑ
+   paletteNum = gSprites[eventObject->spriteId].oam.paletteNum;
    DestroySprite(&gSprites[eventObject->spriteId]);
+   FieldEffectFreePaletteIfUnused(paletteNum);

}

sub_808E1B8()

Code:

static void sub_808E1B8(u8 eventObjectId, s16 x, s16 y)
{
    u8 spriteId;
-   u8 paletteSlot;
    struct EventObject *eventObject;
    const struct SubspriteTable *subspriteTables;
    const struct EventObjectGraphicsInfo *graphicsInfo;
    struct SpriteFrameImage spriteFrameImage;
    struct SpriteTemplate spriteTemplate;
    struct Sprite *sprite;

#define i spriteId
    for (i = 0; i < ARRAY_COUNT(gLinkPlayerEventObjects); i++)
    {
        if (gLinkPlayerEventObjects[i].active && eventObjectId == gLinkPlayerEventObjects[i].eventObjId)
        {
            return;
        }
    }
#undef i

    eventObject = &gEventObjects[eventObjectId];
    subspriteTables = NULL;
    graphicsInfo = GetEventObjectGraphicsInfo(eventObject->graphicsId);
    spriteFrameImage.size = graphicsInfo->size;
    MakeObjectTemplateFromEventObjectGraphicsInfoWithCallbackIndex(eventObject->graphicsId, eventObject->movementType, &spriteTemplate, &subspriteTables);
    spriteTemplate.images = &spriteFrameImage;
+   if (spriteTemplate.paletteTag != 0xffff)
+   {
+       sub_808E894(spriteTemplate.paletteTag);
+   }
-   *(u16 *)&spriteTemplate.paletteTag = 0xffff;
-   paletteSlot = graphicsInfo->paletteSlot;
-   if (paletteSlot == 0)
-   {
-       LoadPlayerObjectReflectionPalette(graphicsInfo->paletteTag1, graphicsInfo->paletteSlot);
-   }
-   else if (paletteSlot == 10)
-   {
-       LoadSpecialObjectReflectionPalette(graphicsInfo->paletteTag1, graphicsInfo->paletteSlot);
-   }
-   else if (paletteSlot >= 16)
-   {
-       paletteSlot -= 16;
-       sub_808EAB0(graphicsInfo->paletteTag1, paletteSlot);
-   }
-   *(u16 *)&spriteTemplate.paletteTag = 0xffff;
    spriteId = CreateSprite(&spriteTemplate, 0, 0, 0);
    if (spriteId != MAX_SPRITES)
    {
        sprite = &gSprites[spriteId];
        sub_8092FF0(x + eventObject->currentCoords.x, y + eventObject->currentCoords.y, &sprite->pos1.x, &sprite->pos1.y);
        sprite->centerToCornerVecX = -(graphicsInfo->width >> 1);
        sprite->centerToCornerVecY = -(graphicsInfo->height >> 1);
        sprite->pos1.x += 8;
        sprite->pos1.y += 16 + sprite->centerToCornerVecY;
        sprite->images = graphicsInfo->images;
        if (eventObject->movementType == 0x0b)
        {
            SetPlayerAvatarEventObjectIdAndObjectId(eventObjectId, spriteId);
            eventObject->warpArrowSpriteId = sub_8154228();
        }
        if (subspriteTables != NULL)
        {
            SetSubspriteTables(sprite, subspriteTables);
        }
-       sprite->oam.paletteNum = paletteSlot;
        sprite->coordOffsetEnabled = TRUE;
        sprite->data[0] = eventObjectId;
        eventObject->spriteId = spriteId;
        if (!eventObject->inanimate && eventObject->movementType != 0x0b)
        {
            StartSpriteAnim(sprite, GetFaceDirectionAnimNum(eventObject->facingDirection));
        }
        sub_808E38C(eventObject);
        SetObjectSubpriorityByZCoord(eventObject->previousElevation, sprite, 1);
    }
}

Part II: Replacing Overworlds and Adding Unique Palettes

Source: https://github.com/pret/pokeemerald/wiki/Adding-new-overworlds

Spoiler:

Part III: Troubleshooting

Spoiler:

Hanu P · Jan 5, 2021

Hey! This tut need to be modified a little...
In here:
{gEventObjectPalette_<PALETTE NAME>, EVENT_OBJ_PAL_<PALETTE NAME>},
change this to {gEventObjectPalette_<NAME OF THE SPRITE YOU ARE MODIFYING>, EVENT_OBJ_PAL_<PALETTE NAME>},
eg:
{gObjectEventPalette_Youngster, OBJ_EVENT_PAL_youngsterhgss},
here I was replacing a youngster sprite...
and this:
#define EVENT_OBJ_PAL_<PALETTE NAME> 0x<HEX NUMBER>
to this:
#define EVENT_OBJ_EVENT_PAL_<PALETTE NAME> 0x<HEX NUMBER>
Credits Ryuusei Boy/Fubuki Shirou(I don't know his PC name.. it' the discord one!)

[Pokeemerald] [TUTORIAL] Replacing Overworlds and adding Unique Palettes

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vxo

ROM Hacker

Replacing Overworlds and adding Unique Palettes

Part I: Adding Dynamic Overworld Palette System

src/overworld.c

src/event_object_movement.c

Part II: Replacing Overworlds and Adding Unique Palettes

1. Formatting the Image

2. Replacing a Sprite

3. Adding the Palette

4. Applying the newly modified Palette

Part III: Troubleshooting

Method 1. Re-indexing the Image

Method 2. Double Checking your modified entries

Hanu P

DRAGON GOD<3