Make space for EWRAM Data for Summary screen

The summary screen in RSE is surprisingly wasteful, which for Castform in particular has it so all forms are loaded in memory, despite only using 1. This tweak will fix it so it's more optimized

Thanks to ShinyDragonHunter for this

First, we'll set up this struct in src/pokemon.c

- EWRAM_DATA static struct MonSpritesGfxManager *sMonSpritesGfxManagers[MON_SPR_GFX_MANAGERS_COUNT] = {NULL};
+ EWRAM_DATA static struct MonSpritesGfxManager *sMonSpritesGfxManager = NULL;

Then, we'll set up InitMonSpritesGfx_Battle function near bottom to do the following

Change this

void SetMultiuseSpriteTemplateToPokemon(u16 speciesTag, u8 battlerPosition)
{
    if (gMonSpritesGfxPtr != NULL)
        gMultiuseSpriteTemplate = gMonSpritesGfxPtr->templates[battlerPosition];
    else if (sMonSpritesGfxManagers[MON_SPR_GFX_MANAGER_A])
        gMultiuseSpriteTemplate = sMonSpritesGfxManagers[MON_SPR_GFX_MANAGER_A]->templates[battlerPosition];
    else if (sMonSpritesGfxManagers[MON_SPR_GFX_MANAGER_B])
        gMultiuseSpriteTemplate = sMonSpritesGfxManagers[MON_SPR_GFX_MANAGER_B]->templates[battlerPosition];
    else
        gMultiuseSpriteTemplate = gBattlerSpriteTemplates[battlerPosition];

To

void SetMultiuseSpriteTemplateToPokemon(u16 speciesTag, u8 battlerPosition)
{
    if (gMonSpritesGfxPtr != NULL)
        gMultiuseSpriteTemplate = gMonSpritesGfxPtr->templates[battlerPosition];
    else if (sMonSpritesGfxManager)
        gMultiuseSpriteTemplate = sMonSpritesGfxManager->templates[battlerPosition];

Change the integer to a u32 (current version)

static void InitMonSpritesGfx_Battle(struct MonSpritesGfxManager* gfx)
{
-    u16 i, j;
+    u32 i, j; 
    for (i = 0; i < gfx->numSprites; i++)
    {
        gfx->templates[i] = gBattlerSpriteTemplates[i];
        for (j = 0; j < gfx->numFrames; j++)
            gfx->frameImages[i * gfx->numFrames + j].data = &gfx->spritePointers[i][j * MON_PIC_SIZE];
 
        gfx->templates[i].images = &gfx->frameImages[i * gfx->numFrames];
    }
}

Next, in the struct below it (this is big) change

struct MonSpritesGfxManager *CreateMonSpritesGfxManager(u8 managerId, u8 mode)
{
    u8 i;
    u8 failureFlags;
    struct MonSpritesGfxManager *gfx;

    failureFlags = 0;
    managerId %= MON_SPR_GFX_MANAGERS_COUNT;
    gfx = AllocZeroed(sizeof(*gfx));
    if (gfx == NULL)
        return NULL;

    switch (mode)
    {
    case MON_SPR_GFX_MODE_FULL_PARTY:
        gfx->numSprites = PARTY_SIZE + 1;
        gfx->numSprites2 = PARTY_SIZE + 1;
        gfx->numFrames = GFX_MANAGER_NUM_FRAMES;
        gfx->dataSize = 1;
        gfx->mode = MON_SPR_GFX_MODE_FULL_PARTY;
        break;
 // case MON_SPR_GFX_MODE_BATTLE:       
    case MON_SPR_GFX_MODE_NORMAL:
    default:
        gfx->numSprites = MAX_BATTLERS_COUNT;
        gfx->numSprites2 = MAX_BATTLERS_COUNT;
        gfx->numFrames = GFX_MANAGER_NUM_FRAMES;
        gfx->dataSize = 1;
        gfx->mode = MON_SPR_GFX_MODE_NORMAL;
        break;
    }

    // Set up sprite / sprite pointer buffers
    gfx->spriteBuffer = AllocZeroed(gfx->dataSize * GFX_MANAGER_SPR_SIZE * gfx->numSprites);
    gfx->spritePointers = AllocZeroed(gfx->numSprites * 32); // ? Only * 4 is necessary, perhaps they were thinking bits.
    if (gfx->spriteBuffer == NULL || gfx->spritePointers == NULL)
    {
        failureFlags |= ALLOC_FAIL_BUFFER;
    }
    else
    {
        for (i = 0; i < gfx->numSprites; i++)
            gfx->spritePointers[i] = gfx->spriteBuffer + (gfx->dataSize * GFX_MANAGER_SPR_SIZE * i);
    }

    // Set up sprite structs
    gfx->templates = AllocZeroed(sizeof(struct SpriteTemplate) * gfx->numSprites);
    gfx->frameImages = AllocZeroed(sizeof(struct SpriteFrameImage) * gfx->numSprites * gfx->numFrames);
    if (gfx->templates == NULL || gfx->frameImages == NULL)
    {
        failureFlags |= ALLOC_FAIL_STRUCT;
    }
    else
    {
        for (i = 0; i < gfx->numFrames * gfx->numSprites; i++)
            gfx->frameImages[i].size = MON_PIC_SIZE;

        switch (gfx->mode)
        {
        case MON_SPR_GFX_MODE_FULL_PARTY:
            InitMonSpritesGfx_FullParty(gfx);
            break;
        case MON_SPR_GFX_MODE_NORMAL:
        case MON_SPR_GFX_MODE_BATTLE:
        default:
            InitMonSpritesGfx_Battle(gfx);
            break;
        }
    }

    // If either of the allocations failed free their respective members
    if (failureFlags & ALLOC_FAIL_STRUCT)
    {
        TRY_FREE_AND_SET_NULL(gfx->frameImages);
        TRY_FREE_AND_SET_NULL(gfx->templates);
    }
    if (failureFlags & ALLOC_FAIL_BUFFER)
    {
        TRY_FREE_AND_SET_NULL(gfx->spritePointers);
        TRY_FREE_AND_SET_NULL(gfx->spriteBuffer);
    }

    if (failureFlags)
    {
        // Clear, something failed to allocate
        memset(gfx, 0, sizeof(*gfx));
        Free(gfx);
    }
    else
    {
        gfx->active = GFX_MANAGER_ACTIVE;
        sMonSpritesGfxManagers[managerId] = gfx;
    }

    return sMonSpritesGfxManagers[managerId];
} 

To

struct MonSpritesGfxManager *CreateMonSpritesGfxManager(void)
{
    u32 i;
    u8 failureFlags;
    struct MonSpritesGfxManager *gfx;
 
    failureFlags = 0;
    gfx = AllocZeroed(sizeof(*gfx));
    if (gfx == NULL)
        return NULL;
 
    gfx->numSprites = MAX_BATTLERS_COUNT;
    gfx->numFrames = GFX_MANAGER_NUM_FRAMES;
    gfx->spriteBuffer = AllocZeroed(GFX_MANAGER_SPR_SIZE * gfx->numSprites);
    gfx->spritePointers = AllocZeroed(gfx->numSprites * 4);
    if (gfx->spriteBuffer == NULL || gfx->spritePointers == NULL)
    {
        failureFlags |= ALLOC_FAIL_BUFFER;
    }
    else
    {
        for (i = 0; i < gfx->numSprites; i++)
            gfx->spritePointers[i] = gfx->spriteBuffer + (GFX_MANAGER_SPR_SIZE * i);
    }
 
    // Set up sprite structs
    gfx->templates = AllocZeroed(sizeof(struct SpriteTemplate) * gfx->numSprites);
    gfx->frameImages = AllocZeroed(sizeof(struct SpriteFrameImage) * gfx->numSprites * gfx->numFrames);
    if (gfx->templates == NULL || gfx->frameImages == NULL)
    {
        failureFlags |= ALLOC_FAIL_STRUCT;
    }
    else
    {
        for (i = 0; i < gfx->numFrames * gfx->numSprites; i++)
            gfx->frameImages[i].size = MON_PIC_SIZE;
        InitMonSpritesGfx_Battle(gfx);
    }
 
    // If either of the allocations failed free their respective members
    if (failureFlags & ALLOC_FAIL_STRUCT)
    {
        TRY_FREE_AND_SET_NULL(gfx->frameImages);
        TRY_FREE_AND_SET_NULL(gfx->templates);
    }
    if (failureFlags & ALLOC_FAIL_BUFFER)
    {
        TRY_FREE_AND_SET_NULL(gfx->spritePointers);
        TRY_FREE_AND_SET_NULL(gfx->spriteBuffer);
    }
 
    if (failureFlags)
    {
        // Clear, something failed to allocate
        memset(gfx, 0, sizeof(*gfx));
        Free(gfx);
    }
    else
    {
        gfx->active = TRUE;
        sMonSpritesGfxManager = gfx;
    }
 
    return sMonSpritesGfxManager;
}

Then this

void DestroyMonSpritesGfxManager(u8 managerId)
{
    struct MonSpritesGfxManager *gfx;

    managerId %= MON_SPR_GFX_MANAGERS_COUNT;
    gfx = sMonSpritesGfxManagers[managerId];
    if (gfx == NULL)
        return;

    if (gfx->active != GFX_MANAGER_ACTIVE)
    {
        memset(gfx, 0, sizeof(*gfx));
    }
    else
    {
        TRY_FREE_AND_SET_NULL(gfx->frameImages);
        TRY_FREE_AND_SET_NULL(gfx->templates);
        TRY_FREE_AND_SET_NULL(gfx->spritePointers);
        TRY_FREE_AND_SET_NULL(gfx->spriteBuffer);
        memset(gfx, 0, sizeof(*gfx));
        Free(gfx);
    }
}

To

void DestroyMonSpritesGfxManager(void)
{
    struct MonSpritesGfxManager *gfx = sMonSpritesGfxManager;
 
    if (gfx == NULL)
        return;
 
    if (gfx->active)
    {
        TRY_FREE_AND_SET_NULL(gfx->frameImages);
        TRY_FREE_AND_SET_NULL(gfx->templates);
        TRY_FREE_AND_SET_NULL(gfx->spritePointers);
        TRY_FREE_AND_SET_NULL(gfx->spriteBuffer);
        memset(gfx, 0, sizeof(*gfx));
        Free(gfx);
    }
    else
        memset(gfx, 0, sizeof(*gfx));
}

And finally, this

u8 *MonSpritesGfxManager_GetSpritePtr(u8 managerId, u8 spriteNum)
{
    struct MonSpritesGfxManager *gfx = sMonSpritesGfxManagers[managerId % MON_SPR_GFX_MANAGERS_COUNT];
    if (gfx->active != GFX_MANAGER_ACTIVE)
    {
        return NULL;
    }
    else
    {
        if (spriteNum >= gfx->numSprites)
            spriteNum = 0;

        return gfx->spritePointers[spriteNum];
    }
}

To this

u8 *MonSpritesGfxManager_GetSpritePtr(u8 spriteNum)
{
    struct MonSpritesGfxManager *gfx = sMonSpritesGfxManager;
 
    if (gfx->active)
    {
        if (spriteNum >= gfx->numSprites)
            spriteNum = 0;
 
        return gfx->spritePointers[spriteNum];
    }
    return NULL;
}

After all that, head on to include/pokemon.h to reduce this

struct MonSpritesGfxManager
{
    u32 numSprites:4;
    u32 numSprites2:4; // Never read
    u32 numFrames:8;
    u32 active:8;
    u32 dataSize:4;
    u32 mode:4; // MON_SPR_GFX_MODE_*
    void *spriteBuffer;
    u8 **spritePointers;
    struct SpriteTemplate *templates;
    struct SpriteFrameImage *frameImages;
};

To this

struct MonSpritesGfxManager
{
    u8 numSprites;
    u8 numFrames;
    bool16 active;
    void *spriteBuffer;
    u8 **spritePointers;
    struct SpriteTemplate *templates;
    struct SpriteFrameImage *frameImages;
};

And then the void changes of these

- struct MonSpritesGfxManager *CreateMonSpritesGfxManager(u8 managerId, u8 mode);
- void DestroyMonSpritesGfxManager(u8 managerId);
- u8 *MonSpritesGfxManager_GetSpritePtr(u8 managerId, u8 spriteNum);
+ struct MonSpritesGfxManager *CreateMonSpritesGfxManager(void);
+ void DestroyMonSpritesGfxManager(void);
+ u8 *MonSpritesGfxManager_GetSpritePtr(u8 spriteNum);

Along with in src/pokemon_summary_screen.c

    if (gMonSpritesGfxPtr == NULL)
-        CreateMonSpritesGfxManager(MON_SPR_GFX_MANAGER_A, MON_SPR_GFX_MODE_NORMAL);
+        CreateMonSpritesGfxManager();

and

static void CloseSummaryScreen(u8 taskId)
{
    if (MenuHelpers_CallLinkSomething() != TRUE && !gPaletteFade.active)
    {
        SetMainCallback2(sMonSummaryScreen->callback);
        gLastViewedMonIndex = sMonSummaryScreen->curMonIndex;
        SummaryScreen_DestroyAnimDelayTask();
        ResetSpriteData();
        FreeAllSpritePalettes();
        StopCryAndClearCrySongs();
        m4aMPlayVolumeControl(&gMPlayInfo_BGM, 0xFFFF, 0x100);
        if (gMonSpritesGfxPtr == NULL)
-            DestroyMonSpritesGfxManager(MON_SPR_GFX_MANAGER_A);
+            DestroyMonSpritesGfxManager();
        FreeSummaryScreen();
        DestroyTask(taskId);
    }
}

And in static u8 LoadMonGfxAndSprite

                if (sMonSummaryScreen->monList.mons == gPlayerParty || sMonSummaryScreen->mode == SUMMARY_MODE_BOX || sMonSummaryScreen->unk40EF == TRUE)
                    HandleLoadSpecialPokePic_2(&gMonFrontPicTable[summary->species2],
-                                                MonSpritesGfxManager_GetSpritePtr(MON_SPR_GFX_MANAGER_A, B_POSITION_OPPONENT_LEFT),
+                                                MonSpritesGfxManager_GetSpritePtr(B_POSITION_OPPONENT_LEFT),
                                                summary->species2,
                                                summary->pid);
                else
                    HandleLoadSpecialPokePic_DontHandleDeoxys(&gMonFrontPicTable[summary->species2],
-                                                              MonSpritesGfxManager_GetSpritePtr(MON_SPR_GFX_MANAGER_A, B_POSITION_OPPONENT_LEFT),
+                                                              MonSpritesGfxManager_GetSpritePtr(B_POSITION_OPPONENT_LEFT),
                                                              summary->species2,
                                                              summary->pid);

With all this set, you can edit the frames used on the summary screen to whatever you want

Going back to src/pokemon.c

#define ALLOC_FAIL_BUFFER (1 << 0)
#define ALLOC_FAIL_STRUCT (1 << 1)
#define GFX_MANAGER_ACTIVE 0xA3 // Arbitrary value
#define GFX_MANAGER_SPR_SIZE (MON_PIC_SIZE * 4) // * 4 is unnecessary, MON_PIC_SIZE is sufficient
#define GFX_MANAGER_NUM_FRAMES 4  // Only 2 frames are needed 

Change #define GFX_MANAGER_NUM_FRAMES 4 to whatever value you want. 2 is typically preferred

If you're crazy enough to add more Castform forms later, #define GFX_MANAGER_SPR_SIZE (MON_PIC_SIZE * 4) will need to be increased to compensate added forms

Otherwise

- #define GFX_MANAGER_NUM_FRAMES 4
+ #define GFX_MANAGER_NUM_FRAMES 2

And you're done