Added follower transform effect and Castform forms. Credit: larryturbo

Castform forms from https://www.deviantart.com/larryturbo/art/351-Castform-Froms-830190053

graphics/pokemon/castform/normal_sunny_form.pal

@@ -6,7 +6,7 @@ JASC-PAL
 205 90 74
 238 123 74
 255 156 65
-0 0 0
+255 197 136
 255 246 106
 230 213 106
 255 156 98

include/event_object_movement.h

@@ -26,6 +26,13 @@ enum ReflectionTypes
     NUM_REFLECTION_TYPES
 };
 
+enum FollowerTransformTypes
+{
+    TRANSFORM_TYPE_NONE,
+    TRANSFORM_TYPE_PERMANENT,
+    TRANSFORM_TYPE_RANDOM_WILD,
+};
+
 #define FIGURE_8_LENGTH 72
 
 #define GROUND_EFFECT_FLAG_TALL_GRASS_ON_SPAWN   (1 << 0)

spritesheet_rules.mk

@@ -1820,6 +1820,15 @@ $(OBJEVENTGFXDIR)/pokemon/milotic.4bpp: %.4bpp: %.png
 $(OBJEVENTGFXDIR)/pokemon/castform.4bpp: %.4bpp: %.png
 	$(GFX) $< $@ -mwidth 4 -mheight 4
 
+$(OBJEVENTGFXDIR)/pokemon/castform_sunny.4bpp: %.4bpp: %.png
+	$(GFX) $< $@ -mwidth 4 -mheight 4
+
+$(OBJEVENTGFXDIR)/pokemon/castform_rainy.4bpp: %.4bpp: %.png
+	$(GFX) $< $@ -mwidth 4 -mheight 4
+
+$(OBJEVENTGFXDIR)/pokemon/castform_snowy.4bpp: %.4bpp: %.png
+	$(GFX) $< $@ -mwidth 4 -mheight 4
+
 $(OBJEVENTGFXDIR)/pokemon/kecleon.4bpp: %.4bpp: %.png
 	$(GFX) $< $@ -mwidth 4 -mheight 4
 

src/data/object_events/object_event_graphics.h

@@ -721,6 +721,12 @@ const u32 gObjectEventPic_Armaldo[] = INCBIN_U32("graphics/object_events/pics/po
 const u32 gObjectEventPic_Feebas[] = INCBIN_U32("graphics/object_events/pics/pokemon/feebas.4bpp");
 const u32 gObjectEventPic_Milotic[] = INCBIN_U32("graphics/object_events/pics/pokemon/milotic.4bpp");
 const u32 gObjectEventPic_Castform[] = INCBIN_U32("graphics/object_events/pics/pokemon/castform.4bpp");
+const u32 gObjectEventPic_CastformSunny[] = INCBIN_U32("graphics/object_events/pics/pokemon/castform_sunny.4bpp");
+const u16 gObjectEventPal_CastformSunny[] = INCBIN_U16("graphics/pokemon/castform/normal_sunny_form.gbapal");
+const u32 gObjectEventPic_CastformRainy[] = INCBIN_U32("graphics/object_events/pics/pokemon/castform_rainy.4bpp");
+const u16 gObjectEventPal_CastformRainy[] = INCBIN_U16("graphics/pokemon/castform/normal_rainy_form.gbapal");
+const u32 gObjectEventPic_CastformSnowy[] = INCBIN_U32("graphics/object_events/pics/pokemon/castform_snowy.4bpp");
+const u16 gObjectEventPal_CastformSnowy[] = INCBIN_U16("graphics/pokemon/castform/normal_snowy_form.gbapal");
 const u32 gObjectEventPic_Kecleon[] = INCBIN_U32("graphics/object_events/pics/pokemon/kecleon.4bpp");
 const u32 gObjectEventPic_Shuppet[] = INCBIN_U32("graphics/object_events/pics/pokemon/shuppet.4bpp");
 const u32 gObjectEventPic_Banette[] = INCBIN_U32("graphics/object_events/pics/pokemon/banette.4bpp");

src/data/object_events/object_event_graphics_info_followers.h

@@ -414,3 +414,11 @@ const struct ObjectEventGraphicsInfo gPokemonObjectGraphics[] = {
   [SPECIES_JIRACHI] = {0xFFFF, OBJ_EVENT_PAL_TAG_DYNAMIC, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_NONE, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_Jirachi, gDummySpriteAffineAnimTable},
   [SPECIES_DEOXYS] = {0xFFFF, OBJ_EVENT_PAL_TAG_DYNAMIC, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_FOOT, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_Deoxys, gDummySpriteAffineAnimTable},
 };
+
+// Normal, sunny, rainy, snowy
+const struct ObjectEventGraphicsInfo gCastformObjectGraphics[] = {
+    {0xFFFF, OBJ_EVENT_PAL_TAG_DYNAMIC, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_NONE, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_Castform, gDummySpriteAffineAnimTable},
+    {0xFFFF, OBJ_EVENT_PAL_TAG_CASTFORM_SUNNY, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_NONE, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_CastformSunny, gDummySpriteAffineAnimTable},
+    {0xFFFF, OBJ_EVENT_PAL_TAG_CASTFORM_RAINY, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_NONE, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_CastformRainy, gDummySpriteAffineAnimTable},
+    {0xFFFF, OBJ_EVENT_PAL_TAG_CASTFORM_SNOWY, OBJ_EVENT_PAL_TAG_NONE, 512, 32, 32, 2, SHADOW_SIZE_M, FALSE, FALSE, TRACKS_NONE, &gObjectEventBaseOam_32x32, sOamTables_32x32, sAnimTable_Following, sPicTable_CastformSnowy, gDummySpriteAffineAnimTable},
+};

src/data/object_events/object_event_pic_tables.h

@@ -5014,6 +5014,30 @@ static const struct SpriteFrameImage sPicTable_Castform[] = {
     overworld_frame(gObjectEventPic_Castform, 4, 4, 4),
     overworld_frame(gObjectEventPic_Castform, 4, 4, 5),
 };
+static const struct SpriteFrameImage sPicTable_CastformSunny[] = {
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 0),
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 1),
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 2),
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 3),
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 4),
+    overworld_frame(gObjectEventPic_CastformSunny, 4, 4, 5),
+};
+static const struct SpriteFrameImage sPicTable_CastformRainy[] = {
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 0),
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 1),
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 2),
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 3),
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 4),
+    overworld_frame(gObjectEventPic_CastformRainy, 4, 4, 5),
+};
+static const struct SpriteFrameImage sPicTable_CastformSnowy[] = {
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 0),
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 1),
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 2),
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 3),
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 4),
+    overworld_frame(gObjectEventPic_CastformSnowy, 4, 4, 5),
+};
 static const struct SpriteFrameImage sPicTable_Kecleon[] = {
     overworld_frame(gObjectEventPic_Kecleon, 4, 4, 0),
     overworld_frame(gObjectEventPic_Kecleon, 4, 4, 1),

src/event_object_movement.c

@@ -17,6 +17,7 @@
 #include "field_weather.h"
 #include "fieldmap.h"
 #include "follower_helper.h"
+#include "gpu_regs.h"
 #include "mauville_old_man.h"
 #include "metatile_behavior.h"
 #include "overworld.h"
@@ -31,6 +32,7 @@
 #include "trainer_see.h"
 #include "trainer_hill.h"
 #include "util.h"
+#include "wild_encounter.h"
 #include "constants/event_object_movement.h"
 #include "constants/abilities.h"
 #include "constants/battle.h"
@@ -157,6 +159,7 @@ static struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8, u8,
 static void RemoveObjectEventIfOutsideView(struct ObjectEvent *);
 static void SpawnObjectEventOnReturnToField(u8, s16, s16);
 static void SetPlayerAvatarObjectEventIdAndObjectId(u8, u8);
+static u8 UpdateSpritePalette(const struct SpritePalette * spritePalette, struct Sprite * sprite);
 static void ResetObjectEventFldEffData(struct ObjectEvent *);
 static u8 LoadSpritePaletteIfTagExists(const struct SpritePalette *);
 static u8 FindObjectEventPaletteIndexByTag(u16);
@@ -462,6 +465,9 @@ const u8 gInitialMovementTypeFacingDirections[] = {
 #define OBJ_EVENT_PAL_TAG_RS_BRENDAN              0x1122
 #define OBJ_EVENT_PAL_TAG_RS_MAY                  0x1123
 #define OBJ_EVENT_PAL_TAG_DYNAMIC                 0x1124
+#define OBJ_EVENT_PAL_TAG_CASTFORM_SUNNY          0x1125
+#define OBJ_EVENT_PAL_TAG_CASTFORM_RAINY          0x1126
+#define OBJ_EVENT_PAL_TAG_CASTFORM_SNOWY          0x1127
 #define OBJ_EVENT_PAL_TAG_EMOTES                  0x8002
 #define OBJ_EVENT_PAL_TAG_NONE 0x11FF
 
@@ -510,7 +516,9 @@ static const struct SpritePalette sObjectEventSpritePalettes[] = {
     {gObjectEventPal_Lugia,                 OBJ_EVENT_PAL_TAG_LUGIA},
     {gObjectEventPal_RubySapphireBrendan,   OBJ_EVENT_PAL_TAG_RS_BRENDAN},
     {gObjectEventPal_RubySapphireMay,       OBJ_EVENT_PAL_TAG_RS_MAY},
-    {gObjectEventPal_Npc1, OBJ_EVENT_PAL_TAG_DYNAMIC},
+    {gObjectEventPal_CastformSunny, OBJ_EVENT_PAL_TAG_CASTFORM_SUNNY},
+    {gObjectEventPal_CastformRainy, OBJ_EVENT_PAL_TAG_CASTFORM_RAINY},
+    {gObjectEventPal_CastformSnowy, OBJ_EVENT_PAL_TAG_CASTFORM_SNOWY},
     {gObjectEventPaletteEmotes, OBJ_EVENT_PAL_TAG_EMOTES},
     {NULL,                  OBJ_EVENT_PAL_TAG_NONE},
 };
@@ -1701,6 +1709,9 @@ static const struct ObjectEventGraphicsInfo * SpeciesToGraphicsInfo(u16 species,
       form %= NUM_UNOWN_FORMS;
       graphicsInfo = &gPokemonObjectGraphics[form ? SPECIES_UNOWN_B + form - 1 : species];
       break;
+    case SPECIES_CASTFORM: // Sunny, rainy, snowy forms stored separately
+      graphicsInfo = &gCastformObjectGraphics[form % NUM_CASTFORM_FORMS];
+      break;
     default:
       graphicsInfo = &gPokemonObjectGraphics[species];
       break;
@@ -1739,7 +1750,56 @@ static void FollowerSetGraphics(struct ObjectEvent *objEvent, u16 species, u8 fo
       FieldEffectFreePaletteIfUnused(sprite->oam.paletteNum);
       sprite->inUse = TRUE;
       sprite->oam.paletteNum = LoadDynamicFollowerPalette(species, form, shiny);
-  }
+  } else if (gWeatherPtr->currWeather != WEATHER_FOG_HORIZONTAL) // don't want to weather blend in fog
+      UpdateSpritePaletteWithWeather(gSprites[objEvent->spriteId].oam.paletteNum);
+}
+
+// Like FollowerSetGraphics, but does not reposition sprite; intended to be used for mid-movement form changes, etc.
+// TODO: Reposition sprite if size changes
+static void RefreshFollowerGraphics(struct ObjectEvent *objEvent) {
+    u16 species = objEvent->extra.mon.species;
+    u8 form = objEvent->extra.mon.form;
+    u8 shiny = objEvent->extra.mon.shiny;
+    const struct ObjectEventGraphicsInfo *graphicsInfo = SpeciesToGraphicsInfo(species, form);
+    struct Sprite *sprite = &gSprites[objEvent->spriteId];
+    u8 i = FindObjectEventPaletteIndexByTag(graphicsInfo->paletteTag);
+
+    sprite->oam.shape = graphicsInfo->oam->shape;
+    sprite->oam.size = graphicsInfo->oam->size;
+    sprite->images = graphicsInfo->images;
+    sprite->anims = graphicsInfo->anims;
+    sprite->subspriteTables = graphicsInfo->subspriteTables;
+    objEvent->inanimate = graphicsInfo->inanimate;
+    sprite->centerToCornerVecX = -(graphicsInfo->width >> 1);
+    sprite->centerToCornerVecY = -(graphicsInfo->height >> 1);
+
+    if (graphicsInfo->paletteTag == OBJ_EVENT_PAL_TAG_DYNAMIC) {
+        sprite->inUse = FALSE;
+        FieldEffectFreePaletteIfUnused(sprite->oam.paletteNum);
+        sprite->inUse = TRUE;
+        sprite->oam.paletteNum = LoadDynamicFollowerPalette(species, form, shiny);
+    } else if (i != 0xFF) {
+        UpdateSpritePalette(&sObjectEventSpritePalettes[i], sprite);
+        if (gWeatherPtr->currWeather != WEATHER_FOG_HORIZONTAL) // don't want to weather blend in fog
+          UpdateSpritePaletteWithWeather(sprite->oam.paletteNum);
+    }
+}
+
+// Like CastformDataTypeChange, but for overworld weather
+static u8 GetOverworldCastformForm(void) {
+    switch (GetCurrentWeather())
+    {
+    case WEATHER_SUNNY_CLOUDS:
+    case WEATHER_DROUGHT:
+        return CASTFORM_FIRE;
+    case WEATHER_RAIN:
+    case WEATHER_RAIN_THUNDERSTORM:
+    case WEATHER_DOWNPOUR:
+        return CASTFORM_WATER;
+    case WEATHER_SNOW:
+        return CASTFORM_ICE;
+    }
+    return CASTFORM_NORMAL;
 }
 
 // Retrieve graphic information about the following pokemon, if any
@@ -1753,7 +1813,16 @@ static bool8 GetFollowerInfo(u16 *species, u8 *form, u8 *shiny) {
     }
     *species = GetMonData(mon, MON_DATA_SPECIES);
     *shiny = IsMonShiny(mon);
-    *form = *species == SPECIES_UNOWN ? GET_UNOWN_LETTER(mon->box.personality) : 0;
+    *form = 0; // default
+    switch (*species)
+    {
+    case SPECIES_UNOWN:
+        *form = GET_UNOWN_LETTER(mon->box.personality);
+        break;
+    case SPECIES_CASTFORM: // form is based on overworld weather
+        *form = GetOverworldCastformForm();
+        break;
+    }
     return TRUE;
 }
 
@@ -1764,7 +1833,7 @@ void UpdateFollowingPokemon(void) { // Update following pokemon if any
   bool8 shiny;
   u8 form;
   // Avoid spawning large (64x64) follower pokemon inside buildings
-  if (GetFollowerInfo(&species, &form, &shiny) && !(gMapHeader.mapType == MAP_TYPE_INDOOR && SpeciesToGraphicsInfo(species, 0)->width == 64)) {
+  if (GetFollowerInfo(&species, &form, &shiny) && !(gMapHeader.mapType == MAP_TYPE_INDOOR && SpeciesToGraphicsInfo(species, 0)->height == 64)) {
     if (objEvent == NULL) { // Spawn follower
       struct ObjectEventTemplate template = {
         .localId = OBJ_EVENT_ID_FOLLOWER,
@@ -2242,13 +2311,7 @@ static u8 UpdateSpritePalette(const struct SpritePalette * spritePalette, struct
   sprite->inUse = FALSE;
   FieldEffectFreePaletteIfUnused(sprite->oam.paletteNum);
   sprite->inUse = TRUE;
-  if (IndexOfSpritePaletteTag(spritePalette->tag) == 0xFF) {
-    sprite->oam.paletteNum = LoadSpritePalette(spritePalette);
-  } else {
-    sprite->oam.paletteNum = LoadSpritePalette(spritePalette);
-  }
-
-  return sprite->oam.paletteNum;
+  return sprite->oam.paletteNum = LoadSpritePalette(spritePalette);
 }
 
 // Find and update based on template's paletteTag
@@ -4803,6 +4866,73 @@ bool8 CopyablePlayerMovement_Jump2(struct ObjectEvent *objectEvent, struct Sprit
     return TRUE;
 }
 
+static bool8 EndFollowerTransformEffect(struct ObjectEvent *objectEvent, struct Sprite *sprite) {
+    if (!sprite)
+        return FALSE;
+    SetGpuReg(REG_OFFSET_MOSAIC, 0);
+    if (!sprite->data[7])
+        return FALSE;
+    sprite->oam.mosaic = FALSE;
+    sprite->data[7] = 0;
+    return FALSE;
+}
+
+static bool8 TryStartFollowerTransformEffect(struct ObjectEvent *objectEvent, struct Sprite *sprite) {
+    u32 multi;
+    if (objectEvent->extra.mon.species == SPECIES_CASTFORM && objectEvent->extra.mon.form != (multi = GetOverworldCastformForm())) {
+        sprite->data[7] = TRANSFORM_TYPE_PERMANENT << 8;
+        objectEvent->extra.mon.form = multi;
+        return TRUE;
+    } else if ((gRngValue >> 16) < 18 && GetLocalWildMon(FALSE)
+            && (objectEvent->extra.mon.species == SPECIES_MEW || objectEvent->extra.mon.species == SPECIES_DITTO)) {
+        sprite->data[7] = TRANSFORM_TYPE_RANDOM_WILD << 8;
+        PlaySE(SE_M_MINIMIZE);
+        return TRUE;
+    }
+    return FALSE;
+}
+
+static bool8 UpdateFollowerTransformEffect(struct ObjectEvent *objectEvent, struct Sprite *sprite) {
+    u8 type = sprite->data[7] >> 8;
+    u8 frames = sprite->data[7] & 0xFF;
+    u8 stretch;
+    u32 multi;
+    if (!type)
+        return TryStartFollowerTransformEffect(objectEvent, sprite);
+    sprite->oam.mosaic = TRUE;
+    if (frames < 8)
+        stretch = frames >> 1;
+    else if (frames < 16)
+        stretch = (16 - frames) >> 1;
+    else {
+        return EndFollowerTransformEffect(objectEvent, sprite);
+    }
+    if (frames == 8) {
+        switch (type)
+        {
+        case TRANSFORM_TYPE_PERMANENT:
+            RefreshFollowerGraphics(objectEvent);
+            break;
+        case TRANSFORM_TYPE_RANDOM_WILD:
+            multi = objectEvent->extra.asU16;
+            objectEvent->extra.mon.species = GetLocalWildMon(FALSE);
+            if (!objectEvent->extra.mon.species) {
+                objectEvent->extra.asU16 = multi;
+                break;
+            }
+            objectEvent->extra.mon.form = 0;
+            RefreshFollowerGraphics(objectEvent);
+            objectEvent->extra.asU16 = multi;
+            break;
+        }
+    }
+
+    SetGpuReg(REG_OFFSET_MOSAIC, (stretch << 12) | (stretch << 8));
+    frames++;
+    sprite->data[7] = (sprite->data[7] & 0xFF00) | frames;
+    return TRUE;
+}
+
 movement_type_def(MovementType_FollowPlayer, gMovementTypeFuncs_FollowPlayer)
 
 bool8 MovementType_FollowPlayer_Shadow(struct ObjectEvent *objectEvent, struct Sprite *sprite)
@@ -4859,6 +4989,8 @@ bool8 MovementType_FollowPlayer_Moving(struct ObjectEvent *objectEvent, struct S
         if (sprite->data[1]) { // restore nonzero state
           sprite->data[1] = 1;
         }
+    } else if (objectEvent->movementActionId != MOVEMENT_ACTION_EXIT_POKEBALL) {
+        UpdateFollowerTransformEffect(objectEvent, sprite);
     }
     return FALSE;
 }
@@ -4874,6 +5006,7 @@ bool8 FollowablePlayerMovement_Idle(struct ObjectEvent *objectEvent, struct Spri
     } else if (ObjectEventExecSingleMovementAction(objectEvent, sprite)) { // finish movement action
         objectEvent->singleMovementActive = 0;
     }
+    UpdateFollowerTransformEffect(objectEvent, sprite);
     return FALSE;
 }
 
@@ -6542,6 +6675,7 @@ bool8 MovementAction_EnterPokeball_Step0(struct ObjectEvent *objectEvent, struct
     u8 direction = objectEvent->facingDirection;
     InitMoveInPlace(objectEvent, sprite, direction, GetMoveDirectionFasterAnimNum(direction), 16);
     sprite->data[6] = direction == DIR_EAST ? 3 : 2; // affine animation number
+    EndFollowerTransformEffect(objectEvent, sprite);
     return MovementAction_EnterPokeball_Step1(objectEvent, sprite);
 }
 

src/field_effect.c

@@ -2998,12 +2998,8 @@ static void SurfFieldEffect_Init(struct Task *task)
     FreezeObjectEvents();
     // Put follower into pokeball before using Surf
     if (followerObject && !followerObject->invisible) {
-      // TODO: ClearObjectEventMovement (
-      followerObject->singleMovementActive = 0;
-      ObjectEventClearHeldMovement(followerObject);
-      gSprites[followerObject->spriteId].data[1] = 0;
+      ClearObjectEventMovement(followerObject, &gSprites[followerObject->spriteId]);
       gSprites[followerObject->spriteId].animCmdIndex = 0; // Needed because of weird animCmdIndex stuff
-      // )
       ObjectEventSetHeldMovement(followerObject, MOVEMENT_ACTION_ENTER_POKEBALL);
     }
     gPlayerAvatar.preventStep = TRUE;

src/field_screen_effect.c

@@ -688,12 +688,8 @@ static void Task_DoDoorWarp(u8 taskId)
         PlayerGetDestCoords(x, y);
         PlaySE(GetDoorSoundEffect(*x, *y - 1));
         if (followerObject) { // Put follower into pokeball
-          // TODO: ClearObjectEventMovement (
-          followerObject->singleMovementActive = 0;
-          ObjectEventClearHeldMovement(followerObject);
-          gSprites[followerObject->spriteId].data[1] = 0;
+          ClearObjectEventMovement(followerObject, &gSprites[followerObject->spriteId]);
           gSprites[followerObject->spriteId].animCmdIndex = 0; // Needed because of weird animCmdIndex stuff
-          // )
           ObjectEventSetHeldMovement(followerObject, MOVEMENT_ACTION_ENTER_POKEBALL);
         }
         task->data[1] = FieldAnimateDoorOpen(*x, *y - 1);