feely_pona/feely_pona.cpp

#if defined(__clang__)
#pragma once
#include "feely_pona_unity.h"
#endif

Dqn_f32 const PHYSICS_STEP = 1 / 60.f;
struct FP_GlobalAnimations
{
    Dqn_String8 terry_walk_idle       = DQN_STRING8("terry_walk_idle");
    Dqn_String8 terry_walk_up         = DQN_STRING8("terry_walk_up");
    Dqn_String8 terry_walk_down       = DQN_STRING8("terry_walk_down");
    Dqn_String8 terry_walk_left       = DQN_STRING8("terry_walk_left");
    Dqn_String8 terry_walk_right      = DQN_STRING8("terry_walk_right");
    Dqn_String8 terry_attack_up       = DQN_STRING8("terry_attack_up");
    Dqn_String8 terry_attack_side     = DQN_STRING8("terry_attack_side");
    Dqn_String8 terry_attack_down     = DQN_STRING8("terry_attack_down");
    Dqn_String8 terry_merchant        = DQN_STRING8("terry_merchant");
    Dqn_String8 smoochie_walk_up      = DQN_STRING8("smoochie_walk_up");
    Dqn_String8 smoochie_walk_down    = DQN_STRING8("smoochie_walk_down");
    Dqn_String8 smoochie_walk_left    = DQN_STRING8("smoochie_walk_left");
    Dqn_String8 smoochie_walk_right   = DQN_STRING8("smoochie_walk_right");
    Dqn_String8 smoochie_attack_down  = DQN_STRING8("smoochie_attack");
    Dqn_String8 smoochie_attack_side  = DQN_STRING8("smoochie_attack_side");
    Dqn_String8 smoochie_attack_heart = DQN_STRING8("smoochie_attack_heart");
    Dqn_String8 smoochie_death        = DQN_STRING8("smoochie_death");
}
g_anim_names;

TELY_AssetSpriteSheet FP_LoadSpriteSheetFromSpec(TELY_Platform *platform, TELY_Assets *assets, Dqn_Arena *arena, Dqn_String8 sheet_name)
{
    TELY_AssetSpriteSheet result  = {};
    Dqn_ThreadScratch     scratch = Dqn_Thread_GetScratch(arena);
    result.sprite_size            = Dqn_V2I_InitNx2(185, 170);
    result.type                   = TELY_AssetSpriteSheetType_Rects;

    // NOTE: Load the sprite meta file =========================================================
    Dqn_String8 sprite_spec_path      = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/%.*s.txt", DQN_STRING_FMT(assets->textures_dir), DQN_STRING_FMT(sheet_name));
    Dqn_String8 sprite_spec_buffer    = platform->func_load_file(scratch.arena, sprite_spec_path);
    Dqn_String8SplitAllocResult lines = Dqn_String8_SplitAlloc(scratch.allocator, sprite_spec_buffer, DQN_STRING8("\n"));
    Dqn_usize sprite_rect_index       = 0;
    Dqn_usize sprite_anim_index       = 0;

    DQN_FOR_UINDEX(line_index, lines.size) {
        Dqn_String8 line                        = lines.data[line_index];
        Dqn_String8SplitAllocResult line_splits = Dqn_String8_SplitAlloc(scratch.allocator, line, DQN_STRING8(";"));

        if (line_index == 0) {
            DQN_ASSERTF(line_splits.size == 4, "Expected 4 splits for @file lines");
            DQN_ASSERT(Dqn_String8_StartsWith(line_splits.data[0], DQN_STRING8("@file"), Dqn_String8EqCase_Sensitive));

            // NOTE: Sprite sheet path
            Dqn_String8 sprite_sheet_path = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/%.*s", DQN_STRING_FMT(assets->textures_dir), DQN_STRING_FMT(line_splits.data[1]));
            result.tex_handle             = platform->func_load_texture(assets, sheet_name, sprite_sheet_path);
            DQN_ASSERTF(Dqn_Fs_Exists(sprite_sheet_path), "Required file does not exist '%.*s'", DQN_STRING_FMT(sprite_sheet_path));

            // NOTE: Total sprite frame count
            Dqn_String8ToU64Result total_frame_count = Dqn_String8_ToU64(line_splits.data[2], 0);
            DQN_ASSERT(total_frame_count.success);
            result.rects = Dqn_Slice_Alloc<Dqn_Rect>(arena, total_frame_count.value, Dqn_ZeroMem_No);

            // NOTE: Total animation count
            Dqn_String8ToU64Result total_anim_count = Dqn_String8_ToU64(line_splits.data[3], 0);
            DQN_ASSERT(total_anim_count.success);
            result.anims = Dqn_Slice_Alloc<TELY_AssetSpriteAnimation>(arena, total_anim_count.value, Dqn_ZeroMem_No);

            // TODO: Sprite size?

            // TODO: Texture name?
            continue;
        }

        if (Dqn_String8_StartsWith(line, DQN_STRING8("@anim"))) {
            DQN_ASSERTF(line_splits.size == 4, "Expected 4 splits for @anim lines");
            Dqn_String8 anim_name                    = line_splits.data[1];
            Dqn_String8ToU64Result frames_per_second = Dqn_String8_ToU64(line_splits.data[2], 0);
            Dqn_String8ToU64Result frame_count       = Dqn_String8_ToU64(line_splits.data[3], 0);

            DQN_ASSERT(anim_name.size);
            DQN_ASSERT(frame_count.success);
            DQN_ASSERT(frames_per_second.success);

            Dqn_Allocator allocator         = Dqn_Arena_Allocator(arena);
            TELY_AssetSpriteAnimation *anim = result.anims.data + sprite_anim_index++;
            anim->label                     = Dqn_String8_Copy(allocator, anim_name);
            anim->index                     = DQN_CAST(uint16_t)sprite_rect_index;
            anim->count                     = DQN_CAST(uint16_t)frame_count.value;
            anim->ms_per_frame              = DQN_CAST(uint32_t)(1000.f / frames_per_second.value);
            DQN_ASSERT(anim->ms_per_frame != 0);
        } else {
            DQN_ASSERTF(line_splits.size == 4, "Expected 4 splits for sprite frame lines");
            Dqn_String8ToU64Result x = Dqn_String8_ToU64(line_splits.data[0], 0);
            Dqn_String8ToU64Result y = Dqn_String8_ToU64(line_splits.data[1], 0);
            Dqn_String8ToU64Result w = Dqn_String8_ToU64(line_splits.data[2], 0);
            Dqn_String8ToU64Result h = Dqn_String8_ToU64(line_splits.data[3], 0);

            DQN_ASSERT(x.success);
            DQN_ASSERT(y.success);
            DQN_ASSERT(w.success);
            DQN_ASSERT(h.success);

            result.rects.data[sprite_rect_index++] =
                Dqn_Rect_InitNx4(DQN_CAST(Dqn_f32) x.value,
                                 DQN_CAST(Dqn_f32) y.value,
                                 DQN_CAST(Dqn_f32) w.value,
                                 DQN_CAST(Dqn_f32) h.value);
        }
    }

    DQN_ASSERT(result.rects.size == sprite_rect_index);
    DQN_ASSERT(result.anims.size == sprite_anim_index);

    return result;
}

extern "C" __declspec(dllexport)
void TELY_DLL_Reload(void *user_data)
{
    TELY_Platform *platform = DQN_CAST(TELY_Platform *)user_data;
    Dqn_Library_SetPointer(platform->core.dqn_lib);
}

extern "C" __declspec(dllexport)
void TELY_DLL_Init(void *user_data)
{
    TELY_Platform *platform   = DQN_CAST(TELY_Platform *)user_data;
    TELY_DLL_Reload(user_data);

    FP_UnitTests(platform);

    // NOTE: TELY Game =============================================================================
    TELY_Assets *assets    = &platform->assets;
    FP_Game *game          = Dqn_Arena_New(&platform->arena, FP_Game, Dqn_ZeroMem_Yes);
    game->chunk_pool       = &platform->chunk_pool;
    game->meters_to_pixels = 65.416f;

    platform->user_data = game;
    {
        TELY_AssetSpriteSheet *sheet = &game->hero_sprite_sheet;
        Dqn_ThreadScratch scratch    = Dqn_Thread_GetScratch(nullptr);
        Dqn_String8 sheet_path       = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/adventurer-v1.5-sheet.png", DQN_STRING_FMT(assets->textures_dir));
        sheet->tex_handle            = platform->func_load_texture(assets, DQN_STRING8("Hero"), sheet_path);
        sheet->sprite_count          = 109;
        sheet->sprites_per_row       = 7;
        sheet->sprite_size           = Dqn_V2I_InitNx2(50, 37);

        TELY_AssetSpriteAnimation hero_anims[] = {
            {DQN_STRING8("Everything"),     /*index*/ 0,   /*count*/ sheet->sprite_count, /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Idle"),           /*index*/ 0,   /*count*/ 3,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 4.f)},
            {DQN_STRING8("Run"),            /*index*/ 8,   /*count*/ 6,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 8.f)},
            {DQN_STRING8("Jump"),           /*index*/ 14,  /*count*/ 10,                  /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Floor slide"),    /*index*/ 24,  /*count*/ 5,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Unknown"),        /*index*/ 29,  /*count*/ 9,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Attack A"),       /*index*/ 42,  /*count*/ 7,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Attack B"),       /*index*/ 49,  /*count*/ 4,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 8.f)},
            {DQN_STRING8("Attack C"),       /*index*/ 53,  /*count*/ 6,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Hurt A"),         /*index*/ 59,  /*count*/ 5,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Hurt B"),         /*index*/ 64,  /*count*/ 5,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Unsheath sword"), /*index*/ 69,  /*count*/ 4,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Sheath sword"),   /*index*/ 73,  /*count*/ 4,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Air drift"),      /*index*/ 77,  /*count*/ 2,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Air drop"),       /*index*/ 79,  /*count*/ 2,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Ladder climb"),   /*index*/ 81,  /*count*/ 4,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Chi push"),       /*index*/ 85,  /*count*/ 8,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Leap slice A"),   /*index*/ 93,  /*count*/ 7,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Leap slice B"),   /*index*/ 100, /*count*/ 3,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
            {DQN_STRING8("Leap slice C"),   /*index*/ 103, /*count*/ 6,                   /*ms_per_frame*/ DQN_CAST(uint32_t)(1000.f / 12.f)},
        };

        game->hero_sprite_anims = Dqn_Slice_Alloc<TELY_AssetSpriteAnimation>(&platform->arena, DQN_ARRAY_UCOUNT(hero_anims), Dqn_ZeroMem_No);
        DQN_MEMCPY(game->hero_sprite_anims.data, &hero_anims, sizeof(hero_anims[0]) * DQN_ARRAY_UCOUNT(hero_anims));
    }

    // NOTE: Load sprite sheets ====================================================================
    {
        game->terry_sprite_sheet          = FP_LoadSpriteSheetFromSpec(platform, assets, &platform->arena, DQN_STRING8("terry_resized_25%"));
        game->terry_merchant_sprite_sheet = FP_LoadSpriteSheetFromSpec(platform, assets, &platform->arena, DQN_STRING8("terry_merchant_resized_25%"));
        game->smoochie_sprite_sheet       = FP_LoadSpriteSheetFromSpec(platform, assets, &platform->arena, DQN_STRING8("smoochie_resized_25%"));
    }

    game->entities    = Dqn_VArray_Init<FP_GameEntity>(&platform->arena, 1024 * 8);
    game->root_entity = Dqn_VArray_Make(&game->entities, Dqn_ZeroMem_No);
    Dqn_FArray_Add(&game->parent_entity_stack, game->root_entity->handle);

    // NOTE: Hero
    {
        FP_GameEntityHandle terry = FP_Entity_CreateTerry(game, Dqn_V2_InitNx2(1334, 396), "Terry");
        game->clicked_entity      = terry;
        game->player              = terry;
    }

    FP_Entity_CreateMerchant(game, Dqn_V2_InitNx2(1000, 124), "Merchant");

    game->tile_size  = 37;
    Dqn_V2I max_tile = platform->core.window_size / game->tile_size;

    // NOTE: Wall ==================================================================================
    if (0) {
        Dqn_V2I vert_wall_tile_size    = Dqn_V2I_InitNx2(1, 12);
        Dqn_V2I right_wall_tile_pos    = Dqn_V2I_InitNx2(max_tile.x - vert_wall_tile_size.x - 0, (max_tile.y / 2.f) - (vert_wall_tile_size.y * .5f));

        Dqn_V2I left_wall_top_tile     = Dqn_V2I_InitNx2(max_tile.x - vert_wall_tile_size.x - 12, (max_tile.y / 2.f) - (vert_wall_tile_size.y * .5f));
        Dqn_V2I left_wall_bottom_tile  = Dqn_V2I_InitNx2(left_wall_top_tile.x, left_wall_top_tile.y + vert_wall_tile_size.y);


        {
            Dqn_V2I const vert_wall_part_tile_size = Dqn_V2I_InitNx2(1, (vert_wall_tile_size.y / 2) - 2);
            FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base left-top wall"), left_wall_top_tile,  vert_wall_part_tile_size);

            Dqn_V2I bottom_part_tile = Dqn_V2I_InitNx2(left_wall_top_tile.x, left_wall_top_tile.y + vert_wall_tile_size.y - vert_wall_part_tile_size.y);
            FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base left-bottom wall"), bottom_part_tile, vert_wall_part_tile_size);
        }

        FP_GameEntityHandle right_wall   = FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base right wall"), right_wall_tile_pos, vert_wall_tile_size);
        Dqn_Rect right_wall_box          = FP_Game_CalcEntityWorldHitBox(game, right_wall);
        Dqn_V2I right_wall_bottom_tile   = FP_Game_WorldPosToTilePos(game, right_wall_box.pos + Dqn_V2_InitNx2(0, right_wall_box.size.y));
        Dqn_V2I right_wall_top_left_tile = FP_Game_WorldPosToTilePos(game, right_wall_box.pos);

        {
            Dqn_V2I hori_wall_tile_size = Dqn_V2I_InitNx2((right_wall_tile_pos.x - left_wall_top_tile.x - 1) / 2 - 1, 1);
            {
                Dqn_V2I bottom_left_wall_tile_pos = Dqn_V2I_InitNx2(left_wall_bottom_tile.x + 1, left_wall_bottom_tile.y - 1);
                FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base bottom-left wall"), bottom_left_wall_tile_pos, hori_wall_tile_size);

                Dqn_V2I bottom_right_wall_tile_pos      = Dqn_V2I_InitNx2(right_wall_bottom_tile.x - hori_wall_tile_size.x, right_wall_bottom_tile.y - 1);
                FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base bottom-right wall"), bottom_right_wall_tile_pos, hori_wall_tile_size);
            }

            {
                Dqn_V2I top_left_wall_tile_pos = Dqn_V2I_InitNx2(left_wall_top_tile.x + 1, left_wall_top_tile.y);
                FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base top-left wall"), top_left_wall_tile_pos, hori_wall_tile_size);

                Dqn_V2I top_right_wall_tile_pos = Dqn_V2I_InitNx2(right_wall_top_left_tile.x - hori_wall_tile_size.x, right_wall_top_left_tile.y);
                FP_Entity_CreateWallAtTile(game, DQN_STRING8("Base top-right wall"), top_right_wall_tile_pos, hori_wall_tile_size);
            }
        }
    }

    // NOTE: Mob spawner ===========================================================================
    {
        Dqn_V2 mob_spawner_pos          = FP_Game_MetersToPixelsNx2(game, 2.f, 5.f);
        FP_GameEntityHandle mob_spawner = FP_Entity_CreateMobSpawner(game, mob_spawner_pos, 16 /*spawn_cap*/, "Mob spawner");
        FP_Game_PushParentEntity(game, mob_spawner);
        FP_Entity_CreateWaypointF(game, FP_Game_MetersToPixelsNx2(game, 2.f, 4.f), "Waypoint A");
        FP_Entity_CreateWaypointF(game, FP_Game_MetersToPixelsNx2(game, 14.f, 8.f), "Waypoint B");
        FP_Game_PopParentEntity(game);
    }

    uint16_t font_size        = 18;
    game->camera.scale        = Dqn_V2_InitNx1(1);
    game->inter_regular_font  = platform->func_load_font(assets,  DQN_STRING8("Inter (Regular)"),             DQN_STRING8("Data/Inter-Regular.otf"), font_size);
    game->inter_italic_font   = platform->func_load_font(assets,  DQN_STRING8("Inter (Italic)"),              DQN_STRING8("Data/Inter-Italic.otf"),  font_size);
    game->jetbrains_mono_font = platform->func_load_font(assets,  DQN_STRING8("JetBrains Mono NL (Regular)"), DQN_STRING8("Data/JetBrainsMonoNL-Regular.ttf"),  font_size);
    game->test_audio          = platform->func_load_audio(assets, DQN_STRING8("Test Audio"),                  DQN_STRING8("Data/Audio/Purrple Cat - Moonwinds.qoa"));
}

void FP_EntityActionStateMachine(FP_Game *game, TELY_PlatformInput *input, FP_GameEntity *entity, Dqn_V2 dir_vector)
{
    FP_GameEntityAction *action      = &entity->action;
    bool const we_are_clicked_entity = entity->handle == game->clicked_entity;
    bool const entity_has_velocity   = entity->velocity.x || entity->velocity.y;
    bool const entering_new_state    = action->state != action->next_state;
    bool const action_has_finished   = !entering_new_state && game->clock_ms >= action->end_at_clock_ms;
    action->state                    = action->next_state;

    switch (entity->type) {
        case FP_EntityType_Nil: {
        } break;

        case FP_EntityType_Terry: {
            FP_EntityTerryState   *state = DQN_CAST(FP_EntityTerryState *) & action->state;
            TELY_AssetSpriteSheet *sheet = &game->terry_sprite_sheet;

            switch (*state) {
                case FP_EntityTerryState_Nil: {
                    action->next_state = FP_EntityTerryState_Idle;
                } break;

                case FP_EntityTerryState_Idle: {
                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_walk_idle, TELY_AssetFlip_No);
                        uint64_t duration_ms            = FP_GAME_ENTITY_ACTION_INFINITE_TIMER;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (we_are_clicked_entity) {
                        if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_J) ||
                            TELY_Platform_InputGamepadButtonCodeIsPressed(input, 0, TELY_PlatformInputGamepadButtonCode_X)) {
                            switch (entity->direction) {
                                case FP_GameDirection_Up: {
                                    action->next_state = FP_EntityTerryState_AttackUp;
                                } break;

                                case FP_GameDirection_Left: {
                                    action->next_state = FP_EntityTerryState_AttackSide;
                                } break;

                                case FP_GameDirection_Right: {
                                    action->next_state = FP_EntityTerryState_AttackSide;
                                } break;

                                case FP_GameDirection_Down: {
                                    action->next_state = FP_EntityTerryState_AttackDown;
                                } break;
                            }
                        } else if (dir_vector.x || dir_vector.y) {
                            action->next_state = FP_EntityTerryState_Run;
                        }
                    }
                } break;

                case FP_EntityTerryState_AttackUp: {
                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_attack_up, TELY_AssetFlip_No);
                        uint64_t duration_ms            = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (action_has_finished) {
                        action->next_state = FP_EntityTerryState_Idle;
                    }
                } break;

                case FP_EntityTerryState_AttackDown: {
                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_attack_down, TELY_AssetFlip_No);
                        uint64_t duration_ms             = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (action_has_finished)
                        action->next_state = FP_EntityTerryState_Idle;
                } break;

                case FP_EntityTerryState_AttackSide: {
                    if (entering_new_state) {
                        TELY_AssetFlip flip             = entity->direction == FP_GameDirection_Right ? TELY_AssetFlip_X : TELY_AssetFlip_No;
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_attack_side, flip);
                        uint64_t duration_ms              = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (action_has_finished)
                        action->next_state = FP_EntityTerryState_Idle;
                } break;

                case FP_EntityTerryState_Run: {
                    Dqn_String8 desired_action_name = {};
                    switch (entity->direction) {
                        case FP_GameDirection_Up:    desired_action_name = g_anim_names.terry_walk_up;    break;
                        case FP_GameDirection_Down:  desired_action_name = g_anim_names.terry_walk_down;  break;
                        case FP_GameDirection_Left:  desired_action_name = g_anim_names.terry_walk_left;  break;
                        case FP_GameDirection_Right: desired_action_name = g_anim_names.terry_walk_right; break;
                    }

                    if (entering_new_state || action->sprite.anim->label != desired_action_name) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, desired_action_name, TELY_AssetFlip_No);
                        uint64_t duration_ms              = FP_GAME_ENTITY_ACTION_INFINITE_TIMER;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (we_are_clicked_entity) {
                        if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_J) ||
                            TELY_Platform_InputGamepadButtonCodeIsPressed(input, 0, TELY_PlatformInputGamepadButtonCode_X)) {
                            switch (entity->direction) {
                                case FP_GameDirection_Up: {
                                    action->next_state = FP_EntityTerryState_AttackUp;
                                } break;

                                case FP_GameDirection_Left: {
                                    action->next_state = FP_EntityTerryState_AttackSide;
                                } break;

                                case FP_GameDirection_Right: {
                                    action->next_state = FP_EntityTerryState_AttackSide;
                                } break;

                                case FP_GameDirection_Down: {
                                    action->next_state = FP_EntityTerryState_AttackDown;
                                } break;
                            }
                        } else if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_LeftShift) ||
                                   TELY_Platform_InputGamepadButtonCodeIsPressed(input, 0, TELY_PlatformInputGamepadButtonCode_A)) {
                            action->next_state = FP_EntityTerryState_Dash;
                        }
                    }

                    if (!entity_has_velocity /*&& !has_collision*/) {
                        action->next_state = FP_EntityTerryState_Idle;
                    }
                } break;

                case FP_EntityTerryState_Dash: {

                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_walk_right, TELY_AssetFlip_No);
                        uint64_t duration_ms              = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);

                        Dqn_V2 dash_dir          = {};
                        switch (entity->direction) {
                            case FP_GameDirection_Up:    dash_dir.y = -1.f; break;
                            case FP_GameDirection_Down:  dash_dir.y = +1.f; break;
                            case FP_GameDirection_Left:  dash_dir.x = -1.f; break;
                            case FP_GameDirection_Right: dash_dir.x = +1.f; break;
                        }

                        Dqn_V2 dash_acceleration = dash_dir * 400'000'000.f;
                        Dqn_f32 t                = DQN_CAST(Dqn_f32)DQN_SQUARED(PHYSICS_STEP);
                        entity->velocity         = (dash_acceleration * t) + entity->velocity * 2.0f;
                    }

                    if (action_has_finished) {
                        if (entity_has_velocity) {
                            // TODO(doyle): Not sure if this branch triggers properly.
                            action->next_state = FP_EntityTerryState_Run;
                        } else {
                            action->next_state = FP_EntityTerryState_Idle;
                        }
                    }
                } break;
            }

            if (*state == FP_EntityTerryState_AttackUp ||
                *state == FP_EntityTerryState_AttackDown ||
                *state == FP_EntityTerryState_AttackSide) {
                entity->attack_box_size = entity->local_hit_box_size;

                // NOTE: Position the attack box
                if (entity->direction == FP_GameDirection_Left) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x - entity->attack_box_size.w,
                                                               entity->local_hit_box_offset.y);
                } else if (entity->direction == FP_GameDirection_Right) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x + entity->attack_box_size.w,
                                                               entity->local_hit_box_offset.y);
                } else if (entity->direction == FP_GameDirection_Up) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x,
                                                               entity->local_hit_box_offset.y - entity->attack_box_size.h);
                } else if (entity->direction == FP_GameDirection_Down) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x,
                                                               entity->local_hit_box_offset.y + entity->attack_box_size.h);
                }
            } else {
                entity->attack_box_size = {};
            }
        } break;

        case FP_EntityType_Smoochie: {
            FP_EntitySmoochieState *state = DQN_CAST(FP_EntitySmoochieState *) & action->state;
            TELY_AssetSpriteSheet  *sheet = &game->smoochie_sprite_sheet;

            switch (*state) {
                case FP_EntitySmoochieState_Nil: {
                    action->next_state = FP_EntitySmoochieState_Idle;
                } break;

                case FP_EntitySmoochieState_Idle: {

                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.smoochie_walk_down, TELY_AssetFlip_No);
                        uint64_t duration_ms              = FP_GAME_ENTITY_ACTION_INFINITE_TIMER;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (we_are_clicked_entity) {
                        if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_J) ||
                            TELY_Platform_InputGamepadButtonCodeIsPressed(input, 0, TELY_PlatformInputGamepadButtonCode_X)) {

                            switch (entity->direction) {
                                case FP_GameDirection_Up: /*FALLTHRU*/
                                case FP_GameDirection_Right: /*FALLTHRU*/
                                case FP_GameDirection_Left: {
                                    action->next_state = FP_EntitySmoochieState_AttackSide;
                                } break;

                                case FP_GameDirection_Down: {
                                    action->next_state = FP_EntitySmoochieState_AttackDown;
                                } break;
                            }
                        } else if (dir_vector.x || dir_vector.y) {
                            action->next_state = FP_EntitySmoochieState_Run;
                        }
                    }
                } break;

                case FP_EntitySmoochieState_AttackDown: {
                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.smoochie_attack_down, TELY_AssetFlip_No);
                        uint64_t duration_ms              = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (action_has_finished) {
                        action->next_state = FP_EntitySmoochieState_Idle;
                    }
                } break;

                case FP_EntitySmoochieState_AttackSide: {
                    if (entering_new_state) {
                        TELY_AssetFlip flip             = entity->direction == FP_GameDirection_Right ? TELY_AssetFlip_X : TELY_AssetFlip_No;
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.smoochie_attack_side, flip);
                        uint64_t duration_ms              = sprite.anim->count * sprite.anim->ms_per_frame;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (action_has_finished)
                        action->next_state = FP_EntitySmoochieState_Idle;
                } break;

                case FP_EntitySmoochieState_AttackHeart: {
                } break;

                case FP_EntitySmoochieState_Run: {
                    Dqn_String8 desired_action_name = {};
                    switch (entity->direction) {
                        case FP_GameDirection_Up:    desired_action_name = g_anim_names.smoochie_walk_up;    break;
                        case FP_GameDirection_Down:  desired_action_name = g_anim_names.smoochie_walk_down;  break;
                        case FP_GameDirection_Left:  desired_action_name = g_anim_names.smoochie_walk_left;  break;
                        case FP_GameDirection_Right: desired_action_name = g_anim_names.smoochie_walk_right; break;
                    }

                    if (entering_new_state || action->sprite.anim->label != desired_action_name) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, desired_action_name, TELY_AssetFlip_No);
                        uint64_t duration_ms              = FP_GAME_ENTITY_ACTION_INFINITE_TIMER;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                    if (we_are_clicked_entity) {
                        if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_J) ||
                            TELY_Platform_InputGamepadButtonCodeIsPressed(input, 0, TELY_PlatformInputGamepadButtonCode_X)) {

                            switch (entity->direction) {
                                case FP_GameDirection_Up: /*FALLTHRU*/
                                case FP_GameDirection_Right: /*FALLTHRU*/
                                case FP_GameDirection_Left: {
                                    action->next_state = FP_EntitySmoochieState_AttackSide;
                                } break;

                                case FP_GameDirection_Down: {
                                    action->next_state = FP_EntitySmoochieState_AttackDown;
                                } break;
                            }
                        }
                    }

                    if (!entity_has_velocity /*&& !has_collision*/) {
                        action->next_state = FP_EntitySmoochieState_Idle;
                    }
                } break;
            }

            if (*state == FP_EntitySmoochieState_AttackSide || *state == FP_EntitySmoochieState_AttackDown) {
                entity->attack_box_size = entity->local_hit_box_size;
                // NOTE: Position the attack box
                if (entity->direction == FP_GameDirection_Left) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x - entity->attack_box_size.w,
                                                               entity->local_hit_box_offset.y);
                } else if (entity->direction == FP_GameDirection_Right) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x + entity->attack_box_size.w,
                                                               entity->local_hit_box_offset.y);
                } else if (entity->direction == FP_GameDirection_Up) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x,
                                                               entity->local_hit_box_offset.y - entity->attack_box_size.h);
                } else if (entity->direction == FP_GameDirection_Down) {
                    entity->attack_box_offset = Dqn_V2_InitNx2(entity->local_hit_box_offset.x,
                                                               entity->local_hit_box_offset.y + entity->attack_box_size.h);
                }
            } else {
                entity->attack_box_size = {};
            }
        } break;

        case FP_EntityType_Merchant: {
            FP_EntityTerryMerchantState *state = DQN_CAST(FP_EntityTerryMerchantState *)&action->state;
            TELY_AssetSpriteSheet  *sheet      = &game->terry_merchant_sprite_sheet;

            switch (*state) {
                case FP_EntityTerryMerchantState_Nil: {
                    action->next_state = FP_EntityTerryMerchantState_Idle;
                } break;

                case FP_EntityTerryMerchantState_Idle: {
                    if (entering_new_state) {
                        TELY_AssetAnimatedSprite sprite = TELY_Asset_MakeAnimatedSprite(sheet, g_anim_names.terry_merchant, TELY_AssetFlip_No);
                        uint64_t duration_ms            = FP_GAME_ENTITY_ACTION_INFINITE_TIMER;
                        FP_Game_EntityActionReset(game, entity->handle, duration_ms, sprite);
                    }

                } break;
            }
        } break;
    }
}

void FP_Update(TELY_Platform *platform, FP_Game *game, TELY_PlatformInput *input)
{
    Dqn_Profiler_ZoneScopeWithIndex("FP_Update", FP_ProfileZone_FPUpdate);

    if (TELY_Platform_InputKeyIsReleased(input->mouse_left))
        game->clicked_entity = game->prev_active_entity;

    game->clock_ms    = DQN_CAST(uint64_t)(platform->input.timer_s * 1000.f);
    Dqn_V2 dir_vector = {};

    // NOTE: Keyboard movement input
    if (TELY_Platform_InputScanCodeIsDown(input, TELY_PlatformInputScanCode_W))
        dir_vector.y = -1.f;
    if (TELY_Platform_InputScanCodeIsDown(input, TELY_PlatformInputScanCode_A))
        dir_vector.x = -1.f;
    if (TELY_Platform_InputScanCodeIsDown(input, TELY_PlatformInputScanCode_S))
        dir_vector.y = +1.f;
    if (TELY_Platform_InputScanCodeIsDown(input, TELY_PlatformInputScanCode_D))
        dir_vector.x = +1.f;

    // NOTE: Gamepad movement input
    // NOTE: button_codes 0 should be the first gamepad connected, we can 
    // get this working with other gamepads later
    uint32_t gamepad = 0;
    if (input->button_codes[gamepad]) {
        dir_vector.x += input->left_stick[gamepad].x;
        dir_vector.y += input->left_stick[gamepad].y;
    }

    if (dir_vector.x && dir_vector.y) {
        dir_vector.x *= 0.7071067811865475244f;
        dir_vector.y *= 0.7071067811865475244f;
    }

    if (game->clicked_entity.id) {
        if (TELY_Platform_InputScanCodeIsPressed(input, TELY_PlatformInputScanCode_Delete))
            FP_Game_DeleteEntity(game, game->clicked_entity);
    } else {
        game->camera.world_pos += dir_vector * 5.f;
    }

    Dqn_ProfilerZone update_zone = Dqn_Profiler_BeginZoneWithIndex(DQN_STRING8("FP_Update: Entity loop"), FP_ProfileZone_FPUpdate_EntityLoop);
    for (FP_GameEntityIterator it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &it, game->root_entity); ) {
        FP_GameEntity *entity  = it.entity;
        entity->alive_time_s  += PHYSICS_STEP;

        // NOTE: Move entity by keyboard and gamepad ===============================================
        Dqn_V2 acceleration_meters_per_s = {};
        if (game->clicked_entity == entity->handle) {
            if (entity->flags & (FP_GameEntityFlag_MoveByKeyboard | FP_GameEntityFlag_MoveByGamepad)) {
                bool move_entity = false;
                switch (entity->type) {
                    case FP_EntityType_Terry: {
                        auto *state = DQN_CAST(FP_EntityTerryState *)&entity->action.state;
                        move_entity = *state == FP_EntityTerryState_Run || *state == FP_EntityTerryState_Idle;
                    } break;

                    case FP_EntityType_Smoochie: {
                        auto *state = DQN_CAST(FP_EntitySmoochieState *)&entity->action.state;
                        move_entity = *state == FP_EntitySmoochieState_Run || *state == FP_EntitySmoochieState_Idle;
                    } break;

                    case FP_EntityType_Merchant: move_entity = true; break;
                    case FP_EntityType_Nil:      move_entity = true; break;
                }

                if (move_entity) {
                    acceleration_meters_per_s = dir_vector * 8;
                    if (dir_vector.x)
                        entity->direction = dir_vector.x > 0.f ? FP_GameDirection_Right : FP_GameDirection_Left;
                    else if (dir_vector.y)
                        entity->direction = dir_vector.y > 0.f ? FP_GameDirection_Down : FP_GameDirection_Up;
                }
            }
        }

        // NOTE: Determine AI movement =============================================================
        if (acceleration_meters_per_s.x == 0 && acceleration_meters_per_s.y == 0) {
            Dqn_V2 entity_pos = FP_Game_CalcEntityWorldPos(game, entity->handle);

            if (entity->flags & FP_GameEntityFlag_AggrosWhenNearTerry) {
                Dqn_f32 closest_terry_dist   = DQN_F32_MAX;
                Dqn_V2 closest_terry_pos     = Dqn_V2_InitNx1(DQN_F32_MAX);
                FP_GameEntity *closest_terry = nullptr;
                for (FP_GameEntityIterator terry_it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &terry_it, game->root_entity); ) {
                    FP_GameEntity *terry = terry_it.entity;
                    if (terry->type != FP_EntityType_Terry)
                        continue;

                    Dqn_V2 terry_pos      = FP_Game_CalcEntityWorldPos(game, terry->handle);
                    Dqn_f32 dist_to_terry = Dqn_V2_LengthSq_V2x2(terry_pos, entity_pos);
                    if (dist_to_terry < closest_terry_dist) {
                        closest_terry_pos  = terry_pos;
                        closest_terry_dist = dist_to_terry;
                        closest_terry      = terry;
                    }
                }

                if (closest_terry_dist < DQN_SQUARED(FP_Game_MetersToPixelsNx1(game, 5.f))) {
                    FP_SentinelListLink<FP_GameEntityHandle> *first_waypoint = FP_SentinelList_Front(&entity->waypoints);
                    if (first_waypoint->data != closest_terry->handle) {
                        FP_SentinelListLink<FP_GameEntityHandle> *link = FP_SentinelList_MakeBefore(&entity->waypoints, first_waypoint, game->chunk_pool);
                        link->data                                     = closest_terry->handle;
                    }
                }
            }

            while (entity->waypoints.size) {
                FP_SentinelListLink<FP_GameEntityHandle> *waypoint_link = entity->waypoints.sentinel->next;
                FP_GameEntity *waypoint = FP_Game_GetEntity(game, waypoint_link->data);
                if (FP_Game_IsNilEntity(waypoint)) {
                    FP_SentinelList_Erase(&entity->waypoints, waypoint_link, game->chunk_pool);
                    continue;
                }

                // NOTE: We found a waypoint that is valid to move towards
                Dqn_V2 waypoint_pos       = FP_Game_CalcEntityWorldPos(game, waypoint->handle);
                Dqn_V2 entity_to_waypoint = waypoint_pos - entity_pos;

                // NOTE: Check if we've arrived at the waypoint
                Dqn_f32 dist_to_waypoint_sq = Dqn_V2_LengthSq(entity_to_waypoint);
                Dqn_f32 arrival_threshold   = DQN_MIN(DQN_SQUARED(entity->local_hit_box_size.x * .5f), 10.f);
                if (dist_to_waypoint_sq < arrival_threshold) {
                    FP_SentinelList_Erase(&entity->waypoints, waypoint_link, game->chunk_pool);
                    continue;
                }

                // NOTE: We haven't arrived yet, calculate an acceleration vector to the waypoint
                Dqn_V2 entity_to_waypoint_norm = Dqn_V2_Normalise(entity_to_waypoint);
                acceleration_meters_per_s      = entity_to_waypoint_norm * 4.f;
                break;
            }
        }

        // NOTE: Core equations of motion ==========================================================
        bool has_collision = false;
        {
            // f"(t) = a
            // f'(t) = at + v
            // f (t) = 0.5f*a(t^2) + vt + p
            Dqn_f32 t          = DQN_CAST(Dqn_f32)DQN_SQUARED(PHYSICS_STEP);
            Dqn_f32 t_squared  = DQN_SQUARED(t);

            Dqn_f32 velocity_falloff_coefficient  = 0.82f;
            Dqn_f32 acceleration_feel_good_factor = 15'000.f;
            Dqn_V2 acceleration                   = FP_Game_MetersToPixelsV2(game, acceleration_meters_per_s) * acceleration_feel_good_factor;
            entity->velocity                      = (acceleration * t) + entity->velocity * velocity_falloff_coefficient;

            // NOTE: Zero out velocity with epsilon
            if (DQN_ABS(entity->velocity.x) < 5.f)
                entity->velocity.x = 0.f;
            if (DQN_ABS(entity->velocity.y) < 5.f)
                entity->velocity.y = 0.f;

            Dqn_V2 delta_pos              = (acceleration * 0.5f * t_squared) + (entity->velocity * t);
            Dqn_Rect entity_world_hit_box = FP_Game_CalcEntityWorldHitBox(game, entity->handle);
            Dqn_V2 entity_pos             = Dqn_Rect_Center(entity_world_hit_box);
            Dqn_V2 entity_new_pos         = entity_pos + delta_pos;

            for (FP_GameEntityIterator collider_it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &collider_it, game->root_entity); ) {
                FP_GameEntity *collider = collider_it.entity;
                if (collider->handle == entity->handle)
                    continue;

                // TODO(doyle): Calculate the list of collidables at the start of the frame
                if ((collider->flags & FP_GameEntityFlag_NonTraversable) == 0)
                    continue;

                // NOTE: Sweep collider with half the radius of the source entity
                Dqn_Rect collider_world_hit_box       = FP_Game_CalcEntityWorldHitBox(game, collider->handle);
                Dqn_Rect swept_collider_world_hit_box = collider_world_hit_box;
                swept_collider_world_hit_box.pos      -= (entity_world_hit_box.size * .5f);
                swept_collider_world_hit_box.size     += entity_world_hit_box.size;

                if (!Dqn_Rect_ContainsPoint(swept_collider_world_hit_box, entity_new_pos))
                    continue;

                Dqn_f32 collider_left_wall_x   = swept_collider_world_hit_box.pos.x;
                Dqn_f32 collider_right_wall_x  = swept_collider_world_hit_box.pos.x + swept_collider_world_hit_box.size.w;
                Dqn_f32 collider_top_wall_y    = swept_collider_world_hit_box.pos.y;
                Dqn_f32 collider_bottom_wall_y = swept_collider_world_hit_box.pos.y + swept_collider_world_hit_box.size.h;

                Dqn_V2 o = entity_pos;
                Dqn_V2 d = delta_pos;

                // NOTE: Solve collision by determining the 't' value at which
                // we hit one of the walls of the collider and move the entity
                // at exactly that point.
                // O + td = x
                // td     = x - O
                // t      = (x - O) / d

                Dqn_f32 const SENTINEL_T = 999.f;
                Dqn_f32 earliest_t       = SENTINEL_T;
                if (d.x != 0.f) {
                    Dqn_f32 left_t  = (collider_left_wall_x  - o.x) / d.x;
                    Dqn_f32 right_t = (collider_right_wall_x - o.x) / d.x;
                    if (left_t >= 0.f && left_t <= 1.f)
                        earliest_t = DQN_MIN(earliest_t, left_t);
                    if (right_t >= 0.f && right_t <= 1.f)
                        earliest_t = DQN_MIN(earliest_t, right_t);
                }

                if (d.y != 0.f) {
                    Dqn_f32 top_t    = (collider_top_wall_y    - o.y) / d.y;
                    Dqn_f32 bottom_t = (collider_bottom_wall_y - o.y) / d.y;
                    if (top_t >= 0.f && top_t <= 1.f)
                        earliest_t = DQN_MIN(earliest_t, top_t);
                    if (bottom_t >= 0.f && bottom_t <= 1.f)
                        earliest_t = DQN_MIN(earliest_t, bottom_t);
                }

                if (earliest_t != SENTINEL_T) {
                    Dqn_V2 pos_just_before_collide = entity_pos + (d * earliest_t);
                    Dqn_V2 new_delta_p             = pos_just_before_collide - entity_pos;
                    entity->local_pos             += new_delta_p;
                    has_collision                  = true;
                }
            }

            if (!has_collision) {
                entity->local_pos += delta_pos;
            }
        }
        
        // NOTE: Attack collisions =================================================================
        {
            // NOTE: Check if there's an active attack box
            if (entity->attack_box_size.x != 0 && entity->attack_box_size.y != 0) {
                Dqn_Rect entity_attack_box = {};
                // NOTE: Convert from centre origin to top-left origin
                entity_attack_box.pos  = entity->local_pos + entity->attack_box_offset - (entity->attack_box_size * 0.5f);
                entity_attack_box.size = entity->attack_box_size;

                for (FP_GameEntityIterator target_it = {}; FP_Game_DFSPreOrderWalkEntityTree(game, &target_it, game->root_entity);) {
                    FP_GameEntity *target = target_it.entity;
                    if (target->handle == entity->handle)
                        continue;

                    // TODO(josh): This check should be updated based on an entity attackable flag
                    if (target->flags & FP_GameEntityFlag_Attackable) {
                        Dqn_Rect target_world_hit_box = FP_Game_CalcEntityWorldHitBox(game, target->handle);

                        if (Dqn_Rect_Intersects(entity_attack_box, target_world_hit_box)) {
                            target->hp -= 1;

                            if (target->hp <= 0) {
                                FP_Game_DeleteEntity(game, target->handle);
                            }
                        }
                    }
                }
            }
        }

        // NOTE: Move entity by mouse ==============================================================
        if (game->active_entity == entity->handle && entity->flags & FP_GameEntityFlag_MoveByMouse) {
            if (entity->flags & FP_GameEntityFlag_MoveByMouse) {
                entity->velocity   = {};
                entity->local_pos += input->mouse_p_delta;
            }
        }

        if (entity->flags & FP_GameEntityFlag_DeriveHitBoxFromChildrenBoundingBox) {
            Dqn_Rect children_bbox = {};

            // TODO(doyle): Is the hit box supposed to include the containing
            // entity itself? Not sure
            children_bbox.pos = FP_Game_CalcEntityWorldPos(game, entity->handle);

            for (FP_GameEntityIterator child_it = {}; FP_Game_DFSPreOrderWalkEntityTree(game, &child_it, entity);) {
                FP_GameEntity *child = child_it.entity;
                DQN_ASSERT(child != entity);

                Dqn_Rect bbox = FP_Game_CalcEntityWorldBoundingBox(game, child->handle);
                children_bbox = Dqn_Rect_Union(children_bbox, bbox);
            }

            Dqn_Rect padded_bbox         = Dqn_Rect_Expand(children_bbox, 16.f);
            entity->local_hit_box_offset = padded_bbox.pos - entity->local_pos + (padded_bbox.size * .5f);
            entity->local_hit_box_size   = padded_bbox.size;
        }

        // NOTE: Handle input on entity ============================================================
        FP_EntityActionStateMachine(game, input, entity, dir_vector);

        // NOTE: Mob spawner =======================================================================
        if (entity->flags & FP_GameEntityFlag_MobSpawner) {

            // NOTE: Flush any spawn entities that are dead
            for (FP_SentinelListLink<FP_GameEntityHandle> *link = nullptr; FP_SentinelList_Iterate<FP_GameEntityHandle>(&entity->spawn_list, &link); ) {
                FP_GameEntity *spawned_entity = FP_Game_GetEntity(game, link->data);
                if (FP_Game_IsNilEntity(spawned_entity)) // NOTE: Entity is dead remove it from the linked list
                    link = FP_SentinelList_Erase(&entity->spawn_list, link, game->chunk_pool);
            }

            if (entity->spawn_list.size < entity->spawn_cap) { // NOTE: Spawn new entities
                if (input->timer_s >= entity->next_spawn_timestamp_s) {
                    entity->next_spawn_timestamp_s = DQN_CAST(uint64_t)(input->timer_s + 5.f);

                    Dqn_V2 entity_world_pos                        = FP_Game_CalcEntityWorldPos(game, entity->handle);
                    FP_SentinelListLink<FP_GameEntityHandle> *link = FP_SentinelList_Make(&entity->spawn_list, game->chunk_pool);
                    link->data                                     = FP_Entity_CreateSmoochie(game, entity_world_pos, "Smoochie");

                    // NOTE: Setup the mob with waypoints
                    FP_GameEntity *mob  = FP_Game_GetEntity(game, link->data);
                    mob->waypoints      = FP_SentinelList_Init<FP_GameEntityHandle>(game->chunk_pool);
                    mob->flags         |= FP_GameEntityFlag_AggrosWhenNearTerry;

                    for (FP_GameEntity *waypoint_entity = entity->first_child; waypoint_entity; waypoint_entity = waypoint_entity->next) {
                        if ((waypoint_entity->flags & FP_GameEntityFlag_MobSpawnerWaypoint) == 0)
                            continue;

                        // NOTE: Add the waypoint
                        FP_SentinelListLink<FP_GameEntityHandle> *waypoint = FP_SentinelList_Make(&mob->waypoints, game->chunk_pool);
                        waypoint->data                                     = waypoint_entity->handle;
                    }
                }
            }
        }
    }
    Dqn_Profiler_EndZone(update_zone);

    // NOTE: Do attacks ============================================================================
    auto attack_zone = Dqn_Profiler_BeginZoneWithIndex(DQN_STRING8("FP_Update: Attacks"), FP_ProfileZone_FPUpdate_Attacks);
    for (FP_GameEntityIterator attacker_it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &attacker_it, game->root_entity); ) {
        FP_GameEntity *attacker = attacker_it.entity;

        // NOTE: Resolve attack boxes
        if (!Dqn_V2_Area(attacker->attack_box_size))
            continue;

        Dqn_Rect attacker_box     = FP_Game_CalcEntityAttackWorldHitBox(game, attacker->handle);
        Dqn_V2 attacker_world_pos = FP_Game_CalcEntityWorldPos(game, attacker->handle);

        for (FP_GameEntityIterator defender_it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &defender_it, game->root_entity); ) {
            FP_GameEntity *defender = defender_it.entity;
            if (defender->handle == attacker->handle)
                continue;

            Dqn_Rect defender_box = FP_Game_CalcEntityWorldHitBox(game, defender->handle);
            if (!Dqn_Rect_Intersects(attacker_box, defender_box))
                continue;

            Dqn_V2 defender_world_pos = Dqn_Rect_Center(defender_box);
            Dqn_V2 attack_dir_vector  = {};
            if (attacker_world_pos.x < defender_world_pos.x)
                attack_dir_vector.x = 1.f;
            else
                attack_dir_vector.x = -1.f;

            Dqn_V2 acceleration  = attack_dir_vector * 500'000.f;
            Dqn_f32 t            = DQN_CAST(Dqn_f32)DQN_SQUARED(PHYSICS_STEP);
            Dqn_f32 t_squared    = DQN_SQUARED(t);

            Dqn_V2 delta_p     = (acceleration * 0.5f * t_squared) + (defender->velocity * t);
            defender->velocity = (acceleration * t) + defender->velocity * 2.0f;
        }
    }
    Dqn_Profiler_EndZone(attack_zone);
}

void FP_Render(FP_Game *game, TELY_Platform *platform, TELY_Renderer *renderer)
{
    Dqn_Profiler_ZoneScopeWithIndex("FP_Render", FP_ProfileZone_FPRender);
    TELY_PlatformInput *input = &platform->input;
    Dqn_M2x3 model_view       = FP_Game_CameraModelViewM2x3(game->camera, platform);
    Dqn_V2 world_mouse_p      = Dqn_M2x3_MulV2(model_view, input->mouse_p);

    // NOTE: Draw tiles ============================================================================
    Dqn_usize tile_count_x = DQN_CAST(Dqn_usize)(platform->core.window_size.w / game->tile_size);
    Dqn_usize tile_count_y = DQN_CAST(Dqn_usize)(platform->core.window_size.h / game->tile_size);

    for (Dqn_usize x = 0; x < tile_count_x; x++) {
        Dqn_V2 start = Dqn_V2_InitNx2((x + 1) * game->tile_size, 0);
        Dqn_V2 end   = Dqn_V2_InitNx2(start.x, platform->core.window_size.h);
        TELY_Render_LineColourV4(renderer, start, end, TELY_Colour_V4Alpha(TELY_COLOUR_WHITE_V4, .25f), 1.f);
    }

    for (Dqn_usize y = 0; y < tile_count_y; y++) {
        Dqn_V2 start = Dqn_V2_InitNx2(0, (y + 1) * game->tile_size);
        Dqn_V2 end   = Dqn_V2_InitNx2(platform->core.window_size.w, start.y);
        TELY_Render_LineColourV4(renderer, start, end, TELY_Colour_V4Alpha(TELY_COLOUR_WHITE_V4, .25f), 1.f);
    }

    // NOTE: Draw entities =========================================================================
    for (FP_GameEntityIterator it = {}; FP_Game_DFSPostOrderWalkEntityTree(game, &it, game->root_entity); ) {
        FP_GameEntity *entity  = it.entity;

        // NOTE: Render shapes in entity ===========================================================
        Dqn_V2 world_pos = FP_Game_CalcEntityWorldPos(game, entity->handle);
        for (FP_GameShape const &shape_ : entity->shapes) {
            FP_GameShape const *shape = &shape_;
            Dqn_V2 local_to_world_p1    = world_pos + shape->p1;
            Dqn_V2 local_to_world_p2    = world_pos + shape->p2;
            switch (shape->type) {
                case FP_GameShapeType_None: {
                } break;

                case FP_GameShapeType_Circle: {
                    TELY_Render_CircleColourV4(renderer, local_to_world_p1, shape->circle_radius, shape->render_mode, shape->colour);
                } break;

                case FP_GameShapeType_Rect: {
                    Dqn_Rect rect = Dqn_Rect_InitV2x2(local_to_world_p1, local_to_world_p2 - local_to_world_p1);
                    rect.pos     -= rect.size * .5f;
                    TELY_Render_RectColourV4(renderer, rect, shape->render_mode, shape->colour);
                } break;

                case FP_GameShapeType_Line: {
                    TELY_Render_LineColourV4(renderer, local_to_world_p1, local_to_world_p2, shape->colour, shape->line_thickness);
                } break;
            }
        }

        // NOTE: Render entity sprites =============================================================
        if (entity->action.sprite.anim) {
            FP_GameEntityAction      const *action = &entity->action;
            TELY_AssetAnimatedSprite const sprite  = action->sprite;

            uint64_t elapsed_ms = game->clock_ms - action->started_at_clock_ms;
            uint16_t anim_frame = DQN_CAST(uint16_t)(elapsed_ms / sprite.anim->ms_per_frame) % sprite.anim->count;

            Dqn_usize sprite_index = sprite.anim->index + anim_frame;
            Dqn_Rect  src_rect     = {};
            switch (sprite.sheet->type) {
                case TELY_AssetSpriteSheetType_Uniform: {
                    Dqn_usize sprite_sheet_row    = sprite_index / sprite.sheet->sprites_per_row;
                    Dqn_usize sprite_sheet_column = sprite_index % sprite.sheet->sprites_per_row;
                    src_rect.pos.x                = DQN_CAST(Dqn_f32)(sprite_sheet_column * sprite.sheet->sprite_size.w);
                    src_rect.pos.y                = DQN_CAST(Dqn_f32)(sprite_sheet_row    * sprite.sheet->sprite_size.y);
                    src_rect.size.w               = DQN_CAST(Dqn_f32)sprite.sheet->sprite_size.w;
                    src_rect.size.h               = DQN_CAST(Dqn_f32)sprite.sheet->sprite_size.h;
                } break;

                case TELY_AssetSpriteSheetType_Rects: {
                    DQN_ASSERT(sprite_index < sprite.sheet->rects.size);
                    src_rect = sprite.sheet->rects.data[sprite_index];
                } break;
            }

            Dqn_f32 sprite_in_meters = src_rect.size.y * FP_Game_PixelsToMeters(game);
            Dqn_f32 size_scale       = entity->sprite_height.meters / sprite_in_meters;

            Dqn_Rect dest_rect = {};
            dest_rect.size     = src_rect.size * size_scale;
            dest_rect.pos      = world_pos - (dest_rect.size * .5f);

            if (sprite.flip & TELY_AssetFlip_X)
                dest_rect.size.w *= -1.f; // NOTE: Flip the texture horizontally

            if (sprite.flip & TELY_AssetFlip_Y)
                dest_rect.size.h *= -1.f; // NOTE: Flip the texture vertically

            TELY_Render_TextureColourV4(renderer, sprite.sheet->tex_handle, src_rect, dest_rect, TELY_COLOUR_WHITE_V4);
        }

        if (entity->flags & FP_GameEntityFlag_MobSpawner) {
            Dqn_V2 start = world_pos;
            for (FP_GameEntity *waypoint_entity = entity->first_child; waypoint_entity; waypoint_entity = waypoint_entity->next) {
                if ((waypoint_entity->flags & FP_GameEntityFlag_MobSpawnerWaypoint) == 0)
                    continue;

                Dqn_V2 end = FP_Game_CalcEntityWorldPos(game, waypoint_entity->handle);
                TELY_Render_LineColourV4(renderer, start, end, TELY_COLOUR_BLUE_CADET_V4, 2.f);
                start = end;
            }
        }

        // NOTE: Render attack box =================================================================
        {
            Dqn_Rect attack_box = FP_Game_CalcEntityAttackWorldHitBox(game, entity->handle);
            TELY_Render_RectColourV4(renderer, attack_box, TELY_RenderShapeMode_Line, TELY_COLOUR_RED_TOMATO_V4);
        }

        // NOTE: Render world position =============================================================
        TELY_Render_CircleColourV4(renderer, world_pos, 4.f, TELY_RenderShapeMode_Fill, TELY_COLOUR_RED_TOMATO_V4);

        // NOTE: Render hot/active entity ==========================================================
        Dqn_Rect world_hit_box = FP_Game_CalcEntityWorldHitBox(game, entity->handle);
        if (game->clicked_entity == entity->handle) {
            TELY_Render_RectColourV4(renderer, world_hit_box, TELY_RenderShapeMode_Line, TELY_COLOUR_WHITE_PALE_GOLDENROD_V4);

            // NOTE: Draw the waypoints that the entity is moving along
            if (entity->waypoints.size) {
                Dqn_V2 start = world_pos;
                for (FP_SentinelListLink<FP_GameEntityHandle> *link = nullptr; FP_SentinelList_Iterate(&entity->waypoints, &link); ) {
                    FP_GameEntity *waypoint = FP_Game_GetEntity(game, link->data);
                    if (FP_Game_IsNilEntity(waypoint))
                        continue;

                    Dqn_V2 end = FP_Game_CalcEntityWorldPos(game, waypoint->handle);
                    TELY_Render_LineColourV4(renderer, start, end, TELY_COLOUR_WHITE_PALE_GOLDENROD_V4, 2.f);
                    start      = end;
                }
            }

        } else if (game->hot_entity == entity->handle || (entity->flags & FP_GameEntityFlag_DrawHitBox)) {
            Dqn_V4 hot_colour = game->hot_entity == entity->handle ? TELY_COLOUR_RED_TOMATO_V4 : TELY_Colour_V4Alpha(TELY_COLOUR_YELLOW_SANDY_V4, .5f);
            TELY_Render_RectColourV4(renderer, world_hit_box, TELY_RenderShapeMode_Line, hot_colour);
        }

        if (game->hot_entity == entity->handle) {
            if (entity->name.size) {
                Dqn_V2I player_tile       = Dqn_V2I_InitNx2(world_pos.x / game->tile_size, world_pos.y / game->tile_size);
                Dqn_V2 entity_world_pos   = FP_Game_CalcEntityWorldPos(game, entity->handle);
                Dqn_ThreadScratch scratch = Dqn_Thread_GetScratch(nullptr);
                Dqn_String8 label         = Dqn_String8_InitF(scratch.allocator,
                                                              "%.*s (%.1f, %.1f) (%I32d, %I32d)",
                                                              DQN_STRING_FMT(entity->name),
                                                              entity_world_pos.x,
                                                              entity_world_pos.y,
                                                              player_tile.x,
                                                              player_tile.y);
                TELY_Render_Text(renderer, world_mouse_p, Dqn_V2_InitNx2(0.f, 1), label);
            }
        }
    }
}

extern "C" __declspec(dllexport)
void TELY_DLL_FrameUpdate(void *user_data)
{
    TELY_Platform      *platform = DQN_CAST(TELY_Platform *) user_data;
    TELY_PlatformInput *input    = &platform->input;
    TELY_Assets        *assets   = &platform->assets;
    TELY_Renderer      *renderer = &platform->renderer;
    FP_Game            *game     = DQN_CAST(FP_Game *) platform->user_data;
    TELY_RFui          *rfui     = &game->rfui;

    TELY_Render_ClearColourV3(renderer, TELY_COLOUR_BLACK_MIDNIGHT_V4.rgb);
    TELY_Render_PushFont(renderer, game->jetbrains_mono_font);

    TELY_RFui_FrameSetup(rfui, &platform->frame_arena);
    TELY_RFui_PushFont(rfui, game->jetbrains_mono_font);
    TELY_RFui_PushLabelColourV4(rfui, TELY_COLOUR_WHITE_PALE_GOLDENROD_V4);

    // =============================================================================================

    game->prev_clicked_entity = game->clicked_entity;
    game->prev_hot_entity     = game->hot_entity;
    game->prev_active_entity  = game->active_entity;
    game->hot_entity          = {};
    game->active_entity       = {};
    Dqn_FArray_Clear(&game->parent_entity_stack);
    Dqn_FArray_Add(&game->parent_entity_stack, game->root_entity->handle);

    Dqn_M2x3 model_view  = FP_Game_CameraModelViewM2x3(game->camera, platform);
    TELY_Render_PushTransform(renderer, model_view);
    Dqn_V2 world_mouse_p = Dqn_M2x3_MulV2(model_view, input->mouse_p);

    // =============================================================================================

    TELY_Audio *audio = &platform->audio;
    if (audio->playback_size == 0) {
        TELY_Audio_Play(audio, game->test_audio, 1.f /*volume*/);
    }

    // =============================================================================================

    if (TELY_Platform_InputKeyWasDown(input->mouse_left) && TELY_Platform_InputKeyIsDown(input->mouse_left)) {
        if (game->prev_active_entity.id)
            game->active_entity = game->prev_active_entity;
    } else {
        for (FP_GameEntityIterator it = {}; FP_Game_DFSPreOrderWalkEntityTree(game, &it, game->root_entity); ) {
            FP_GameEntity *entity = it.entity;
            if (entity->local_hit_box_size.x <= 0 || entity->local_hit_box_size.y <= 0)
                continue;

            if ((entity->flags & FP_GameEntityFlag_Clickable) == 0)
                continue;

            Dqn_Rect world_hit_box = FP_Game_CalcEntityWorldHitBox(game, entity->handle);
            if (!Dqn_Rect_ContainsPoint(world_hit_box, world_mouse_p))
                continue;

            game->hot_entity = entity->handle;
            if (TELY_Platform_InputKeyIsPressed(input->mouse_left)) {
                game->active_entity  = entity->handle;
                game->clicked_entity = entity->handle;
            }
        }
    }

    for (game->delta_s_accumulator += DQN_CAST(Dqn_f32)input->delta_s;
         game->delta_s_accumulator > PHYSICS_STEP;
         game->delta_s_accumulator -= PHYSICS_STEP) {
        FP_Update(platform, game, input);
    }

    FP_Render(game, platform, renderer);

    // NOTE: UI ====================================================================================
    {
        TELY_Render_PushTransform(renderer, Dqn_M2x3_Identity());
        DQN_DEFER { TELY_Render_PopTransform(renderer); };

        // NOTE: Info bar ==========================================================================
        {
            TELY_RFuiResult info_bar = TELY_RFui_Row(rfui, DQN_STRING8("Info Bar"));
            info_bar.widget->semantic_position[TELY_RFuiAxis_X].kind  = TELY_RFuiPositionKind_Absolute;
            info_bar.widget->semantic_position[TELY_RFuiAxis_X].value = 10.f;
            info_bar.widget->semantic_position[TELY_RFuiAxis_Y].kind  = TELY_RFuiPositionKind_Absolute;
            info_bar.widget->semantic_position[TELY_RFuiAxis_Y].value = 10.f;

            TELY_RFui_PushParent(rfui, info_bar.widget);
            DQN_DEFER { TELY_RFui_PopParent(rfui); };

            Dqn_ThreadScratch scratch  = Dqn_Thread_GetScratch(nullptr);
            TELY_RFui_TextF(rfui, "TELY");
            if (Dqn_String8_IsValid(platform->core.os_name)) {
                TELY_RFui_TextF(rfui, " | %.*s", DQN_STRING_FMT(platform->core.os_name));
            }

            TELY_RFui_TextF(rfui,
                            " | %dx%d %.1fHz | TSC %.1f GHz",
                            platform->core.display.size.w,
                            platform->core.display.size.h,
                            platform->core.display.refresh_rate,
                            platform->core.tsc_per_second / 1'000'000'000.0);

            if (platform->core.ram_mb)
                TELY_RFui_TextF(rfui, " | RAM %.1fGB", platform->core.ram_mb / 1024.0);

            TELY_RFui_TextF(rfui,
                            " | Work %04.1fms/f (%04.1f%%) | %05.1f FPS | Frame %'I64u | Timer %.1fs",
                            input->work_ms,
                            input->work_ms * 100.0 / input->delta_ms,
                            1000.0 / input->delta_ms,
                            input->frame_counter,
                            input->timer_s);
        }

        // NOTE: Profiler
        {
            TELY_RFuiResult profiler_layout = TELY_RFui_Column(rfui, DQN_STRING8("Profiler Bar"));
            profiler_layout.widget->semantic_position[TELY_RFuiAxis_X].kind  = TELY_RFuiPositionKind_Absolute;
            profiler_layout.widget->semantic_position[TELY_RFuiAxis_X].value = 10.f;
            profiler_layout.widget->semantic_position[TELY_RFuiAxis_Y].kind  = TELY_RFuiPositionKind_Absolute;
            profiler_layout.widget->semantic_position[TELY_RFuiAxis_Y].value = TELY_Asset_GetFont(assets, TELY_RFui_ActiveFont(rfui))->pixel_height * 1.5f;

            TELY_RFui_PushParent(rfui, profiler_layout.widget);
            DQN_DEFER { TELY_RFui_PopParent(rfui); };

            Dqn_ProfilerAnchor *anchors = Dqn_Profiler_AnchorBuffer(Dqn_ProfilerAnchorBuffer_Back);
            for (size_t anchor_index = 1; anchor_index < DQN_PROFILER_ANCHOR_BUFFER_SIZE; anchor_index++) {
                Dqn_ProfilerAnchor const *anchor   = anchors + anchor_index;
                if (!anchor->hit_count)
                    continue;

                uint64_t tsc_exclusive             = anchor->tsc_exclusive;
                uint64_t tsc_inclusive             = anchor->tsc_inclusive;
                Dqn_f64 tsc_exclusive_milliseconds = tsc_exclusive * 1000 / DQN_CAST(Dqn_f64)platform->core.tsc_per_second;
                if (tsc_exclusive == tsc_inclusive) {
                    TELY_RFui_TextF(rfui,
                                    "%.*s[%u]: %.1fms",
                                    DQN_STRING_FMT(anchor->name),
                                    anchor->hit_count,
                                    tsc_exclusive_milliseconds);
                } else {
                    Dqn_f64 tsc_inclusive_milliseconds        = tsc_inclusive * 1000 / DQN_CAST(Dqn_f64)platform->core.tsc_per_second;
                    TELY_RFui_TextF(rfui,
                                    "%.*s[%u]: %.1f/%.1fms",
                                    DQN_STRING_FMT(anchor->name),
                                    anchor->hit_count,
                                    tsc_exclusive_milliseconds,
                                    tsc_inclusive_milliseconds);
                }
            }
        }
    }

    TELY_RFui_Flush(rfui, renderer, input, assets);
    //TELY_Audio_MixPlaybackSamples(audio, assets);
}