#include "sim.h"
#include "sim_ent.h"
#include "sim_client.h"
#include "sim_msg.h"
#include "sim_snapshot.h"
#include "sys.h"
#include "util.h"
#include "sprite.h"
#include "math.h"
#include "scratch.h"
#include "atomic.h"
#include "app.h"
#include "log.h"
#include "phys.h"
#include "collider.h"
#include "rng.h"
#include "space.h"
#include "byteio.h"
#include "host.h"

/* ========================== *
 * Ctx
 * ========================== */


struct sim_ctx *sim_ctx_alloc(struct sprite_startup_receipt *sprite_sr,
                              struct phys_startup_receipt *phys_sr,
                              struct host_startup_receipt *host_sr,
                              u16 host_port)
{
    struct arena arena = arena_alloc(GIGABYTE(64));
    struct sim_ctx *ctx = arena_push_zero(&arena, struct sim_ctx);
    ctx->arena = arena;

    (UNUSED)sprite_sr;
    (UNUSED)phys_sr;
    (UNUSED)host_sr;

    /* Intialize host */
    ctx->host = host_alloc(host_port);

    /* Create bookkeeping */
    ctx->contact_lookup = sim_ent_lookup_alloc(4096);
#if COLLIDER_DEBUG
    ctx->collision_debug_lookup = sim_ent_lookup_alloc(4096);
#endif
    ctx->space = space_alloc(SPACE_CELL_SIZE, SPACE_CELL_BUCKETS_SQRT);

    /* Create emtpy snapshot */
    sim_snapshot_alloc(&ctx->world);
    ctx->world.world_timescale = SIM_TIMESCALE;

    return ctx;
}

void sim_ctx_release(struct sim_ctx *ctx)
{
    __prof;

    /* Release snapshot */
    sim_snapshot_release(&ctx->world);

    /* Release bookkeeping */
    space_release(ctx->space);
#if COLLIDER_DEBUG
    sim_ent_lookup_release(&ctx->collision_debug_lookup);
#endif
    sim_ent_lookup_release(&ctx->contact_lookup);

    host_release(ctx->host);
    arena_release(&ctx->arena);
}

/* ========================== *
 * Test
 * ========================== */

/* TODO: Remove this */

INTERNAL void spawn_test_entities(struct sim_ctx *ctx)
{
    struct sim_ent *root = sim_ent_from_handle(ctx->world.ent_store, ctx->world.ent_store->root);
    root->mass_unscaled = F32_INFINITY;
    root->inertia_unscaled = F32_INFINITY;

    /* Enemy */
    {
        struct sim_ent *e = sim_ent_alloc(root);

        struct v2 pos = V2(1, -2);
        f32 r = 0;
        struct v2 size = V2(1, 1);
        struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
        sim_ent_set_xform(e, xf);

        e->sprite = sprite_tag_from_path(LIT("res/graphics/tim.ase"));
        e->sprite_collider_slice = LIT("shape");
        e->layer = SIM_LAYER_SHOULDERS;

        sim_ent_enable_prop(e, SIM_ENT_PROP_PHYSICAL_DYNAMIC);
        e->mass_unscaled = 10;
        e->inertia_unscaled = 10;
        e->linear_ground_friction = 250;
        e->angular_ground_friction = 200;
    }


    /* Big box */
#if 0
    {
        struct sim_ent *e = sim_ent_alloc(root);

        struct v2 pos = V2(1, -0.5);
        f32 r = 0;
        struct v2 size = V2(0.5, 0.25);
        struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
        sim_ent_set_xform(e, xf);

        e->sprite = sprite_tag_from_path(LIT("res/graphics/box.ase"));
        e->sprite_collider_slice = LIT("shape");
        e->layer = SIM_LAYER_SHOULDERS;

        sim_ent_enable_prop(e, SIM_ENT_PROP_PHYSICAL_DYNAMIC);
        e->mass_unscaled = 100;
        e->inertia_unscaled = 10;
        e->linear_ground_friction = 100;
        e->angular_ground_friction = 5;
    }
#endif

    /* Tiny box */
#if 0
    {
        struct sim_ent *e = sim_ent_alloc(root);

        struct v2 pos = V2(1, -0.5);
        f32 r = PI / 4;
        struct v2 size = V2(0.5, 0.25);
        struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
        sim_ent_set_xform(e, xf);

        e->sprite = sprite_tag_from_path(LIT("res/graphics/bullet.ase"));
        e->sprite_collider_slice = LIT("shape");
        e->layer = SIM_LAYER_SHOULDERS;

        sim_ent_enable_prop(e, SIM_ENT_PROP_PHYSICAL_DYNAMIC);
        e->mass_unscaled = 0.5;
        e->inertia_unscaled = 1000;
        e->linear_ground_friction = 0.001;
    }
#endif
}

INTERNAL struct sim_ent *spawn_test_player(struct sim_ctx *ctx)
{
    struct sim_ent_store *store = ctx->world.ent_store;
    struct sim_ent *root = sim_ent_from_handle(store, store->root);

    /* Player */
    struct sim_ent *player_ent = sim_ent_nil();
    //if (!ctx->extra_spawn) {
    {

        struct sim_ent *e = sim_ent_alloc(root);

        struct v2 pos = V2(1, -1);

        //struct v2 size = V2(0.5, 0.5);
        //struct v2 size = V2(0.5, 0.25);
        struct v2 size = V2(1.0, 1.0);

        //f32 r = PI / 4;
        f32 r = 0;

        {
            sim_ent_enable_prop(e, SIM_ENT_PROP_TEST);
            e->sprite = sprite_tag_from_path(LIT("res/graphics/tim.ase"));
            e->mass_unscaled = 10;
            e->inertia_unscaled = 5;
        }

        e->local_collider.points[0] = v2_with_len(V2(0.08f, 0.17f), 0.15f);
        e->local_collider.points[1] = v2_with_len(V2(-0.07f, -0.2f), 0.15f);
        e->local_collider.count = 2;
        e->local_collider.radius = 0.075f;

        //e->sprite = sprite_tag_from_path(LIT("res/graphics/box_rounded.ase"));
        //e->sprite_span_name = LIT("idle.unarmed");
        //e->sprite_span_name = LIT("idle.one_handed");
        e->sprite_span_name = LIT("idle.two_handed");
        e->layer = SIM_LAYER_SHOULDERS;

        struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
        //xf.bx.y = -1.f;

        sim_ent_set_xform(e, xf);

        e->linear_ground_friction = 250;
        e->angular_ground_friction = 200;

        //e->control_force = 500;
        e->control_force = 500;
        //e->control_force_max_speed = 4;
        e->control_torque = 5000;
        e->control_force_max_speed = 4;

        sim_ent_enable_prop(e, SIM_ENT_PROP_PHYSICAL_DYNAMIC);

        player_ent = e;
    }

    /* Player weapon */
    if (player_ent->valid) {
        struct sim_ent *e = sim_ent_alloc(player_ent);
        e->sprite = sprite_tag_from_path(LIT("res/graphics/gun.ase"));

        sim_ent_enable_prop(e, SIM_ENT_PROP_ATTACHED);
        e->attach_slice = LIT("attach.wep");
        e->layer = SIM_LAYER_RELATIVE_WEAPON;

        sim_ent_enable_prop(e, SIM_ENT_PROP_WEAPON);
        e->trigger_delay = 1.0f / 10.0f;
        //e->trigger_delay = 1.0f / 100.0f;

        player_ent->equipped = e->handle;
    }

    return player_ent;
}

INTERNAL struct sim_ent *spawn_test_player_camera(struct sim_ctx *ctx, struct sim_ent *player_ent)
{
    struct sim_ent_store *store = ctx->world.ent_store;
    struct sim_ent *root = sim_ent_from_handle(store, store->root);

    struct sim_ent *camera_ent = sim_ent_nil();
    if (player_ent->valid) {
        camera_ent = sim_ent_alloc(root);
        sim_ent_set_xform(camera_ent, XFORM_IDENT);

        sim_ent_enable_prop(camera_ent, SIM_ENT_PROP_CAMERA);
        sim_ent_enable_prop(camera_ent, SIM_ENT_PROP_CAMERA_ACTIVE);
        camera_ent->camera_follow = player_ent->handle;

        f32 width = (f32)DEFAULT_CAMERA_WIDTH;
        f32 height = (f32)DEFAULT_CAMERA_HEIGHT;
        camera_ent->camera_quad_xform = XFORM_TRS(.s = V2(width, height));
    }

    return camera_ent;
}

/* ========================== *
 * Release entities
 * ========================== */

INTERNAL void release_entities_with_prop(struct sim_ctx *ctx, enum sim_ent_prop prop)
{
    struct temp_arena scratch = scratch_begin_no_conflict();
    struct sim_ent_store *store = ctx->world.ent_store;
    struct space *space = ctx->space;

    struct sim_ent **ents_to_release = arena_dry_push(scratch.arena, struct sim_ent *);
    u64 ents_to_release_count = 0;
    for (u64 ent_index = 0; ent_index < store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &store->entities[ent_index];
        if (!ent->valid) continue;

        if (sim_ent_has_prop(ent, prop)) {
            *arena_push(scratch.arena, struct sim_ent *) = ent;
            ++ents_to_release_count;
        }
    }

    /* Release references */
    for (u64 i = 0; i < ents_to_release_count; ++i) {
        struct sim_ent *ent = ents_to_release[i];
        /* Release space entry */
        {
            struct space_entry *space_entry = space_entry_from_handle(space, ent->space_handle);
            if (space_entry->valid) {
                space_entry_release(space_entry);
            }
        }
    }

    /* Release from store */
    /* TODO: Breadth first iteration to only release parent entities (since
     * child entities will be released along with parent anyway) */
    for (u64 i = 0; i < ents_to_release_count; ++i) {
        struct sim_ent *ent = ents_to_release[i];
        if (ent->valid) {
            sim_ent_release(store, ent);
        }
    }

    scratch_end(scratch);
}

/* ========================== *
 * Respond to physics collisions
 * ========================== */

INTERNAL PHYS_COLLISION_CALLBACK_FUNC_DEF(on_collision, collision_data_array, udata)
{
    struct sim_ctx *ctx = (struct sim_ctx *)udata;
    struct sim_ent_store *store = ctx->world.ent_store;
    struct sim_ent *root = sim_ent_from_handle(store, store->root);

    for (u64 i = 0; i < collision_data_array.count; ++i) {
        struct phys_collision_data *data = &collision_data_array.a[i];

        struct phys_contact_constraint *constraint = data->constraint;
        struct sim_ent *e0 = sim_ent_from_handle(store, data->e0);
        struct sim_ent *e1 = sim_ent_from_handle(store, data->e1);

        if (sim_ent_is_valid_and_active(e0) && sim_ent_is_valid_and_active(e1)) {
            /* Bullet hit entity */
            if (sim_ent_has_prop(e0, SIM_ENT_PROP_BULLET) || sim_ent_has_prop(e1, SIM_ENT_PROP_BULLET)) {
                struct v2 normal = data->normal;        /* Impact normal */
                struct v2 vrel = v2_neg(data->vrel);    /* Impact velocity */

                struct sim_ent *target = e0;
                struct sim_ent *bullet = e1;
                if (sim_ent_has_prop(e0, SIM_ENT_PROP_BULLET)) {
                    target = e1;
                    bullet = e0;
                    normal = v2_neg(normal);
                    vrel = v2_neg(vrel);
                }
                struct sim_ent *src = sim_ent_from_handle(store, bullet->bullet_src);

                if (bullet->bullet_has_hit || sim_ent_handle_eq(src->top, target->top)) {
                    /* Ignore collision if bullet already spent or if weapon and
                     * target share same top level parent */
                    /* NOTE: Since bullet is most likely just a sensor skip_solve is probably already true */
                    constraint->skip_solve = true;
                } else {
                    struct v2 point = data->point;

                    /* Update bullet */
                    bullet->bullet_has_hit = true;
                    sim_ent_enable_prop(bullet, SIM_ENT_PROP_RELEASE_THIS_TICK);

                    /* Update tracer */
                    struct sim_ent *tracer = sim_ent_from_handle(store, bullet->bullet_tracer);
                    if (sim_ent_is_valid_and_active(tracer)) {
                        struct xform xf = sim_ent_get_xform(tracer);
                        xf.og = point;
                        sim_ent_set_xform(tracer, xf);
                        sim_ent_set_linear_velocity(tracer, V2(0, 0));
                    }

                    /* Update target */
                    struct v2 knockback = v2_mul(v2_norm(vrel), bullet->bullet_knockback);
                    sim_ent_apply_linear_impulse(target, knockback, point);

                    /* Create test blood */
                    /* TODO: Remove this */
                    {
                        struct xform xf = XFORM_TRS(.t = point, .r = rng_rand_f32(0, TAU));
                        struct sim_ent *decal = sim_ent_alloc(root);
                        decal->sprite = sprite_tag_from_path(LIT("res/graphics/blood.ase"));
                        decal->sprite_tint = RGBA_32_F(1, 1, 1, 0.25f);
                        decal->layer = SIM_LAYER_FLOOR_DECALS;
                        sim_ent_set_xform(decal, xf);

                        f32 perp_range = 0.5;
                        struct v2 linear_velocity = v2_mul(normal, 0.5);
                        linear_velocity = v2_add(linear_velocity, v2_mul(v2_perp(normal), rng_rand_f32(-perp_range, perp_range)));

                        f32 angular_velocity_range = 5;
                        f32 angular_velocity = rng_rand_f32(-angular_velocity_range, angular_velocity_range);

                        sim_ent_enable_prop(decal, SIM_ENT_PROP_PHYSICAL_KINEMATIC);
                        sim_ent_set_linear_velocity(decal, linear_velocity);
                        sim_ent_set_angular_velocity(decal, angular_velocity);

                        decal->linear_damping = 5.0f;
                        decal->angular_damping = 5.0f;
                    }
                }
            }
        }
    }
}

/* ========================== *
 * Update
 * ========================== */

void sim_update(struct sim_ctx *ctx, i64 target_dt_ns)
{
    __prof;

    struct temp_arena scratch = scratch_begin_no_conflict();

    /* ========================== *
     * Begin frame
     * ========================== */

    ++ctx->world.tick;

    ctx->world.real_dt_ns = max_i64(0, target_dt_ns);
    ctx->world.real_time_ns += ctx->world.real_dt_ns;

    ctx->world.world_dt_ns = max_i64(0, target_dt_ns * ctx->world.world_timescale);
    ctx->world.world_time_ns += ctx->world.world_dt_ns;

    f64 sim_time = SECONDS_FROM_NS(ctx->world.world_time_ns);
    ctx->sprite_frame_scope = sprite_scope_begin();

    f64 real_dt = SECONDS_FROM_NS(ctx->world.real_dt_ns);
    f64 real_time = SECONDS_FROM_NS(ctx->world.real_time_ns);
    f64 world_dt = SECONDS_FROM_NS(ctx->world.world_dt_ns);
    f64 world_time = SECONDS_FROM_NS(ctx->world.world_time_ns);
    (UNUSED)real_dt;
    (UNUSED)real_time;
    (UNUSED)world_dt;
    (UNUSED)world_time;

    struct sim_ent *root = sim_ent_from_handle(ctx->world.ent_store, ctx->world.ent_store->root);;
    struct sim_ent_store *ent_store = ctx->world.ent_store;
    struct space *space = ctx->space;
    struct sprite_scope *sprite_frame_scope = ctx->sprite_frame_scope;

    /* ========================== *
     * Spawn test entities
     * ========================== */

     /* TODO: remove this (testing) */
     /* Initialize entities */
    {
        static b32 run = 0;
        if (!run) {
            run = 1;
            spawn_test_entities(ctx);
        }
    }

    /* ========================== *
     * Release entities
     * ========================== */

    release_entities_with_prop(ctx, SIM_ENT_PROP_RELEASE_NEXT_TICK);

    /* ========================== *
     * Activate entities
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!ent->valid) continue;

        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_ACTIVE)) {
            u64 atick = ent->activation_tick;
            if (atick != 0 || ctx->world.tick >= atick) {
                sim_ent_activate(ent, ctx->world.tick);
            }
        }
    }

    /* ========================== *
     * Reset triggered entities
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;

        if (sim_ent_has_prop(ent, SIM_ENT_PROP_TRIGGER_NEXT_TICK)) {
            sim_ent_disable_prop(ent, SIM_ENT_PROP_TRIGGER_NEXT_TICK);
            sim_ent_enable_prop(ent, SIM_ENT_PROP_TRIGGERED_THIS_TICK);
        } else if (sim_ent_has_prop(ent, SIM_ENT_PROP_TRIGGERED_THIS_TICK)) {
            sim_ent_disable_prop(ent, SIM_ENT_PROP_TRIGGERED_THIS_TICK);
        }
    }

    /* ========================== *
     * Process host events into sim cmds
     * ========================== */

    struct sim_cmd_list *client_cmds;
    {
        host_update(ctx->host);
        struct host_event_array host_events = host_pop_events(scratch.arena, ctx->host);

        struct sim_cmd_list sim_cmds = ZI;
        sim_cmds_from_host_events(scratch.arena, host_events, &sim_cmds);

        /* Create connecting clients */
        for (struct sim_cmd *cmd = sim_cmds.first; cmd; cmd = cmd->next) {
            enum sim_cmd_kind kind = cmd->kind;
            struct host_channel_id channel_id = cmd->channel_id;
            struct sim_client *client = sim_client_from_channel_id(ctx->world.client_store, channel_id);
            if (!client->valid && kind == SIM_CMD_KIND_SIM_CLIENT_CONNECT && !host_channel_id_is_nil(channel_id)) {
                client = sim_client_alloc(ctx->world.client_store, channel_id);
                /* TODO: Create player ent not here */
                /* FIXME: Player ent never released upon disconnect */
                struct sim_ent *player_ent = spawn_test_player(ctx);
                sim_ent_enable_prop(player_ent, SIM_ENT_PROP_CONTROLLED);
                struct sim_ent *camera_ent = spawn_test_player_camera(ctx, player_ent);
                client->control_ent = player_ent->handle;
                client->camera_ent = camera_ent->handle;
                player_ent->controlling_client = client->handle;
            }
        }

        /* Split cmds by client */
        client_cmds = arena_push_array_zero(scratch.arena, struct sim_cmd_list, ctx->world.client_store->num_reserved);
        {
            struct sim_cmd *cmd = sim_cmds.first;
            while (cmd) {
                struct sim_cmd *next = cmd->next;
                struct host_channel_id channel_id = cmd->channel_id;
                struct sim_client *client = sim_client_from_channel_id(ctx->world.client_store, channel_id);
                if (client->valid) {
                    struct sim_cmd_list *cmd_list = &client_cmds[client->handle.idx];
                    if (cmd_list->last) {
                        cmd_list->last->next = cmd;
                    } else {
                        cmd_list->first = cmd;
                    }
                    cmd_list->last = cmd;
                    cmd->next = NULL;
                }
                cmd = next;
            }
        }
    }

    /* ========================== *
     * Process sim cmds
     * ========================== */

    /* Process client cmds */
    for (u64 i = 0; i < ctx->world.client_store->num_reserved; ++i) {
        struct sim_client *client = &ctx->world.client_store->clients[i];
        if (client->valid) {
            struct host_channel_id channel_id = client->channel_id;
            struct sim_cmd_list cmds = client_cmds[client->handle.idx];
            struct sim_control *control = &client->control;

            client->dbg_drag_start = false;
            client->dbg_drag_stop = false;

            for (struct sim_cmd *cmd = cmds.first; cmd; cmd = cmd->next) {
                enum sim_cmd_kind kind = cmd->kind;
                b32 start = cmd->state == SIM_CMD_STATE_START;
                b32 stop = cmd->state == SIM_CMD_STATE_STOP;
                switch (kind) {
                    /* TODO: Combine movement from multiple inputs? E.ctx-> a sudden
                     * start and immediate stop cmd should still move the player a
                     * tad. */
                    case SIM_CMD_KIND_PLAYER_CONTROL:
                    {
                        struct v2 move = cmd->move_dir;
                        struct v2 focus = cmd->aim_dir;
                        if (v2_len_sq(move) > 1) {
                            /* Cap movement vector magnitude at 1 */
                            move = v2_norm(move);
                        }
                        control->move = move;
                        control->focus = focus;
                    } break;

                    case SIM_CMD_KIND_PLAYER_FIRE:
                    {
                        /* TODO: Allow sub-tick firing (start & stop on same tick should still fire for one tick */
                        b32 firing = control->firing;
                        if (start) {
                            firing = true;
                        }
                        if (stop) {
                            firing = false;
                        }
                        control->firing = firing;
                    } break;

                    /* Cursor */
                    case SIM_CMD_KIND_CURSOR_MOVE:
                    {
                        client->cursor_pos = cmd->cursor_pos;
                    } break;

                    case SIM_CMD_KIND_DRAG_OBJECT:
                    {
                        if (cmd->state == SIM_CMD_STATE_START) {
                            client->dbg_drag_start = true;
                        } else if (cmd->state == SIM_CMD_STATE_STOP) {
                            client->dbg_drag_stop = true;
                        }
                    } break;

                    /* Clear level */
                    case SIM_CMD_KIND_CLEAR_ALL:
                    {
                        /* TODO */
                    } break;

                    /* Spawn test */
                    case SIM_CMD_KIND_SPAWN_TEST:
                    {
                        logf_info("Spawning (test)");
                        spawn_test_entities(ctx);
                    } break;

                    /* Disconnect client */
                    case SIM_CMD_KIND_SIM_CLIENT_DISCONNECT:
                    {
                        host_queue_disconnect(ctx->host, channel_id);
                        sim_client_release(client);
                    } break;

                    default: break;
                };
            }
        }
    }

    /* ========================== *
     * Update entity control from client control
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;

        if (sim_ent_has_prop(ent, SIM_ENT_PROP_CONTROLLED)) {
            struct sim_client *client = sim_client_from_handle(ctx->world.client_store, ent->controlling_client);
            if (client->valid) {
                ent->control = client->control;
                /* TODO: Move this */
                if (ent->control.firing) {
                    sim_ent_enable_prop(ent, SIM_ENT_PROP_TRIGGERING_EQUIPPED);
                } else {
                    sim_ent_disable_prop(ent, SIM_ENT_PROP_TRIGGERING_EQUIPPED);
                }
            }
        }
    }

    /* ========================== *
     * Update entities from sprite
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (sprite_tag_is_nil(ent->sprite)) continue;

        /* Update animation */

        struct sprite_sheet *sheet = sprite_sheet_from_tag_await(sprite_frame_scope, ent->sprite);
        {
            struct sprite_sheet_span span = sprite_sheet_get_span(sheet, ent->sprite_span_name);

            f64 time_in_frame = ent->animation_time_in_frame + world_dt;
            u64 frame_index = ent->animation_frame;
            if (frame_index < span.start || frame_index > span.end) {
                frame_index = span.start;
            }

            struct sprite_sheet_frame frame = sprite_sheet_get_frame(sheet, frame_index);
            while (time_in_frame > frame.duration) {
                time_in_frame -= frame.duration;
                ++frame_index;
                if (frame_index > span.end) {
                    /* Loop animation */
                    frame_index = span.start;
                }
                frame = sprite_sheet_get_frame(sheet, frame_index);
            }

            ent->animation_time_in_frame = time_in_frame;
            ent->animation_frame = frame_index;
        }

        /* Update sprite local xform */
        {
            struct sprite_sheet_slice slice = sprite_sheet_get_slice(sheet, LIT("pivot"), ent->animation_frame);
            struct v2 sprite_size = v2_div(sheet->frame_size, (f32)IMAGE_PIXELS_PER_UNIT);

            struct v2 dir = v2_mul_v2(sprite_size, slice.dir);
            f32 rot = v2_angle(dir) + PI / 2;

            struct xform xf = XFORM_IDENT;
            xf = xform_rotated(xf, -rot);
            xf = xform_scaled(xf, sprite_size);
            xf = xform_translated(xf, v2_neg(slice.center));
            ent->sprite_local_xform = xf;
        }

        /* Update collider from sprite */
        if (ent->sprite_collider_slice.len > 0) {
            struct xform cxf = ent->sprite_local_xform;

            struct sprite_sheet_slice slice = sprite_sheet_get_slice(sheet, ent->sprite_collider_slice, ent->animation_frame);
            ent->local_collider = collider_from_quad(xform_mul_quad(cxf, quad_from_rect(slice.rect)));
        }

        /* Test collider */
#if 0
        if (sim_ent_has_prop(ent, SIM_ENT_PROP_TEST)) {
            //if ((true)) {
#if 0
            ent->local_collider.points[0] = V2(0, 0);
            ent->local_collider.count = 1;
            ent->local_collider.radius = 0.5;
#elif 0
            ent->local_collider.points[0] = v2_with_len(V2(0.08f, 0.17f), 0.15f);
            ent->local_collider.points[1] = v2_with_len(V2(-0.07f, -0.2f), 0.15f);
            ent->local_collider.count = 2;
            ent->local_collider.radius = 0.075f;
#elif 1
#if 0
                /* "Bad" winding order */
            ent->local_collider.points[0] = V2(-0.15, 0.15);
            ent->local_collider.points[1] = V2(0.15, 0.15);
            ent->local_collider.points[2] = V2(0, -0.15);
#else
            ent->local_collider.points[0] = V2(0, -0.15);
            ent->local_collider.points[1] = V2(0.15, 0.15);
            ent->local_collider.points[2] = V2(-0.15, 0.15);
#endif
            ent->local_collider.count = 3;
            ent->local_collider.radius = 0.25;
            //ent->local_collider.radius = math_fabs(math_sin(ctx->tick.time) / 3);
#else
                //ent->local_collider.radius = 0.5;
            ent->local_collider.radius = 0.25;
            //ent->local_collider.radius = 0.;
#endif
        }
#endif
    }

    /* ========================== *
     * Update attachments
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_ATTACHED)) continue;

        struct sim_ent *parent = sim_ent_from_handle(ent_store, ent->parent);
        struct sprite_tag parent_sprite = parent->sprite;
        struct sprite_sheet *parent_sheet = sprite_sheet_from_tag_await(sprite_frame_scope, parent_sprite);

        struct xform parent_sprite_xf = parent->sprite_local_xform;

        struct sprite_sheet_slice attach_slice = sprite_sheet_get_slice(parent_sheet, ent->attach_slice, parent->animation_frame);
        struct v2 attach_pos = xform_mul_v2(parent_sprite_xf, attach_slice.center);
        struct v2 attach_dir = xform_basis_mul_v2(parent_sprite_xf, attach_slice.dir);

        struct xform xf = sim_ent_get_local_xform(ent);
        xf.og = attach_pos;
        xf = xform_basis_with_rotation_world(xf, v2_angle(attach_dir) + PI / 2);
        sim_ent_set_local_xform(ent, xf);
    }

    /* ========================== *
     * Test
     * ========================== */

#if 0
    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_TEST)) continue;

#if 0
        if (!ent->test_initialized) {
            ent->test_initialized = true;
            ent->test_start_local_xform = sim_ent_get_local_xform(ent);
            ent->test_start_sprite_xform = ent->sprite_local_xform;
        }

        f32 t = (f32)time;
        struct v2 og = v2_mul(V2(math_cos(t), math_sin(t)), 3);
        f32 r = t * 3;
        struct v2 s = V2(1 + (math_fabs(math_sin(t * 5)) * 3), 1);
        (UNUSED)og;
        (UNUSED)r;
        (UNUSED)s;

        og = v2_add(og, ent->test_start_local_xform.og);
        r += xform_get_rotation(ent->test_start_local_xform);
        s = v2_add(s, xform_get_scale(ent->test_start_local_xform));

        struct xform xf = sim_ent_get_local_xform(ent);
        xf.og = og;
        xf = xform_rotated_to(xf, r);
        xf = xform_scaled_to(xf, s);
        sim_ent_set_local_xform(ent, xf);
#else
        f32 t = (f32)time;
        struct v2 og = v2_mul(V2(math_cos(t), math_sin(t)), 3);
        f32 rot = t * PI / 3;
        struct v2 scale = V2(1 + (math_fabs(math_sin(t * 5)) * 3), 1);
        (UNUSED)og;
        (UNUSED)rot;
        (UNUSED)scale;

        struct xform xf = sim_ent_get_local_xform(ent);
        xf = xform_rotated_to(xf, rot);
        xf = xform_scaled_to(xf, scale);
        sim_ent_set_local_xform(ent, xf);
#endif
    }
#endif

    /* ========================== *
     * Trigger equipped
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;

        if (sim_ent_has_prop(ent, SIM_ENT_PROP_TRIGGERING_EQUIPPED)) {
            struct sim_ent *eq = sim_ent_from_handle(ent_store, ent->equipped);
            if (sim_ent_is_valid_and_active(eq)) {
                sim_ent_enable_prop(eq, SIM_ENT_PROP_TRIGGERED_THIS_TICK);
            }
        }
    }

    /* ========================== *
     * Process triggered entities
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_TRIGGERED_THIS_TICK)) continue;
        if ((sim_time - ent->last_triggered < ent->trigger_delay) && ent->last_triggered != 0) continue;

        ent->last_triggered = sim_time;

        /* Fire weapon */
        if (sim_ent_has_prop(ent, SIM_ENT_PROP_WEAPON)) {
            struct sprite_tag sprite = ent->sprite;
            u32 animation_frame = ent->animation_frame;
            struct sprite_sheet *sheet = sprite_sheet_from_tag_await(sprite_frame_scope, sprite);

            struct xform sprite_local_xform = ent->sprite_local_xform;

            struct sprite_sheet_slice out_slice = sprite_sheet_get_slice(sheet, LIT("out"), animation_frame);
            struct v2 rel_pos = xform_mul_v2(sprite_local_xform, out_slice.center);
            struct v2 rel_dir = xform_basis_mul_v2(sprite_local_xform, out_slice.dir);

            /* Spawn bullet */
            struct sim_ent *bullet;
            {
                bullet = sim_ent_alloc(root);

                bullet->bullet_src = ent->handle;
                bullet->bullet_src_pos = rel_pos;
                bullet->bullet_src_dir = rel_dir;
                bullet->bullet_impulse = 0.75f;
                bullet->bullet_knockback = 10;
                bullet->mass_unscaled = 0.04f;
                bullet->inertia_unscaled = 0.00001f;
                bullet->layer = SIM_LAYER_BULLETS;

#if 1
                /* Point collider */
                bullet->local_collider.points[0] = V2(0, 0);
                bullet->local_collider.count = 1;
#else
                bullet->sprite = sprite_tag_from_path(LIT("res/graphics/bullet.ase"));
                bullet->sprite_collider_slice = LIT("shape");
#endif

                sim_ent_enable_prop(bullet, SIM_ENT_PROP_BULLET);
                sim_ent_enable_prop(bullet, SIM_ENT_PROP_SENSOR);
            }

            /* Spawn tracer */
            {
                struct sim_ent *tracer = sim_ent_alloc(root);
                tracer->tracer_fade_duration = 0.025f;
                tracer->layer = SIM_LAYER_TRACERS;
                sim_ent_enable_prop(tracer, SIM_ENT_PROP_TRACER);

                bullet->bullet_tracer = tracer->handle;
            }
        }
    }

    /* ========================== *
     * Create motor joints from control move
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;

        if (sim_ent_has_prop(ent, SIM_ENT_PROP_CONTROLLED)) {
            struct sim_ent *joint_ent = sim_ent_from_handle(ent_store, ent->move_joint);
            if (!sim_ent_is_valid_and_active(joint_ent)) {
                joint_ent = sim_ent_alloc(root);
                joint_ent->mass_unscaled = F32_INFINITY;
                joint_ent->inertia_unscaled = F32_INFINITY;
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_MOTOR_JOINT);
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_ACTIVE);
                ent->move_joint = joint_ent->handle;

                struct phys_motor_joint_def def = ZI;
                def.e0 = joint_ent->handle;  /* Re-using joint entity as e0 */
                def.e1 = ent->handle;
                def.correction_rate = 0;
                def.max_force = ent->control_force;
                def.max_torque = 0;
                joint_ent->motor_joint_data = phys_motor_joint_from_def(def);
            }

            sim_ent_set_xform(joint_ent, XFORM_IDENT);  /* Reset joint ent position */
            sim_ent_set_linear_velocity(joint_ent, v2_mul(v2_clamp_len(ent->control.move, 1), ent->control_force_max_speed));
        }
    }

    /* ========================== *
     * Create motor joints from control focus (aim)
     * ========================== */

#if SIM_PLAYER_AIM
    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;

        if (sim_ent_has_prop(ent, SIM_ENT_PROP_CONTROLLED)) {
            struct xform xf = sim_ent_get_xform(ent);
            struct xform sprite_xf = xform_mul(xf, ent->sprite_local_xform);

            /* Retrieve / create aim joint */
            struct sim_ent *joint_ent = sim_ent_from_handle(ent_store, ent->aim_joint);
            if (!sim_ent_is_valid_and_active(joint_ent)) {
                joint_ent = sim_ent_alloc(root);
                joint_ent->mass_unscaled = F32_INFINITY;
                joint_ent->inertia_unscaled = F32_INFINITY;
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_PHYSICAL_KINEMATIC);  /* Since we'll be setting velocity */
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_MOTOR_JOINT);
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_ACTIVE);
                ent->aim_joint = joint_ent->handle;

                struct phys_motor_joint_def def = ZI;
                def.e0 = joint_ent->handle;  /* Re-using joint entity as e0 */
                def.e1 = ent->handle;
                def.max_force = 0;
                def.max_torque = ent->control_torque;
                joint_ent->motor_joint_data = phys_motor_joint_from_def(def);
            }

            /* Set correction rate dynamically since motor velocity is only set for one frame */
            joint_ent->motor_joint_data.correction_rate = 10 * world_dt;


            /* Solve for final angle using law of sines */
            f32 new_angle;
            {
                struct v2 ent_pos = xf.og;
                struct v2 focus_pos = v2_add(ent_pos, ent->control.focus);

                struct v2 sprite_hold_pos;
                struct v2 sprite_hold_dir;
                {
                    struct sprite_sheet *sheet = sprite_sheet_from_tag_await(sprite_frame_scope, ent->sprite);
                    struct sprite_sheet_slice slice = sprite_sheet_get_slice(sheet, LIT("attach.wep"), ent->animation_frame);
                    sprite_hold_pos = slice.center;
                    sprite_hold_dir = slice.dir;
                }

                struct v2 hold_dir = xform_basis_mul_v2(sprite_xf, sprite_hold_dir);
                struct v2 hold_pos = xform_mul_v2(sprite_xf, sprite_hold_pos);
                if (v2_eq(hold_pos, ent_pos)) {
                    /* If hold pos is same as origin (E.G if pivot is being used as hold pos), then move hold pos forward a tad to avoid issue */
                    sprite_hold_pos = v2_add(sprite_hold_pos, V2(0, -1));
                    hold_pos = xform_mul_v2(sprite_xf, sprite_hold_pos);
                }

                f32 forward_hold_angle_offset;
                {
                    struct xform xf_unrotated = xform_basis_with_rotation_world(xf, 0);
                    struct v2 hold_pos_unrotated = xform_mul_v2(xf_unrotated, xform_mul_v2(ent->sprite_local_xform, sprite_hold_pos));
                    forward_hold_angle_offset = v2_angle_from_dirs(V2(0, -1), v2_sub(hold_pos_unrotated, xf_unrotated.og));
                }

                struct v2 hold_ent_dir = v2_sub(ent_pos, hold_pos);
                struct v2 focus_ent_dir = v2_sub(ent_pos, focus_pos);

                f32 hold_ent_len = v2_len(hold_ent_dir);
                f32 focus_ent_len = v2_len(focus_ent_dir);

                f32 final_hold_angle_btw_ent_and_focus = v2_angle_from_dirs(hold_ent_dir, hold_dir);
                f32 final_focus_angle_btw_ent_and_hold = math_asin((math_sin(final_hold_angle_btw_ent_and_focus) * hold_ent_len) / focus_ent_len);
                f32 final_ent_angle_btw_focus_and_hold = PI - (final_focus_angle_btw_ent_and_hold + final_hold_angle_btw_ent_and_focus);

                new_angle = math_unwind_angle(v2_angle_from_dirs(V2(0, -1), v2_sub(focus_pos, ent_pos)) + final_ent_angle_btw_focus_and_hold - forward_hold_angle_offset);
            }

            f32 new_vel = 0;
            if (!F32_IS_NAN(new_angle)) {
                const f32 angle_error_allowed = 0.001f;
                struct xform joint_xf = sim_ent_get_xform(joint_ent);
                f32 diff = math_unwind_angle(new_angle - xform_get_rotation(joint_xf));
                if (math_fabs(diff) > angle_error_allowed) {
                    /* Instantly snap joint ent to new angle */
                    new_vel = diff / real_dt;
                }
            }
            sim_ent_set_angular_velocity(joint_ent, new_vel);
        }
    }
#endif

    /* ========================== *
     * Create motor joints from ground friction (gravity)
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_PHYSICAL_DYNAMIC)) continue;

        struct sim_ent *joint_ent = sim_ent_from_handle(ent_store, ent->ground_friction_joint);

        struct phys_motor_joint_def def = ZI;
        def.e0 = root->handle;
        def.e1 = ent->handle;
        def.correction_rate = 0;
        def.max_force = ent->linear_ground_friction;
        def.max_torque = ent->angular_ground_friction;
        if (joint_ent->motor_joint_data.max_force != def.max_force || joint_ent->motor_joint_data.max_torque != def.max_torque) {
            if (!sim_ent_is_valid_and_active(joint_ent)) {
                joint_ent = sim_ent_alloc(root);
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_MOTOR_JOINT);
                sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_ACTIVE);
                joint_ent->motor_joint_data = phys_motor_joint_from_def(def);
                ent->ground_friction_joint = joint_ent->handle;
            }
        }
    }

    /* ========================== *
     * Create mouse joints from client debug drag
     * ========================== */

    for (u64 i = 0; i < ctx->world.client_store->num_reserved; ++i) {
        struct sim_client *client = &ctx->world.client_store->clients[i];
        if (client->valid) {
            struct v2 cursor = client->cursor_pos;
            b32 start_dragging = client->dbg_drag_start;
            b32 stop_dragging = client->dbg_drag_stop;

            struct sim_ent *joint_ent = sim_ent_from_handle(ent_store, client->dbg_drag_joint_ent);
            struct sim_ent *target_ent = sim_ent_from_handle(ent_store, joint_ent->mouse_joint_data.target);

            if (start_dragging) {
                struct xform mouse_xf = xform_from_pos(cursor);
                struct collider_shape mouse_shape = ZI;
                mouse_shape.points[0] = V2(0, 0);
                mouse_shape.count = 1;

                for (u64 sim_ent_index = 0; sim_ent_index < ent_store->num_reserved; ++sim_ent_index) {
                    struct sim_ent *ent = &ent_store->entities[sim_ent_index];
                    if (!sim_ent_is_valid_and_active(ent)) continue;
                    if (!sim_ent_has_prop(ent, SIM_ENT_PROP_PHYSICAL_DYNAMIC)) continue;

                    struct collider_shape ent_collider = ent->local_collider;
                    if (ent_collider.count > 0) {
                        struct xform ent_xf = sim_ent_get_xform(ent);
                        /* TODO: Can just use boolean GJK */
                        struct collider_collision_points_result res = collider_collision_points(&ent_collider, &mouse_shape, ent_xf, mouse_xf);
                        if (res.num_points > 0) {
                            target_ent = ent;
                            break;
                        }
                    }
                }
            }
            if (stop_dragging) {
                target_ent = sim_ent_nil();
            }

            if (sim_ent_is_valid_and_active(target_ent)) {
                if (!sim_ent_is_valid_and_active(joint_ent)) {
                    /* FIXME: Joint ent never released */
                    joint_ent = sim_ent_alloc(root);
                    joint_ent->mass_unscaled = F32_INFINITY;
                    joint_ent->inertia_unscaled = F32_INFINITY;
                    client->dbg_drag_joint_ent = joint_ent->handle;
                    sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_MOUSE_JOINT);
                    sim_ent_enable_prop(joint_ent, SIM_ENT_PROP_ACTIVE);
                }
                struct xform xf = sim_ent_get_xform(target_ent);
                f32 mass = target_ent->mass_unscaled * math_fabs(xform_get_determinant(xf));

                struct phys_mouse_joint_def def = ZI;
                def.target = target_ent->handle;
                if (!sim_ent_handle_eq(joint_ent->mouse_joint_data.target, target_ent->handle)) {
                    def.point_local_start = xform_invert_mul_v2(xf, cursor);
                }
                def.point_local_end = xform_invert_mul_v2(xf, cursor);
                def.max_force = mass * 1000;
                joint_ent->mouse_joint_data = phys_mouse_joint_from_def(def);
            } else if (sim_ent_is_valid_and_active(joint_ent)) {
                joint_ent->mouse_joint_data.target = target_ent->handle;
            }
        }
    }

    /* ========================== *
     * Physics
     * ========================== */

    {
        struct phys_ctx phys = ZI;
        phys.tick = ctx->world.tick;
        phys.store = ent_store;
        phys.space = space;
        phys.contact_lookup = &ctx->contact_lookup;
        phys.pre_solve_callback = on_collision;
        phys.pre_solve_callback_udata = ctx;
#if COLLIDER_DEBUG
        phys.debug_lookup = &phys->collision_debug_lookup;
#endif

        /* Step */
        ctx->last_phys_iteration = phys_step(&phys, world_dt, ctx->last_phys_iteration);
    }

    /* ========================== *
     * Update tracers
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_TRACER)) continue;

        struct v2 end = sim_ent_get_xform(ent).og;

        struct v2 tick_velocity = v2_mul(ent->tracer_start_velocity, world_dt);
        struct v2 gradient_start = v2_add(ent->tracer_gradient_start, tick_velocity);
        struct v2 gradient_end = v2_add(ent->tracer_gradient_end, tick_velocity);

        if (v2_dot(tick_velocity, v2_sub(gradient_start, end)) > 0) {
            /* Tracer has disappeared */
            sim_ent_enable_prop(ent, SIM_ENT_PROP_RELEASE_NEXT_TICK);
        }

        ent->tracer_gradient_start = gradient_start;
        ent->tracer_gradient_end = gradient_end;
    }

    /* ========================== *
     * Initialize bullet kinematics from sources
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_BULLET)) continue;

        if (ent->activation_tick == ctx->world.tick) {
            struct sim_ent *src = sim_ent_from_handle(ent_store, ent->bullet_src);
            struct xform src_xf = sim_ent_get_xform(src);

            struct v2 pos = xform_mul_v2(src_xf, ent->bullet_src_pos);
            struct v2 impulse = xform_basis_mul_v2(src_xf, ent->bullet_src_dir);
            impulse = v2_with_len(impulse, ent->bullet_impulse);

#if 0
            /* Add shooter velocity to bullet */
            {
                /* TODO: Add angular velocity as well? */
                struct sim_ent *top = sim_ent_from_handle(ent_store, src->top);
                impulse = v2_add(impulse, v2_mul(top->linear_velocity, dt));
            }
#endif

            struct xform xf = XFORM_TRS(.t = pos, .r = v2_angle(impulse) + PI / 2);
            sim_ent_set_xform(ent, xf);
            sim_ent_enable_prop(ent, SIM_ENT_PROP_PHYSICAL_KINEMATIC);

            sim_ent_apply_linear_impulse_to_center(ent, impulse);

            /* Initialize tracer */
            struct sim_ent *tracer = sim_ent_from_handle(ent_store, ent->bullet_tracer);
            if (sim_ent_is_valid_and_active(tracer)) {
                sim_ent_set_xform(tracer, xf);
                sim_ent_enable_prop(tracer, SIM_ENT_PROP_PHYSICAL_KINEMATIC);
                sim_ent_set_linear_velocity(tracer, ent->linear_velocity);
                tracer->tracer_start = pos;
                tracer->tracer_start_velocity = ent->linear_velocity;
                tracer->tracer_gradient_end = pos;
                tracer->tracer_gradient_start = v2_sub(pos, v2_mul(ent->linear_velocity, tracer->tracer_fade_duration));
            }

            /* Spawn quake */
            {
                struct sim_ent *quake = sim_ent_alloc(root);
                sim_ent_set_xform(quake, XFORM_POS(pos));
                quake->quake_intensity = 0.2f;
                quake->quake_fade = quake->quake_intensity / 0.1f;
                sim_ent_enable_prop(quake, SIM_ENT_PROP_QUAKE);
            }
        }
    }

    /* ========================== *
     * Update cameras
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_CAMERA)) continue;

        struct xform xf = sim_ent_get_xform(ent);

        /* Camera follow */
        {
            struct sim_ent *follow = sim_ent_from_handle(ent_store, ent->camera_follow);

            f32 aspect_ratio = 1.0;
            {
                struct xform quad_xf = xform_mul(sim_ent_get_xform(ent), ent->camera_quad_xform);
                struct v2 camera_size = xform_get_scale(quad_xf);
                if (!v2_is_zero(camera_size)) {
                    aspect_ratio = camera_size.x / camera_size.y;
                }
            }
            f32 ratio_y = 0.33f;
            f32 ratio_x = ratio_y / aspect_ratio;
            struct v2 camera_focus_dir = v2_mul_v2(follow->control.focus, V2(ratio_x, ratio_y));
            struct v2 camera_focus_pos = v2_add(sim_ent_get_xform(follow).og, camera_focus_dir);
            ent->camera_xform_target = xf;
            ent->camera_xform_target.og = camera_focus_pos;

            /* Lerp camera */
            if (ent->camera_applied_lerp_continuity_gen_plus_one == ent->camera_lerp_continuity_gen + 1) {
                f32 t = 1 - math_pow(2.f, -20.f * (f32)world_dt);
                xf = xform_lerp(xf, ent->camera_xform_target, t);
            } else {
                /* Skip lerp */
                xf = ent->camera_xform_target;
            }
            ent->camera_applied_lerp_continuity_gen_plus_one = ent->camera_lerp_continuity_gen + 1;
        }

        /* Camera shake */
        {
            /* TODO: Update based on distance to quake */
            ent->shake = 0;
            for (u64 quake_ent_index = 0; quake_ent_index < ent_store->num_reserved; ++quake_ent_index) {
                struct sim_ent *quake = &ent_store->entities[quake_ent_index];
                if (!sim_ent_is_valid_and_active(quake)) continue;
                if (!sim_ent_has_prop(quake, SIM_ENT_PROP_QUAKE)) continue;
                ent->shake += quake->quake_intensity;
            }
        }

        sim_ent_set_xform(ent, xf);
    }

    /* ========================== *
     * Update quakes
     * ========================== */

    for (u64 ent_index = 0; ent_index < ent_store->num_reserved; ++ent_index) {
        struct sim_ent *ent = &ent_store->entities[ent_index];
        if (!sim_ent_is_valid_and_active(ent)) continue;
        if (!sim_ent_has_prop(ent, SIM_ENT_PROP_QUAKE)) continue;

        ent->quake_intensity = max_f32(0, ent->quake_intensity - (ent->quake_fade * world_dt));
        if (ent->quake_intensity <= 0) {
            sim_ent_enable_prop(ent, SIM_ENT_PROP_RELEASE_NEXT_TICK);
        }
    }

    /* ========================== *
     * Update relative layers
     * ========================== */

    {
        struct temp_arena temp = arena_temp_begin(scratch.arena);

        struct sim_ent **stack = arena_push(temp.arena, struct sim_ent *);
        u64 stack_count = 1;
        *stack = root;

        while (stack_count > 0) {
            struct sim_ent *parent;
            arena_pop(temp.arena, struct sim_ent *, &parent);
            --stack_count;

            i32 parent_layer = parent->final_layer;
            for (struct sim_ent *child = sim_ent_from_handle(ent_store, parent->first); child->valid; child = sim_ent_from_handle(ent_store, child->next)) {
                if (sim_ent_is_valid_and_active(child)) {
                    child->final_layer = parent_layer + child->layer;
                    *arena_push(temp.arena, struct sim_ent *) = child;
                    ++stack_count;
                }
            }
        }

        arena_temp_end(temp);
    }

    /* ========================== *
     * Release entities
     * ========================== */

    release_entities_with_prop(ctx, SIM_ENT_PROP_RELEASE_THIS_TICK);

    /* ========================== *
     * Publish tick
     * ========================== */

    for (u64 i = 0; i < ctx->world.client_store->num_reserved; ++i) {
        struct sim_client *client = &ctx->world.client_store->clients[i];
        if (client->valid) {
            struct temp_arena temp = arena_temp_begin(scratch.arena);

            /* TODO: Not like this */
            struct sim_event snapshot_event = ZI;
            snapshot_event.tick = ctx->world.tick;
            snapshot_event.kind = SIM_EVENT_KIND_SNAPSHOT;
            snapshot_event.snapshot_data = sim_snapshot_encode(temp.arena, client, &ctx->world);

            struct sim_event_list l = ZI;
            l.first = &snapshot_event;
            l.last = &snapshot_event;
            struct string msg = sim_string_from_events(temp.arena, l);

            host_queue_write(ctx->host, client->channel_id, msg, 0);
            //host_queue_write(ctx->host, HOST_CHANNEL_ID_ALL, msg, 0);

            arena_temp_end(temp);
        }
    }

    host_update(ctx->host);
    __profframe("Sim");

    /* ========================== *
     * End frame cache scopes
     * ========================== */

    sprite_scope_end(sprite_frame_scope);

    scratch_end(scratch);
}