Momentum-Apps/game/enemy.c

// enemy.c
#include <game/enemy.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#define EPSILON 0.1f

static EnemyContext *enemy_context_generic;

// Allocation function
static EnemyContext *enemy_generic_alloc(
    const char *id,
    int index,
    Vector size,
    Vector start_position,
    Vector end_position,
    float move_timer, // Wait duration before moving again
    float speed,
    float attack_timer,
    float strength,
    float health)
{
    if (!enemy_context_generic)
    {
        enemy_context_generic = malloc(sizeof(EnemyContext));
    }
    if (!enemy_context_generic)
    {
        FURI_LOG_E("Game", "Failed to allocate EnemyContext");
        return NULL;
    }
    snprintf(enemy_context_generic->id, sizeof(enemy_context_generic->id), "%s", id);
    enemy_context_generic->index = index;
    enemy_context_generic->size = size;
    enemy_context_generic->start_position = start_position;
    enemy_context_generic->end_position = end_position;
    enemy_context_generic->move_timer = move_timer;   // Set wait duration
    enemy_context_generic->elapsed_move_timer = 0.0f; // Initialize elapsed timer
    enemy_context_generic->speed = speed;
    enemy_context_generic->attack_timer = attack_timer;
    enemy_context_generic->strength = strength;
    enemy_context_generic->health = health;
    // Initialize other fields as needed
    enemy_context_generic->sprite_right = NULL;         // Assign appropriate sprite
    enemy_context_generic->sprite_left = NULL;          // Assign appropriate sprite
    enemy_context_generic->direction = ENEMY_RIGHT;     // Default direction
    enemy_context_generic->state = ENEMY_MOVING_TO_END; // Start in IDLE state
    // Set radius based on size, for example, average of size.x and size.y divided by 2
    enemy_context_generic->radius = (size.x + size.y) / 4.0f;
    return enemy_context_generic;
}

// Free function
static void enemy_generic_free(void *context)
{
    if (!context)
    {
        FURI_LOG_E("Game", "Enemy generic free: Invalid context");
        return;
    }
    free(context);
    context = NULL;
    if (enemy_context_generic)
    {
        free(enemy_context_generic);
        enemy_context_generic = NULL;
    }
}

// Enemy start function
static void enemy_start(Entity *self, GameManager *manager, void *context)
{
    UNUSED(manager);
    if (!self || !context)
    {
        FURI_LOG_E("Game", "Enemy start: Invalid parameters");
        return;
    }
    if (!enemy_context_generic)
    {
        FURI_LOG_E("Game", "Enemy start: Enemy context not set");
        return;
    }

    EnemyContext *enemy_context = (EnemyContext *)context;
    // Copy fields from generic context
    snprintf(enemy_context->id, sizeof(enemy_context->id), "%s", enemy_context_generic->id);
    enemy_context->index = enemy_context_generic->index;
    enemy_context->size = enemy_context_generic->size;
    enemy_context->start_position = enemy_context_generic->start_position;
    enemy_context->end_position = enemy_context_generic->end_position;
    enemy_context->move_timer = enemy_context_generic->move_timer;
    enemy_context->elapsed_move_timer = enemy_context_generic->elapsed_move_timer;
    enemy_context->speed = enemy_context_generic->speed;
    enemy_context->attack_timer = enemy_context_generic->attack_timer;
    enemy_context->strength = enemy_context_generic->strength;
    enemy_context->health = enemy_context_generic->health;
    enemy_context->sprite_right = enemy_context_generic->sprite_right;
    enemy_context->sprite_left = enemy_context_generic->sprite_left;
    enemy_context->direction = enemy_context_generic->direction;
    enemy_context->state = enemy_context_generic->state;
    enemy_context->radius = enemy_context_generic->radius;

    // Set enemy's initial position based on start_position
    entity_pos_set(self, enemy_context->start_position);

    // Add collision circle based on the enemy's radius
    entity_collider_add_circle(self, enemy_context->radius);
}

// Enemy render function
static void enemy_render(Entity *self, GameManager *manager, Canvas *canvas, void *context)
{
    UNUSED(manager);
    if (!self || !context || !canvas)
        return;

    EnemyContext *enemy_context = (EnemyContext *)context;

    // Get the position of the enemy
    Vector pos = entity_pos_get(self);

    // Choose sprite based on direction
    Sprite *current_sprite = NULL;
    if (enemy_context->direction == ENEMY_LEFT)
    {
        current_sprite = enemy_context->sprite_left;
    }
    else
    {
        current_sprite = enemy_context->sprite_right;
    }

    // Draw enemy sprite relative to camera, centered on the enemy's position
    canvas_draw_sprite(
        canvas,
        current_sprite,
        pos.x - camera_x - (enemy_context->size.x / 2),
        pos.y - camera_y - (enemy_context->size.y / 2));
}

// Enemy collision function
static void enemy_collision(Entity *self, Entity *other, GameManager *manager, void *context)
{
    if (!self || !other || !context)
    {
        FURI_LOG_E("Game", "Enemy collision: Invalid parameters");
        return;
    }

    // Check if the enemy collided with the player
    if (entity_description_get(other) == &player_desc)
    {

        // Retrieve enemy context
        EnemyContext *enemy_context = (EnemyContext *)context;
        if (!enemy_context)
        {
            FURI_LOG_E("Game", "Enemy collision: EnemyContext is NULL");
            return;
        }

        // Get positions of the enemy and the player
        Vector enemy_pos = entity_pos_get(self);
        Vector player_pos = entity_pos_get(other);

        // Determine if the enemy is facing the player
        bool is_facing_player = false;

        if (enemy_context->direction == ENEMY_LEFT && player_pos.x < enemy_pos.x)
        {
            is_facing_player = true;
            enemy_context->state = ENEMY_ATTACKING;
        }
        else if (enemy_context->direction == ENEMY_RIGHT && player_pos.x > enemy_pos.x)
        {
            is_facing_player = true;
            enemy_context->state = ENEMY_ATTACKING;
        }

        // If the enemy is facing the player, perform an attack (log message)
        if (is_facing_player)
        {
            FURI_LOG_I("Game", "Enemy '%s' attacked the player!", enemy_context->id);

            // Decrease player health
            GameContext *game_context = game_manager_game_context_get(manager);
            if (game_context)
            {
                if (game_context->player_context->health <= 0)
                {
                    FURI_LOG_I("Game", "Player is dead.. resetting player position and health");
                    game_context->player_context->state = PLAYER_DEAD;

                    // reset player position and health
                    entity_pos_set(other, game_context->player_context->start_position);
                    game_context->player_context->health = 100;
                }
                else
                {
                    FURI_LOG_I("Game", "Player took %f damage from enemy '%s'", (double)enemy_context->strength, enemy_context->id);
                    game_context->player_context->health -= enemy_context->strength;
                    game_context->player_context->state = PLAYER_ATTACKED;
                }
            }
            else
            {
                FURI_LOG_E("Game", "Enemy collision: Failed to get GameContext");
            }
        }

        // Reset enemy's position and state
        entity_pos_set(self, enemy_context->start_position);
        enemy_context->state = ENEMY_IDLE;
        enemy_context->elapsed_move_timer = 0.0f;

        FURI_LOG_D("Game", "Enemy '%s' reset to start position after collision", enemy_context->id);
    }
}

// Enemy update function
static void enemy_update(Entity *self, GameManager *manager, void *context)
{
    if (!self || !context || !manager)
        return;

    EnemyContext *enemy_context = (EnemyContext *)context;

    GameContext *game_context = game_manager_game_context_get(manager);
    if (!game_context)
    {
        FURI_LOG_E("Game", "Enemy update: Failed to get GameContext");
        return;
    }

    float delta_time = 1.0f / game_context->fps;

    switch (enemy_context->state)
    {
    case ENEMY_IDLE:
        // Increment the elapsed_move_timer
        enemy_context->elapsed_move_timer += delta_time;

        // Check if it's time to move again
        if (enemy_context->elapsed_move_timer >= enemy_context->move_timer)
        {
            // Determine the next state based on the current position
            Vector current_pos = entity_pos_get(self);
            if (fabs(current_pos.x - enemy_context->start_position.x) < (double)EPSILON &&
                fabs(current_pos.y - enemy_context->start_position.y) < (double)EPSILON)
            {
                enemy_context->state = ENEMY_MOVING_TO_END;
            }
            else
            {
                enemy_context->state = ENEMY_MOVING_TO_START;
            }
            enemy_context->elapsed_move_timer = 0.0f;

            FURI_LOG_D("Game", "Enemy %s transitioning to state %d", enemy_context->id, enemy_context->state);
        }
        break;

    case ENEMY_MOVING_TO_END:
    case ENEMY_MOVING_TO_START:
    {
        // Determine the target position based on the current state
        Vector target_position = (enemy_context->state == ENEMY_MOVING_TO_END) ? enemy_context->end_position : enemy_context->start_position;

        // Get current position
        Vector current_pos = entity_pos_get(self);
        Vector direction_vector = {0, 0};

        // Calculate direction towards the target
        if (current_pos.x < target_position.x)
        {
            direction_vector.x = 1.0f;
            enemy_context->direction = ENEMY_RIGHT;
        }
        else if (current_pos.x > target_position.x)
        {
            direction_vector.x = -1.0f;
            enemy_context->direction = ENEMY_LEFT;
        }

        if (current_pos.y < target_position.y)
        {
            direction_vector.y = 1.0f;
            enemy_context->direction = ENEMY_DOWN;
        }
        else if (current_pos.y > target_position.y)
        {
            direction_vector.y = -1.0f;
            enemy_context->direction = ENEMY_UP;
        }

        // Normalize direction vector
        float length = sqrt(direction_vector.x * direction_vector.x + direction_vector.y * direction_vector.y);
        if (length != 0)
        {
            direction_vector.x /= length;
            direction_vector.y /= length;
        }

        // Update position based on direction and speed
        Vector new_pos = current_pos;
        new_pos.x += direction_vector.x * enemy_context->speed * delta_time;
        new_pos.y += direction_vector.y * enemy_context->speed * delta_time;

        // Clamp the position to the target to prevent overshooting
        if ((direction_vector.x > 0.0f && new_pos.x > target_position.x) ||
            (direction_vector.x < 0.0f && new_pos.x < target_position.x))
        {
            new_pos.x = target_position.x;
        }

        if ((direction_vector.y > 0.0f && new_pos.y > target_position.y) ||
            (direction_vector.y < 0.0f && new_pos.y < target_position.y))
        {
            new_pos.y = target_position.y;
        }

        entity_pos_set(self, new_pos);

        // Check if the enemy has reached or surpassed the target_position
        bool reached_x = fabs(new_pos.x - target_position.x) < (double)EPSILON;
        bool reached_y = fabs(new_pos.y - target_position.y) < (double)EPSILON;

        // If reached the target position on both axes, transition to IDLE
        if (reached_x && reached_y)
        {
            enemy_context->state = ENEMY_IDLE;
            enemy_context->elapsed_move_timer = 0.0f;

            FURI_LOG_D("Game", "Enemy %s reached target and transitioning to IDLE", enemy_context->id);
        }
    }
    break;

    default:
        FURI_LOG_E("Game", "Enemy update: Unknown state %d", enemy_context->state);
        break;
    }
}

// Free function for the entity
static void enemy_free(Entity *self, GameManager *manager, void *context)
{
    UNUSED(self);
    UNUSED(manager);
    enemy_generic_free(context);
}

// Enemy behavior structure
static const EntityDescription _generic_enemy = {
    .start = enemy_start,
    .stop = enemy_free,
    .update = enemy_update,
    .render = enemy_render,
    .collision = enemy_collision,
    .event = NULL,
    .context_size = sizeof(EnemyContext),
};

// Enemy function to return the entity description
const EntityDescription *enemy(
    GameManager *manager,
    const char *id,
    int index,
    Vector size,
    Vector start_position,
    Vector end_position,
    float move_timer, // Wait duration before moving again
    float speed,
    float attack_timer,
    float strength,
    float health)
{
    // Allocate a new EnemyContext with provided parameters
    enemy_context_generic = enemy_generic_alloc(
        id,
        index,
        size,
        start_position,
        end_position,
        move_timer, // Set wait duration
        speed,
        attack_timer,
        strength,
        health);
    if (!enemy_context_generic)
    {
        FURI_LOG_E("Game", "Failed to allocate EnemyContext");
        return NULL;
    }
    char right_edited[64];
    char left_edited[64];
    snprintf(right_edited, sizeof(right_edited), "%s_right.fxbm", id);
    snprintf(left_edited, sizeof(left_edited), "%s_left.fxbm", id);

    enemy_context_generic->sprite_right = game_manager_sprite_load(manager, right_edited);
    enemy_context_generic->sprite_left = game_manager_sprite_load(manager, left_edited);

    // Set initial direction based on start and end positions
    if (start_position.x < end_position.x)
    {
        enemy_context_generic->direction = ENEMY_RIGHT;
    }
    else
    {
        enemy_context_generic->direction = ENEMY_LEFT;
    }

    // Set initial state based on movement
    if (start_position.x != end_position.x || start_position.y != end_position.y)
    {
        enemy_context_generic->state = ENEMY_MOVING_TO_END;
    }
    else
    {
        enemy_context_generic->state = ENEMY_IDLE;
    }

    return &_generic_enemy;
}