#include <algorithm>
#include <stdlib.h>
#include <stdio.h>
#include "glad/glad.h"
#include <GLFW/glfw3.h>

#include "stb_image.h"

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/constants.hpp>

#include <iostream>
#include <filesystem>
#include <vector>
#include <deque>
#include <math.h>

#include "collisions.h"
#include "player.h"
#include "shader.h"
#include "ghost.h"
#include "text.h"
#include "config.h"

// Forward declarations for GLFW callbacks configured at start-up.
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void set_light_front(int xoffset, int yoffset);

// player
Player *player;

// settings
unsigned int WINDOWWIDTH = 1600;
unsigned int WINDOWHEIGHT = 900;

// camera
bool first_frame = false;
float timed = 0.0f;
float last_frame = 0.0f;

float camera_speed = 20.0f;
float ghost_reset_distance = 10.0f;
int ghost_count = 800;

// Runtime configuration and palette for the minimap overlay.
struct MinimapConfig {
    bool enabled = true;
    int width = 200;
    int height = 200;
    int margin = 16;
    float zoom = 2.0f;
    glm::vec3 wall_color = glm::vec3(0.0f, 0.0f, 0.0f);
    glm::vec3 background_color = glm::vec3(1.0f, 1.0f, 1.0f);
    glm::vec3 arrow_color = glm::vec3(1.0f, 0.0f, 0.0f);
    float breadcrumb_radius = 3.0f;
    glm::vec3 breadcrumb_color = glm::vec3(1.0f, 0.3f, 0.3f);
    float breadcrumb_max_distance = 200.0f;
    float ghost_radius = 4.0f;
    glm::vec3 ghost_fill_color = glm::vec3(0.9f, 0.9f, 1.0f);
    glm::vec3 ghost_border_color = glm::vec3(0.2f, 0.2f, 0.4f);
};

struct MinimapSegment {
    glm::vec2 start;
    glm::vec2 end;
};

struct MinimapBounds {
    float xmin = 0.0f;
    float xmax = 0.0f;
    float zmin = 0.0f;
    float zmax = 0.0f;
};

struct TrailConfig {
    bool enabled = true;
    float lifetime_minutes = 3.0f;
    float sample_spacing = 1.0f;
    float width = 0.25f;
    float y_position = 0.06f;
    float simplify_epsilon = 0.15f;
    float reset_marker_size = 2.0f;
    glm::vec3 recent_color = glm::vec3(1.0f, 0.0f, 0.0f);
    glm::vec3 old_color = glm::vec3(0.35f, 0.18f, 0.05f);
};

struct TrailPoint {
    glm::vec3 position;
    float timestamp;
    // True for the first point after spawn/reset; prevents drawing teleport segments.
    bool starts_segment;
};

struct TrailVertex {
    glm::vec3 position;
    float timestamp;
};

struct TrailResetMarker {
    glm::vec3 position;
    // Player yaw at reset time, used to orient the flattened marker sprite.
    float yaw;
    float timestamp;
};

void render_minimap(const glm::vec3 &player_pos, float player_yaw, const std::deque<TrailPoint> &trail_points, const std::vector<Ghost *> &ghosts);
bool update_trail(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time);
bool end_trail_segment(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time);
bool begin_trail_segment(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time);
void add_trail_reset_marker(std::deque<TrailResetMarker> &reset_markers, const glm::vec3 &player_pos, float player_yaw, float current_time);
bool prune_trail_reset_markers(std::deque<TrailResetMarker> &reset_markers, float current_time);
void render_trail_reset_markers(int ghost_program, unsigned int ghostVAO, const std::deque<TrailResetMarker> &reset_markers);
void rebuild_trail_mesh(const std::deque<TrailPoint> &trail_points, std::vector<TrailVertex> &trail_vertices);
float distance_xz(const glm::vec3 &a, const glm::vec3 &b);
bool is_redundant_trail_point(const TrailPoint &a, const TrailPoint &b, const TrailPoint &c);
glm::vec2 trail_segment_direction(const std::deque<TrailPoint> &trail_points, size_t from_ix, size_t to_ix);
glm::vec3 trail_join_offset(const std::deque<TrailPoint> &trail_points, size_t point_ix, const glm::vec2 &fallback_normal, float half_width);

MinimapConfig minimap_config;
TrailConfig trail_config;
std::vector<MinimapSegment> minimap_segments;
MinimapBounds minimap_bounds;
unsigned int minimapVAO = 0;
unsigned int minimapVBO = 0;
int minimap_program = -1;

const char *projectionC = "projection";
const char *viewC = "view";
const char *modelC = "model";

const char *viewposC = "viewPos";
const char *shininessC = "material.shininess";
const char *colorC = "material.color";
const char *lightposC = "light.position";
const char *directionC = "light.direction";
const char *largecutoffC = "light.largecutoff";
const char *smallcutoffC = "light.smallcutoff";
const char *ambientC = "light.ambient";
const char *diffuseC = "light.diffuse";
const char *specularC = "light.specular";

int num_walls;
float *wall_vertices;

int main(int argc, char *argv[]) {

    int success;
    glm::vec3 position;
    glm::vec3 start_position;
    float start_yaw;

    // Load configuration knobs before spinning up the world.
    Config::loadFromFile("ghostland.json");
    camera_speed = Config::getFloat("camera_speed", camera_speed);
    ghost_reset_distance = Config::getFloat("ghost_reset_distance", ghost_reset_distance);
    minimap_config.enabled = Config::getInt("minimap_enabled", minimap_config.enabled ? 1 : 0) != 0;
    minimap_config.width = Config::getInt("minimap_width", minimap_config.width);
    minimap_config.height = Config::getInt("minimap_height", minimap_config.height);
    minimap_config.margin = Config::getInt("minimap_margin", minimap_config.margin);
    minimap_config.zoom = Config::getFloat("minimap_zoom", minimap_config.zoom);
    minimap_config.wall_color.r = Config::getFloat("minimap_wall_r", minimap_config.wall_color.r);
    minimap_config.wall_color.g = Config::getFloat("minimap_wall_g", minimap_config.wall_color.g);
    minimap_config.wall_color.b = Config::getFloat("minimap_wall_b", minimap_config.wall_color.b);
    minimap_config.background_color.r = Config::getFloat("minimap_background_r", minimap_config.background_color.r);
    minimap_config.background_color.g = Config::getFloat("minimap_background_g", minimap_config.background_color.g);
    minimap_config.background_color.b = Config::getFloat("minimap_background_b", minimap_config.background_color.b);
    minimap_config.arrow_color.r = Config::getFloat("minimap_arrow_r", minimap_config.arrow_color.r);
    minimap_config.arrow_color.g = Config::getFloat("minimap_arrow_g", minimap_config.arrow_color.g);
    minimap_config.arrow_color.b = Config::getFloat("minimap_arrow_b", minimap_config.arrow_color.b);
    minimap_config.breadcrumb_color.r = Config::getFloat("minimap_breadcrumb_r", minimap_config.breadcrumb_color.r);
    minimap_config.breadcrumb_color.g = Config::getFloat("minimap_breadcrumb_g", minimap_config.breadcrumb_color.g);
    minimap_config.breadcrumb_color.b = Config::getFloat("minimap_breadcrumb_b", minimap_config.breadcrumb_color.b);
    minimap_config.breadcrumb_radius = Config::getFloat("minimap_breadcrumb_radius", minimap_config.breadcrumb_radius);
    minimap_config.breadcrumb_max_distance = Config::getFloat("breadcrumb_max_distance", minimap_config.breadcrumb_max_distance);
    trail_config.enabled = Config::getInt("trail_enabled", trail_config.enabled ? 1 : 0) != 0;
    trail_config.lifetime_minutes = Config::getFloat("trail_lifetime_minutes", trail_config.lifetime_minutes);
    trail_config.sample_spacing = Config::getFloat("trail_sample_spacing", trail_config.sample_spacing);
    trail_config.width = Config::getFloat("trail_width", trail_config.width);
    trail_config.y_position = Config::getFloat("trail_y_offset", trail_config.y_position);
    trail_config.y_position = Config::getFloat("trail_y_position", trail_config.y_position);
    trail_config.simplify_epsilon = Config::getFloat("trail_simplify_epsilon", trail_config.simplify_epsilon);
    trail_config.reset_marker_size = Config::getFloat("trail_reset_marker_size", trail_config.reset_marker_size);
    trail_config.recent_color.r = Config::getFloat("trail_recent_r", trail_config.recent_color.r);
    trail_config.recent_color.g = Config::getFloat("trail_recent_g", trail_config.recent_color.g);
    trail_config.recent_color.b = Config::getFloat("trail_recent_b", trail_config.recent_color.b);
    trail_config.old_color.r = Config::getFloat("trail_old_r", trail_config.old_color.r);
    trail_config.old_color.g = Config::getFloat("trail_old_g", trail_config.old_color.g);
    trail_config.old_color.b = Config::getFloat("trail_old_b", trail_config.old_color.b);
    minimap_config.ghost_fill_color.r = Config::getFloat("minimap_ghost_fill_r", minimap_config.ghost_fill_color.r);
    minimap_config.ghost_fill_color.g = Config::getFloat("minimap_ghost_fill_g", minimap_config.ghost_fill_color.g);
    minimap_config.ghost_fill_color.b = Config::getFloat("minimap_ghost_fill_b", minimap_config.ghost_fill_color.b);
    minimap_config.ghost_border_color.r = Config::getFloat("minimap_ghost_border_r", minimap_config.ghost_border_color.r);
    minimap_config.ghost_border_color.g = Config::getFloat("minimap_ghost_border_g", minimap_config.ghost_border_color.g);
    minimap_config.ghost_border_color.b = Config::getFloat("minimap_ghost_border_b", minimap_config.ghost_border_color.b);
    minimap_config.ghost_radius = Config::getFloat("minimap_ghost_radius", minimap_config.ghost_radius);
    ghost_count = Config::getInt("ghost_count", ghost_count);

    // Maze file contains serialized spawn and wall mesh data generated by mazeparser.py.
    FILE *fp = fopen("maze.txt", "r");
    float yaw;
    if (fscanf(fp, "%f %f %f %f\n", &position.x, &position.y, &position.z, &yaw) == EOF) {
        printf("1st fscanf failed.\n");
        return -1;
    }
    start_position = position;
    start_yaw = yaw;
    player = new Player(position, yaw);
    if (fscanf(fp, "%d\n", &num_walls) == EOF) {
        printf("2nd fscanf failed.\n");
        return -1;
    }
    player->num_walls = num_walls;
    // num surfaces * 6 (vertices per point) * 6 (floats per point)
    int num_wall_vertices = num_walls * 6 * 6;
    wall_vertices = (float *)calloc(sizeof(float), num_wall_vertices);
    float xmin_wall, xmax_wall, zmin_wall, zmax_wall;
    xmin_wall = 9999.9;
    xmax_wall = -9999.9;
    zmin_wall = 9999.9;
    zmax_wall = -9999.9;
    // read walls
    for (int i = 0; i < num_walls; i++) {
        glm::vec2 wall_floor_pts[2];
        for (int j = 0; j < 6; j++) {
            int vix = i*6*6 + j*6;
            if (fscanf(
                fp,
                "%f %f %f %f %f %f\n",
                &wall_vertices[vix],
                &wall_vertices[vix+1],
                &wall_vertices[vix+2],
                &wall_vertices[vix+3],
                &wall_vertices[vix+4],
                &wall_vertices[vix+5]
            ) == EOF) {
                printf("3rd fscanf failed.\n");
                return -1;
            }
            if (wall_vertices[vix] < xmin_wall) {
                xmin_wall = wall_vertices[vix];
            } else if (wall_vertices[vix] > xmax_wall) {
                xmax_wall = wall_vertices[vix];
            }
            if (wall_vertices[vix + 2] < zmin_wall) {
                zmin_wall = wall_vertices[vix + 2];
            } else if (wall_vertices[vix + 2] > zmax_wall) {
                zmax_wall = wall_vertices[vix + 2];
            }
            if (j < 2) {
                wall_floor_pts[j].x = wall_vertices[vix];
                wall_floor_pts[j].y = wall_vertices[vix + 2];
                if (j == 1) {
                    minimap_segments.push_back({wall_floor_pts[0], wall_floor_pts[1]});
                }
            }
        }
        if (fscanf(fp, "\n") == EOF) {
            printf("4th fscanf failed.\n");
            return -1;
        }
    }
    player->wall_vertices = wall_vertices;
    minimap_bounds.xmin = xmin_wall;
    minimap_bounds.xmax = xmax_wall;
    minimap_bounds.zmin = zmin_wall;
    minimap_bounds.zmax = zmax_wall;

    // read floor
    float *floor_vertices = (float *)calloc(sizeof(float), 6*6);
    for (int j = 0; j < 6; j++) {
        int vix = j*6;
        if (fscanf(
            fp,
            "%f %f %f %f %f %f\n",
            &floor_vertices[vix],
            &floor_vertices[vix+1],
            &floor_vertices[vix+2],
            &floor_vertices[vix+3],
            &floor_vertices[vix+4],
            &floor_vertices[vix+5]
        ) == EOF) {
            printf("floor fscanf failed.\n");
            return -1;
        }
    }
    fclose(fp);

    // Initialize GLFW/GLAD and windowing.
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    GLFWmonitor *monitor = glfwGetPrimaryMonitor();
    const GLFWvidmode *monitor_mode = glfwGetVideoMode(monitor);

    WINDOWWIDTH = monitor_mode->width;
    WINDOWHEIGHT = monitor_mode->height;
    //WINDOWWIDTH = 1280;
    //WINDOWHEIGHT = 960;

    GLFWwindow* window = glfwCreateWindow(WINDOWWIDTH, WINDOWHEIGHT, "Ghostland!", monitor, NULL);
    //GLFWwindow* window = glfwCreateWindow(WINDOWWIDTH, WINDOWHEIGHT, "Ghostland!", NULL, NULL);
    if (window == NULL)
    {
        printf("Failed to create GLFW window.\n");
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    //glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
    glfwSetCursorPosCallback(window, mouse_callback);
    glfwSetScrollCallback(window, scroll_callback);

    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);

    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        printf("Failed to initialize GLAD.\n");
        glfwTerminate();
        return -1;
    }

    printf("OpenGL version: %s\n", glGetString(GL_VERSION));
    printf("GLSL version: %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));

    glEnable(GL_DEPTH_TEST);
    //glEnable(GL_CULL_FACE);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    int wall_program = create_shader_program("vertexshader.glsl", "fragmentshader.glsl");
    if (wall_program < 0) {
        glfwTerminate();
        return -1;
    }

    // Perhaps there's a better way of doing this, rather than re-compiling the same files?
    int floor_program = create_shader_program("vertexshader.glsl", "fragmentshader.glsl");
    if (floor_program < 0) {
        glfwTerminate();
        return -1;
    }

    // do stuff for walls
    unsigned int wallsVBO, wallsVAO;
    glGenVertexArrays(1, &wallsVAO);
    glGenBuffers(1, &wallsVBO);

    glBindVertexArray(wallsVAO);

    glBindBuffer(GL_ARRAY_BUFFER, wallsVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(float) * num_wall_vertices, wall_vertices, GL_STATIC_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    // normal attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    // do stuff for floor
    unsigned int floorVBO, floorVAO;
    glGenVertexArrays(1, &floorVAO);
    glGenBuffers(1, &floorVBO);

    glBindVertexArray(floorVAO);

    glBindBuffer(GL_ARRAY_BUFFER, floorVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 6 * 1, floor_vertices, GL_STATIC_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    // normal attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    // The trail is a dynamic ribbon mesh. Each vertex carries the timestamp of
    // its source path sample so the shader can fade red-to-brown by age.
    unsigned int trailVBO, trailVAO;
    glGenVertexArrays(1, &trailVAO);
    glGenBuffers(1, &trailVBO);

    glBindVertexArray(trailVAO);

    glBindBuffer(GL_ARRAY_BUFFER, trailVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(TrailVertex), NULL, GL_DYNAMIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(TrailVertex), (void *)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 1, GL_FLOAT, GL_FALSE, sizeof(TrailVertex), (void *)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    int trail_program = create_shader_program("trailshader.glsl", "trailfragshader.glsl");
    if (trail_program < 0) {
        glfwTerminate();
        return -1;
    }

    std::deque<TrailPoint> trail_points;
    std::vector<TrailVertex> trail_vertices;
    std::deque<TrailResetMarker> trail_reset_markers;
    bool trail_dirty = update_trail(trail_points, player->get_pos(), 0.0f);

    // do stuff for ghosts
    // create program
    int ghost_program = create_shader_program("ghostshader.glsl", "ghostfragshader.glsl");
    if (ghost_program < 0) {
        glfwTerminate();
        return -1;
    }
    // ghost vertices
    float ghost_vertices[] = {
        -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
         0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,
         0.5f,  0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
         0.5f,  0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
        -0.5f,  0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f,
        -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
    };
    unsigned int ghostVBO, ghostVAO;
    glGenVertexArrays(1, &ghostVAO);
    glBindVertexArray(ghostVAO);
    glGenBuffers(1, &ghostVBO);
    glBindBuffer(GL_ARRAY_BUFFER, ghostVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(ghost_vertices), ghost_vertices, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(6 * sizeof(float)));
    glEnableVertexAttribArray(2);
    // ghost texture
    unsigned int ghost_texture;
    glGenTextures(1, &ghost_texture);
    glBindTexture(GL_TEXTURE_2D, ghost_texture);
    // set the texture wrapping parameters
    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_);
    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // set texture filtering parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    int width, height, numberChannels;
    //stbi_set_flip_vertically_on_load(true);
    unsigned char *ghost_data = stbi_load("ghost_facing_right.png", &width, &height, &numberChannels, 0);
    printf("Num channels: %d\n", numberChannels);
    if (!ghost_data) {
        printf("Failed to load texture!\n");
        glfwTerminate();
        return -1;
    }
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, ghost_data);
    glGenerateMipmap(GL_TEXTURE_2D);
    stbi_image_free(ghost_data);

    // do stuff for text
    int text_program;
    if (init_text(&text_program) < 0) {
        printf("Failed to load text module!\n");
        glfwTerminate();
        return -1;
    }
    
    if (minimap_config.enabled) {
        minimap_program = create_shader_program("minimapshader.glsl", "minimapfragshader.glsl");
        if (minimap_program < 0) {
            glfwTerminate();
            return -1;
        }
        glGenVertexArrays(1, &minimapVAO);
        glGenBuffers(1, &minimapVBO);
        glBindVertexArray(minimapVAO);
        glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
        size_t minimap_buffer_capacity = std::max<size_t>(minimap_segments.size() * 4 + 12, 256);
        glBufferData(GL_ARRAY_BUFFER, minimap_buffer_capacity * sizeof(float), NULL, GL_DYNAMIC_DRAW);
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindVertexArray(0);
    }
 
    // TODO move these into config file??
    int time_secI = 0, num_frames = 1;
    float time_sec;
    glm::vec3 wall_color = glm::vec3(0.61f, 0.6f, 0.59f);
    float wall_shininess = 6.5;
    glm::vec3 floor_color = glm::vec3(0.11f, 0.1f, 0.09f);
    float floor_shininess = 3.25;
    glm::vec3 ambient = glm::vec3(0.007f, 0.006f, 0.005f);
    glm::vec3 diffuse = glm::vec3(0.61f, 0.60f, 0.59f);
    glm::vec3 specular = glm::vec3(0.11f, 0.10f, 0.09f);
    // Persistent danger tint state. The target can change abruptly as ghosts move,
    // so the displayed intensity is smoothed below to avoid camera flicker.
    float danger_tint_intensity = 0.0f;
    bool danger_tint_active = false;

    float largecutoff = glm::cos(glm::radians(30.0f));
    float smallcutoff = glm::cos(glm::radians(7.5f));

    std::vector<Ghost *> ghosts;
    for (int i = 0; i < std::max(1, ghost_count); i++) {
        Ghost *ghost = new Ghost(xmin_wall, xmax_wall, zmin_wall, zmax_wall);
        
        // Ensure ghost is not within 30.0 units of start_position
        while (glm::length(ghost->get_pos() - start_position) <= 30.0f) {
            ghost->regenerate_position();
        }
        
        ghosts.push_back(ghost);
    }

    player->mouse_callback(window, WINDOWWIDTH/2, WINDOWHEIGHT/2);

    int FPS = -1;

    // Main render/game loop.
    while (!glfwWindowShouldClose(window))
    {
        float current_frame = static_cast<float>(glfwGetTime());
        int current_frameI = (int)current_frame;
        if (current_frameI != time_secI) {  // show stats every second
            FPS = num_frames;
            glm::vec3 player_pos = player->get_pos();
            float yaw, pitch;
            yaw = player->get_yaw();
            pitch = player->get_pitch();
            printf("FPS: %d\n", num_frames);
            printf("Player is at: (%f, %f, %f) facing (%f, %f)\n", player_pos.x, player_pos.y, player_pos.z, yaw, pitch);
            time_sec = current_frame;
            time_secI = current_frameI;
            num_frames = 1;
        } else { // otherwise increase number of frames
            num_frames++;
        }
        timed = current_frame - last_frame;
        last_frame = current_frame;
        if (!first_frame) {
            first_frame = true;
            continue;
        }

        player->process_input(window);

        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glUseProgram(wall_program);

        float fov = player->get_fov();
        glm::mat4 projection = glm::perspective(glm::radians(fov), (float)WINDOWWIDTH / (float)WINDOWHEIGHT, 0.1f, 256.0f);
        set_uniform(wall_program, projectionC, projection);

        glm::vec3 camera_pos, camera_front, camera_up;
        camera_pos = player->get_camera_pos();
        camera_front = player->get_camera_front();
        camera_up = player->get_camera_up();

        glm::mat4 view = glm::lookAt(camera_pos, camera_pos + camera_front, camera_up);
        set_uniform(wall_program, viewC, view);

        glm::mat4 model = glm::mat4(1.0f);
        set_uniform(wall_program, modelC, model);

        // light position
        glm::vec3 light_pos = player->get_light_pos();
        //printf("light_pos: (%f, %f, %f)\n", light_pos.x, light_pos.y, light_pos.z);
        glm::vec3 light_front = player->get_light_front();
        //printf("light_pos: (%f, %f, %f)\n", light_front.x, light_front.y, light_front.z);

        glm::vec3 player_pos = player->get_pos();
        if (trail_config.enabled) {
            trail_dirty = update_trail(trail_points, player_pos, current_frame) || trail_dirty;
            prune_trail_reset_markers(trail_reset_markers, current_frame);
            // Upload after sample/prune changes so the world trail VBO is ready
            // when rendered later in this frame. The minimap reads the deque.
            if (trail_dirty) {
                rebuild_trail_mesh(trail_points, trail_vertices);
                glBindBuffer(GL_ARRAY_BUFFER, trailVBO);
                glBufferData(
                    GL_ARRAY_BUFFER,
                    std::max<size_t>(trail_vertices.size(), 1) * sizeof(TrailVertex),
                    trail_vertices.empty() ? NULL : trail_vertices.data(),
                    GL_DYNAMIC_DRAW
                );
                trail_dirty = false;
            }
        }
        // Sort ghosts by distance to player for render-order optimization.
        struct {
            bool operator()(const Ghost *a, const Ghost *b) const {
                glm::vec3 a_diff, b_diff;
                a_diff = player->get_pos() - a->get_pos();
                b_diff = player->get_pos() - b->get_pos();
                float a_dist, b_dist;
                a_dist = glm::length(a_diff);
                b_dist = glm::length(b_diff);
                return a_dist < b_dist;
            }
        } ghost_compare;
        // Only the closest 20% need perfect ordering for blending, so partial_sort is cheaper than full sort.
        std::partial_sort(ghosts.begin(), ghosts.begin() + ghosts.size() / 5, ghosts.end(), ghost_compare);
        
        // Drive the danger tint from the actual nearest ghost. Use X/Z distance
        // so vertical ghost bobbing cannot push the warning in and out.
        float nearest_ghost_distance = distance_xz(ghosts[0]->get_pos(), player_pos);
        for (size_t i = 1; i < ghosts.size(); i++) {
            float ghost_distance = distance_xz(ghosts[i]->get_pos(), player_pos);
            if (ghost_distance < nearest_ghost_distance) {
                nearest_ghost_distance = ghost_distance;
            }
        }
        
        // Interpolate flashlight color based on nearest ghost distance. The
        // active band has hysteresis so tiny distance changes at the edge do
        // not flicker the tint on/off.
        // At 30.0+ units: (0.61, 0.60, 0.59) - normal color
        // At 10.0 units: (0.99, 0.60, 0.59) - red shift
        if (nearest_ghost_distance <= 30.0f) {
            danger_tint_active = true;
        } else if (nearest_ghost_distance >= 35.0f) {
            danger_tint_active = false;
        }

        float color_factor = 1.0f;
        if (danger_tint_active) {
            color_factor = (nearest_ghost_distance - 10.0f) / (30.0f - 10.0f);
            color_factor = glm::clamp(color_factor, 0.0f, 1.0f);
        }
        float target_danger_intensity = 1.0f - color_factor;
        if (danger_tint_active) {
            target_danger_intensity = std::max(target_danger_intensity, 0.35f);
        }
        // Attack quickly when danger rises, release more slowly when it falls.
        float tint_response = target_danger_intensity > danger_tint_intensity ? 16.0f : 4.0f;
        float tint_blend = 1.0f - exp(-tint_response * timed);
        danger_tint_intensity = glm::mix(danger_tint_intensity, target_danger_intensity, tint_blend);
        
        glm::vec3 normal_color = glm::vec3(0.61f, 0.60f, 0.59f);
        glm::vec3 danger_color = glm::vec3(0.99f, 0.60f, 0.59f);
        diffuse = glm::mix(normal_color, danger_color, danger_tint_intensity);

        // fragment requirements
        set_uniform(wall_program, viewposC, camera_pos);
        set_uniform(wall_program, shininessC, wall_shininess);
        set_uniform(wall_program, colorC, wall_color);
        set_uniform(wall_program, lightposC, light_pos);
        set_uniform(wall_program, directionC, light_front);
        set_uniform(wall_program, largecutoffC, largecutoff);
        set_uniform(wall_program, smallcutoffC, smallcutoff);
        set_uniform(wall_program, ambientC, ambient);
        set_uniform(wall_program, diffuseC, diffuse);
        set_uniform(wall_program, specularC, specular);

        glBindVertexArray(wallsVAO);
        glDrawArrays(GL_TRIANGLES, 0, num_wall_vertices);

        glUseProgram(floor_program);

        set_uniform(floor_program, projectionC, projection);
        set_uniform(floor_program, viewC, view);
        set_uniform(floor_program, modelC, model);
        set_uniform(floor_program, viewposC, camera_pos);

        // fragment requirements
        set_uniform(floor_program, shininessC, floor_shininess);
        set_uniform(floor_program, colorC, floor_color);
        set_uniform(floor_program, lightposC, light_pos);
        set_uniform(floor_program, directionC, light_front);
        set_uniform(floor_program, largecutoffC, largecutoff);
        set_uniform(floor_program, smallcutoffC, smallcutoff);
        set_uniform(floor_program, ambientC, ambient);
        set_uniform(floor_program, diffuseC, diffuse);
        set_uniform(floor_program, specularC, specular);

        glBindVertexArray(floorVAO);
        glDrawArrays(GL_TRIANGLES, 0, 6 * 6 * 1);

        glUseProgram(ghost_program);
        
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, ghost_texture);

        set_uniform(ghost_program, projectionC, projection);
        set_uniform(ghost_program, viewC, view);
        bool player_reset_this_frame = false;
        for (int i = ghosts.size()/5; i >= 0; i--) {
            glm::mat4 ghost_model = ghosts[i]->get_model(camera_pos);
            ghosts[i]->apply_movement(current_frame, timed);
            
            // When ghosts close in, reset player back to the maze entrance.
            glm::vec3 ghost_pos = ghosts[i]->get_pos();
            glm::vec3 player_pos = player->get_pos();
            float distance = glm::length(ghost_pos - player_pos);
            if (!player_reset_this_frame && distance <= ghost_reset_distance) {
                glm::vec3 reset_pos = player->get_pos();
                float reset_yaw = player->get_yaw();
                if (trail_config.enabled) {
                    trail_dirty = end_trail_segment(trail_points, reset_pos, current_frame) || trail_dirty;
                    add_trail_reset_marker(trail_reset_markers, reset_pos, reset_yaw, current_frame);
                }
                player->reset_position(start_position, start_yaw);
                if (trail_config.enabled) {
                    trail_dirty = begin_trail_segment(trail_points, start_position, current_frame) || trail_dirty;
                }
                player_reset_this_frame = true;
            }
            
            // Nudge ghosts away from the spawn area so the player gets a breather.
            float start_distance = glm::length(ghost_pos - start_position);
            if (start_distance <= 30.0f) {
                ghosts[i]->reverse_direction_from_position(start_position);
            }
            
            set_uniform(ghost_program, modelC, ghost_model);
            glBindVertexArray(ghostVAO);
            glDrawArrays(GL_TRIANGLES, 0, (3 + 3 + 2) * 6);
        }

        if (trail_config.enabled) {
            // Ghost resets can split the trail after the initial upload above.
            // Rebuild here before drawing so reset markers, world trail, and
            // minimap all reflect the same reset on the current frame.
            if (trail_dirty) {
                rebuild_trail_mesh(trail_points, trail_vertices);
                glBindBuffer(GL_ARRAY_BUFFER, trailVBO);
                glBufferData(
                    GL_ARRAY_BUFFER,
                    std::max<size_t>(trail_vertices.size(), 1) * sizeof(TrailVertex),
                    trail_vertices.empty() ? NULL : trail_vertices.data(),
                    GL_DYNAMIC_DRAW
                );
                trail_dirty = false;
            }

            if (!trail_vertices.empty()) {
                glUseProgram(trail_program);

                set_uniform(trail_program, projectionC, projection);
                set_uniform(trail_program, viewC, view);
                set_uniform(trail_program, modelC, glm::mat4(1.0f));
                set_uniform(trail_program, "currentTime", current_frame);
                set_uniform(trail_program, "maxAge", std::max(0.001f, trail_config.lifetime_minutes * 60.0f));
                set_uniform(trail_program, "recentColor", trail_config.recent_color);
                set_uniform(trail_program, "oldColor", trail_config.old_color);
                glBindVertexArray(trailVAO);
                glDrawArrays(GL_TRIANGLES, 0, trail_vertices.size());
            }

            if (!trail_reset_markers.empty()) {
                glUseProgram(ghost_program);
                glActiveTexture(GL_TEXTURE0);
                glBindTexture(GL_TEXTURE_2D, ghost_texture);
                set_uniform(ghost_program, projectionC, projection);
                set_uniform(ghost_program, viewC, view);
                render_trail_reset_markers(ghost_program, ghostVAO, trail_reset_markers);
            }
        }

        if (minimap_config.enabled) {
            render_minimap(player->get_pos(), player->get_yaw(), trail_points, ghosts);
        }

        if (FPS != -1) {
            glUseProgram(text_program);
            projection = glm::ortho(0.0f, static_cast<float>(WINDOWWIDTH), 0.0f, static_cast<float>(WINDOWHEIGHT));
            set_uniform(text_program, projectionC, projection);
            char fps_buff[256];
            sprintf(fps_buff, "FPS: %d", FPS);
            render_text(text_program, std::string(fps_buff), 25.0F, WINDOWHEIGHT - 35.0f, 0.5f, glm::vec3(1.0f, 0.0f, 0.0f));
        }

        player->apply_movement(timed);

        glfwSwapBuffers(window);
        glfwPollEvents();

    }

    glDeleteVertexArrays(1, &wallsVAO);
    glDeleteBuffers(1, &wallsVBO);

    glDeleteVertexArrays(1, &floorVAO);
    glDeleteBuffers(1, &floorVBO);

    glDeleteVertexArrays(1, &trailVAO);
    glDeleteBuffers(1, &trailVBO);
    glDeleteProgram(trail_program);

    if (minimap_config.enabled) {
        glDeleteVertexArrays(1, &minimapVAO);
        glDeleteBuffers(1, &minimapVBO);
        glDeleteProgram(minimap_program);
    }

    glfwTerminate();
    return 0;
}

void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
    glViewport(0, 0, width, height);
}

void mouse_callback(GLFWwindow* window, double xpos, double ypos) {
    player->mouse_callback(window, xpos, ypos);
}

void scroll_callback(GLFWwindow* window, double xoffset, double yoffset) {
    player->scroll_callback(window, xoffset, yoffset);
}

float distance_xz(const glm::vec3 &a, const glm::vec3 &b) {
    float dx = a.x - b.x;
    float dz = a.z - b.z;
    return sqrt(dx * dx + dz * dz);
}

bool is_redundant_trail_point(const TrailPoint &a, const TrailPoint &b, const TrailPoint &c) {
    if (trail_config.simplify_epsilon <= 0.0f) {
        return false;
    }

    glm::vec2 ab(b.position.x - a.position.x, b.position.z - a.position.z);
    glm::vec2 ac(c.position.x - a.position.x, c.position.z - a.position.z);
    float ac_len_sq = glm::dot(ac, ac);
    if (ac_len_sq <= 0.0001f) {
        return false;
    }

    float t = glm::dot(ab, ac) / ac_len_sq;
    if (t <= 0.0f || t >= 1.0f) {
        return false;
    }

    glm::vec2 closest = ac * t;
    return glm::length(ab - closest) <= trail_config.simplify_epsilon;
}

bool update_trail(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time) {
    if (!trail_config.enabled) {
        bool had_points = !trail_points.empty();
        trail_points.clear();
        return had_points;
    }

    bool dirty = false;
    // Keep a time window instead of a fixed sample count so trail length is
    // stable across different movement speeds and frame rates.
    float max_age = std::max(0.001f, trail_config.lifetime_minutes * 60.0f);
    while (!trail_points.empty() && current_time - trail_points.front().timestamp > max_age) {
        trail_points.pop_front();
        dirty = true;
    }

    glm::vec3 sample_pos(player_pos.x, trail_config.y_position, player_pos.z);
    float min_spacing = std::max(0.001f, trail_config.sample_spacing);
    if (trail_points.empty() || distance_xz(sample_pos, trail_points.back().position) >= min_spacing) {
        TrailPoint new_point = {sample_pos, current_time, trail_points.empty()};
        if (trail_points.size() >= 2 && !trail_points.back().starts_segment) {
            TrailPoint previous = trail_points.back();
            TrailPoint before_previous = trail_points[trail_points.size() - 2];
            if (!previous.starts_segment && is_redundant_trail_point(before_previous, previous, new_point)) {
                trail_points.pop_back();
            }
        }
        trail_points.push_back(new_point);
        dirty = true;
    }

    return dirty;
}

bool end_trail_segment(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time) {
    glm::vec3 sample_pos(player_pos.x, trail_config.y_position, player_pos.z);
    if (trail_points.empty()) {
        trail_points.push_back({sample_pos, current_time, true});
        return true;
    }

    if (distance_xz(sample_pos, trail_points.back().position) <= 0.0001f) {
        // If the last regular sample is already at the reset location, refresh
        // its age rather than adding a zero-length segment.
        trail_points.back().position = sample_pos;
        trail_points.back().timestamp = current_time;
        return true;
    }

    trail_points.push_back({sample_pos, current_time, false});
    return true;
}

bool begin_trail_segment(std::deque<TrailPoint> &trail_points, const glm::vec3 &player_pos, float current_time) {
    glm::vec3 sample_pos(player_pos.x, trail_config.y_position, player_pos.z);
    if (!trail_points.empty()
        && trail_points.back().starts_segment
        && distance_xz(sample_pos, trail_points.back().position) <= 0.0001f) {
        trail_points.back().timestamp = current_time;
        return true;
    }

    TrailPoint new_point = {sample_pos, current_time, true};
    trail_points.push_back(new_point);
    return true;
}

void add_trail_reset_marker(std::deque<TrailResetMarker> &reset_markers, const glm::vec3 &player_pos, float player_yaw, float current_time) {
    glm::vec3 marker_pos(player_pos.x, trail_config.y_position + 0.002f, player_pos.z);
    reset_markers.push_back({marker_pos, player_yaw, current_time});
}

bool prune_trail_reset_markers(std::deque<TrailResetMarker> &reset_markers, float current_time) {
    bool dirty = false;
    float max_age = std::max(0.001f, trail_config.lifetime_minutes * 60.0f);
    while (!reset_markers.empty() && current_time - reset_markers.front().timestamp > max_age) {
        reset_markers.pop_front();
        dirty = true;
    }
    return dirty;
}

void render_trail_reset_markers(int ghost_program, unsigned int ghostVAO, const std::deque<TrailResetMarker> &reset_markers) {
    if (trail_config.reset_marker_size <= 0.0f) {
        return;
    }

    glBindVertexArray(ghostVAO);
    for (const TrailResetMarker &marker : reset_markers) {
        glm::mat4 marker_model = glm::mat4(1.0f);
        marker_model = glm::translate(marker_model, marker.position);
        marker_model = glm::rotate(marker_model, glm::radians(90.0f - marker.yaw), glm::vec3(0.0f, 1.0f, 0.0f));
        marker_model = glm::rotate(marker_model, glm::radians(90.0f), glm::vec3(1.0f, 0.0f, 0.0f));
        marker_model = glm::scale(marker_model, glm::vec3(trail_config.reset_marker_size, trail_config.reset_marker_size, 1.0f));
        set_uniform(ghost_program, modelC, marker_model);
        glDrawArrays(GL_TRIANGLES, 0, 6);
    }
}

glm::vec2 trail_segment_direction(const std::deque<TrailPoint> &trail_points, size_t from_ix, size_t to_ix) {
    glm::vec3 delta = trail_points[to_ix].position - trail_points[from_ix].position;
    glm::vec2 delta_xz(delta.x, delta.z);
    float len = glm::length(delta_xz);
    if (len <= 0.0001f) {
        return glm::vec2(0.0f, 0.0f);
    }
    return delta_xz / len;
}

glm::vec3 trail_join_offset(const std::deque<TrailPoint> &trail_points, size_t point_ix, const glm::vec2 &fallback_normal, float half_width) {
    bool has_prev = point_ix > 0 && !trail_points[point_ix].starts_segment;
    bool has_next = point_ix + 1 < trail_points.size() && !trail_points[point_ix + 1].starts_segment;

    if (!has_prev && !has_next) {
        return glm::vec3(fallback_normal.x * half_width, 0.0f, fallback_normal.y * half_width);
    }

    if (!has_prev || !has_next) {
        glm::vec2 dir = has_prev
            ? trail_segment_direction(trail_points, point_ix - 1, point_ix)
            : trail_segment_direction(trail_points, point_ix, point_ix + 1);
        if (glm::length(dir) <= 0.0001f) {
            return glm::vec3(fallback_normal.x * half_width, 0.0f, fallback_normal.y * half_width);
        }
        glm::vec2 normal(-dir.y, dir.x);
        return glm::vec3(normal.x * half_width, 0.0f, normal.y * half_width);
    }

    glm::vec2 prev_dir = trail_segment_direction(trail_points, point_ix - 1, point_ix);
    glm::vec2 next_dir = trail_segment_direction(trail_points, point_ix, point_ix + 1);
    if (glm::length(prev_dir) <= 0.0001f || glm::length(next_dir) <= 0.0001f) {
        return glm::vec3(fallback_normal.x * half_width, 0.0f, fallback_normal.y * half_width);
    }

    glm::vec2 prev_normal(-prev_dir.y, prev_dir.x);
    glm::vec2 next_normal(-next_dir.y, next_dir.x);
    glm::vec2 miter = prev_normal + next_normal;
    float miter_len = glm::length(miter);
    if (miter_len <= 0.0001f) {
        return glm::vec3(fallback_normal.x * half_width, 0.0f, fallback_normal.y * half_width);
    }

    miter /= miter_len;
    float denom = glm::dot(miter, fallback_normal);
    if (denom <= 0.1f) {
        return glm::vec3(fallback_normal.x * half_width, 0.0f, fallback_normal.y * half_width);
    }

    // Clamp miters so tight turns do not produce long spikes in the ribbon.
    float miter_scale = std::min(half_width / denom, half_width * 2.5f);
    return glm::vec3(miter.x * miter_scale, 0.0f, miter.y * miter_scale);
}

void rebuild_trail_mesh(const std::deque<TrailPoint> &trail_points, std::vector<TrailVertex> &trail_vertices) {
    trail_vertices.clear();
    if (trail_points.size() < 2 || trail_config.width <= 0.0f) {
        return;
    }

    trail_vertices.reserve((trail_points.size() - 1) * 6);
    float half_width = trail_config.width * 0.5f;
    for (size_t i = 1; i < trail_points.size(); i++) {
        const TrailPoint &p0 = trail_points[i - 1];
        const TrailPoint &p1 = trail_points[i];
        if (p1.starts_segment) {
            continue;
        }
        glm::vec2 dir = trail_segment_direction(trail_points, i - 1, i);
        if (glm::length(dir) <= 0.0001f) {
            continue;
        }

        glm::vec2 normal(-dir.y, dir.x);
        glm::vec3 start_offset = trail_join_offset(trail_points, i - 1, normal, half_width);
        glm::vec3 end_offset = trail_join_offset(trail_points, i, normal, half_width);
        TrailVertex v0 = {p0.position + start_offset, p0.timestamp};
        TrailVertex v1 = {p0.position - start_offset, p0.timestamp};
        TrailVertex v2 = {p1.position + end_offset, p1.timestamp};
        TrailVertex v3 = {p1.position - end_offset, p1.timestamp};

        trail_vertices.push_back(v0);
        trail_vertices.push_back(v1);
        trail_vertices.push_back(v2);
        trail_vertices.push_back(v2);
        trail_vertices.push_back(v1);
        trail_vertices.push_back(v3);
    }
}

void render_minimap(const glm::vec3 &player_pos, float player_yaw, const std::deque<TrailPoint> &trail_points, const std::vector<Ghost *> &ghosts) {
    // 2D overlay renders last so sorting/blending for 3D content is unaffected.
    if (!minimap_config.enabled || minimap_program < 0) {
        return;
    }

    glDisable(GL_DEPTH_TEST);
    glUseProgram(minimap_program);

    glm::mat4 ortho = glm::ortho(0.0f, static_cast<float>(WINDOWWIDTH), 0.0f, static_cast<float>(WINDOWHEIGHT));
    set_uniform(minimap_program, projectionC, ortho);

    glBindVertexArray(minimapVAO);

    float left = static_cast<float>(minimap_config.margin);
    float bottom = static_cast<float>(minimap_config.margin);
    float right = left + minimap_config.width;
    float top = bottom + minimap_config.height;

    glEnable(GL_SCISSOR_TEST);
    glScissor(static_cast<int>(left), static_cast<int>(bottom), minimap_config.width, minimap_config.height);

    float rect_vertices[] = {
        left,  bottom,
        right, bottom,
        right, top,
        left,  top,
        left,  bottom,
        right, top
    };

    glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(rect_vertices), rect_vertices);
    set_uniform(minimap_program, "inColor", minimap_config.background_color);
    glDrawArrays(GL_TRIANGLES, 0, 6);

    glm::vec2 player_flat(player_pos.x, player_pos.z);
    glm::vec2 map_center(left + minimap_config.width * 0.5f, bottom + minimap_config.height * 0.5f);
    float span_x = std::max(1.0f, minimap_bounds.xmax - minimap_bounds.xmin);
    float span_z = std::max(1.0f, minimap_bounds.zmax - minimap_bounds.zmin);
    float span_scale = std::min(
        static_cast<float>(minimap_config.width) / span_x,
        static_cast<float>(minimap_config.height) / span_z
    );
    float scale = minimap_config.zoom > 0.0f ? minimap_config.zoom : span_scale;

    static std::vector<float> line_vertices;
    line_vertices.clear();
    line_vertices.reserve(minimap_segments.size() * 4);
    for (const auto &segment : minimap_segments) {
        glm::vec2 rs = segment.start - player_flat;
        glm::vec2 re = segment.end - player_flat;
        line_vertices.push_back(map_center.x + rs.x * scale);
        line_vertices.push_back(map_center.y + rs.y * scale);
        line_vertices.push_back(map_center.x + re.x * scale);
        line_vertices.push_back(map_center.y + re.y * scale);
    }
    if (!line_vertices.empty()) {
        glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
        glBufferData(GL_ARRAY_BUFFER, line_vertices.size() * sizeof(float), line_vertices.data(), GL_DYNAMIC_DRAW);
        set_uniform(minimap_program, "inColor", minimap_config.wall_color);
        glDrawArrays(GL_LINES, 0, line_vertices.size() / 2);
    }

    // The minimap mirrors the world trail as a real screen-space stroke. The
    // old breadcrumb radius now acts as stroke half-width in pixels.
    if (trail_points.size() >= 2 && minimap_config.breadcrumb_radius > 0.0f) {
        static std::vector<float> trail_line_vertices;
        trail_line_vertices.clear();
        trail_line_vertices.reserve((trail_points.size() - 1) * 12);
        float max_dist_sq = minimap_config.breadcrumb_max_distance > 0.0f
            ? minimap_config.breadcrumb_max_distance * minimap_config.breadcrumb_max_distance
            : -1.0f;
        float half_width = minimap_config.breadcrumb_radius;
        for (size_t i = 1; i < trail_points.size(); i++) {
            if (trail_points[i].starts_segment) {
                continue;
            }
            glm::vec2 rel0 = glm::vec2(trail_points[i - 1].position.x, trail_points[i - 1].position.z) - player_flat;
            glm::vec2 rel1 = glm::vec2(trail_points[i].position.x, trail_points[i].position.z) - player_flat;
            if (max_dist_sq > 0.0f && glm::dot(rel0, rel0) > max_dist_sq && glm::dot(rel1, rel1) > max_dist_sq) {
                continue;
            }
            glm::vec2 p0 = map_center + rel0 * scale;
            glm::vec2 p1 = map_center + rel1 * scale;
            glm::vec2 segment = p1 - p0;
            float segment_len = glm::length(segment);
            if (segment_len <= 0.0001f) {
                continue;
            }

            glm::vec2 normal = glm::vec2(-segment.y, segment.x) / segment_len * half_width;
            glm::vec2 p0_left = p0 + normal;
            glm::vec2 p0_right = p0 - normal;
            glm::vec2 p1_left = p1 + normal;
            glm::vec2 p1_right = p1 - normal;

            trail_line_vertices.push_back(p0_left.x);
            trail_line_vertices.push_back(p0_left.y);
            trail_line_vertices.push_back(p0_right.x);
            trail_line_vertices.push_back(p0_right.y);
            trail_line_vertices.push_back(p1_left.x);
            trail_line_vertices.push_back(p1_left.y);
            trail_line_vertices.push_back(p1_left.x);
            trail_line_vertices.push_back(p1_left.y);
            trail_line_vertices.push_back(p0_right.x);
            trail_line_vertices.push_back(p0_right.y);
            trail_line_vertices.push_back(p1_right.x);
            trail_line_vertices.push_back(p1_right.y);
        }
        if (!trail_line_vertices.empty()) {
            glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
            glBufferData(GL_ARRAY_BUFFER, trail_line_vertices.size() * sizeof(float), trail_line_vertices.data(), GL_DYNAMIC_DRAW);
            set_uniform(minimap_program, "inColor", minimap_config.breadcrumb_color);
            glDrawArrays(GL_TRIANGLES, 0, trail_line_vertices.size() / 2);
        }
    }

    // Ghosts are shown as border+fill circles; re-use a small triangle fan per ghost.
    if (!ghosts.empty() && minimap_config.ghost_radius > 0.0f) {
        const int ghost_segments = 16;
        const float ghost_angle_step = glm::two_pi<float>() / static_cast<float>(ghost_segments);
        std::vector<float> ghost_vertices((ghost_segments + 2) * 2);
        auto draw_circle = [&](const glm::vec2 &center, float radius, const glm::vec3 &color) {
            if (radius <= 0.0f) return;
            ghost_vertices[0] = center.x;
            ghost_vertices[1] = center.y;
            for (int seg = 0; seg <= ghost_segments; ++seg) {
                float angle = seg * ghost_angle_step;
                ghost_vertices[(seg + 1) * 2 + 0] = center.x + cos(angle) * radius;
                ghost_vertices[(seg + 1) * 2 + 1] = center.y + sin(angle) * radius;
            }
            glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
            glBufferData(GL_ARRAY_BUFFER, ghost_vertices.size() * sizeof(float), ghost_vertices.data(), GL_DYNAMIC_DRAW);
            set_uniform(minimap_program, "inColor", color);
            glDrawArrays(GL_TRIANGLE_FAN, 0, ghost_vertices.size() / 2);
        };
        float border_radius = minimap_config.ghost_radius;
        float fill_radius = std::max(0.0f, border_radius - 1.0f);
        for (const Ghost *ghost : ghosts) {
            glm::vec3 ghost_pos = ghost->get_pos();
            glm::vec2 rel = glm::vec2(ghost_pos.x, ghost_pos.z) - player_flat;
            glm::vec2 center = map_center + rel * scale;
            draw_circle(center, border_radius, minimap_config.ghost_border_color);
            draw_circle(center, fill_radius, minimap_config.ghost_fill_color);
        }
    }

    float arrow_length = std::min(minimap_config.width, minimap_config.height) * 0.2f;
    float arrow_half_width = arrow_length * 0.35f;
    float yaw_radians = glm::radians(player_yaw - 90.0f);
    float cos_yaw = cos(yaw_radians);
    float sin_yaw = sin(yaw_radians);
    auto rotate = [&](float x, float y) -> glm::vec2 {
        return glm::vec2(
            x * cos_yaw - y * sin_yaw,
            x * sin_yaw + y * cos_yaw
        );
    };
    glm::vec2 tip = map_center + rotate(0.0f, arrow_length * 0.5f);
    glm::vec2 left_pt = map_center + rotate(-arrow_half_width, -arrow_length * 0.5f);
    glm::vec2 right_pt = map_center + rotate(arrow_half_width, -arrow_length * 0.5f);
    float arrow_vertices[] = {
        tip.x, tip.y,
        left_pt.x, left_pt.y,
        right_pt.x, right_pt.y
    };
    glBindBuffer(GL_ARRAY_BUFFER, minimapVBO);
    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(arrow_vertices), arrow_vertices);
    set_uniform(minimap_program, "inColor", minimap_config.arrow_color);
    glDrawArrays(GL_TRIANGLES, 0, 3);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
    glDisable(GL_SCISSOR_TEST);
    glEnable(GL_DEPTH_TEST);
}