Code_main
/**
* Set initial delta time, used to calculate the time difference between frame generations
*/
float delta_time = 0;
/**
* The SDL window and renderer used to dispaly the game
*/
SDL_Window* window = NULL;
SDL_Renderer* renderer = NULL;
/**
* Flag for vertical synchronisation (not properly implemented, vsync is ALWAYS enabled)
*/
static bool vsync_enabled = 1;
/**
* Bullet and Enemy manager to manage entities, pointing to NULL on init
*/
struct bullets_manager* BM = NULL;
struct enemy_manager* EM = NULL;
/**
* Rate at which new enemies are spawned into the scene - upper bound for `enemy_timer`
*/
#define ENEMY_SPAWN_INTERVAL 1.0f
/**
* Counter, reset when `ENEMY_SPAWN_INTERVAL` is reached
*/
float enemy_timer = 0.0f;
/**
* Current game state
*/
Game_state game_state;
/**
* User controlled player character
*/
Player_ship ship;
---
/**
* Runs every frame
*/
while(game_state != QUIT) {
if (game_state == RUNNING) {
/*
* this manages the behavious when keys (mouse or keyboard)
* are pressed and calls relevant functions accordingly
*/
while (SDL_PollEvent(&event)) {
if (event.type == SDL_EVENT_QUIT) {
printf("quit event hit\n");
game_state = QUIT;
} else if(event.type == SDL_EVENT_KEY_UP && event.key.key == SDLK_ESCAPE) {
game_state = PAUSED;
/*
* when mouse motion is detected
*/
} else if (event.type == SDL_EVENT_MOUSE_MOTION) {
SDL_GetMouseState(&mouse_pos_x, &mouse_pos_y);
turn_the_thing(&mouse_pos_x, &mouse_pos_y);
/*
* when a keyboard key-press is detected
*/
} else if (event.type == SDL_EVENT_KEY_DOWN) {
set_key_active(event.key.key);
/*
* when a keyboard key-release is detected
*/
} else if (event.type == SDL_EVENT_KEY_UP) {
set_key_inactive(event.key.key);
/*
* this spawns different kinds of bullets
* when either left or right mouse button
* is clicked
*/
} else if (event.type == SDL_EVENT_MOUSE_BUTTON_DOWN && event.button.button == SDL_BUTTON_LEFT) {
SDL_GetMouseState(&mouse_pos_x, &mouse_pos_y);
create_bullet(BASIC);
} else if (event.type == SDL_EVENT_MOUSE_BUTTON_DOWN && event.button.button == SDL_BUTTON_RIGHT) {
SDL_GetMouseState(&mouse_pos_x, &mouse_pos_y);
create_bullet(EXPLOSIVE);
}
}
/**
* WASD keyboard movement
*/
if (is_key_active(SDLK_W)) {
move_ship_up();
}
if (is_key_active(SDLK_A)) {
move_ship_left();
}
if (is_key_active(SDLK_S)) {
move_ship_down();
}
if (is_key_active(SDLK_D)) {
move_ship_right();
}
if (is_key_active(SDLK_Q)) {
game_state = QUIT;
}
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
/**
* renders the player ship on the screen
*/
SDL_RenderGeometry(renderer, NULL, ship.shape, 3, NULL, 0);
/**
* frames per second counter
*/
++frame_count;
/*
* to not update the FPS counter each frame,
* we only update is every 1000ms
*/
current_tick = SDL_GetTicks();
if (current_tick - last_tick >= 1000) {
frames_per_second = frame_count * 1000.0f / (current_tick - last_tick);
snprintf(frames_string, 99, "vsync: %i, fps: %.3f", vsync_enabled, frames_per_second);
frame_count = 0;
last_tick = current_tick;
}
/*
* print control string info etc to the screen
*/
print_text_to_screen(frames_string, WINDOW_WIDTH / 2, 0, renderer);
print_text_to_screen(controls_esc, 0, 0, renderer);
snprintf(score_string, 12, "score: %d", ship.score);
print_text_to_screen(score_string, WINDOW_WIDTH - 100, 0, renderer);
/*
* checks if it is time to spawn a new enemy
*/
if (enemy_timer >= ENEMY_SPAWN_INTERVAL) {
create_enemy();
enemy_timer = 0;
}
/*
* move bullets and enemies one step forwards
*/
update_bullets();
update_enemies(BM);
/*
* display the renderer to the screen, I guess
*/
SDL_RenderPresent(renderer);
/*
* calculate how much time passed from the
* last frame to the current frame and use
* this as a multiplicand on all movement
* operations
*/
delta_time = (current_tick - last_delta_tick) / 1000.0f;
last_delta_tick = current_tick;
enemy_timer += delta_time;
/*
* game over screen if u failed lol
*/
if (got_hit_by_enemy(EM)) {
game_state = GAME_OVER;
}
/**
* pause screen when ESC is pressed
*/
} else if (game_state == PAUSED) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_EVENT_QUIT || event.key.key == SDLK_Q) {
printf("quit event hit\n");
game_state = QUIT;
} else if(event.type == SDL_EVENT_KEY_UP && event.key.key == SDLK_ESCAPE) {
game_state = RUNNING;
last_delta_tick = SDL_GetTicks();
}
}
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
SDL_RenderGeometry(renderer, NULL, ship.shape, 3, NULL, 0);
print_text_to_screen_with_color(paused_text, ((WINDOW_WIDTH / 2.0f) - 60), WINDOW_HEIGHT / 2.0f, renderer, paused_color);
print_text_to_screen(controls, 0, 0, renderer);
SDL_RenderPresent(renderer);
} else if (game_state == GAME_OVER) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_EVENT_QUIT || event.key.key == SDLK_Q) {
printf("quit event hit\n");
game_state = QUIT;
} else if(event.type == SDL_EVENT_KEY_UP && event.key.key == SDLK_R) {
free_all_bullets();
free_all_enemies();
if (bullets_manager_init() != 0) {
printf("bullet manager not initialized\n");
return SDL_APP_FAILURE;
}
if (enemy_manager_init() != 0) {
printf("enemy manager not initialized\n");
return SDL_APP_FAILURE;
}
create_player(&ship);
flush_keystate();
flush_mousepos();
flush_playerpos();
game_state = RUNNING;
last_delta_tick = SDL_GetTicks();
}
}
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
print_text_to_screen_with_color(gameover_text, WINDOW_WIDTH / 2 - 60, WINDOW_HEIGHT / 2, renderer, paused_color);
print_text_to_screen(score_string, WINDOW_WIDTH / 2 - 60, WINDOW_HEIGHT / 2 + 20, renderer);
print_text_to_screen(gameover_controls, WINDOW_WIDTH / 2 - 60, WINDOW_HEIGHT / 2 + 40, renderer);
SDL_RenderPresent(renderer);
}
}Cleanup
printf("ending program\n");
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
kill_font();
/**
* remember to free your pointers
*/
free_all_bullets();
free_all_enemies();
free_map_uint_bool(&key_state);
