Very basic 2D game example made with Raylib

cMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(raylib-basic-game)

# use C++20
set(CMAKE_CXX_STANDARD 20)

# autocomplete with YCM
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_BUILD_TYPE Release)

# copy assets
file(COPY player.png DESTINATION ${CMAKE_BINARY_DIR})

# executable
add_executable(${PROJECT_NAME} main.cpp)
target_link_libraries(${PROJECT_NAME} raylib)

main.cpp

#include <raylib.h>
#include <string>

/* Get upper-left corner position from center position */
static Vector2 get_position_ul(const Vector2& position_center, const Vector2& size_sprite) {
  Vector2 position_ul = {
    position_center.x - size_sprite.x/2.0f,
    position_center.y - size_sprite.y/2.0f
  };
  return position_ul;
}

static Vector2 get_random_position(const Vector2& size_sprite, const Vector2& size_window) {
  auto [ width_window, height_window ] = size_window;
  auto [ width_sprite, height_sprite ] = size_sprite;

  Vector2 position_center = {
    static_cast<float>(GetRandomValue(width_sprite/2, width_window - width_sprite/2)),
    static_cast<float>(GetRandomValue(height_sprite/2, height_window - height_sprite/2))
  };

  return get_position_ul(position_center, size_sprite);
}

/* Detect collision between mouse cursor & sprite bbox */
static bool check_collision(const Vector2& position_enemy, const Vector2& size_sprite) {
    Rectangle rectangle_sprite = { position_enemy.x, position_enemy.y, size_sprite.x, size_sprite.y };
    Vector2 position_mouse = GetMousePosition();
    bool is_in_rect = CheckCollisionPointRec(position_mouse, rectangle_sprite);

    return is_in_rect;
}

int main() {
  const int WIDTH_WINDOW = 800;
  const int HEIGHT_WINDOW = 600;
  const Vector2 size_window = { static_cast<float>(WIDTH_WINDOW), static_cast<float>(HEIGHT_WINDOW) };
  InitWindow(WIDTH_WINDOW, HEIGHT_WINDOW, "My game");

  const float TIME_SPAWN_ENEMY = 1.0;
  float timer = TIME_SPAWN_ENEMY;

  Texture2D texture_player = LoadTexture("player.png");
  int width_player = texture_player.width;
  int height_player = texture_player.height;
  const Vector2 size_sprite = { static_cast<float>(width_player), static_cast<float>(height_player) };

  Vector2 position_enemy = get_random_position(size_sprite, size_window);
  bool is_hit = false;
  unsigned int score = 0;

  while (!WindowShouldClose()) {
    BeginDrawing();

    ClearBackground(WHITE);
    DrawRectangle(200, 200, 400, 400, SKYBLUE);

    // player at mouse location
    // position center (not upper-left corner by default)
    Vector2 position_mouse = GetMousePosition();
    Vector2 position_player = get_position_ul(position_mouse, size_sprite);
    DrawTexture(texture_player, position_player.x, position_player.y, WHITE);

    // spawn enemy every second
    timer -= GetFrameTime();
    if (timer < 0 || is_hit) {
      timer = TIME_SPAWN_ENEMY;

      position_enemy = get_random_position(size_sprite, size_window);
      is_hit = false;
    }

    Color tint = { 0x0, 0x0, 0xff, 0xff }; // basic multiplication with 255: opaque, 0: transparent
    DrawTexture(texture_player, position_enemy.x, position_enemy.y, tint);

    // display score
    std::string score_text = "Score: " + std::to_string(score);
    DrawText(score_text.c_str(), WIDTH_WINDOW - 100, HEIGHT_WINDOW - 20, 20, LIGHTGRAY);

    EndDrawing();

    // detect mouse cursor collision with enemy
    bool is_in_rect = check_collision(position_enemy, size_sprite);
    if (IsMouseButtonDown(MOUSE_BUTTON_LEFT) && is_in_rect) {
      ++score;
      is_hit = true;
    }
  }

  UnloadTexture(texture_player);

  CloseWindow();

  return 0;
}

Raylib-notes.md

Dependencies

$ sudo pacman -Sy raylib

How to run

$ mkdir build
$ cd build
$ cmake .. && make -j
$ ./raylib-basic-game

Inspiration

AndrewHamel111/raylib-AppleCatcher