raylib/games/snake.c
2017-10-22 11:12:10 +02:00

301 lines
9.8 KiB
C

/*******************************************************************************************
*
* raylib - sample game: snake
*
* Sample game developed by Ian Eito, Albert Martos and Ramon Santamaria
*
* This game has been created using raylib v1.3 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* Copyright (c) 2015 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#include "raylib.h"
#if defined(PLATFORM_ANDROID)
#include "android_native_app_glue.h"
#endif
#if defined(PLATFORM_WEB)
#include <emscripten/emscripten.h>
#endif
//----------------------------------------------------------------------------------
// Some Defines
//----------------------------------------------------------------------------------
#define SNAKE_LENGTH 256
#define SQUARE_SIZE 31
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
typedef struct Snake {
Vector2 position;
Vector2 size;
Vector2 speed;
Color color;
} Snake;
typedef struct Food {
Vector2 position;
Vector2 size;
bool active;
Color color;
} Food;
//------------------------------------------------------------------------------------
// Global Variables Declaration
//------------------------------------------------------------------------------------
static int screenWidth = 800;
static int screenHeight = 450;
static int framesCounter;
static bool gameOver;
static bool pause;
static Food fruit;
static Snake snake[SNAKE_LENGTH];
static Vector2 snakePosition[SNAKE_LENGTH];
static bool allowMove;
static Vector2 offset;
static int counterTail;
//------------------------------------------------------------------------------------
// Module Functions Declaration (local)
//------------------------------------------------------------------------------------
static void InitGame(void); // Initialize game
static void UpdateGame(void); // Update game (one frame)
static void DrawGame(void); // Draw game (one frame)
static void UnloadGame(void); // Unload game
static void UpdateDrawFrame(void); // Update and Draw (one frame)
//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
#if defined(PLATFORM_ANDROID)
void android_main(struct android_app *app)
#else
int main(void)
#endif
{
// Initialization
//---------------------------------------------------------
#if defined(PLATFORM_ANDROID)
InitWindow(screenWidth, screenHeight, app);
#else
InitWindow(screenWidth, screenHeight, "sample game: snake");
#endif
InitGame();
#if defined(PLATFORM_WEB)
emscripten_set_main_loop(UpdateDrawFrame, 0, 1);
#else
SetTargetFPS(60);
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update and Draw
//----------------------------------------------------------------------------------
UpdateDrawFrame();
//----------------------------------------------------------------------------------
}
#endif
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadGame(); // Unload loaded data (textures, sounds, models...)
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
#if !defined(PLATFORM_ANDROID)
return 0;
#endif
}
//------------------------------------------------------------------------------------
// Module Functions Definitions (local)
//------------------------------------------------------------------------------------
// Initialize game variables
void InitGame(void)
{
framesCounter = 0;
gameOver = false;
pause = false;
counterTail = 1;
allowMove = false;
offset.x = screenWidth%SQUARE_SIZE;
offset.y = screenHeight%SQUARE_SIZE;
for (int i = 0; i < SNAKE_LENGTH; i++)
{
snake[i].position = (Vector2){ offset.x/2, offset.y/2 };
snake[i].size = (Vector2){ SQUARE_SIZE, SQUARE_SIZE };
snake[i].speed = (Vector2){ SQUARE_SIZE, 0 };
if (i == 0) snake[i].color = DARKBLUE;
else snake[i].color = BLUE;
}
for (int i = 0; i < SNAKE_LENGTH; i++)
{
snakePosition[i] = (Vector2){ 0.0f, 0.0f };
}
fruit.size = (Vector2){ SQUARE_SIZE, SQUARE_SIZE };
fruit.color = SKYBLUE;
fruit.active = false;
}
// Update game (one frame)
void UpdateGame(void)
{
if (!gameOver)
{
if (IsKeyPressed('P')) pause = !pause;
if (!pause)
{
// control
if (IsKeyPressed(KEY_RIGHT) && (snake[0].speed.x == 0) && allowMove)
{
snake[0].speed = (Vector2){ SQUARE_SIZE, 0 };
allowMove = false;
}
if (IsKeyPressed(KEY_LEFT) && (snake[0].speed.x == 0) && allowMove)
{
snake[0].speed = (Vector2){ -SQUARE_SIZE, 0 };
allowMove = false;
}
if (IsKeyPressed(KEY_UP) && (snake[0].speed.y == 0) && allowMove)
{
snake[0].speed = (Vector2){ 0, -SQUARE_SIZE };
allowMove = false;
}
if (IsKeyPressed(KEY_DOWN) && (snake[0].speed.y == 0) && allowMove)
{
snake[0].speed = (Vector2){ 0, SQUARE_SIZE };
allowMove = false;
}
// movement
for (int i = 0; i < counterTail; i++) snakePosition[i] = snake[i].position;
if ((framesCounter%5) == 0)
{
for (int i = 0; i < counterTail; i++)
{
if (i == 0)
{
snake[0].position.x += snake[0].speed.x;
snake[0].position.y += snake[0].speed.y;
allowMove = true;
}
else snake[i].position = snakePosition[i-1];
}
}
// wall behaviour
if (((snake[0].position.x) > (screenWidth - offset.x)) ||
((snake[0].position.y) > (screenHeight - offset.y)) ||
(snake[0].position.x < 0) || (snake[0].position.y < 0))
{
gameOver = true;
}
// collision with yourself
for (int i = 1; i < counterTail; i++)
{
if ((snake[0].position.x == snake[i].position.x) && (snake[0].position.y == snake[i].position.y)) gameOver = true;
}
// TODO: review logic: fruit.position calculation
if (!fruit.active)
{
fruit.active = true;
fruit.position = (Vector2){ GetRandomValue(0, (screenWidth/SQUARE_SIZE) - 1)*SQUARE_SIZE + offset.x/2, GetRandomValue(0, (screenHeight/SQUARE_SIZE) - 1)*SQUARE_SIZE + offset.y/2 };
for (int i = 0; i < counterTail; i++)
{
while ((fruit.position.x == snake[i].position.x) && (fruit.position.y == snake[i].position.y))
{
fruit.position = (Vector2){ GetRandomValue(0, (screenWidth/SQUARE_SIZE) - 1)*SQUARE_SIZE, GetRandomValue(0, (screenHeight/SQUARE_SIZE) - 1)*SQUARE_SIZE };
i = 0;
}
}
}
// collision
if (CheckCollisionRecs((Rectangle){(int)snake[0].position.x, (int)snake[0].position.y, (int)snake[0].size.x, (int)snake[0].size.y},
(Rectangle){(int)fruit.position.x, (int)fruit.position.y, (int)fruit.size.x, (int)fruit.size.y}))
{
snake[counterTail].position = snakePosition[counterTail - 1];
counterTail += 1;
fruit.active = false;
}
framesCounter++;
}
}
else
{
if (IsKeyPressed(KEY_ENTER))
{
InitGame();
gameOver = false;
}
}
}
// Draw game (one frame)
void DrawGame(void)
{
BeginDrawing();
ClearBackground(RAYWHITE);
if (!gameOver)
{
// Draw grid lines
for (int i = 0; i < screenWidth/SQUARE_SIZE + 1; i++)
{
DrawLineV((Vector2){SQUARE_SIZE*i + offset.x/2, offset.y/2}, (Vector2){SQUARE_SIZE*i + offset.x/2, screenHeight - offset.y/2}, LIGHTGRAY);
}
for (int i = 0; i < screenHeight/SQUARE_SIZE + 1; i++)
{
DrawLineV((Vector2){offset.x/2, SQUARE_SIZE*i + offset.y/2}, (Vector2){screenWidth - offset.x/2, SQUARE_SIZE*i + offset.y/2}, LIGHTGRAY);
}
// Draw snake
for (int i = 0; i < counterTail; i++) DrawRectangleV(snake[i].position, snake[i].size, snake[i].color);
// Draw fruit to pick
DrawRectangleV(fruit.position, fruit.size, fruit.color);
if (pause) DrawText("GAME PAUSED", screenWidth/2 - MeasureText("GAME PAUSED", 40)/2, screenHeight/2 - 40, 40, GRAY);
}
else DrawText("PRESS [ENTER] TO PLAY AGAIN", GetScreenWidth()/2 - MeasureText("PRESS [ENTER] TO PLAY AGAIN", 20)/2, GetScreenHeight()/2 - 50, 20, GRAY);
EndDrawing();
}
// Unload game variables
void UnloadGame(void)
{
// TODO: Unload all dynamic loaded data (textures, sounds, models...)
}
// Update and Draw (one frame)
void UpdateDrawFrame(void)
{
UpdateGame();
DrawGame();
}