/******************************************************************************************* * * raylib [textures] example - Fog of war * * Example originally created with raylib 4.2, last time updated with raylib 4.2 * * Example licensed under an unmodified zlib/libpng license, which is an OSI-certified, * BSD-like license that allows static linking with closed source software * * Copyright (c) 2018-2023 Ramon Santamaria (@raysan5) * ********************************************************************************************/ #include "raylib.h" #include // Required for: calloc(), free() #define MAP_TILE_SIZE 32 // Tiles size 32x32 pixels #define PLAYER_SIZE 16 // Player size #define PLAYER_TILE_VISIBILITY 2 // Player can see 2 tiles around its position // Map data type typedef struct Map { unsigned int tilesX; // Number of tiles in X axis unsigned int tilesY; // Number of tiles in Y axis unsigned char *tileIds; // Tile ids (tilesX*tilesY), defines type of tile to draw unsigned char *tileFog; // Tile fog state (tilesX*tilesY), defines if a tile has fog or half-fog } Map; //------------------------------------------------------------------------------------ // Program main entry point //------------------------------------------------------------------------------------ int main(void) { // Initialization //-------------------------------------------------------------------------------------- int screenWidth = 800; int screenHeight = 450; InitWindow(screenWidth, screenHeight, "raylib [textures] example - fog of war"); Map map = { 0 }; map.tilesX = 25; map.tilesY = 15; // NOTE: We can have up to 256 values for tile ids and for tile fog state, // probably we don't need that many values for fog state, it can be optimized // to use only 2 bits per fog state (reducing size by 4) but logic will be a bit more complex map.tileIds = (unsigned char *)calloc(map.tilesX*map.tilesY, sizeof(unsigned char)); map.tileFog = (unsigned char *)calloc(map.tilesX*map.tilesY, sizeof(unsigned char)); // Load map tiles (generating 2 random tile ids for testing) // NOTE: Map tile ids should be probably loaded from an external map file for (unsigned int i = 0; i < map.tilesY*map.tilesX; i++) map.tileIds[i] = GetRandomValue(0, 1); // Player position on the screen (pixel coordinates, not tile coordinates) Vector2 playerPosition = { 180, 130 }; int playerTileX = 0; int playerTileY = 0; // Render texture to render fog of war // NOTE: To get an automatic smooth-fog effect we use a render texture to render fog // at a smaller size (one pixel per tile) and scale it on drawing with bilinear filtering RenderTexture2D fogOfWar = LoadRenderTexture(map.tilesX, map.tilesY); SetTextureFilter(fogOfWar.texture, TEXTURE_FILTER_BILINEAR); SetTargetFPS(60); // Set our game to run at 60 frames-per-second //-------------------------------------------------------------------------------------- // Main game loop while (!WindowShouldClose()) // Detect window close button or ESC key { // Update //---------------------------------------------------------------------------------- // Move player around if (IsKeyDown(KEY_RIGHT)) playerPosition.x += 5; if (IsKeyDown(KEY_LEFT)) playerPosition.x -= 5; if (IsKeyDown(KEY_DOWN)) playerPosition.y += 5; if (IsKeyDown(KEY_UP)) playerPosition.y -= 5; // Check player position to avoid moving outside tilemap limits if (playerPosition.x < 0) playerPosition.x = 0; else if ((playerPosition.x + PLAYER_SIZE) > (map.tilesX*MAP_TILE_SIZE)) playerPosition.x = (float)map.tilesX*MAP_TILE_SIZE - PLAYER_SIZE; if (playerPosition.y < 0) playerPosition.y = 0; else if ((playerPosition.y + PLAYER_SIZE) > (map.tilesY*MAP_TILE_SIZE)) playerPosition.y = (float)map.tilesY*MAP_TILE_SIZE - PLAYER_SIZE; // Previous visited tiles are set to partial fog for (unsigned int i = 0; i < map.tilesX*map.tilesY; i++) if (map.tileFog[i] == 1) map.tileFog[i] = 2; // Get current tile position from player pixel position playerTileX = (int)((playerPosition.x + MAP_TILE_SIZE/2)/MAP_TILE_SIZE); playerTileY = (int)((playerPosition.y + MAP_TILE_SIZE/2)/MAP_TILE_SIZE); // Check visibility and update fog // NOTE: We check tilemap limits to avoid processing tiles out-of-array-bounds (it could crash program) for (int y = (playerTileY - PLAYER_TILE_VISIBILITY); y < (playerTileY + PLAYER_TILE_VISIBILITY); y++) for (int x = (playerTileX - PLAYER_TILE_VISIBILITY); x < (playerTileX + PLAYER_TILE_VISIBILITY); x++) if ((x >= 0) && (x < (int)map.tilesX) && (y >= 0) && (y < (int)map.tilesY)) map.tileFog[y*map.tilesX + x] = 1; //---------------------------------------------------------------------------------- // Draw //---------------------------------------------------------------------------------- // Draw fog of war to a small render texture for automatic smoothing on scaling BeginTextureMode(fogOfWar); ClearBackground(BLANK); for (unsigned int y = 0; y < map.tilesY; y++) for (unsigned int x = 0; x < map.tilesX; x++) if (map.tileFog[y*map.tilesX + x] == 0) DrawRectangle(x, y, 1, 1, BLACK); else if (map.tileFog[y*map.tilesX + x] == 2) DrawRectangle(x, y, 1, 1, Fade(BLACK, 0.8f)); EndTextureMode(); BeginDrawing(); ClearBackground(RAYWHITE); for (unsigned int y = 0; y < map.tilesY; y++) { for (unsigned int x = 0; x < map.tilesX; x++) { // Draw tiles from id (and tile borders) DrawRectangle(x*MAP_TILE_SIZE, y*MAP_TILE_SIZE, MAP_TILE_SIZE, MAP_TILE_SIZE, (map.tileIds[y*map.tilesX + x] == 0)? BLUE : Fade(BLUE, 0.9f)); DrawRectangleLines(x*MAP_TILE_SIZE, y*MAP_TILE_SIZE, MAP_TILE_SIZE, MAP_TILE_SIZE, Fade(DARKBLUE, 0.5f)); } } // Draw player DrawRectangleV(playerPosition, (Vector2){ PLAYER_SIZE, PLAYER_SIZE }, RED); // Draw fog of war (scaled to full map, bilinear filtering) DrawTexturePro(fogOfWar.texture, (Rectangle){ 0, 0, (float)fogOfWar.texture.width, (float)-fogOfWar.texture.height }, (Rectangle){ 0, 0, (float)map.tilesX*MAP_TILE_SIZE, (float)map.tilesY*MAP_TILE_SIZE }, (Vector2){ 0, 0 }, 0.0f, WHITE); // Draw player current tile DrawText(TextFormat("Current tile: [%i,%i]", playerTileX, playerTileY), 10, 10, 20, LIME); EndDrawing(); //---------------------------------------------------------------------------------- } // De-Initialization //-------------------------------------------------------------------------------------- free(map.tileIds); // Free allocated map tile ids free(map.tileFog); // Free allocated map tile fog state UnloadRenderTexture(fogOfWar); // Unload render texture CloseWindow(); // Close window and OpenGL context //-------------------------------------------------------------------------------------- return 0; }