/******************************************************************************************* * * raylib [shaders] example - Simple shader mask * * Example originally created with raylib 2.5, last time updated with raylib 3.7 * * Example contributed by Chris Camacho (@chriscamacho) and reviewed by Ramon Santamaria (@raysan5) * * 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) 2019-2023 Chris Camacho (@chriscamacho) and Ramon Santamaria (@raysan5) * ******************************************************************************************** * * The shader makes alpha holes in the forground to give the appearance of a top * down look at a spotlight casting a pool of light... * * The right hand side of the screen there is just enough light to see whats * going on without the spot light, great for a stealth type game where you * have to avoid the spotlights. * * The left hand side of the screen is in pitch dark except for where the spotlights are. * * Although this example doesn't scale like the letterbox example, you could integrate * the two techniques, but by scaling the actual colour of the render texture rather * than using alpha as a mask. * ********************************************************************************************/ #include "raylib.h" #include "raymath.h" #if defined(PLATFORM_DESKTOP) #define GLSL_VERSION 330 #else // PLATFORM_ANDROID, PLATFORM_WEB #define GLSL_VERSION 100 #endif #define MAX_SPOTS 3 // NOTE: It must be the same as define in shader #define MAX_STARS 400 // Spot data typedef struct Spot { Vector2 position; Vector2 speed; float inner; float radius; // Shader locations unsigned int positionLoc; unsigned int innerLoc; unsigned int radiusLoc; } Spot; // Stars in the star field have a position and velocity typedef struct Star { Vector2 position; Vector2 speed; } Star; static void UpdateStar(Star *s); static void ResetStar(Star *s); //------------------------------------------------------------------------------------ // Program main entry point //------------------------------------------------------------------------------------ int main(void) { // Initialization //-------------------------------------------------------------------------------------- const int screenWidth = 800; const int screenHeight = 450; InitWindow(screenWidth, screenHeight, "raylib [shaders] example - shader spotlight"); HideCursor(); Texture texRay = LoadTexture("resources/raysan.png"); Star stars[MAX_STARS] = { 0 }; for (int n = 0; n < MAX_STARS; n++) ResetStar(&stars[n]); // Progress all the stars on, so they don't all start in the centre for (int m = 0; m < screenWidth/2.0; m++) { for (int n = 0; n < MAX_STARS; n++) UpdateStar(&stars[n]); } int frameCounter = 0; // Use default vert shader Shader shdrSpot = LoadShader(0, TextFormat("resources/shaders/glsl%i/spotlight.fs", GLSL_VERSION)); // Get the locations of spots in the shader Spot spots[MAX_SPOTS]; for (int i = 0; i < MAX_SPOTS; i++) { char posName[32] = "spots[x].pos\0"; char innerName[32] = "spots[x].inner\0"; char radiusName[32] = "spots[x].radius\0"; posName[6] = '0' + i; innerName[6] = '0' + i; radiusName[6] = '0' + i; spots[i].positionLoc = GetShaderLocation(shdrSpot, posName); spots[i].innerLoc = GetShaderLocation(shdrSpot, innerName); spots[i].radiusLoc = GetShaderLocation(shdrSpot, radiusName); } // Tell the shader how wide the screen is so we can have // a pitch black half and a dimly lit half. unsigned int wLoc = GetShaderLocation(shdrSpot, "screenWidth"); float sw = (float)GetScreenWidth(); SetShaderValue(shdrSpot, wLoc, &sw, SHADER_UNIFORM_FLOAT); // Randomize the locations and velocities of the spotlights // and initialize the shader locations for (int i = 0; i < MAX_SPOTS; i++) { spots[i].position.x = (float)GetRandomValue(64, screenWidth - 64); spots[i].position.y = (float)GetRandomValue(64, screenHeight - 64); spots[i].speed = (Vector2){ 0, 0 }; while ((fabs(spots[i].speed.x) + fabs(spots[i].speed.y)) < 2) { spots[i].speed.x = GetRandomValue(-400, 40) / 10.0f; spots[i].speed.y = GetRandomValue(-400, 40) / 10.0f; } spots[i].inner = 28.0f * (i + 1); spots[i].radius = 48.0f * (i + 1); SetShaderValue(shdrSpot, spots[i].positionLoc, &spots[i].position.x, SHADER_UNIFORM_VEC2); SetShaderValue(shdrSpot, spots[i].innerLoc, &spots[i].inner, SHADER_UNIFORM_FLOAT); SetShaderValue(shdrSpot, spots[i].radiusLoc, &spots[i].radius, SHADER_UNIFORM_FLOAT); } SetTargetFPS(60); // Set to run at 60 frames-per-second //-------------------------------------------------------------------------------------- // Main game loop while (!WindowShouldClose()) // Detect window close button or ESC key { // Update //---------------------------------------------------------------------------------- frameCounter++; // Move the stars, resetting them if the go offscreen for (int n = 0; n < MAX_STARS; n++) UpdateStar(&stars[n]); // Update the spots, send them to the shader for (int i = 0; i < MAX_SPOTS; i++) { if (i == 0) { Vector2 mp = GetMousePosition(); spots[i].position.x = mp.x; spots[i].position.y = screenHeight - mp.y; } else { spots[i].position.x += spots[i].speed.x; spots[i].position.y += spots[i].speed.y; if (spots[i].position.x < 64) spots[i].speed.x = -spots[i].speed.x; if (spots[i].position.x > (screenWidth - 64)) spots[i].speed.x = -spots[i].speed.x; if (spots[i].position.y < 64) spots[i].speed.y = -spots[i].speed.y; if (spots[i].position.y > (screenHeight - 64)) spots[i].speed.y = -spots[i].speed.y; } SetShaderValue(shdrSpot, spots[i].positionLoc, &spots[i].position.x, SHADER_UNIFORM_VEC2); } // Draw //---------------------------------------------------------------------------------- BeginDrawing(); ClearBackground(DARKBLUE); // Draw stars and bobs for (int n = 0; n < MAX_STARS; n++) { // Single pixel is just too small these days! DrawRectangle((int)stars[n].position.x, (int)stars[n].position.y, 2, 2, WHITE); } for (int i = 0; i < 16; i++) { DrawTexture(texRay, (int)((screenWidth/2.0f) + cos((frameCounter + i*8)/51.45f)*(screenWidth/2.2f) - 32), (int)((screenHeight/2.0f) + sin((frameCounter + i*8)/17.87f)*(screenHeight/4.2f)), WHITE); } // Draw spot lights BeginShaderMode(shdrSpot); // Instead of a blank rectangle you could render here // a render texture of the full screen used to do screen // scaling (slight adjustment to shader would be required // to actually pay attention to the colour!) DrawRectangle(0, 0, screenWidth, screenHeight, WHITE); EndShaderMode(); DrawFPS(10, 10); DrawText("Move the mouse!", 10, 30, 20, GREEN); DrawText("Pitch Black", (int)(screenWidth*0.2f), screenHeight/2, 20, GREEN); DrawText("Dark", (int)(screenWidth*.66f), screenHeight/2, 20, GREEN); EndDrawing(); //---------------------------------------------------------------------------------- } // De-Initialization //-------------------------------------------------------------------------------------- UnloadTexture(texRay); UnloadShader(shdrSpot); CloseWindow(); // Close window and OpenGL context //-------------------------------------------------------------------------------------- return 0; } static void ResetStar(Star *s) { s->position = (Vector2){ GetScreenWidth()/2.0f, GetScreenHeight()/2.0f }; do { s->speed.x = (float)GetRandomValue(-1000, 1000)/100.0f; s->speed.y = (float)GetRandomValue(-1000, 1000)/100.0f; } while (!(fabs(s->speed.x) + (fabs(s->speed.y) > 1))); s->position = Vector2Add(s->position, Vector2Multiply(s->speed, (Vector2){ 8.0f, 8.0f })); } static void UpdateStar(Star *s) { s->position = Vector2Add(s->position, s->speed); if ((s->position.x < 0) || (s->position.x > GetScreenWidth()) || (s->position.y < 0) || (s->position.y > GetScreenHeight())) { ResetStar(s); } }