256 lines
8.9 KiB
C
256 lines
8.9 KiB
C
/*******************************************************************************************
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*
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* raylib [shaders] example - Simple shader mask
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*
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* Example originally created with raylib 2.5, last time updated with raylib 3.7
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*
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* Example contributed by Chris Camacho (@chriscamacho) and reviewed by Ramon Santamaria (@raysan5)
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*
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* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
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* BSD-like license that allows static linking with closed source software
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*
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* Copyright (c) 2019-2024 Chris Camacho (@chriscamacho) and Ramon Santamaria (@raysan5)
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*
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********************************************************************************************
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*
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* The shader makes alpha holes in the forground to give the appearance of a top
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* down look at a spotlight casting a pool of light...
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*
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* The right hand side of the screen there is just enough light to see whats
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* going on without the spot light, great for a stealth type game where you
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* have to avoid the spotlights.
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*
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* The left hand side of the screen is in pitch dark except for where the spotlights are.
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*
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* Although this example doesn't scale like the letterbox example, you could integrate
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* the two techniques, but by scaling the actual colour of the render texture rather
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* than using alpha as a mask.
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*
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********************************************************************************************/
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#include "raylib.h"
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#include "raymath.h"
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#if defined(PLATFORM_DESKTOP)
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#define GLSL_VERSION 330
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#else // PLATFORM_ANDROID, PLATFORM_WEB
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#define GLSL_VERSION 100
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#endif
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#define MAX_SPOTS 3 // NOTE: It must be the same as define in shader
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#define MAX_STARS 400
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// Spot data
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typedef struct Spot {
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Vector2 position;
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Vector2 speed;
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float inner;
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float radius;
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// Shader locations
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unsigned int positionLoc;
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unsigned int innerLoc;
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unsigned int radiusLoc;
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} Spot;
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// Stars in the star field have a position and velocity
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typedef struct Star {
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Vector2 position;
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Vector2 speed;
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} Star;
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static void UpdateStar(Star *s);
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static void ResetStar(Star *s);
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//------------------------------------------------------------------------------------
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// Program main entry point
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//------------------------------------------------------------------------------------
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int main(void)
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{
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// Initialization
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//--------------------------------------------------------------------------------------
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const int screenWidth = 800;
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const int screenHeight = 450;
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InitWindow(screenWidth, screenHeight, "raylib [shaders] example - shader spotlight");
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HideCursor();
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Texture texRay = LoadTexture("resources/raysan.png");
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Star stars[MAX_STARS] = { 0 };
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for (int n = 0; n < MAX_STARS; n++) ResetStar(&stars[n]);
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// Progress all the stars on, so they don't all start in the centre
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for (int m = 0; m < screenWidth/2.0; m++)
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{
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for (int n = 0; n < MAX_STARS; n++) UpdateStar(&stars[n]);
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}
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int frameCounter = 0;
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// Use default vert shader
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Shader shdrSpot = LoadShader(0, TextFormat("resources/shaders/glsl%i/spotlight.fs", GLSL_VERSION));
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// Get the locations of spots in the shader
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Spot spots[MAX_SPOTS];
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for (int i = 0; i < MAX_SPOTS; i++)
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{
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char posName[32] = "spots[x].pos\0";
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char innerName[32] = "spots[x].inner\0";
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char radiusName[32] = "spots[x].radius\0";
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posName[6] = '0' + i;
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innerName[6] = '0' + i;
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radiusName[6] = '0' + i;
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spots[i].positionLoc = GetShaderLocation(shdrSpot, posName);
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spots[i].innerLoc = GetShaderLocation(shdrSpot, innerName);
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spots[i].radiusLoc = GetShaderLocation(shdrSpot, radiusName);
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}
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// Tell the shader how wide the screen is so we can have
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// a pitch black half and a dimly lit half.
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unsigned int wLoc = GetShaderLocation(shdrSpot, "screenWidth");
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float sw = (float)GetScreenWidth();
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SetShaderValue(shdrSpot, wLoc, &sw, SHADER_UNIFORM_FLOAT);
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// Randomize the locations and velocities of the spotlights
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// and initialize the shader locations
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for (int i = 0; i < MAX_SPOTS; i++)
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{
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spots[i].position.x = (float)GetRandomValue(64, screenWidth - 64);
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spots[i].position.y = (float)GetRandomValue(64, screenHeight - 64);
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spots[i].speed = (Vector2){ 0, 0 };
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while ((fabs(spots[i].speed.x) + fabs(spots[i].speed.y)) < 2)
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{
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spots[i].speed.x = GetRandomValue(-400, 40) / 10.0f;
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spots[i].speed.y = GetRandomValue(-400, 40) / 10.0f;
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}
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spots[i].inner = 28.0f * (i + 1);
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spots[i].radius = 48.0f * (i + 1);
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SetShaderValue(shdrSpot, spots[i].positionLoc, &spots[i].position.x, SHADER_UNIFORM_VEC2);
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SetShaderValue(shdrSpot, spots[i].innerLoc, &spots[i].inner, SHADER_UNIFORM_FLOAT);
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SetShaderValue(shdrSpot, spots[i].radiusLoc, &spots[i].radius, SHADER_UNIFORM_FLOAT);
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}
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SetTargetFPS(60); // Set to run at 60 frames-per-second
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//--------------------------------------------------------------------------------------
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// Main game loop
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while (!WindowShouldClose()) // Detect window close button or ESC key
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{
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// Update
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//----------------------------------------------------------------------------------
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frameCounter++;
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// Move the stars, resetting them if the go offscreen
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for (int n = 0; n < MAX_STARS; n++) UpdateStar(&stars[n]);
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// Update the spots, send them to the shader
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for (int i = 0; i < MAX_SPOTS; i++)
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{
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if (i == 0)
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{
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Vector2 mp = GetMousePosition();
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spots[i].position.x = mp.x;
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spots[i].position.y = screenHeight - mp.y;
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}
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else
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{
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spots[i].position.x += spots[i].speed.x;
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spots[i].position.y += spots[i].speed.y;
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if (spots[i].position.x < 64) spots[i].speed.x = -spots[i].speed.x;
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if (spots[i].position.x > (screenWidth - 64)) spots[i].speed.x = -spots[i].speed.x;
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if (spots[i].position.y < 64) spots[i].speed.y = -spots[i].speed.y;
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if (spots[i].position.y > (screenHeight - 64)) spots[i].speed.y = -spots[i].speed.y;
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}
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SetShaderValue(shdrSpot, spots[i].positionLoc, &spots[i].position.x, SHADER_UNIFORM_VEC2);
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}
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// Draw
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//----------------------------------------------------------------------------------
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BeginDrawing();
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ClearBackground(DARKBLUE);
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// Draw stars and bobs
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for (int n = 0; n < MAX_STARS; n++)
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{
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// Single pixel is just too small these days!
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DrawRectangle((int)stars[n].position.x, (int)stars[n].position.y, 2, 2, WHITE);
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}
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for (int i = 0; i < 16; i++)
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{
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DrawTexture(texRay,
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(int)((screenWidth/2.0f) + cos((frameCounter + i*8)/51.45f)*(screenWidth/2.2f) - 32),
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(int)((screenHeight/2.0f) + sin((frameCounter + i*8)/17.87f)*(screenHeight/4.2f)), WHITE);
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}
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// Draw spot lights
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BeginShaderMode(shdrSpot);
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// Instead of a blank rectangle you could render here
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// a render texture of the full screen used to do screen
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// scaling (slight adjustment to shader would be required
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// to actually pay attention to the colour!)
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DrawRectangle(0, 0, screenWidth, screenHeight, WHITE);
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EndShaderMode();
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DrawFPS(10, 10);
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DrawText("Move the mouse!", 10, 30, 20, GREEN);
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DrawText("Pitch Black", (int)(screenWidth*0.2f), screenHeight/2, 20, GREEN);
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DrawText("Dark", (int)(screenWidth*.66f), screenHeight/2, 20, GREEN);
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EndDrawing();
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//----------------------------------------------------------------------------------
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}
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// De-Initialization
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//--------------------------------------------------------------------------------------
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UnloadTexture(texRay);
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UnloadShader(shdrSpot);
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CloseWindow(); // Close window and OpenGL context
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//--------------------------------------------------------------------------------------
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return 0;
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}
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static void ResetStar(Star *s)
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{
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s->position = (Vector2){ GetScreenWidth()/2.0f, GetScreenHeight()/2.0f };
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do
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{
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s->speed.x = (float)GetRandomValue(-1000, 1000)/100.0f;
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s->speed.y = (float)GetRandomValue(-1000, 1000)/100.0f;
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} while (!(fabs(s->speed.x) + (fabs(s->speed.y) > 1)));
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s->position = Vector2Add(s->position, Vector2Multiply(s->speed, (Vector2){ 8.0f, 8.0f }));
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}
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static void UpdateStar(Star *s)
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{
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s->position = Vector2Add(s->position, s->speed);
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if ((s->position.x < 0) || (s->position.x > GetScreenWidth()) ||
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(s->position.y < 0) || (s->position.y > GetScreenHeight()))
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{
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ResetStar(s);
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}
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}
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