/*******************************************************************************************
*
* raylib [shaders] example - Simple shader mask
*
* This example has been created using raylib 2.5 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* Example contributed by Chris Camacho (@codifies - http://bedroomcoders.co.uk/)
* and reviewed by Ramon Santamaria (@raysan5)
*
* Copyright (c) 2019 Chris Camacho (@codifies) and Ramon Santamaria (@raysan5)
*
********************************************************************************************
*
* The shader makes alpha holes in the forground to give the apearance 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"
#include <stddef.h>
#include <stdint.h>
#if defined(PLATFORM_DESKTOP)
#define GLSL_VERSION 330
#else // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB
#define GLSL_VERSION 100
#endif
#define MAXSPOT 3 // NB must be the same as define in shader
#define numStars 400
// Spot data
typedef struct {
Vector2 pos;
Vector2 vel;
float inner;
float radius;
// Shader locations
unsigned int posLoc;
unsigned int innerLoc;
unsigned int radiusLoc;
} Spot;
// Stars in the star field have a position and velocity
typedef struct Star {
Vector2 pos;
Vector2 vel;
} Star;
void UpdateStar(Star *s);
void ResetStar(Star *s);
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib - shader spotlight");
HideCursor();
Texture texRay = LoadTexture("resources/raysan.png");
Star stars[numStars] = { 0 };
for (int n = 0; n < numStars; 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 < numStars; n++) UpdateStar(&stars[n]);
}
int frameCounter = 0;
// Use default vert shader
Shader spotShader = LoadShader(0, FormatText("resources/shaders/glsl%i/spotlight.fs", GLSL_VERSION));
// Get the locations of spots in the shader
Spot spots[MAXSPOT];
/*
unsigned int posLoc;
unsigned int innerLoc;
unsigned int radiusLoc;
*/
for (int i = 0; i < MAXSPOT; 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].posLoc = GetShaderLocation(spotShader, posName);
spots[i].innerLoc = GetShaderLocation(spotShader, innerName);
spots[i].radiusLoc = GetShaderLocation(spotShader, 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(spotShader, "screenWidth");
float sw = (float)GetScreenWidth();
SetShaderValue(spotShader, wLoc, &sw, UNIFORM_FLOAT);
}
// randomise the locations and velocities of the spotlights
// and initialise the shader locations
for (int i = 0; i < MAXSPOT; i++)
{
spots[i].pos.x = GetRandomValue(64, screenWidth - 64);
spots[i].pos.y = GetRandomValue(64, screenHeight - 64);
spots[i].vel = (Vector2){ 0, 0 };
while ((fabs(spots[i].vel.x) + fabs(spots[i].vel.y)) < 2)
{
spots[i].vel.x = GetRandomValue(-40, 40)/10.0;
spots[i].vel.y = GetRandomValue(-40, 40)/10.0;
}
spots[i].inner = 28 * (i + 1);
spots[i].radius = 48 * (i + 1);
SetShaderValue(spotShader, spots[i].posLoc, &spots[i].pos.x, UNIFORM_VEC2);
SetShaderValue(spotShader, spots[i].innerLoc, &spots[i].inner, UNIFORM_FLOAT);
SetShaderValue(spotShader, spots[i].radiusLoc, &spots[i].radius, 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 < numStars; n++) UpdateStar(&stars[n]);
// Update the spots, send them to the shader
for (int i = 0; i < MAXSPOT; i++)
{
if ( i == 0 ) {
Vector2 mp = GetMousePosition();
spots[i].pos.x = mp.x;
spots[i].pos.y = screenHeight - mp.y;
} else {
spots[i].pos.x += spots[i].vel.x;
spots[i].pos.y += spots[i].vel.y;
if (spots[i].pos.x < 64) spots[i].vel.x = -spots[i].vel.x;
if (spots[i].pos.x > screenWidth - 64) spots[i].vel.x = -spots[i].vel.x;
if (spots[i].pos.y < 64) spots[i].vel.y = -spots[i].vel.y;
if (spots[i].pos.y > screenHeight - 64) spots[i].vel.y = -spots[i].vel.y;
}
SetShaderValue(spotShader, spots[i].posLoc, &spots[i].pos.x, UNIFORM_VEC2);
}
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(DARKBLUE);
// Draw stars and bobs
for (int n = 0; n < numStars; n++)
{
// Single pixel is just too small these days!
DrawRectangle(stars[n].pos.x, stars[n].pos.y, 2, 2, WHITE);
}
for (int i = 0; i < 16; i++)
{
DrawTexture(texRay,
(screenWidth/2.0) + cos((frameCounter + i*8)/51.45f)*(screenWidth/2.2) - 32,
(screenHeight/2.0) + sin((frameCounter + i*8)/17.87f)*(screenHeight/4.2),
WHITE);
}
// Draw spot lights
BeginShaderMode(spotShader);
// 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", screenWidth * .2, screenHeight / 2, 20, GREEN);
DrawText("Dark", screenWidth * .66, screenHeight / 2, 20, GREEN);
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadTexture(texRay);
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
void ResetStar(Star *s)
{
s->pos = (Vector2){ GetScreenWidth()/2.0f, GetScreenHeight()/2.0f };
do
{
s->vel.x = (float)GetRandomValue(-1000, 1000)/100.0f;
s->vel.y = (float)GetRandomValue(-1000, 1000)/100.0f;
} while (!(fabs(s->vel.x) + fabs(s->vel.y) > 1));
s->pos = Vector2Add(s->pos, Vector2Multiply(s->vel, (Vector2){ 8, 8 }));
}
void UpdateStar(Star *s)
{
s->pos = Vector2Add(s->pos, s->vel);
if (s->pos.x < 0 || s->pos.x > GetScreenWidth() ||
s->pos.y < 0 || s->pos.y > GetScreenHeight())
{
ResetStar(s);
}
}