[examples] Add lights_bloom_post (#6081)

Add a bloom light effect example

examples/shaders/resources/shaders/glsl100/lights_bloom.fs

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+#version 100
+
+precision mediump float;
+
+// Input values from vertex shader
+varying vec3 fragPosition;
+varying vec3 fragNormal;
+varying vec2 fragTexCoord;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec3 viewPos;
+uniform vec3 lightPositions[8];
+uniform vec3 lightColors[8];
+
+void main()
+{
+    vec4 texColor = texture2D(texture0, fragTexCoord);
+    vec3 norm = normalize(fragNormal);
+    vec3 viewDir = normalize(viewPos - fragPosition);
+
+    vec3 ambient = 0.05*texColor.rgb;
+    vec3 totalDiffuse = vec3(0.0);
+    vec3 totalSpecular = vec3(0.0);
+
+    for (int i = 0; i < 8; i++)
+    {
+        vec3 lightDir = normalize(lightPositions[i] - fragPosition);
+        float dist = length(lightPositions[i] - fragPosition);
+        float attenuation = 1.0/(1.0 + 0.8*dist + 0.4*dist*dist);
+
+        // Diffuse shading
+        float diff = max(dot(norm, lightDir), 0.0);
+        totalDiffuse += diff*lightColors[i]*attenuation*1.2;
+
+        // Blinn-Phong specular
+        vec3 halfwayDir = normalize(lightDir + viewDir);
+        float spec = pow(max(dot(norm, halfwayDir), 0.0), 32.0);
+        totalSpecular += spec*lightColors[i]*attenuation*0.8;
+    }
+
+    vec3 result = ambient + (totalDiffuse*texColor.rgb) + totalSpecular;
+    gl_FragColor = vec4(result, texColor.a);
+}

examples/shaders/resources/shaders/glsl100/lights_bloom.vs

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+#version 100
+
+// Input vertex attributes
+attribute vec3 vertexPosition;
+attribute vec2 vertexTexCoord;
+attribute vec3 vertexNormal;
+
+// Output values to fragment shader
+varying vec3 fragPosition;
+varying vec3 fragNormal;
+varying vec2 fragTexCoord;
+
+// Input uniform values
+uniform mat4 mvp;
+uniform mat4 matModel;
+
+void main()
+{
+    fragPosition = vec3(matModel*vec4(vertexPosition, 1.0));
+    fragNormal = normalize(vec3(matModel*vec4(vertexNormal, 0.0)));
+    fragTexCoord = vertexTexCoord;
+    gl_Position = mvp*vec4(vertexPosition, 1.0);
+}

examples/shaders/resources/shaders/glsl100/lights_bloom_post.fs

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+#version 100
+
+precision mediump float;
+
+varying vec2 fragTexCoord;
+
+uniform sampler2D texture0;
+
+void main()
+{
+    vec4 color = texture2D(texture0, fragTexCoord);
+
+    // High-pass threshold blur: only pixels brighter than 0.75 in any channel contribute
+    vec4 bloom = vec4(0.0);
+    vec2 texel = vec2(1.0/1280.0, 1.0/720.0)*2.5;
+
+    for (int x = -2; x <= 2; x++)
+    {
+        for (int y = -2; y <= 2; y++)
+        {
+            vec4 smp = texture2D(texture0, fragTexCoord + vec2(float(x), float(y))*texel);
+            float brightness = max(smp.r, max(smp.g, smp.b));
+            if (brightness > 0.75) bloom += smp;
+        }
+    }
+    bloom /= 25.0;
+
+    // Combine original with the bloom glow, then Reinhard tone-map back to [0, 1]
+    vec3 hdr = color.rgb + bloom.rgb*1.2;
+    vec3 ldr = hdr/(hdr + vec3(1.0));
+
+    gl_FragColor = vec4(ldr, color.a);
+}

examples/shaders/resources/shaders/glsl330/lights_bloom.fs

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+#version 330
+
+// Input values from vertex shader
+in vec3 fragPosition;
+in vec3 fragNormal;
+in vec2 fragTexCoord;
+
+out vec4 finalColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec3 viewPos;
+uniform vec3 lightPositions[8];
+uniform vec3 lightColors[8];
+
+void main()
+{
+    vec4 texColor = texture(texture0, fragTexCoord);
+    vec3 norm = normalize(fragNormal);
+    vec3 viewDir = normalize(viewPos - fragPosition);
+
+    vec3 ambient = 0.05*texColor.rgb;
+    vec3 totalDiffuse = vec3(0.0);
+    vec3 totalSpecular = vec3(0.0);
+
+    for (int i = 0; i < 8; i++)
+    {
+        vec3 lightDir = normalize(lightPositions[i] - fragPosition);
+        float dist = length(lightPositions[i] - fragPosition);
+        float attenuation = 1.0/(1.0 + 0.8*dist + 0.4*dist*dist);
+
+        // Diffuse shading
+        float diff = max(dot(norm, lightDir), 0.0);
+        totalDiffuse += diff*lightColors[i]*attenuation*1.2;
+
+        // Blinn-Phong specular
+        vec3 halfwayDir = normalize(lightDir + viewDir);
+        float spec = pow(max(dot(norm, halfwayDir), 0.0), 32.0);
+        totalSpecular += spec*lightColors[i]*attenuation*0.8;
+    }
+
+    vec3 result = ambient + (totalDiffuse*texColor.rgb) + totalSpecular;
+    finalColor = vec4(result, texColor.a);
+}

examples/shaders/resources/shaders/glsl330/lights_bloom.vs

@@ -0,0 +1,23 @@
+#version 330
+
+// Input vertex attributes
+in vec3 vertexPosition;
+in vec2 vertexTexCoord;
+in vec3 vertexNormal;
+
+// Output values to fragment shader
+out vec3 fragPosition;
+out vec3 fragNormal;
+out vec2 fragTexCoord;
+
+// Input uniform values
+uniform mat4 mvp;
+uniform mat4 matModel;
+
+void main()
+{
+    fragPosition = vec3(matModel*vec4(vertexPosition, 1.0));
+    fragNormal = normalize(vec3(matModel*vec4(vertexNormal, 0.0)));
+    fragTexCoord = vertexTexCoord;
+    gl_Position = mvp*vec4(vertexPosition, 1.0);
+}

examples/shaders/resources/shaders/glsl330/lights_bloom_post.fs

@@ -0,0 +1,32 @@
+#version 330
+
+in vec2 fragTexCoord;
+out vec4 finalColor;
+
+uniform sampler2D texture0;
+
+void main()
+{
+    vec4 color = texture(texture0, fragTexCoord);
+
+    // High-pass threshold blur: only pixels brighter than 0.75 in any channel contribute
+    vec4 bloom = vec4(0.0);
+    vec2 texel = vec2(1.0/1280.0, 1.0/720.0)*2.5;
+
+    for (int x = -2; x <= 2; x++)
+    {
+        for (int y = -2; y <= 2; y++)
+        {
+            vec4 smp = texture(texture0, fragTexCoord + vec2(float(x), float(y))*texel);
+            float brightness = max(smp.r, max(smp.g, smp.b));
+            if (brightness > 0.75) bloom += smp;
+        }
+    }
+    bloom /= 25.0;
+
+    // Combine original with the bloom glow, then Reinhard tone-map back to [0, 1]
+    vec3 hdr = color.rgb + bloom.rgb*1.2;
+    vec3 ldr = hdr/(hdr + vec3(1.0));
+
+    finalColor = vec4(ldr, color.a);
+}

examples/shaders/shaders_lights_bloom.c

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+/*******************************************************************************************
+*
+*   raylib [shaders] example - forward multi-lighting with bloom
+*
+*   Example demonstrates forward multi-point lighting (8 point lights, attenuation and
+*   Blinn-Phong specular) combined with a threshold-based bloom pass and Reinhard tone
+*   mapping, applied as a full-screen post-process pass
+*
+*   Example complexity rating: [★★★☆] 3/4
+*
+*   Example uses resources/shaders/glsl100 and resources/shaders/glsl330, shared with the
+*   rest of the shaders examples
+*
+*   Example originally created with raylib 6.0, last time updated with raylib 6.0
+*
+*   Example contributed by PanicTitan (@PanicTitan) 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) 2025 PanicTitan (@PanicTitan)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+#include "raymath.h"
+#include "rlgl.h"
+
+#include <math.h>       // Required for: sinf(), cosf()
+
+#if defined(PLATFORM_DESKTOP)
+    #define GLSL_VERSION            330
+#else   // PLATFORM_ANDROID, PLATFORM_WEB
+    #define GLSL_VERSION            100
+#endif
+
+//--------------------------------------------------------------------------------------
+// Global Definitions
+//--------------------------------------------------------------------------------------
+#define MAX_LIGHTS      8
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 1280;
+    const int screenHeight = 720;
+
+    SetConfigFlags(FLAG_MSAA_4X_HINT | FLAG_VSYNC_HINT);
+    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - forward multi-lighting bloom");
+
+    Camera3D camera = { 0 };
+    camera.position = (Vector3){ 0.0f, 5.0f, 9.0f };
+    camera.target = (Vector3){ 0.0f, 0.5f, 0.0f };
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
+    camera.fovy = 45.0f;
+    camera.projection = CAMERA_PERSPECTIVE;
+
+    RenderTexture2D target = LoadRenderTexture(screenWidth, screenHeight);
+
+    // Forward multi-light shader and bloom post-process shader, both loaded from the
+    // resources folder shared with the rest of the shaders examples. If the GLSL version
+    // guessed from the PLATFORM_DESKTOP build flag turns out to be wrong for whatever
+    // raylib was built against, linking fails and silently falls back to the default
+    // shader - so this retries once with the other version, and either way the result
+    // is checked explicitly and reported on screen rather than staying silently wrong
+    int glslVersion = GLSL_VERSION;
+    Shader lightShader = LoadShader(TextFormat("resources/shaders/glsl%i/lights_bloom.vs", glslVersion),
+                                     TextFormat("resources/shaders/glsl%i/lights_bloom.fs", glslVersion));
+    Shader bloomShader = LoadShader(0, TextFormat("resources/shaders/glsl%i/lights_bloom_post.fs", glslVersion));
+
+    if ((lightShader.id == rlGetShaderIdDefault()) || (bloomShader.id == rlGetShaderIdDefault()))
+    {
+        glslVersion = (glslVersion == 330)? 100 : 330;
+        UnloadShader(lightShader);
+        UnloadShader(bloomShader);
+        lightShader = LoadShader(TextFormat("resources/shaders/glsl%i/lights_bloom.vs", glslVersion),
+                                  TextFormat("resources/shaders/glsl%i/lights_bloom.fs", glslVersion));
+        bloomShader = LoadShader(0, TextFormat("resources/shaders/glsl%i/lights_bloom_post.fs", glslVersion));
+    }
+
+    bool shadersLoaded = (lightShader.id != rlGetShaderIdDefault()) && (bloomShader.id != rlGetShaderIdDefault());
+
+    Model cube = LoadModelFromMesh(GenMeshCube(2.0f, 2.0f, 2.0f));
+    Model floor = LoadModelFromMesh(GenMeshPlane(14.0f, 14.0f, 1, 1));
+    cube.materials[0].shader = lightShader;
+    floor.materials[0].shader = lightShader;
+
+    int lightPosLoc = GetShaderLocation(lightShader, "lightPositions");
+    int lightColLoc = GetShaderLocation(lightShader, "lightColors");
+    int viewPosLoc = GetShaderLocation(lightShader, "viewPos");
+
+    Vector3 lightPositions[MAX_LIGHTS] = { 0 };
+    Vector3 lightColors[MAX_LIGHTS] = {
+        { 1.0f, 0.2f, 0.2f },   // Red
+        { 0.2f, 1.0f, 0.3f },   // Green
+        { 0.2f, 0.5f, 1.0f },   // Blue
+        { 1.0f, 0.8f, 0.1f },   // Yellow
+        { 1.0f, 0.1f, 0.8f },   // Magenta
+        { 0.1f, 1.0f, 1.0f },   // Cyan
+        { 1.0f, 0.4f, 0.1f },   // Orange
+        { 0.7f, 0.2f, 1.0f },   // Purple
+    };
+
+    SetShaderValueV(lightShader, lightColLoc, lightColors, SHADER_UNIFORM_VEC3, MAX_LIGHTS);
+
+    SetTargetFPS(60);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        UpdateCamera(&camera, CAMERA_ORBITAL);
+
+        float time = (float)GetTime();
+
+        // Orbital path for each point light, its own radius/height offset by index
+        for (int i = 0; i < MAX_LIGHTS; i++)
+        {
+            float angle = (i/(float)MAX_LIGHTS)*2.0f*PI + time*0.6f;
+            float radius = 4.2f + sinf(time*1.2f + i)*0.4f;
+            float height = 1.0f + sinf(time*1.8f + i)*0.6f;
+
+            lightPositions[i] = (Vector3){ sinf(angle)*radius, height, cosf(angle)*radius };
+        }
+
+        SetShaderValueV(lightShader, lightPosLoc, lightPositions, SHADER_UNIFORM_VEC3, MAX_LIGHTS);
+        SetShaderValue(lightShader, viewPosLoc, &camera.position, SHADER_UNIFORM_VEC3);
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        // Render the lit scene to an offscreen texture
+        BeginTextureMode(target);
+
+            ClearBackground((Color){ 12, 12, 18, 255 });
+
+            BeginMode3D(camera);
+
+                DrawModel(cube, (Vector3){ 0.0f, 1.0f, 0.0f }, 1.0f, GRAY);
+                DrawModel(floor, (Vector3){ 0.0f, 0.0f, 0.0f }, 1.0f, DARKGRAY);
+                DrawGrid(10, 1.0f);
+
+                // Glowing bulbs mark each light's position
+                for (int i = 0; i < MAX_LIGHTS; i++)
+                {
+                    Color bulbColor = (Color){
+                        (unsigned char)(lightColors[i].x*255),
+                        (unsigned char)(lightColors[i].y*255),
+                        (unsigned char)(lightColors[i].z*255),
+                        255 };
+
+                    DrawSphere(lightPositions[i], 0.15f, bulbColor);
+                }
+
+            EndMode3D();
+
+        EndTextureMode();
+
+        // Present the offscreen texture through the bloom + tone mapping shader
+        BeginDrawing();
+
+            ClearBackground(BLACK);
+
+            Rectangle srcRec = { 0, 0, (float)target.texture.width, (float)-target.texture.height };
+
+            BeginShaderMode(bloomShader);
+                // NOTE: Render texture must be y-flipped due to default OpenGL coordinates (left-bottom)
+                DrawTextureRec(target.texture, srcRec, (Vector2){ 0, 0 }, WHITE);
+            EndShaderMode();
+
+            DrawText("BALANCED MULTI-LIGHT + REINHARD TONE MAPPED BLOOM", 20, 20, 20, GREEN);
+            DrawFPS(10, 10);
+
+            if (!shadersLoaded) DrawText("WARNING: a custom shader failed to load, showing plain image", 20, screenHeight - 30, 10, RED);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadModel(cube);
+    UnloadModel(floor);
+    UnloadShader(lightShader);
+    UnloadShader(bloomShader);
+    UnloadRenderTexture(target);
+
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}