/*******************************************************************************************
*
* raylib [shaders] example - deferred rendering
*
* Example complexity rating: [★★★★] 4/4
*
* NOTE: This example requires raylib OpenGL 3.3 or OpenGL ES 3.0
*
* Example originally created with raylib 4.5, last time updated with raylib 4.5
*
* Example contributed by Justin Andreas Lacoste (@27justin) 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) 2023-2025 Justin Andreas Lacoste (@27justin)
*
********************************************************************************************/
#include "raylib.h"
#include "rlgl.h"
#include "raymath.h"
#define RLIGHTS_IMPLEMENTATION
#include "rlights.h"
#if defined(PLATFORM_DESKTOP)
#define GLSL_VERSION 330
#else // PLATFORM_ANDROID, PLATFORM_WEB
#define GLSL_VERSION 100
#endif
#include <stdlib.h> // Required for: NULL
#define MAX_CUBES 30
// GBuffer data
typedef struct GBuffer {
unsigned int framebuffer;
unsigned int positionTexture;
unsigned int normalTexture;
unsigned int albedoSpecTexture;
unsigned int depthRenderbuffer;
} GBuffer;
// Deferred mode passes
typedef enum {
DEFERRED_POSITION,
DEFERRED_NORMAL,
DEFERRED_ALBEDO,
DEFERRED_SHADING
} DeferredMode;
//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
// Initialization
// -------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [shaders] example - deferred render");
Camera camera = { 0 };
camera.position = (Vector3){ 5.0f, 4.0f, 5.0f }; // Camera position
camera.target = (Vector3){ 0.0f, 1.0f, 0.0f }; // Camera looking at point
camera.up = (Vector3){ 0.0f, 1.0f, 0.0f }; // Camera up vector (rotation towards target)
camera.fovy = 60.0f; // Camera field-of-view Y
camera.projection = CAMERA_PERSPECTIVE; // Camera projection type
// Load plane model from a generated mesh
Model model = LoadModelFromMesh(GenMeshPlane(10.0f, 10.0f, 3, 3));
Model cube = LoadModelFromMesh(GenMeshCube(2.0f, 2.0f, 2.0f));
// Load geometry buffer (G-buffer) shader and deferred shader
Shader gbufferShader = LoadShader(TextFormat("resources/shaders/glsl%i/gbuffer.vs", GLSL_VERSION),
TextFormat("resources/shaders/glsl%i/gbuffer.fs", GLSL_VERSION));
Shader deferredShader = LoadShader(TextFormat("resources/shaders/glsl%i/deferred_shading.vs", GLSL_VERSION),
TextFormat("resources/shaders/glsl%i/deferred_shading.fs", GLSL_VERSION));
deferredShader.locs[SHADER_LOC_VECTOR_VIEW] = GetShaderLocation(deferredShader, "viewPosition");
// Initialize the G-buffer
GBuffer gBuffer = { 0 };
gBuffer.framebuffer = rlLoadFramebuffer();
if (!gBuffer.framebuffer)
{
TraceLog(LOG_WARNING, "Failed to create framebuffer");
exit(1);
}
rlEnableFramebuffer(gBuffer.framebuffer);
// NOTE: Vertex positions are stored in a texture for simplicity. A better approach would use a depth texture
// (instead of a detph renderbuffer) to reconstruct world positions in the final render shader via clip-space position,
// depth, and the inverse view/projection matrices.
// 16-bit precision ensures OpenGL ES 3 compatibility, though it may lack precision for real scenarios.
// But as mentioned above, the positions could be reconstructed instead of stored. If not targeting OpenGL ES
// and you wish to maintain this approach, consider using `RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32`.
gBuffer.positionTexture = rlLoadTexture(NULL, screenWidth, screenHeight, RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16, 1);
// Similarly, 16-bit precision is used for normals ensures OpenGL ES 3 compatibility.
// This is generally sufficient, but a 16-bit fixed-point format offer a better uniform precision in all orientations.
gBuffer.normalTexture = rlLoadTexture(NULL, screenWidth, screenHeight, RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16, 1);
// Albedo (diffuse color) and specular strength can be combined into one texture.
// The color in RGB, and the specular strength in the alpha channel.
gBuffer.albedoSpecTexture = rlLoadTexture(NULL, screenWidth, screenHeight, RL_PIXELFORMAT_UNCOMPRESSED_R8G8B8A8, 1);
// Activate the draw buffers for our framebuffer
rlActiveDrawBuffers(3);
// Now we attach our textures to the framebuffer.
rlFramebufferAttach(gBuffer.framebuffer, gBuffer.positionTexture, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D, 0);
rlFramebufferAttach(gBuffer.framebuffer, gBuffer.normalTexture, RL_ATTACHMENT_COLOR_CHANNEL1, RL_ATTACHMENT_TEXTURE2D, 0);
rlFramebufferAttach(gBuffer.framebuffer, gBuffer.albedoSpecTexture, RL_ATTACHMENT_COLOR_CHANNEL2, RL_ATTACHMENT_TEXTURE2D, 0);
// Finally we attach the depth buffer.
gBuffer.depthRenderbuffer = rlLoadTextureDepth(screenWidth, screenHeight, true);
rlFramebufferAttach(gBuffer.framebuffer, gBuffer.depthRenderbuffer, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
// Make sure our framebuffer is complete.
// NOTE: rlFramebufferComplete() automatically unbinds the framebuffer, so we don't have
// to rlDisableFramebuffer() here.
if (!rlFramebufferComplete(gBuffer.framebuffer))
{
TraceLog(LOG_WARNING, "Framebuffer is not complete");
}
// Now we initialize the sampler2D uniform's in the deferred shader.
// We do this by setting the uniform's values to the texture units that
// we later bind our g-buffer textures to.
rlEnableShader(deferredShader.id);
int texUnitPosition = 0;
int texUnitNormal = 1;
int texUnitAlbedoSpec = 2;
SetShaderValue(deferredShader, rlGetLocationUniform(deferredShader.id, "gPosition"), &texUnitPosition, RL_SHADER_UNIFORM_SAMPLER2D);
SetShaderValue(deferredShader, rlGetLocationUniform(deferredShader.id, "gNormal"), &texUnitNormal, RL_SHADER_UNIFORM_SAMPLER2D);
SetShaderValue(deferredShader, rlGetLocationUniform(deferredShader.id, "gAlbedoSpec"), &texUnitAlbedoSpec, RL_SHADER_UNIFORM_SAMPLER2D);
rlDisableShader();
// Assign out lighting shader to model
model.materials[0].shader = gbufferShader;
cube.materials[0].shader = gbufferShader;
// Create lights
//--------------------------------------------------------------------------------------
Light lights[MAX_LIGHTS] = { 0 };
lights[0] = CreateLight(LIGHT_POINT, (Vector3){ -2, 1, -2 }, Vector3Zero(), YELLOW, deferredShader);
lights[1] = CreateLight(LIGHT_POINT, (Vector3){ 2, 1, 2 }, Vector3Zero(), RED, deferredShader);
lights[2] = CreateLight(LIGHT_POINT, (Vector3){ -2, 1, 2 }, Vector3Zero(), GREEN, deferredShader);
lights[3] = CreateLight(LIGHT_POINT, (Vector3){ 2, 1, -2 }, Vector3Zero(), BLUE, deferredShader);
const float CUBE_SCALE = 0.25;
Vector3 cubePositions[MAX_CUBES] = { 0 };
float cubeRotations[MAX_CUBES] = { 0 };
for (int i = 0; i < MAX_CUBES; i++)
{
cubePositions[i] = (Vector3){
.x = (float)(rand()%10) - 5,
.y = (float)(rand()%5),
.z = (float)(rand()%10) - 5,
};
cubeRotations[i] = (float)(rand()%360);
}
DeferredMode mode = DEFERRED_SHADING;
rlEnableDepthTest();
SetTargetFPS(60); // Set our game to run at 60 frames-per-second
//---------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose())
{
// Update
//----------------------------------------------------------------------------------
UpdateCamera(&camera, CAMERA_ORBITAL);
// Update the shader with the camera view vector (points towards { 0.0f, 0.0f, 0.0f })
float cameraPos[3] = { camera.position.x, camera.position.y, camera.position.z };
SetShaderValue(deferredShader, deferredShader.locs[SHADER_LOC_VECTOR_VIEW], cameraPos, SHADER_UNIFORM_VEC3);
// Check key inputs to enable/disable lights
if (IsKeyPressed(KEY_Y)) { lights[0].enabled = !lights[0].enabled; }
if (IsKeyPressed(KEY_R)) { lights[1].enabled = !lights[1].enabled; }
if (IsKeyPressed(KEY_G)) { lights[2].enabled = !lights[2].enabled; }
if (IsKeyPressed(KEY_B)) { lights[3].enabled = !lights[3].enabled; }
// Check key inputs to switch between G-buffer textures
if (IsKeyPressed(KEY_ONE)) mode = DEFERRED_POSITION;
if (IsKeyPressed(KEY_TWO)) mode = DEFERRED_NORMAL;
if (IsKeyPressed(KEY_THREE)) mode = DEFERRED_ALBEDO;
if (IsKeyPressed(KEY_FOUR)) mode = DEFERRED_SHADING;
// Update light values (actually, only enable/disable them)
for (int i = 0; i < MAX_LIGHTS; i++) UpdateLightValues(deferredShader, lights[i]);
//----------------------------------------------------------------------------------
// Draw
// ---------------------------------------------------------------------------------
BeginDrawing();
// Draw to the geometry buffer by first activating it
rlEnableFramebuffer(gBuffer.framebuffer);
rlClearColor(0, 0, 0, 0);
rlClearScreenBuffers(); // Clear color and depth buffer
rlDisableColorBlend();
BeginMode3D(camera);
// NOTE: We have to use rlEnableShader here. `BeginShaderMode` or thus `rlSetShader`
// will not work, as they won't immediately load the shader program.
rlEnableShader(gbufferShader.id);
// When drawing a model here, make sure that the material's shaders
// are set to the gbuffer shader!
DrawModel(model, Vector3Zero(), 1.0f, WHITE);
DrawModel(cube, (Vector3) { 0.0, 1.0f, 0.0 }, 1.0f, WHITE);
for (int i = 0; i < MAX_CUBES; i++)
{
Vector3 position = cubePositions[i];
DrawModelEx(cube, position, (Vector3) { 1, 1, 1 }, cubeRotations[i], (Vector3) { CUBE_SCALE, CUBE_SCALE, CUBE_SCALE }, WHITE);
}
rlDisableShader();
EndMode3D();
rlEnableColorBlend();
// Go back to the default framebuffer (0) and draw our deferred shading.
rlDisableFramebuffer();
rlClearScreenBuffers(); // Clear color & depth buffer
switch (mode)
{
case DEFERRED_SHADING:
{
BeginMode3D(camera);
rlDisableColorBlend();
rlEnableShader(deferredShader.id);
// Bind our g-buffer textures
// We are binding them to locations that we earlier set in sampler2D uniforms `gPosition`, `gNormal`,
// and `gAlbedoSpec`
rlActiveTextureSlot(texUnitPosition);
rlEnableTexture(gBuffer.positionTexture);
rlActiveTextureSlot(texUnitNormal);
rlEnableTexture(gBuffer.normalTexture);
rlActiveTextureSlot(texUnitAlbedoSpec);
rlEnableTexture(gBuffer.albedoSpecTexture);
// Finally, we draw a fullscreen quad to our default framebuffer
// This will now be shaded using our deferred shader
rlLoadDrawQuad();
rlDisableShader();
rlEnableColorBlend();
EndMode3D();
// As a last step, we now copy over the depth buffer from our g-buffer to the default framebuffer.
rlBindFramebuffer(RL_READ_FRAMEBUFFER, gBuffer.framebuffer);
rlBindFramebuffer(RL_DRAW_FRAMEBUFFER, 0);
rlBlitFramebuffer(0, 0, screenWidth, screenHeight, 0, 0, screenWidth, screenHeight, 0x00000100); // GL_DEPTH_BUFFER_BIT
rlDisableFramebuffer();
// Since our shader is now done and disabled, we can draw spheres
// that represent light positions in default forward rendering
BeginMode3D(camera);
rlEnableShader(rlGetShaderIdDefault());
for (int i = 0; i < MAX_LIGHTS; i++)
{
if (lights[i].enabled) DrawSphereEx(lights[i].position, 0.2f, 8, 8, lights[i].color);
else DrawSphereWires(lights[i].position, 0.2f, 8, 8, ColorAlpha(lights[i].color, 0.3f));
}
rlDisableShader();
EndMode3D();
DrawText("FINAL RESULT", 10, screenHeight - 30, 20, DARKGREEN);
} break;
case DEFERRED_POSITION:
{
DrawTextureRec((Texture2D){
.id = gBuffer.positionTexture,
.width = screenWidth,
.height = screenHeight,
}, (Rectangle) { 0, 0, (float)screenWidth, (float)-screenHeight }, Vector2Zero(), RAYWHITE);
DrawText("POSITION TEXTURE", 10, screenHeight - 30, 20, DARKGREEN);
} break;
case DEFERRED_NORMAL:
{
DrawTextureRec((Texture2D){
.id = gBuffer.normalTexture,
.width = screenWidth,
.height = screenHeight,
}, (Rectangle) { 0, 0, (float)screenWidth, (float)-screenHeight }, Vector2Zero(), RAYWHITE);
DrawText("NORMAL TEXTURE", 10, screenHeight - 30, 20, DARKGREEN);
} break;
case DEFERRED_ALBEDO:
{
DrawTextureRec((Texture2D){
.id = gBuffer.albedoSpecTexture,
.width = screenWidth,
.height = screenHeight,
}, (Rectangle) { 0, 0, (float)screenWidth, (float)-screenHeight }, Vector2Zero(), RAYWHITE);
DrawText("ALBEDO TEXTURE", 10, screenHeight - 30, 20, DARKGREEN);
} break;
default: break;
}
DrawText("Toggle lights keys: [Y][R][G][B]", 10, 40, 20, DARKGRAY);
DrawText("Switch G-buffer textures: [1][2][3][4]", 10, 70, 20, DARKGRAY);
DrawFPS(10, 10);
EndDrawing();
// -----------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadModel(model); // Unload the models
UnloadModel(cube);
UnloadShader(deferredShader); // Unload shaders
UnloadShader(gbufferShader);
// Unload geometry buffer and all attached textures
rlUnloadFramebuffer(gBuffer.framebuffer);
rlUnloadTexture(gBuffer.positionTexture);
rlUnloadTexture(gBuffer.normalTexture);
rlUnloadTexture(gBuffer.albedoSpecTexture);
rlUnloadTexture(gBuffer.depthRenderbuffer);
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}