/*******************************************************************************************
*
* raylib [shaders] example - Shadowmap
*
* Example complexity rating: [★★★★] 4/4
*
* Example originally created with raylib 5.0, last time updated with raylib 5.0
*
* Example contributed by TheManTheMythTheGameDev (@TheManTheMythTheGameDev) 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 TheManTheMythTheGameDev (@TheManTheMythTheGameDev)
*
********************************************************************************************/
#include "raylib.h"
#include "raymath.h"
#include "rlgl.h"
#if defined(PLATFORM_DESKTOP)
#define GLSL_VERSION 330
#else // PLATFORM_ANDROID, PLATFORM_WEB
#define GLSL_VERSION 120
#endif
#define SHADOWMAP_RESOLUTION 1024
RenderTexture2D LoadShadowmapRenderTexture(int width, int height);
void UnloadShadowmapRenderTexture(RenderTexture2D target);
void DrawScene(Model cube, Model robot);
//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
SetConfigFlags(FLAG_MSAA_4X_HINT);
// Shadows are a HUGE topic, and this example shows an extremely simple implementation of the shadowmapping algorithm,
// which is the industry standard for shadows. This algorithm can be extended in a ridiculous number of ways to improve
// realism and also adapt it for different scenes. This is pretty much the simplest possible implementation.
InitWindow(screenWidth, screenHeight, "raylib [shaders] example - shadowmap");
Camera3D cam = (Camera3D){ 0 };
cam.position = (Vector3){ 10.0f, 10.0f, 10.0f };
cam.target = Vector3Zero();
cam.projection = CAMERA_PERSPECTIVE;
cam.up = (Vector3){ 0.0f, 1.0f, 0.0f };
cam.fovy = 45.0f;
Shader shadowShader = LoadShader(TextFormat("resources/shaders/glsl%i/shadowmap.vs", GLSL_VERSION),
TextFormat("resources/shaders/glsl%i/shadowmap.fs", GLSL_VERSION));
shadowShader.locs[SHADER_LOC_VECTOR_VIEW] = GetShaderLocation(shadowShader, "viewPos");
Vector3 lightDir = Vector3Normalize((Vector3){ 0.35f, -1.0f, -0.35f });
Color lightColor = WHITE;
Vector4 lightColorNormalized = ColorNormalize(lightColor);
int lightDirLoc = GetShaderLocation(shadowShader, "lightDir");
int lightColLoc = GetShaderLocation(shadowShader, "lightColor");
SetShaderValue(shadowShader, lightDirLoc, &lightDir, SHADER_UNIFORM_VEC3);
SetShaderValue(shadowShader, lightColLoc, &lightColorNormalized, SHADER_UNIFORM_VEC4);
int ambientLoc = GetShaderLocation(shadowShader, "ambient");
float ambient[4] = {0.1f, 0.1f, 0.1f, 1.0f};
SetShaderValue(shadowShader, ambientLoc, ambient, SHADER_UNIFORM_VEC4);
int lightVPLoc = GetShaderLocation(shadowShader, "lightVP");
int shadowMapLoc = GetShaderLocation(shadowShader, "shadowMap");
int shadowMapResolution = SHADOWMAP_RESOLUTION;
SetShaderValue(shadowShader, GetShaderLocation(shadowShader, "shadowMapResolution"), &shadowMapResolution, SHADER_UNIFORM_INT);
Model cube = LoadModelFromMesh(GenMeshCube(1.0f, 1.0f, 1.0f));
cube.materials[0].shader = shadowShader;
Model robot = LoadModel("resources/models/robot.glb");
for (int i = 0; i < robot.materialCount; i++)
{
robot.materials[i].shader = shadowShader;
}
int animCount = 0;
ModelAnimation* robotAnimations = LoadModelAnimations("resources/models/robot.glb", &animCount);
RenderTexture2D shadowMap = LoadShadowmapRenderTexture(SHADOWMAP_RESOLUTION, SHADOWMAP_RESOLUTION);
// For the shadowmapping algorithm, we will be rendering everything from the light's point of view
Camera3D lightCam = (Camera3D){ 0 };
lightCam.position = Vector3Scale(lightDir, -15.0f);
lightCam.target = Vector3Zero();
// Use an orthographic projection for directional lights
lightCam.projection = CAMERA_ORTHOGRAPHIC;
lightCam.up = (Vector3){ 0.0f, 1.0f, 0.0f };
lightCam.fovy = 20.0f;
SetTargetFPS(60);
//--------------------------------------------------------------------------------------
int fc = 0;
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
float dt = GetFrameTime();
Vector3 cameraPos = cam.position;
SetShaderValue(shadowShader, shadowShader.locs[SHADER_LOC_VECTOR_VIEW], &cameraPos, SHADER_UNIFORM_VEC3);
UpdateCamera(&cam, CAMERA_ORBITAL);
fc++;
fc %= (robotAnimations[0].frameCount);
UpdateModelAnimation(robot, robotAnimations[0], fc);
const float cameraSpeed = 0.05f;
if (IsKeyDown(KEY_LEFT))
{
if (lightDir.x < 0.6f)
lightDir.x += cameraSpeed * 60.0f * dt;
}
if (IsKeyDown(KEY_RIGHT))
{
if (lightDir.x > -0.6f)
lightDir.x -= cameraSpeed * 60.0f * dt;
}
if (IsKeyDown(KEY_UP))
{
if (lightDir.z < 0.6f)
lightDir.z += cameraSpeed * 60.0f * dt;
}
if (IsKeyDown(KEY_DOWN))
{
if (lightDir.z > -0.6f)
lightDir.z -= cameraSpeed * 60.0f * dt;
}
lightDir = Vector3Normalize(lightDir);
lightCam.position = Vector3Scale(lightDir, -15.0f);
SetShaderValue(shadowShader, lightDirLoc, &lightDir, SHADER_UNIFORM_VEC3);
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
// First, render all objects into the shadowmap
// The idea is, we record all the objects' depths (as rendered from the light source's point of view) in a buffer
// Anything that is "visible" to the light is in light, anything that isn't is in shadow
// We can later use the depth buffer when rendering everything from the player's point of view
// to determine whether a given point is "visible" to the light
// Record the light matrices for future use!
Matrix lightView;
Matrix lightProj;
BeginTextureMode(shadowMap);
ClearBackground(WHITE);
BeginMode3D(lightCam);
lightView = rlGetMatrixModelview();
lightProj = rlGetMatrixProjection();
DrawScene(cube, robot);
EndMode3D();
EndTextureMode();
Matrix lightViewProj = MatrixMultiply(lightView, lightProj);
ClearBackground(RAYWHITE);
SetShaderValueMatrix(shadowShader, lightVPLoc, lightViewProj);
rlEnableShader(shadowShader.id);
int slot = 10; // Can be anything 0 to 15, but 0 will probably be taken up
rlActiveTextureSlot(10);
rlEnableTexture(shadowMap.depth.id);
rlSetUniform(shadowMapLoc, &slot, SHADER_UNIFORM_INT, 1);
BeginMode3D(cam);
// Draw the same exact things as we drew in the shadowmap!
DrawScene(cube, robot);
EndMode3D();
DrawText("Shadows in raylib using the shadowmapping algorithm!", screenWidth - 320, screenHeight - 20, 10, GRAY);
DrawText("Use the arrow keys to rotate the light!", 10, 10, 30, RED);
EndDrawing();
if (IsKeyPressed(KEY_F))
{
TakeScreenshot("shaders_shadowmap.png");
}
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadShader(shadowShader);
UnloadModel(cube);
UnloadModel(robot);
UnloadModelAnimations(robotAnimations, animCount);
UnloadShadowmapRenderTexture(shadowMap);
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
RenderTexture2D LoadShadowmapRenderTexture(int width, int height)
{
RenderTexture2D target = { 0 };
target.id = rlLoadFramebuffer(); // Load an empty framebuffer
target.texture.width = width;
target.texture.height = height;
if (target.id > 0)
{
rlEnableFramebuffer(target.id);
// Create depth texture
// We don't need a color texture for the shadowmap
target.depth.id = rlLoadTextureDepth(width, height, false);
target.depth.width = width;
target.depth.height = height;
target.depth.format = 19; //DEPTH_COMPONENT_24BIT?
target.depth.mipmaps = 1;
// Attach depth texture to FBO
rlFramebufferAttach(target.id, target.depth.id, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_TEXTURE2D, 0);
// Check if fbo is complete with attachments (valid)
if (rlFramebufferComplete(target.id)) TRACELOG(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", target.id);
rlDisableFramebuffer();
}
else TRACELOG(LOG_WARNING, "FBO: Framebuffer object can not be created");
return target;
}
// Unload shadowmap render texture from GPU memory (VRAM)
void UnloadShadowmapRenderTexture(RenderTexture2D target)
{
if (target.id > 0)
{
// NOTE: Depth texture/renderbuffer is automatically
// queried and deleted before deleting framebuffer
rlUnloadFramebuffer(target.id);
}
}
void DrawScene(Model cube, Model robot)
{
DrawModelEx(cube, Vector3Zero(), (Vector3) { 0.0f, 1.0f, 0.0f }, 0.0f, (Vector3) { 10.0f, 1.0f, 10.0f }, BLUE);
DrawModelEx(cube, (Vector3) { 1.5f, 1.0f, -1.5f }, (Vector3) { 0.0f, 1.0f, 0.0f }, 0.0f, Vector3One(), WHITE);
DrawModelEx(robot, (Vector3) { 0.0f, 0.5f, 0.0f }, (Vector3) { 0.0f, 1.0f, 0.0f }, 0.0f, (Vector3) { 1.0f, 1.0f, 1.0f }, RED);
}