Stuff 9.8.2025

CMakeLists.txt

@@ -12,9 +12,25 @@ add_executable(PortalGame
     "src/app.cpp"
     "src/gl.hpp"
     "src/utils.hpp"
+    "src/assets/sectordef.hpp"
+    "src/assets/sectordef.cpp"
+    "src/assets/mesh.hpp"
     "src/assets/mesh.cpp"
+    "src/collision/capsule_triangle_sweep.hpp"
+    "src/collision/capsule_triangle_sweep.cpp"
+    "src/collision/trianglemesh.cpp"
+    "src/game/sector.hpp"    
+    "src/game/sector.cpp"    
+    "src/game/world.hpp"
+    "src/game/world.cpp"
     "src/gfx/buffer_object.cpp"
     "src/gfx/buffer_object.hpp"
+    "src/gfx/renderer.hpp"
+    "src/gfx/renderer.cpp"
+    "src/gfx/shader.hpp"
+    "src/gfx/shader.cpp"
+    "src/gfx/shader_sources.hpp"
+    "src/gfx/shader_sources.cpp"
     "src/gfx/texture.cpp"
     "src/gfx/texture.hpp"
     "src/gfx/vertex_array.cpp"
@@ -35,14 +51,16 @@ if (CMAKE_SYSTEM_NAME STREQUAL Emscripten)
 
     target_compile_options(PortalGame PRIVATE 
         "-sUSE_SDL=2"
+        "-sNO_DISABLE_EXCEPTION_CATCHING=1"
     )
 
     target_link_options(PortalGame PRIVATE 
         "-sUSE_SDL=2"
         "-sASYNCIFY"
         "-sUSE_WEBGL2=1"
+        "-sNO_DISABLE_EXCEPTION_CATCHING=1"
         "--shell-file" "${CMAKE_SOURCE_DIR}/shell.html"
-        "--preload-file" "${CMAKE_SOURCE_DIR}/assets"
+        "--preload-file" "${CMAKE_SOURCE_DIR}/assets/@/"
         )
         
 else()
@@ -63,5 +81,5 @@ else()
 endif()
 
 add_subdirectory(external/glm)
-# target_include_directories(PortalGame PRIVATE "external/glm")
 target_link_libraries(PortalGame PRIVATE glm)
+target_include_directories(PortalGame PRIVATE "external/stb")

CMakePresets.json

@@ -27,7 +27,7 @@
       "description": "Build with Emscripten toolchain using Multi-Config generator",
       "generator": "Ninja Multi-Config",
       "binaryDir": "${sourceDir}/build/wasm",
-      "toolchainFile": "c:/dev/emsdk/cmake/Modules/Platform/Emscripten.cmake",
+      "toolchainFile": "c:/dev/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake",
       "cacheVariables": {
         "CMAKE_EXPORT_COMPILE_COMMANDS": "ON"
       }

assets/test.txt

@@ -1 +0,0 @@
-Test

src/app.cpp

@@ -1,14 +1,51 @@
 #include "app.hpp"
-#include <glm/glm.hpp>
-#include "gl.hpp"
+
+#include <iostream>
 
 App::App()
 {
+	std::cout << "Initializing App..." << std::endl;
+	std::cout << "Loading shader..." << std::endl;
+
+	std::cout << "Loading sector defs..." << std::endl;
+	
+	// Door frame portal def
+	assets::PortalDef& portal100x200 = assets::PortalDef::portal_defs["100x200"];
+	portal100x200.size = glm::vec2(1.0f, 2.0f); // 1m x 2m portal
+	portal100x200.half_frame_thickness = 0.1f; // 10cm offset towards the second sector
+
+    auto room001 = assets::SectorDef::LoadFromFile("data/room_001");
+
+	size_t s1 = world_.AddSector(room001);
+	size_t s2 = world_.AddSector(room001);
+
+	world_.LinkPortals(s1, "NDoor", s2, "WDoor");
+	world_.LinkPortals(s2, "NDoor", s2, "SDoor");
 }
 
 void App::Frame()
 {
-    glm::vec3 clear_color(glm::abs(glm::sin(m_time)), 0.2f, 0.3f);
-    glClearColor(clear_color.r, clear_color.g, clear_color.b, 1.0f);
-    glClear(GL_COLOR_BUFFER_BIT);
+	float aspect = static_cast<float>(m_viewport_size.x) / static_cast<float>(m_viewport_size.y);
+
+	renderer_.Begin(m_viewport_size.x, m_viewport_size.y);
+
+	float cameraDistance = 2.0f;
+	float angle = m_time * 0.1f; // Rotate over time
+	
+	glm::vec3 cameraPos = glm::vec3(
+		cameraDistance * cos(angle),
+		cameraDistance * sin(angle),
+		cameraDistance * 0.13f
+	);
+
+	glm::vec3 center(0.0f, 0.0f, 1.5f);
+	glm::vec3 up(0.0f, 0.0f, 1.0f);
+
+	renderer_.DrawWorld(world_, 1, center + cameraPos, -cameraPos, up, aspect, 60.0f);
+
+}
+
+App::~App()
+{
+
 }

src/app.hpp

@@ -1,8 +1,18 @@
 #pragma once
 
+#include "assets/sectordef.hpp"
+
+#include "game/world.hpp"
+#include "gfx/renderer.hpp"
+
 class App 
 {
     float m_time = 0.0f;
+	glm::ivec2 m_viewport_size = { 800, 600 };
+
+    game::World world_;
+
+    gfx::Renderer renderer_;
 
 public:
     App();
@@ -10,6 +20,8 @@ public:
     void Frame();
 
     void SetTime(float time) { m_time = time; }
+	void SetViewportSize(int width, int height) { m_viewport_size = { width, height }; }
 
+    ~App();
 };
 

src/assets/mesh.cpp

@@ -5,8 +5,21 @@
 #include <vector>
 #include <map>
 
-std::shared_ptr<assets::Mesh> assets::Mesh::LoadFromFile(const std::string& filename)
+assets::Mesh::Mesh(std::span<MeshVertex> verts, std::span<MeshTriangle> tris, std::span<MeshMaterial> materials) :
+    va_(gfx::VA_POSITION | gfx::VA_NORMAL | gfx::VA_UV | gfx::VA_LIGHTMAP_UV, gfx::VF_CREATE_EBO)
 {
+	va_.SetVBOData(verts.data(), verts.size_bytes());
+	va_.SetIndices(reinterpret_cast<const GLuint*>(tris.data()), tris.size() * 3);
+	materials_.assign(materials.begin(), materials.end());
+}
+
+std::shared_ptr<assets::Mesh> assets::Mesh::LoadFromFile(const std::string& filename, bool load_collision)
+{
+    std::shared_ptr<collision::TriangleMesh> collision_mesh;
+
+    if (load_collision)
+		collision_mesh = std::make_shared<collision::TriangleMesh>();
+
     std::ifstream file(filename, std::ios::binary);
 
     if (!file.is_open())
@@ -16,7 +29,7 @@ std::shared_ptr<assets::Mesh> assets::Mesh::LoadFromFile(const std::string& file
 
     std::vector<MeshVertex> verts;
     std::vector<MeshTriangle> tris;
-	std::vector<MeshMaterialSlot> materials;
+	std::vector<MeshMaterial> materials;
 
     std::string line;
 
@@ -42,11 +55,11 @@ std::shared_ptr<assets::Mesh> assets::Mesh::LoadFromFile(const std::string& file
         {
             if (materials.size() > 0)
             {
-				MeshMaterialSlot& last_material = materials.back();
+				MeshMaterial& last_material = materials.back();
 				last_material.num_tris = tris.size() - last_material.first_tri;
             }
 
-			MeshMaterialSlot& material = materials.emplace_back();
+			MeshMaterial& material = materials.emplace_back();
             iss >> material.name;
 			material.first_tri = tris.size();
 
@@ -54,20 +67,53 @@ std::shared_ptr<assets::Mesh> assets::Mesh::LoadFromFile(const std::string& file
         else if (command == "f") // Face
         {
 			MeshTriangle& tri = tris.emplace_back();
-			iss >> tri.vert[0] >> tri.vert[1] >> tri.vert[2];
+            glm::vec3 tri_verts[3];
+            for (size_t i = 0; i < 3; ++i) {
+				uint32_t vert_index;
+                iss >> vert_index;
+                if (vert_index >= verts.size()) {
+                    throw std::runtime_error("Vertex index out of bounds in mesh file: " + filename);
+                }
+                tri.vert[i] = vert_index;
+				tri_verts[i] = verts[vert_index].pos;
+            }
+
+            if (load_collision)
+            {
+                // Add triangle to collision mesh
+                collision_mesh->AddTriangle(tri_verts[0], tri_verts[1], tri_verts[2]);
+			}
         }
     }
 
     if (materials.size() > 0)
     {
-        MeshMaterialSlot& last_material = materials.back();
+        MeshMaterial& last_material = materials.back();
         last_material.num_tris = tris.size() - last_material.first_tri;
 	}
 
     file.close();
+    
     if (verts.empty() || tris.empty())
     {
         throw std::runtime_error("Mesh file is empty or malformed: " + filename);
     }
-	return std::make_shared<Mesh>(verts, tris, materials);
+
+	// Load textures for materials
+    for (MeshMaterial& material : materials)
+    {
+        if (!material.name.empty())
+        {
+            try {
+                material.texture = gfx::Texture::LoadFromFile("data/" + material.name + ".png");
+            } catch (const std::exception& e) {
+                throw std::runtime_error("Failed to load texture for material '" + material.name + "': " + e.what());
+            }
+        }
+    }
+	// Create the mesh object
+
+	std::shared_ptr<Mesh> mesh = std::make_shared<Mesh>(verts, tris, materials);
+	mesh->SetCollisionMesh(std::move(collision_mesh));
+	return mesh;
 }

src/assets/mesh.hpp

@@ -7,6 +7,7 @@
 
 #include "gfx/vertex_array.hpp"
 #include "gfx/texture.hpp"
+#include "collision/trianglemesh.hpp"
 
 namespace assets
 {
@@ -23,7 +24,7 @@ namespace assets
 		uint32_t vert[3];
 	};
 
-	struct MeshMaterialSlot
+	struct MeshMaterial
 	{
 		std::string name;
 		std::shared_ptr<gfx::Texture> texture;
@@ -34,11 +35,23 @@ namespace assets
 	class Mesh
 	{
 		gfx::VertexArray va_;
-		std::vector<MeshMaterialSlot> materials_;
+		std::vector<MeshMaterial> materials_;
+		std::shared_ptr<collision::TriangleMesh> collision_mesh_;
 
 	public:
-		Mesh(std::span<MeshVertex> verts, std::span<MeshTriangle> tris, std::span<MeshMaterialSlot> materials);
+		Mesh(std::span<MeshVertex> verts, std::span<MeshTriangle> tris, std::span<MeshMaterial> materials);
 
-		static std::shared_ptr<Mesh> LoadFromFile(const std::string& filename);
+		void SetCollisionMesh(std::shared_ptr<collision::TriangleMesh> mesh) {
+			collision_mesh_ = std::move(mesh);
+		}
+
+		const std::shared_ptr<collision::TriangleMesh>& GetCollisionMesh() const {
+			return collision_mesh_;
+		}
+
+		const gfx::VertexArray& GetVA() { return va_; }
+		const std::span<MeshMaterial> GetMaterials() { return materials_; }
+
+		static std::shared_ptr<Mesh> LoadFromFile(const std::string& filename, bool load_collision);
 	};
 }

src/assets/roomdef.hpp

@@ -1,8 +0,0 @@
-#pragma once
-
-class RoomDef
-{
-
-
-
-};

src/assets/sectordef.cpp

@@ -0,0 +1,65 @@
+#include "sectordef.hpp"
+#include <stdexcept>
+#include <fstream>
+#include <sstream>
+
+std::map<std::string, assets::PortalDef> assets::PortalDef::portal_defs;
+
+assets::SectorDef::SectorDef(std::shared_ptr<Mesh> mesh, std::span<SectorPortalDef> portals)
+{
+	mesh_ = std::move(mesh);
+	portals_.assign(portals.begin(), portals.end());
+}
+
+std::shared_ptr<assets::SectorDef> assets::SectorDef::LoadFromFile(const std::string& base_name)
+{
+	std::string mesh_file = base_name + ".mesh";
+	auto mesh = Mesh::LoadFromFile(mesh_file, true);
+	if (!mesh)
+	{
+		throw std::runtime_error("Failed to load mesh from file: " + mesh_file);
+	}
+	
+	std::string info_file = base_name + ".info";
+	std::vector<SectorPortalDef> portals;
+
+	std::ifstream info_stream(info_file);
+
+	if (!info_stream.is_open())
+	{
+		throw std::runtime_error("Failed to open sector info file: " + info_file);
+	}
+
+	std::string line;
+
+	while (std::getline(info_stream, line))
+	{
+		if (line.empty() || line[0] == '#') // Skip empty lines and comments
+			continue;
+
+		std::istringstream iss(line);
+
+		std::string command;
+		iss >> command;
+
+		if (command == "portal")
+		{
+			SectorPortalDef portal;
+			iss >> portal.def_name >> portal.name;
+			iss >> portal.origin.x >> portal.origin.y >> portal.origin.z;
+			iss >> portal.angles.x >> portal.angles.y >> portal.angles.z;
+			iss >> portal.scale;
+			if (iss.fail())
+			{
+				throw std::runtime_error("Failed to parse portal definition in file: " + info_file);
+			}
+			portals.push_back(std::move(portal));
+		}
+		else
+		{
+			throw std::runtime_error("Unknown command in sector info file: " + command);
+		}
+	}
+
+	return std::make_shared<SectorDef>(std::move(mesh), portals);
+}

src/assets/sectordef.hpp

@@ -0,0 +1,44 @@
+#pragma once
+
+#include <string>
+#include <memory>
+#include <span>
+#include <map>
+#include "mesh.hpp"
+
+namespace assets
+{
+	struct PortalDef
+	{
+		glm::vec2 size = glm::vec2(1.0f, 1.0f); // Size of the portal in meters
+		float half_frame_thickness = 0.1f; // Offset of the portal towards second sector
+
+		// Portal def map
+		static std::map<std::string, PortalDef> portal_defs;
+	};
+
+	struct SectorPortalDef
+	{
+		std::string def_name;
+		std::string name;
+		glm::vec3 origin;
+		glm::vec3 angles; // Euler angles in degrees
+		float scale = 1.0f;
+	};
+
+	class SectorDef
+	{
+		std::shared_ptr<Mesh> mesh_;
+		std::vector<SectorPortalDef> portals_;
+
+	public:
+		SectorDef(std::shared_ptr<Mesh> mesh, std::span<SectorPortalDef> portals);
+
+		const std::shared_ptr<Mesh>& GetMesh() const { return mesh_; }
+		std::span<const SectorPortalDef> GetPortals() const { return portals_; }
+
+		static std::shared_ptr<SectorDef> LoadFromFile(const std::string& base_name);
+	};
+
+}
+

src/collision/aabb.hpp

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <glm/glm.hpp>
+#include <limits>
+
+namespace collision
+{
+	template <size_t dim>
+	struct AABB
+	{
+		static constexpr float C_INFINITY = std::numeric_limits<float>::infinity();
+		static constexpr float C_DEFAULT_MARGIN = 0.01f; // Margin for AABBs
+
+		using Vec = glm::vec<dim, float, glm::defaultp>;
+
+		Vec min = Vec(C_INFINITY);
+		Vec max = Vec(-C_INFINITY);
+
+		AABB() = default;
+		AABB(const Vec& min, const Vec& max) : min(min), max(max) {}
+
+		void AddPoint(const Vec& point, float margin = C_DEFAULT_MARGIN)
+		{
+			min = glm::min(min, point - margin);
+			max = glm::max(max, point + margin);
+		}
+
+		bool CollidesWith(const AABB<dim>& other) const;
+
+		AABB<dim> Intersection(const AABB<dim>& other) const
+		{
+			Vec new_min = glm::max(min, other.min);
+			Vec new_max = glm::min(max, other.max);
+			return AABB<dim>(new_min, new_max);
+		}
+	};
+
+	template <>
+	inline bool AABB<2>::CollidesWith(const AABB<2>& other) const
+	{
+		return (min.x <= other.max.x && max.x >= other.min.x) &&
+			   (min.y <= other.max.y && max.y >= other.min.y);
+	}
+
+	template <>
+	inline bool AABB<3>::CollidesWith(const AABB<3>& other) const
+	{
+		return (min.x <= other.max.x && max.x >= other.min.x) &&
+			   (min.y <= other.max.y && max.y >= other.min.y) &&
+			   (min.z <= other.max.z && max.z >= other.min.z);
+	}
+
+	using AABB2 = AABB<2>;
+	using AABB3 = AABB<3>;
+}

src/collision/capsule.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <glm/glm.hpp>
+
+namespace collision
+{
+	struct Capsule
+	{
+		glm::vec3 p0;
+		glm::vec3 p1;
+		float radius;
+	};
+}

src/collision/capsule_triangle_sweep.cpp

@@ -0,0 +1,447 @@
+#include "capsule_triangle_sweep.hpp"
+
+#define EPSILON 1e-5f // Used to test if float is close to 0. Tweak this if you get problems.
+
+struct Sweep
+{
+	float time;  // Non-negative time of first contact.
+	float depth; // Non-negative penetration depth if objects start initially colliding.
+	glm::vec3 point;  // Point of first-contact. Only updated when contact occurs.
+	glm::vec3 normal; // Unit-length collision normal. Only updated when contact occurs.
+};
+
+// Return whether point P is contained inside 3D region delimited by triangle T0,T1,T2 edges.
+static bool PointInsideTriangle(const glm::vec3& p, const glm::vec3& t0, const glm::vec3& t1, const glm::vec3& t2)
+{
+	// Real-Time Collision Detection: 3.4: Barycentric Coordinates (pages 46-52).
+	//
+	// The book also has a subsection dedicated to point inside triangle tests:
+	// Real-Time Collision Detection: 5.4.2: Testing Point in Triangle (pages 203-206).
+	// But those tests only work for CCW triangles. This seems to work for either orientation.
+	glm::vec3 t01 = t1 - t0;
+	glm::vec3 t02 = t2 - t0;
+	glm::vec3 t0p = p - t0;
+	float t01t01 = glm::dot(t01, t01);
+	float t01t02 = glm::dot(t01, t02);
+	float t02t02 = glm::dot(t02, t02);
+	float t0pt01 = glm::dot(t0p, t01);
+	float t0pt02 = glm::dot(t0p, t02);
+	float denom = t01t01 * t02t02 - t01t02 * t01t02;
+
+	// Normally I would have to divide vd,wd by denom to get v,w. But divisions are
+	// expensive and cause troubles around 0. If denom isn't negative then we don't
+	// ever need to divide. If in the future it does turn out denom can be negative
+	// then we can always multiply by denom instead of dividing to keep sign the same.
+	float vd = t02t02 * t0pt01 - t01t02 * t0pt02;
+	float wd = t01t01 * t0pt02 - t01t02 * t0pt01;
+	return vd >= 0 && wd >= 0 && vd + wd <= denom;
+}
+
+// Return whether point P is contained inside 3D region delimited by parallelogram P0,P1,P2 edges.
+static bool PointInsideParallelogram(const glm::vec3& p, const glm::vec3& p0, const glm::vec3& p1, const glm::vec3& p2)
+{
+	// There may be a better way.
+	// https://math.stackexchange.com/questions/4381852/point-in-parallelogram-in-3d-space
+	glm::vec3 p3 = p2 + (p1 - p0);
+	return PointInsideTriangle(p, p0, p1, p2) || PointInsideTriangle(p, p1, p3, p2);
+}
+
+// Return whether point P is contained inside a triangular prism A0,A1,A2-B0,B1,B2.
+static bool PointInsideTriangularPrism(
+	const glm::vec3& p, 
+	const glm::vec3& a0, 
+	const glm::vec3& a1, 
+	const glm::vec3& a2, 
+	const glm::vec3& b0, 
+	const glm::vec3& b1, 
+	const glm::vec3& b2) 
+{
+	glm::vec3 faces[5][3] = { { a0,a1,a2 }, { b0,b2,b1 }, { a0,b0,a1 }, { a1,b1,a2 }, { a2,b2,a0 } };
+	float sgn = 0;
+	for (int i = 0; i < 5; i++) {
+		const glm::vec3& p0 = faces[i][0];
+		const glm::vec3& p1 = faces[i][1];
+		const glm::vec3& p2 = faces[i][2];
+
+		// Check which side of plane point is in. If it's always on the same side, it's colliding.
+		glm::vec3 p01 = p1 - p0;
+		glm::vec3 p02 = p2 - p0;
+		glm::vec3 n = glm::cross(p01, p02);
+		float d = glm::dot(n, p - p0);
+		if (i == 0) sgn = d;
+		if (sgn * d <= 0)
+			return false;
+	}
+	return true;
+}
+
+// Sweep sphere C,r with velocity Sv against plane N of triangle T0,T1,T2, ignoring edges.
+static bool SweepSphereTrianglePlane(
+	Sweep& sweep, 
+	const glm::vec3& c, 
+	float r, 
+	const glm::vec3& v, 
+	const glm::vec3& t0, 
+	const glm::vec3& t1, 
+	const glm::vec3& t2, 
+	const glm::vec3& n) 
+{
+	// Real-Time Collision Detection 5.5.3: Intersecting Moving Sphere Against Plane (pages 219-223).
+	float t;
+	float d = glm::dot(n, c - t0);
+	float pen = r - d;
+	if (pen > 0)
+		t = 0; // Sphere already starts coliding with triangle plane.
+	else {
+		// Sphere isn't immediately colliding with the plane. Check if it's moving away.
+		float denom = glm::dot(n, v);
+		if (denom >= 0)
+			return false; // Sphere is moving away from plane.
+
+		// Sphere will collide with plane at some point.
+		t = (r - d) / denom;
+		pen = 0;
+	}
+
+	// If sphere misses entire triangle plane, then it definitely misses the triangle too.
+	if (t >= sweep.time)
+		return false;
+
+	// Is the plane collision point inside the triangle?
+	// Real-Time Collision Detection: 5.4.2: Testing Point in Triangle (pg 203-206).
+	glm::vec3 collision = c + t * v - r * n;
+	if (!PointInsideTriangle(collision, t0, t1, t2))
+		return false;
+
+	// Plane collision point is inside the triangle. So the sphere collides with the triangle.
+	sweep.time = t;
+	sweep.depth = pen;
+	sweep.point = collision;
+	sweep.normal = n;
+	return true;
+}
+
+// Sweep sphere C,r with velocity V against plane N of parallelogram P0,P1,P2 ignoring edges.
+static bool SweepSphereParallelogramPlane(
+	Sweep& sweep, 
+	const glm::vec3& c, 
+	float r,
+	const glm::vec3& v, 
+	const glm::vec3& p0, 
+	const glm::vec3& p1, 
+	const glm::vec3& p2, 
+	const glm::vec3& n)
+{
+	// Real-Time Collision Detection 5.5.3: Intersecting Moving Sphere Against Plane (pages 219-223).
+	float t;
+	float d = glm::dot(c, n - p0);
+	float pen = r - d;
+	if (pen > 0)
+		t = 0; // Sphere already starts coliding with the quad plane.
+	else {
+		// Sphere isn't immediately colliding with the plane. Check if it's moving away.
+		float denom = glm::dot(n, v);
+		if (denom >= 0)
+			return false; // Sphere is moving away from plane.
+
+		// Sphere will collide with plane at some point.
+		t = (r - d) / denom;
+		pen = 0;
+	}
+
+	// If sphere misses entire quad plane, then it definitely misses the quad too.
+	if (t >= sweep.time)
+		return false;
+
+	// Is the plane collision point inside the quad?
+	// Real-Time Collision Detection: 5.4.2: Testing Point in Triangle (pages 203-206).
+	glm::vec3 collision = c + t * v - r * n;
+	if (!PointInsideParallelogram(collision, p0, p1, p2))
+		return false;
+
+	// Plane collision point is inside the quad. So the sphere collides with the quad.
+	sweep.time = t;
+	sweep.depth = pen;
+	sweep.point = collision;
+	sweep.normal = n;
+	return true;
+}
+
+// Sweep point P with velocity V against sphere S,r.
+static bool SweepPointSphere(
+	Sweep& sweep,
+	const glm::vec3& p, 
+	const glm::vec3& v, 
+	const glm::vec3& s, 
+	float r, 
+	const glm::vec3& fallbackNormal)
+{
+	// Real-Time Collision Detection 5.3.2: Intersecting Ray or Segment Against Sphere (pages 177-179).
+
+	// Set up quadratic equation.
+	glm::vec3 d = p - s;
+	float b = glm::dot(d, v);
+	float c = glm::dot(d, d) - r * r;
+	if (c > 0 && b > 0)
+		return false; // Point starts outside (c > 0) and moves away from sphere (b > 0).
+	float a = glm::dot(v, v);
+	float discr = b * b - a * c;
+	if (discr < 0)
+		return false; // Point misses sphere.
+
+	// Point hits sphere. Compute time of first impact.
+	float t = (-b - glm::sqrt(discr)) / a;
+	if (t >= sweep.time)
+		return false;
+
+	// The sphere is the first thing the point hits so far.
+	t = glm::max(t, 0.0f);
+	glm::vec3 collision = p + t * v;
+	glm::vec3 vec = collision - s;
+	float len = glm::length(vec);
+	sweep.time = t;
+	sweep.depth = t > 0 ? 0 : r - len;
+	sweep.point = collision;
+	sweep.normal = len >= EPSILON ? vec / len : fallbackNormal;
+	return true;
+}
+
+// Sweep point P with velocity V against cylinder C0,C1,r, ignoring the endcaps.
+static bool SweepPointUncappedCylinder(
+	Sweep& sweep, 
+	const glm::vec3& p, 
+	const glm::vec3& v, 
+	const glm::vec3& c0, 
+	const glm::vec3& c1,
+	float r, 
+	const glm::vec3& fallbackNormal)
+{
+	// Real-Time Collision Detection 5.3.7: Intersecting Ray or Segment Against Cylinder (pages 194-198).
+
+	// Test if swept point is fully outside of either endcap.
+	glm::vec3 n = c1 - c0;
+	glm::vec3 d = p - c0;
+	float dn = glm::dot(d, n);
+	float vn = glm::dot(v, n);
+	float nn = glm::dot(n, n);
+	if (dn < 0 && dn + vn < 0)
+		return false; // Fully outside c0 end of cylinder.
+	if (dn > nn && dn + vn > nn)
+		return false; // Fully outside c1 end of cylinder.
+
+	// Set up quadratic equations and check if sweep direction is parallel to cylinder.
+	float t;
+	float vv = glm::dot(v, v);
+	float dv = glm::dot(d, v);
+	float dd = glm::dot(d, d);
+	float a = nn * vv - vn * vn;
+	float c = nn * (dd - r * r) - dn * dn;
+	if (a < EPSILON) {
+		// Sweep direction is parallel to cylinder.
+		if (c > 0)
+			return false; // Point starts outside of cylinder, so it never collides.
+		if (dn < 0)
+			return false; // Point starts outside of c0 endcap.
+		if (dn > nn)
+			return false; // Point starts outside of c1 endcap.
+		t = 0;
+	}
+	else {
+		// Sweep direction is not parallel to cylinder. Solve for time of first contact.
+		float b = nn * dv - vn * dn;
+		float discr = b * b - a * c;
+		if (discr < 0)
+			return false; // Sweep misses cylinder.
+		t = (-b - glm::sqrt(discr)) / a;
+	}
+
+	// Check if the sweep missed, or if it hits but another collision happens sooner.
+	if (t < 0 || t >= sweep.time)
+		return false;
+
+	// This is the first collision. Find the closest point on the center of the cylinder.
+	glm::vec3 collision = p + t * v;
+	glm::vec3 center;
+	if (nn < EPSILON)
+		center = c0; // The cylinder is actually a circle.
+	else
+		center = c0 + (glm::dot(collision - c0, n) / nn) * n;
+
+	// Update collision time, depth, and normal.
+	glm::vec3 vec = collision - center;
+	float len = glm::length(vec);
+	float depth = r - len;
+	sweep.time = t;
+	sweep.depth = t > 0 ? 0 : depth;
+	sweep.point = collision;
+	sweep.normal = len >= EPSILON ? vec / len : fallbackNormal;
+	return true;
+}
+
+// Sweep a capsule C0,C1,Cr with velocity Cv against the triangle T0,T1,T2.
+//   c0,c1      capsule line segment endpoints
+//   r          capsule radius
+//   v          capsule velocity
+//   t0,t1,t2   3 triangle vertices
+//   returns    whether the capsule and triangle intersect
+static bool SweepCapsuleTriangle(
+	Sweep& s, 
+	const glm::vec3& c0, 
+	const glm::vec3& c1, 
+	float r, 
+	const glm::vec3& v, 
+	const glm::vec3& t0, 
+	const glm::vec3& t1, 
+	const glm::vec3& t2)
+{
+	// Compute triangle plane equation.
+	glm::vec3 t01 = t1 - t0;
+	glm::vec3 t02 = t2 - t0;
+	glm::vec3 normal = glm::normalize(glm::cross(t01, t02));
+
+	// Extrude triangle along capsule direction.
+	glm::vec3 c01 = c1 - c0;
+	glm::vec3 a0 = t0;
+	glm::vec3 a1 = t1;
+	glm::vec3 a2 = t2;
+	glm::vec3 b0 = t0 - c01;
+	glm::vec3 b1 = t1 - c01;
+	glm::vec3 b2 = t2 - c01;
+
+	// Test for initial collision with the extruded triangle prism.
+	if (PointInsideTriangularPrism(c0, a0, a1, a2, b0, b1, b2)) {
+		// Capsule starts off penetrating triangle. Push it out from the triangle plane.
+		float d0 = glm::dot(normal, c0 - t0);
+		float d1 = glm::dot(normal, c1 - t0);
+		float d = glm::abs(d0) <= glm::abs(d1) ? d0 : d1;
+		glm::vec3 n = d >= 0 ? normal : -normal;
+		s.time = 0;
+		s.depth = glm::abs(d) + r;
+		s.normal = n;
+		s.point = c0 + d0 * normal;
+		return true;
+	}
+
+	// Decompose capsule triangle sweep into: 2 sphere-triangle + 3 sphere-parallelogram + 9 point-cylinder + 6 point-sphere sweeps.
+	bool hit = false;
+	glm::vec3 triangles[2][3] = { {a0,a1,a2}, {b0,b1,b2} };
+	glm::vec3 parallelograms[3][3] = { {a0,a1,b0}, {a1,a2,b1}, {a2,a0,b2} };
+	glm::vec3 cylinders[9][2] = { {a0,a1}, {a1,a2}, {a2,a0}, {b0,b1}, {b1,b2}, {b2,b0}, {a0,b0}, {a1,b1}, {a2,b2} };
+	glm::vec3 spheres[6] = { a0, a1, a2, b0, b1, b2 };
+
+	// Do sphere-triangle sweeps.
+	glm::vec3 triangleNormals[2];
+	for (int i = 0; i < 2; i++) {
+		glm::vec3 p0 = triangles[i][0];
+		glm::vec3 p1 = triangles[i][1];
+		glm::vec3 p2 = triangles[i][2];
+
+		// Compute triangle plane normal.
+		glm::vec3 n = normal;
+		if (glm::dot(n, c0 - p0) < 0) n = -n; // Orient towards sphere.
+		triangleNormals[i] = n;
+
+		// Test for triangle-plane sphere intersection.
+		hit = hit || SweepSphereTrianglePlane(s, c0, r, v, p0, p1, p2, n);
+	}
+
+	// Do sphere-parallelogram sweeps.
+	glm::vec3 parallelogramNormals[3];
+	for (int i = 0; i < 3; i++) {
+		glm::vec3 p0 = parallelograms[i][0];
+		glm::vec3 p1 = parallelograms[i][1];
+		glm::vec3 p2 = parallelograms[i][2];
+
+		// Check if quad is degenerate. Happens when triangle edge completely parallel to capsule.
+		glm::vec3 p01 = p1 - p0;
+		glm::vec3 p02 = p2 - p0;
+		glm::vec3 c = glm::cross(p01, p02);
+		float len = glm::length(c);
+		if (len > EPSILON) {
+			// Compute quad plane equation.
+			glm::vec3 n = c / len;
+			if (glm::dot(n, c0 - p0) < 0) n = -n; // Orient towards sphere.
+			parallelogramNormals[i] = n;
+
+			// Do the sweep test.
+			hit = hit || SweepSphereParallelogramPlane(s, c0, r, v, p0, p1, p2, n);
+		}
+		else parallelogramNormals[i] = triangleNormals[0];
+	}
+
+	// Do point-cylinder sweeps.
+	for (int i = 0; i < 9; i++) {
+		glm::vec3 p0 = cylinders[i][0];
+		glm::vec3 p1 = cylinders[i][1];
+		glm::vec3 n;
+		if (i < 6)
+			n = triangleNormals[i / 3];
+		else
+			n = parallelogramNormals[i - 6];
+		hit = hit || SweepPointUncappedCylinder(s, c0, v, p0, p1, r, n);
+	}
+
+	// Do point-sphere sweeps.
+	for (int i = 0; i < 6; i++) {
+		glm::vec3 c = spheres[i];
+		glm::vec3 n = triangleNormals[i / 3];
+		hit = hit || SweepPointSphere(s, c0, v, c, r, n);
+	}
+
+	return hit;
+}
+
+// Move a capsule and resolve any triangle collisions encountered along the way.
+//   p         - capsule base position
+//   v         - capsule velocity
+//   h         - capsule height
+//   r         - capsule radius
+//   dt        - time-step length
+//   triangles - list of triangles to collide with
+void ResolveCollisions(glm::vec3& p, glm::vec3& v, float h, float r, float dt, std::span<collision::Triangle> triangles) {
+	// Store the leftover movement in this vector.
+	glm::vec3 u = dt * v;
+
+	// Move and resolve collisions while there is still motion. But cap max iterations to ensure simulation terminates.
+	const int MAX_ITER = 16;
+	for (int iter = 0; iter < MAX_ITER && glm::dot(u, u) > 0.0f; iter++) {
+		// Compute capsule endpoints.
+		glm::vec3 c0 = p;
+		glm::vec3 c1 = p;
+		c0.y += r;
+		c1.y += h - r;
+
+		// Perform the sweep test against all triangles.
+		Sweep s;
+		s.time = 1;
+		for (int i = 0; i < triangles.size(); i++) {
+			glm::vec3 t0 = triangles[i].verts[0];
+			glm::vec3 t1 = triangles[i].verts[1];
+			glm::vec3 t2 = triangles[i].verts[2];
+			SweepCapsuleTriangle(s, c0, c1, r, u, t0, t1, t2);
+		}
+
+		// Stop objects from intersecting.
+		if (s.depth > 0)
+			p += (s.depth + EPSILON) * s.normal;
+
+		// Advance the cylinder until the first contact time.
+		glm::vec3 dp = s.time * u;
+		p += dp;
+
+		// If there were no collisions, entire motion is complete and we can terminate early.
+		if (s.time >= 1)
+			break;
+
+		// Cancel out motion parallel to the normal. This causes capsule to slide along surface.
+		u -= dp;
+		u += glm::dot(u, s.normal) * s.normal;
+		v += glm::dot(v, s.normal) * s.normal;
+
+		// Nudge the position and velocity slightly away from surface to avoid another collision.
+		glm::vec3 offset = EPSILON * s.normal;
+		p += offset;
+		v += offset;
+		u += offset;
+	}
+}

src/collision/capsule_triangle_sweep.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "capsule.hpp"
+#include "trianglemesh.hpp"
+
+namespace collision
+{
+
+}

src/collision/trianglemesh.cpp

@@ -0,0 +1,14 @@
+#include "trianglemesh.hpp"
+
+void collision::TriangleMesh::AddTriangle(const glm::vec3& v0, const glm::vec3& v1, const glm::vec3& v2)
+{
+	Triangle& tri = tris_.emplace_back();
+	tri.verts[0] = v0;
+	tri.verts[1] = v1;
+	tri.verts[2] = v2;
+
+	for (size_t i = 0; i < 3; ++i)
+	{
+		tri.aabb.AddPoint(tri.verts[i]);
+	}
+}

src/collision/trianglemesh.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <vector>
+#include <span>
+#include <glm/glm.hpp>
+#include "aabb.hpp"
+
+namespace collision
+{
+	struct Triangle
+	{
+		glm::vec3 verts[3];
+		AABB3 aabb;
+	};
+
+	class TriangleMesh
+	{
+		std::vector<Triangle> tris_;
+		
+	public:
+		TriangleMesh() = default;
+
+		void AddTriangle(const glm::vec3& v0, const glm::vec3& v1, const glm::vec3& v2);
+
+		std::span<const Triangle> GetTriangles() const {
+			return std::span(tris_);
+		}
+	};
+}

src/game/entity.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+namespace game
+{
+	class Entity
+	{
+
+
+	};
+
+}

src/game/sector.cpp

@@ -0,0 +1,88 @@
+#include "sector.hpp"
+
+#include <stdexcept>
+
+#include <glm/gtc/quaternion.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+game::Sector::Sector(World* world, size_t idx, std::shared_ptr<assets::SectorDef> def) :
+	world_(world),
+	idx_(idx),
+	def_(std::move(def)),
+	mesh_(def_->GetMesh())
+{
+	auto def_portals = def_->GetPortals();
+	size_t num_portals = def_portals.size();
+
+	portals_.reserve(num_portals);
+	for (size_t i = 0; i < num_portals; ++i)
+	{
+		const assets::SectorPortalDef& def_portal = def_portals[i];
+
+		Portal& portal = portals_.emplace_back();
+		portal.sector = this;
+		portal.def_sector = &def_portal;
+		portal.def = &assets::PortalDef::portal_defs[def_portal.def_name];
+
+		glm::mat4 rotation(glm::quat(glm::radians(def_portal.angles)));
+		glm::mat4 translation = glm::translate(glm::mat4(1.0f), def_portal.origin);
+		glm::mat4 scale = glm::scale(glm::mat4(1.0f), glm::vec3(def_portal.scale));
+
+		portal.trans = translation * rotation * scale;
+
+		portal.plane = glm::transpose(glm::inverse(portal.trans)) * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f);
+
+		ComputePortalVertex(portal, 0, glm::vec2(-1.0f, -1.0f)); // Bottom-left
+		ComputePortalVertex(portal, 1, glm::vec2(-1.0f, 1.0f));  // Top-left
+		ComputePortalVertex(portal, 3, glm::vec2(1.0f, -1.0f));  // Bottom-right
+		ComputePortalVertex(portal, 2, glm::vec2(1.0f, 1.0f));   // Top-right
+
+		portal.link = nullptr;
+
+		portal_map_[def_portal.name] = i;
+	}
+}
+
+void game::Sector::ComputePortalVertex(Portal& portal, size_t idx, const glm::vec2& base_vert)
+{
+	glm::vec2 vert_xz = base_vert * portal.def->size * 0.5f; // Scale to portal size
+	glm::vec3 vert(vert_xz.x, 0.0f, vert_xz.y); // Convert to 3D vector
+	portal.verts[idx] = glm::vec3(portal.trans * glm::vec4(vert, 1.0f));
+}
+
+int game::Sector::GetPortalIndex(const std::string& name) const
+{
+	auto it = portal_map_.find(name);
+	if (it != portal_map_.end())
+	{
+		return static_cast<int>(it->second);
+	}
+
+	return -1;
+}
+
+void game::Sector::LinkPortals(Sector& s1, size_t idx1, Sector& s2, size_t idx2)
+{
+	Portal& p1 = s1.portals_[idx1];
+	Portal& p2 = s2.portals_[idx2];
+
+	if (p1.link || p2.link)
+	{
+		throw std::runtime_error("One of the portals is already linked");
+	}
+
+
+	// Calculate the link transformation
+	glm::mat4 rotation = glm::rotate(glm::mat4(1.0f), glm::radians(180.0f), glm::vec3(0, 0, 1));
+	glm::mat4 p1_to_p2 = p2.trans * rotation * glm::inverse(p1.trans);
+
+	p1.link = &p2;
+	p1.link_trans = p1_to_p2;
+	
+	if (&p1 != &p2)
+	{
+		p2.link = &p1;
+		p2.link_trans = glm::inverse(p1_to_p2);
+	}
+
+}

src/game/sector.hpp

@@ -0,0 +1,58 @@
+#pragma once
+
+#include "assets/sectordef.hpp"
+#include <vector>
+#include <map>
+
+namespace game
+{
+	class Sector;
+
+	struct Portal
+	{
+		Sector* sector;
+
+		const assets::SectorPortalDef* def_sector;
+		const assets::PortalDef* def;
+		
+		glm::mat4 trans;
+
+		glm::vec4 plane;
+		glm::vec3 verts[4]; // Portal vertices in sector space
+
+		Portal* link;
+		glm::mat4 link_trans;
+	};
+
+	class World;
+
+	class Sector
+	{
+		World* world_;
+		size_t idx_;
+		std::shared_ptr<assets::SectorDef> def_;
+
+		std::shared_ptr<assets::Mesh> mesh_;
+
+		std::vector<Portal> portals_;
+		std::map<std::string, size_t> portal_map_; // Maps portal name to index in portals_
+
+	public:
+		Sector(World* world, size_t idx, std::shared_ptr<assets::SectorDef> def);
+
+	private:
+		void ComputePortalVertex(Portal& portal, size_t idx, const glm::vec2& base_vert);
+
+	public:
+		const std::shared_ptr<assets::Mesh>& GetMesh() const { return mesh_; }
+
+		int GetPortalIndex(const std::string& name) const;
+		const Portal& GetPortal(size_t idx) const { return portals_[idx]; }
+		const size_t GetNumPortals() const { return portals_.size(); }
+
+		static void LinkPortals(Sector& s1, size_t idx1, Sector& s2, size_t idx2);
+
+	};
+
+
+}

src/game/world.cpp

@@ -0,0 +1,29 @@
+#include "world.hpp"
+#include <stdexcept>
+
+game::World::World()
+{
+
+}
+
+size_t game::World::AddSector(std::shared_ptr<assets::SectorDef> def)
+{
+	size_t idx = sectors_.size();
+	sectors_.emplace_back(std::make_unique<Sector>(this, idx, std::move(def)));
+	return idx;
+}
+
+void game::World::LinkPortals(size_t sector1, const std::string& portal_name1, size_t sector2, const std::string& portal_name2)
+{
+	Sector& s1 = *sectors_[sector1];
+	Sector& s2 = *sectors_[sector2];
+	int p1 = s1.GetPortalIndex(portal_name1);
+	int p2 = s2.GetPortalIndex(portal_name2);
+
+	if (p1 < 0 || p2 < 0)
+	{
+		throw std::runtime_error("Invalid portal names for linking");
+	}
+
+	Sector::LinkPortals(s1, p1, s2, p2);
+}

src/game/world.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <vector>
+#include <map>
+#include <memory>
+#include "assets/sectordef.hpp"
+#include "sector.hpp"
+#include "entity.hpp"
+
+namespace game
+{
+	class World
+	{
+		std::vector<std::unique_ptr<Sector>> sectors_;
+		std::vector<std::unique_ptr<Entity>> entities_;
+
+	public:
+		World();
+
+		size_t AddSector(std::shared_ptr<assets::SectorDef> def);
+
+		void LinkPortals(size_t sector1, const std::string& portal_name1, 
+			size_t sector2, const std::string& portal_name2);
+
+		template<class T, class... TArgs>
+		T* Spawn(TArgs&&... args)
+		{
+			auto& entity = entities_.emplace_back(std::make_unique<T>(this, std::forward<TArgs>(args)...));
+			return entity.get();
+		}
+
+		Sector& GetSector(size_t idx) { return *sectors_[idx]; }
+		const Sector& GetSector(size_t idx) const { return *sectors_[idx]; }
+
+	};
+
+}

src/gfx/renderer.cpp

@@ -0,0 +1,262 @@
+#include "renderer.hpp"
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+#include "gl.hpp"
+
+#include "gfx/shader_sources.hpp"
+
+gfx::Renderer::Renderer()
+{
+	ShaderSources::MakeShader(sector_shader_, SS_SECTOR_MESH_VERT, SS_SECTOR_MESH_FRAG);
+	ShaderSources::MakeShader(portal_shader_, SS_PORTAL_VERT, SS_PORTAL_FRAG);
+	proj_ = glm::mat4(1.0f); // Initialize projection matrix to identity
+
+	SetupPortalVAO();
+}
+
+void gfx::Renderer::SetupPortalVAO()
+{
+	const glm::vec3 portal_verts[4] = {
+		{ -0.5f, 0.0f,  0.5f }, // Top-left
+		{ -0.5f, 0.0f, -0.5f }, // Bottom-left
+		{  0.5f, 0.0f, -0.5f }, // Bottom-right
+		{  0.5f, 0.0f,  0.5f }, // Top-right
+	};
+
+	portal_vao_ = std::make_shared<VertexArray>(VA_POSITION, 0);
+	portal_vao_->SetVBOData(portal_verts, sizeof(portal_verts));
+}
+
+void gfx::Renderer::Begin(size_t width, size_t height)
+{
+	glViewport(0, 0, width, height);
+	glClearStencil(0);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+}
+
+void gfx::Renderer::DrawWorld(
+	const game::World& world,
+	size_t sector_idx,
+	const glm::vec3& eye,
+	const glm::vec3& dir,
+	const glm::vec3& up,
+	float aspect,
+	float fov)
+{
+	proj_ = glm::perspective(
+		glm::radians(fov), // FOV
+		aspect,             // Aspect ratio
+		0.1f,              // Near plane
+		1000.0f             // Far plane
+	);
+
+	glm::mat4 view = glm::lookAt(
+		eye,               // Camera position
+		eye + dir,        // Look at point (camera position + look direction)
+		up                 // Up vector
+	);
+
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LESS);
+
+	glEnable(GL_CULL_FACE);
+	glCullFace(GL_BACK);
+
+	glEnable(GL_STENCIL_TEST);
+	glStencilFunc(GL_ALWAYS, 0, 0xFF); // Always pass stencil test
+	glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+	glStencilMask(0xFF);
+
+	const game::Sector& sector = world.GetSector(sector_idx);
+
+	DrawSectorParams params;
+	params.sector = &sector;
+	params.entry_portal = nullptr; // No entry portal for the first sector
+	params.clip_plane = glm::vec4(0.0f, 0.0f, 1.0f, 1000.0f); // Default clip plane
+	params.screen_aabb = collision::AABB2(glm::vec2(-1.0f), glm::vec2(1.0f)); // Full screen
+	params.recursion = 0; // Start with recursion level 0
+	params.view = view;
+	params.view_proj = proj_ * view;
+	params.eye = eye;
+	
+	DrawSector(params);
+
+	//glDisable(GL_STENCIL_TEST);
+	//glDisable(GL_CULL_FACE);
+	//glDisable(GL_DEPTH_TEST);
+
+}
+
+void gfx::Renderer::DrawSector(const DrawSectorParams& params)
+{
+	assets::Mesh& mesh = *params.sector->GetMesh();
+
+	glm::mat4 model = glm::mat4(1.0f); // Identity matrix for model
+
+
+
+// #ifndef PG_GLES
+// 	glEnable(GL_CLIP_DISTANCE0);
+// #else
+// 	glEnable(GL_CLIP_DISTANCE0_EXT);
+// #endif
+
+	glUseProgram(sector_shader_->GetId());
+	glUniformMatrix4fv(sector_shader_->U(gfx::SU_VIEW_PROJ), 1, GL_FALSE, &params.view_proj[0][0]);
+	glUniformMatrix4fv(sector_shader_->U(gfx::SU_MODEL), 1, GL_FALSE, &model[0][0]);
+	glUniform4fv(sector_shader_->U(gfx::SU_CLIP_PLANE), 1, &params.clip_plane[0]);
+
+	glBindVertexArray(mesh.GetVA().GetVAOId());
+	for (auto mesh_materials = mesh.GetMaterials(); const auto& mat : mesh_materials) {
+		glActiveTexture(GL_TEXTURE0);
+		if (mat.texture) {
+			glBindTexture(GL_TEXTURE_2D, mat.texture->GetId());
+			glUniform1i(sector_shader_->U(gfx::SU_TEX), 0); // Bind texture to sampler
+		}
+		else {
+			glBindTexture(GL_TEXTURE_2D, 0); // No texture
+		}
+		glDrawElements(GL_TRIANGLES, mat.num_tris * 3, GL_UNSIGNED_INT, (void*)(mat.first_tri * 3 * sizeof(uint32_t)));
+	}
+	glBindVertexArray(0);
+
+	for (size_t i = 0; i < params.sector->GetNumPortals(); ++i)
+	{
+		const game::Portal& portal = params.sector->GetPortal(i);
+		DrawPortal(params, portal);
+	}
+
+}
+
+void gfx::Renderer::DrawPortal(const DrawSectorParams& params, const game::Portal& portal)
+{
+	if (params.recursion > 10)
+	{
+		return; // Recursion limit reached
+	}
+
+	if (&portal == params.entry_portal)
+	{
+		return; // Skip the portal this sector was rendered through
+		// This should NEVER happen due to portal plane check, but would cause cyclic traversal if it did.
+	}
+
+	if (!portal.link)
+	{
+		return; // Portal not linked, skip
+	}
+
+	// Signed distance of eye to the portal plane
+	float eye_plane_sd = glm::dot(glm::vec3(portal.plane), params.eye) + portal.plane.w;
+	if (eye_plane_sd < 0.0f)
+	{
+		return; // Eye is behind the portal plane, skip
+	}
+
+	collision::AABB2 portal_aabb;
+	if (!ComputePortalScreenAABB(portal, params.view_proj, portal_aabb))
+	{
+		return; // Portal is fully behind the camera, skip
+	}
+
+	if (!portal_aabb.CollidesWith(params.screen_aabb))
+	{
+		return; // Portal AABB does not intersect with the screen AABB, skip
+	}
+
+	// Open portal
+	glStencilFunc(GL_EQUAL, params.recursion, 0xFF);
+	glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
+	glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+	DrawPortalPlane(params, portal, false); // Mark the portal plane in stencil buffer
+	glStencilFunc(GL_EQUAL, params.recursion + 1, 0xFF);
+	glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+	glDepthFunc(GL_ALWAYS);
+	DrawPortalPlane(params, portal, true); // Clear the depth buffer for nested sector
+	glDepthFunc(GL_LESS);
+	glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+
+	const game::Portal& other_portal = *portal.link;
+	const game::Sector& other_sector = *other_portal.sector;
+
+	DrawSectorParams new_params;
+	new_params.sector = &other_sector;
+	new_params.entry_portal = &other_portal;
+	new_params.clip_plane = other_portal.plane; // Use the portal plane as the clip plane
+
+	// Compute the new screen AABB based on the portal AABB and the current screen AABB
+	new_params.screen_aabb = params.screen_aabb.Intersection(portal_aabb);
+
+	new_params.recursion = params.recursion + 1;
+	new_params.view = params.view * other_portal.link_trans;
+	new_params.view_proj = proj_ * new_params.view;
+	new_params.eye = portal.link_trans * glm::vec4(params.eye, 1.0f);
+
+	// Draw the sector through the portal
+	DrawSector(new_params);
+
+	// Close portal
+	glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
+	glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+	glStencilFunc(GL_EQUAL, params.recursion + 1, 0xFF);
+	DrawPortalPlane(params, portal, false);
+	glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+}
+
+bool gfx::Renderer::ComputePortalScreenAABB(const game::Portal& portal, const glm::mat4 view_proj, collision::AABB2& aabb)
+{
+	size_t num_behind = 0;
+
+	for (size_t i = 0; i < 4; ++i)
+	{
+		glm::vec4 vert = glm::vec4(portal.verts[i], 1.0f);
+		glm::vec4 clip = view_proj * vert;
+		
+		if (clip.w <= 0.0f)
+		{
+			num_behind++;
+			continue; // Skip vertices behind the camera
+		}
+		
+		glm::vec2 ndc = clip;
+		ndc /= clip.w;
+
+		aabb.AddPoint(ndc, 0.0f);
+	}
+
+	if (num_behind == 4)
+	{
+		return false; // All vertices are behind the camera, no visible portal
+	}
+
+	if (num_behind > 0)
+	{
+		// Some vertices are behind the camera, cannot use the AABB
+		aabb = collision::AABB2(glm::vec2(-1.0f), glm::vec2(1.0f)); // Full screen AABB
+	}
+
+	return true;
+}
+
+void gfx::Renderer::DrawPortalPlane(const DrawSectorParams& params, const game::Portal& portal, bool clear_depth)
+{
+	if (!clear_depth) // first draw
+	{
+		glUseProgram(portal_shader_->GetId());
+		glUniformMatrix4fv(portal_shader_->U(gfx::SU_VIEW_PROJ), 1, GL_FALSE, &params.view_proj[0][0]);
+		glUniformMatrix4fv(portal_shader_->U(gfx::SU_MODEL), 1, GL_FALSE, &portal.trans[0][0]);
+		glUniform4fv(portal_shader_->U(gfx::SU_CLIP_PLANE), 1, &params.clip_plane[0]);
+		glUniform2fv(portal_shader_->U(gfx::SU_PORTAL_SIZE), 1, &portal.def->size[0]);
+		glUniform1i(portal_shader_->U(gfx::SU_CLEAR_DEPTH), 0);
+
+		glBindVertexArray(portal_vao_->GetVAOId());
+	}
+	else // assume uniforms are already set from previous draw
+	{ 
+		glUniform1i(portal_shader_->U(gfx::SU_CLEAR_DEPTH), 1);
+	}
+	glDrawArrays(GL_TRIANGLE_FAN, 0, 4); // Draw the portal as a quad
+}
+

src/gfx/renderer.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <memory>
+#include "gfx/shader.hpp"
+#include "game/world.hpp"
+#include "game/sector.hpp"
+
+namespace gfx
+{
+	struct DrawSectorParams
+	{
+		const game::Sector* sector;
+		const game::Portal* entry_portal;
+		glm::vec4 clip_plane;
+		collision::AABB2 screen_aabb;
+		size_t recursion;
+		glm::mat4 view;
+		glm::mat4 view_proj;
+		glm::vec3 eye;
+	};
+
+	class Renderer
+	{
+	public:
+		Renderer();
+
+		void Begin(size_t width, size_t height);
+
+		void DrawWorld(
+			const game::World& world,
+			size_t sector_idx,
+			const glm::vec3& eye,
+			const glm::vec3& dir,
+			const glm::vec3& up,
+			float aspect,
+			float fov);
+
+	private:
+		std::unique_ptr<Shader> sector_shader_;
+		std::unique_ptr<Shader> portal_shader_;
+
+		std::shared_ptr<VertexArray> portal_vao_;
+		void SetupPortalVAO();
+
+		glm::mat4 proj_;
+
+		void DrawSector(const DrawSectorParams& params);
+		void DrawPortal(const DrawSectorParams& params, const game::Portal& portal);
+		
+		static bool ComputePortalScreenAABB(const game::Portal& portal, const glm::mat4 view_proj, collision::AABB2& aabb);
+		void DrawPortalPlane(const DrawSectorParams& params, const game::Portal& portal, bool clear_depth);
+	};
+
+}

src/gfx/shader.cpp

@@ -0,0 +1,87 @@
+#include <stdexcept>
+#include <string>
+#include "shader.hpp"
+#define LOG_LENGTH 1024
+
+// Nazvy uniformnich promennych v shaderech
+static const char* const s_uni_names[] = {
+	"u_model",              // SU_MODEL
+	"u_view_proj",          // SU_VIEW_PROJ
+    "u_tex",                // SU_TEX
+	"u_clip_plane",         // SU_CLIP_PLANE
+	"u_portal_size",        // SU_PORTAL_SIZE
+	"u_clear_depth",        // SU_CLEAR_DEPTH
+};
+
+// Vytvori shader z daneho zdroje
+static GLuint CreateShader(const char* src, GLenum type) {
+	GLuint id = glCreateShader(type);
+
+    glShaderSource(id, 1, &src, NULL);
+    glCompileShader(id);
+
+    GLint is_compiled = 0;
+    glGetShaderiv(id, GL_COMPILE_STATUS, &is_compiled);
+    if (is_compiled == GL_FALSE) {
+        GLchar log[LOG_LENGTH];
+        glGetShaderInfoLog(id, LOG_LENGTH, NULL, log);
+
+        glDeleteShader(id);
+
+        throw std::runtime_error(std::string("Nelze zkompilovat shader: ") + log);
+    }
+
+    return id;
+}
+
+gfx::Shader::Shader(const char* vert_src, const char* frag_src) {
+    m_id = glCreateProgram();
+    
+    if (!m_id)
+        throw std::runtime_error("Nelze vytvorit program!");
+    
+    GLuint vert, frag;
+
+    // Vytvoreni vertex shaderu
+    vert = CreateShader(vert_src, GL_VERTEX_SHADER);
+
+    try {
+        // Vyvoreni fragment shaderu
+        frag = CreateShader(frag_src, GL_FRAGMENT_SHADER);
+    }
+    catch (std::exception& e) {
+        glDeleteShader(vert);
+        throw e;
+    }
+
+    // Pripojeni shaderu k programu
+    glAttachShader(m_id, vert);
+    glAttachShader(m_id, frag);
+
+    // Linknuti programu
+    glLinkProgram(m_id);
+
+    // Smazani shaderu
+    glDeleteShader(vert);
+    glDeleteShader(frag);
+
+    GLint is_linked = 0;
+    glGetProgramiv(m_id, GL_LINK_STATUS, &is_linked);
+    if (is_linked == GL_FALSE) {
+        GLchar log[LOG_LENGTH];
+        glGetProgramInfoLog(m_id, LOG_LENGTH, NULL, log);
+
+        glDeleteProgram(m_id);
+
+        throw std::runtime_error(std::string("Nelze linknout shader: ") + log);
+    }
+
+    // Ziskani lokaci uniformnich promennych
+    for (size_t i = 0; i < SU_COUNT; i++)
+        m_uni[i] = glGetUniformLocation(m_id, s_uni_names[i]);
+}
+
+gfx::Shader::~Shader() {
+    // Smazani programu
+    glDeleteProgram(m_id);
+}

src/gfx/shader.hpp

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "gl.hpp"
+#include "utils.hpp"
+
+namespace gfx
+{
+	/**
+	 * \brief Uniformy shaderu
+	 */
+	enum ShaderUniform
+	{
+		SU_MODEL,
+		SU_VIEW_PROJ,
+		SU_TEX,
+		SU_CLIP_PLANE,
+		SU_PORTAL_SIZE,
+		SU_CLEAR_DEPTH,
+	
+		SU_COUNT
+	};
+
+	/**
+	 * \brief Wrapper pro OpenGL shader program
+	 */
+	class Shader : public NonCopyableNonMovable
+	{
+		GLuint m_id;
+		GLint m_uni[SU_COUNT];
+
+	public:
+		Shader(const char* vert_src, const char* frag_src);
+		~Shader();
+
+		/**
+		 * \brief Vrátí lokaci uniformy
+		 *
+		 * \param u Uniforma
+		 * \return Lokace
+		 */
+		GLint U(ShaderUniform u) const { return m_uni[u]; }
+
+		/**
+		 * \brief Vrátí OpenGL název shaderu
+		 *
+		 * \return Název shaderu
+		 */
+		GLuint GetId() const { return m_id; }
+
+	};
+}

src/gfx/shader_sources.cpp

@@ -0,0 +1,115 @@
+#include "shader_sources.hpp"
+
+#ifndef EMSCRIPTEN
+#define GLSL_VERSION \
+    "#version 330 core\n" \
+    "\n"
+#else 
+#define GLSL_VERSION \
+    "#version 300 es\n" \
+    "precision mediump float;\n" \
+    "\n"
+#endif
+
+// Zdrojove kody shaderu
+static const char* const s_srcs[] = {
+
+// SS_SECTOR_MESH_VERT
+GLSL_VERSION
+R"GLSL(
+layout (location = 0) in vec3 a_pos;
+layout (location = 1) in vec3 a_normal;
+layout (location = 3) in vec2 a_uv;
+
+uniform mat4 u_model;
+uniform mat4 u_view_proj;
+uniform vec4 u_clip_plane;
+
+out vec2 v_uv;
+out float v_clip_distance;
+
+void main() {
+    vec4 sector_pos = u_model * vec4(a_pos, 1.0);
+    gl_Position = u_view_proj * sector_pos;
+
+    // Clip against the plane
+    v_clip_distance = dot(sector_pos, u_clip_plane);
+
+    //v_normal = mat3(u_model) * a_normal;
+    v_uv = vec2(a_uv.x, 1.0 - a_uv.y);
+}	
+)GLSL",
+
+// SS_SECTOR_MESH_FRAG
+GLSL_VERSION
+R"GLSL(
+in vec2 v_uv;
+in float v_clip_distance;
+
+uniform sampler2D u_tex;
+
+layout (location = 0) out vec4 o_color;
+
+void main() {
+    if (v_clip_distance < 0.0) {
+        discard; // Discard fragment if it is outside the clip plane
+    }
+
+    o_color = vec4(texture(u_tex, v_uv));
+    //o_color = vec4(1.0, 0.0, 0.0, 1.0);
+}	
+
+)GLSL",
+
+// SS_PORTAL_VERT
+GLSL_VERSION
+R"GLSL(
+layout (location = 0) in vec3 a_pos;
+
+uniform mat4 u_model; // Portal transform
+uniform mat4 u_view_proj;
+uniform vec4 u_clip_plane;
+
+uniform vec2 u_portal_size; // Size of the portal in meters
+
+out float v_clip_distance;
+
+void main() {
+    vec4 pos = vec4(a_pos.x * u_portal_size.x, 0.0, a_pos.z * u_portal_size.y, 1.0);
+    vec4 sector_pos = u_model * pos;
+    gl_Position = u_view_proj * sector_pos;
+
+    // Clip against the plane
+    v_clip_distance = dot(sector_pos, u_clip_plane);
+}	
+)GLSL",
+
+// SS_PORTAL_FRAG
+GLSL_VERSION
+R"GLSL(
+in float v_clip_distance;
+
+uniform bool u_clear_depth;
+
+void main() {
+    if (v_clip_distance < 0.0) {
+        discard; // Discard fragment if it is outside the clip plane
+    }
+
+    if (u_clear_depth) {
+        gl_FragDepth = 1.0;
+    }
+    else
+    {
+        gl_FragDepth = gl_FragCoord.z; // Use the default depth value
+    }
+}	
+
+)GLSL",
+
+};
+
+// Vrati zdrojovy kod shaderu
+const char* gfx::ShaderSources::Get(ShaderSource ss) {
+	return s_srcs[ss];
+}

src/gfx/shader_sources.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <memory>
+#include "shader.hpp"
+
+namespace gfx
+{
+	enum ShaderSource
+	{
+		SS_SECTOR_MESH_VERT,
+		SS_SECTOR_MESH_FRAG,
+
+		SS_PORTAL_VERT,
+		SS_PORTAL_FRAG,
+
+	};
+
+	class ShaderSources
+	{
+
+	public:
+		// Vrati zdrojovy kod shaderu
+		static const char* Get(ShaderSource ss);
+
+		static void MakeShader(std::unique_ptr<Shader>& shader, ShaderSource ss_vert, ShaderSource ss_frag) {
+			shader = std::make_unique<Shader>(
+				Get(ss_vert),
+				Get(ss_frag)
+			);
+		}
+	};
+}
+

src/gfx/texture.cpp

@@ -1,7 +1,10 @@
 #include "texture.hpp"
 #include <stdexcept>
 
-gfx::Texture::Texture(GLuint width, GLuint height, GLint internalformat, GLenum format, GLenum type, GLenum filter) {
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb_image.h>
+
+gfx::Texture::Texture(GLuint width, GLuint height, const void* data, GLint internalformat, GLenum format, GLenum type, GLenum filter) {
     glGenTextures(1, &m_id);
 
     if (!m_id)
@@ -9,7 +12,7 @@ gfx::Texture::Texture(GLuint width, GLuint height, GLint internalformat, GLenum
 
     glBindTexture(GL_TEXTURE_2D, m_id);
 
-    glTexImage2D(GL_TEXTURE_2D, 0, internalformat, width, height, 0, format, type, NULL);
+    glTexImage2D(GL_TEXTURE_2D, 0, internalformat, width, height, 0, format, type, data);
 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
@@ -22,3 +25,24 @@ gfx::Texture::Texture(GLuint width, GLuint height, GLint internalformat, GLenum
 gfx::Texture::~Texture() {
     glDeleteTextures(1, &m_id);
 }
+
+std::shared_ptr<gfx::Texture> gfx::Texture::LoadFromFile(const std::string& filename)
+{
+	int width, height, channels;
+	unsigned char* data = stbi_load(filename.c_str(), &width, &height, &channels, 4);
+
+    if (!data) {
+        throw std::runtime_error("Failed to load texture from file: " + filename);
+    }
+	
+	std::shared_ptr<Texture> texture;
+    try {
+        texture = std::make_shared<Texture>(width, height, data, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, GL_LINEAR);
+    } catch (const std::exception& e) {
+        stbi_image_free(data);
+        throw; // Rethrow the exception after freeing the data
+	}
+
+	stbi_image_free(data);
+	return texture;
+}

src/gfx/texture.hpp

@@ -1,4 +1,6 @@
 #pragma once
+#include <memory>
+#include <string>
 #include "utils.hpp"
 #include "gl.hpp"
 
@@ -12,11 +14,13 @@ class Texture : public NonCopyableNonMovable
 	GLuint m_id;
 
 public:
-	Texture(GLuint width, GLuint height, GLint internalformat, GLenum format, GLenum type, GLenum filter = GL_NEAREST);
+	Texture(GLuint width, GLuint height, const void* data, GLint internalformat, GLenum format, GLenum type, GLenum filter = GL_NEAREST);
 	~Texture();
 
 	GLuint GetId() const { return m_id; }
 
+	static std::shared_ptr<Texture> LoadFromFile(const std::string& filename);
+
 };
 
 }

src/gfx/vertex_array.cpp

@@ -14,10 +14,12 @@ static const VertexAttribInfo s_ATTR_INFO[] = {
     { 0, 3, GL_FLOAT,           GL_FALSE,   sizeof(float) * 3   }, // VA_POSITION
     { 1, 3, GL_FLOAT,           GL_FALSE,   sizeof(float) * 3   }, // VA_NORMAL
     { 2, 4, GL_UNSIGNED_BYTE,   GL_TRUE,    4                   }, // VA_COLOR
+    { 3, 2, GL_FLOAT,           GL_FALSE,   sizeof(float) * 2   }, // VA_UV
+	{ 4, 2, GL_FLOAT,           GL_FALSE,   sizeof(float) * 2   }  // VA_LIGHTMAP_UV
 };
 
 // Pocet typu vertex atributu
-static const size_t s_ATTR_COUNT = 3;
+static const size_t s_ATTR_COUNT = 5;
 
 gfx::VertexArray::VertexArray(int attrs, int flags) : m_usage(GL_STATIC_DRAW), m_num_indices(0) {
     glGenVertexArrays(1, &m_vao);

src/gfx/vertex_array.hpp

@@ -10,49 +10,51 @@
 
 namespace gfx
 {
-// Vycet jednotlivych atributu vrcholu
-enum VertexAttr
-{
-	VA_POSITION = 1 << 0,
-	VA_NORMAL	= 1 << 1,
-	VA_COLOR	= 1 << 2,
-};
+	// Vycet jednotlivych atributu vrcholu
+	enum VertexAttr
+	{
+		VA_POSITION		= 1 << 0,
+		VA_NORMAL		= 1 << 1,
+		VA_COLOR		= 1 << 2,
+		VA_UV			= 1 << 3,
+		VA_LIGHTMAP_UV	= 1 << 4,
+	};
 
-// Informace pro vytvoreni VertexArraye
-enum VertexArrayFlags
-{
-	VF_CREATE_EBO		= 1 << 0,
-	VF_DYNAMIC			= 1 << 1,
-};
+	// Informace pro vytvoreni VertexArraye
+	enum VertexArrayFlags
+	{
+		VF_CREATE_EBO		= 1 << 0,
+		VF_DYNAMIC			= 1 << 1,
+	};
 
-// VertexArray - trida pro praci s modely
-class VertexArray : public NonCopyableNonMovable
-{
-	GLuint m_vao;// , m_vbo, m_ebo;
-	std::unique_ptr<BufferObject> m_vbo;
-	std::unique_ptr<BufferObject> m_ebo;
-	size_t m_num_indices;
-	GLenum m_usage;
+	// VertexArray - trida pro praci s modely
+	class VertexArray : public NonCopyableNonMovable
+	{
+		GLuint m_vao;// , m_vbo, m_ebo;
+		std::unique_ptr<BufferObject> m_vbo;
+		std::unique_ptr<BufferObject> m_ebo;
+		size_t m_num_indices;
+		GLenum m_usage;
 	
-public:
-	VertexArray(int attrs, int flags);
-	~VertexArray();
+	public:
+		VertexArray(int attrs, int flags);
+		~VertexArray();
 
-	// Nastavi data do VBO
-	void SetVBOData(const void* data, size_t size);
+		// Nastavi data do VBO
+		void SetVBOData(const void* data, size_t size);
 	
-	// Nastavi indexy do EBO
-	void SetIndices(const GLuint* data, size_t size);
+		// Nastavi indexy do EBO
+		void SetIndices(const GLuint* data, size_t size);
 
-	GLuint GetVAOId() const { return m_vao; }
-	GLuint GetVBOId() const { return m_vbo->GetId(); }
-	GLuint GetEBOId() const {
-		assert(m_ebo && "GetEBOId() ale !ebo");
-		return m_ebo->GetId();
-	}
+		GLuint GetVAOId() const { return m_vao; }
+		GLuint GetVBOId() const { return m_vbo->GetId(); }
+		GLuint GetEBOId() const {
+			assert(m_ebo && "GetEBOId() ale !ebo");
+			return m_ebo->GetId();
+		}
 
-	//size_t GetVBOSize() const { return m_vbo->; }
-	size_t GetNumIndices() const { return m_num_indices; }
-};
+		//size_t GetVBOSize() const { return m_vbo->; }
+		size_t GetNumIndices() const { return m_num_indices; }
+	};
 
 }

src/gl.hpp

@@ -1,5 +1,8 @@
 #ifdef EMSCRIPTEN
-#include <GLES2/gl2.h>
+#define PG_GLES
+#include <GLES3/gl3.h>
+#include <GLES3/gl2ext.h>
 #else
 #include <glad/glad.h>
 #endif
+

src/main.cpp

@@ -5,6 +5,7 @@
 
 #ifdef EMSCRIPTEN
 #include <emscripten.h>
+#include <emscripten/html5_webgl.h>
 #endif
 
 #include "gl.hpp"
@@ -16,12 +17,28 @@ static std::unique_ptr<App> s_app;
 
 static bool InitSDL()
 {
+	std::cout << "Initializing SDL..." << std::endl;
     if (SDL_Init(SDL_INIT_VIDEO) != 0)
     {
         std::cerr << "SDL_Init Error: " << SDL_GetError() << std::endl;
         return false;
     }
 
+#ifdef EMSCRIPTEN
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
+#else
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+#endif
+
+    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+
+	std::cout << "Creating SDL window..." << std::endl;
     s_window = SDL_CreateWindow("PortalGame", 100, 100, 640, 480, SDL_WINDOW_SHOWN | SDL_WINDOW_MAXIMIZED | SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
     if (!s_window)
     {
@@ -33,18 +50,23 @@ static bool InitSDL()
     return true;
 }
 
+#ifndef EMSCRIPTEN
+static void APIENTRY GLDebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userParam) {
+    //if (severity == 0x826b)
+    //    return;
+    //
+    ////std::cout << message << std::endl;
+    fprintf(stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
+        (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
+        type, severity, message);
+}
+
+#endif // EMSCRIPTEN
+
+
 static bool InitGL()
 {
-#ifdef EMSCRIPTEN
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
-#else
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
-#endif
-
+	std::cout << "Creating OpenGL context..." << std::endl;
     s_context = SDL_GL_CreateContext(s_window);
     if (!s_context)
     {
@@ -62,14 +84,20 @@ static bool InitGL()
 
 #ifndef EMSCRIPTEN
 	// Initialize GLAD
+	std::cout << "Initializing GLAD..." << std::endl;
     if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress))
     {
         std::cerr << "Failed to initialize GLAD" << std::endl;
         SDL_GL_DeleteContext(s_context);
         return false;
 	}
+    glEnable(GL_DEBUG_OUTPUT);
+    glDebugMessageCallback(GLDebugCallback, 0);
+
+    SDL_GL_SetSwapInterval(0);
 #endif
 
+
     return true;
 }
 
@@ -109,22 +137,27 @@ static void Frame()
 {
     Uint32 current_time = SDL_GetTicks();
     s_app->SetTime(current_time / 1000.0f); // Set time in seconds
+
     PollEvents();
+
+	int width, height;
+	SDL_GetWindowSize(s_window, &width, &height);
+	s_app->SetViewportSize(width, height);
+
     s_app->Frame();
     SDL_GL_SwapWindow(s_window);
 }
 
-int main(int argc, char *argv[])
-{
+static void Main() {
     if (!InitSDL())
     {
-        return 1;
+		throw std::runtime_error("Failed to initialize SDL");
     }
 
     if (!InitGL())
     {
         ShutdownSDL();
-        return 1;
+		throw std::runtime_error("Failed to initialize OpenGL");
     }
 
     s_app = std::make_unique<App>();
@@ -142,5 +175,17 @@ int main(int argc, char *argv[])
     ShutdownGL();
     ShutdownSDL();
 #endif
-    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    try {
+        Main();
+    }
+    catch (const std::exception& e) {
+        std::cerr << "[ERROR] " << e.what() << std::endl;
+        return EXIT_FAILURE;
+    }
+
+	return EXIT_SUCCESS;
 }