feat: remove unnecessary code + Blinn-Phong lighting

CMakeLists.txt

@@ -1,55 +1,67 @@
 cmake_minimum_required(VERSION 3.16)
 project(CodingGame LANGUAGES C CXX)
 
-# --- deps via vcpkg ---
-# (vcpkg installs decide static vs shared; no "SDL3-shared" component needed)
-find_package(SDL3 CONFIG REQUIRED)
-find_package(OpenGL REQUIRED)
-find_package(GLEW CONFIG REQUIRED)
-find_package(glm CONFIG REQUIRED)
+if (UNIX)
+	include(FetchContent)
+	FetchContent_Declare(
+		glm
+		GIT_REPOSITORY	https://github.com/g-truc/glm.git
+		GIT_TAG 	bf71a834948186f4097caa076cd2663c69a10e1e #refs/tags/1.0.1
+	)
+	FetchContent_MakeAvailable(glm)
+
+	find_package(SDL3 REQUIRED CONFIG REQUIRED COMPONENTS SDL3-shared)
+	find_package(OpenGL REQUIRED)
+	find_package(GLEW REQUIRED)
+elseif (MSVC) # vcpkg
+	find_package(SDL3 CONFIG REQUIRED)
+	find_package(OpenGL REQUIRED)
+	find_package(GLEW CONFIG REQUIRED)
+	find_package(glm CONFIG REQUIRED)
+endif()
+
+# Add -ggdb to debug builds
+# set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -ggdb")
+# set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -ggdb")
 
-# --- exe ---
 add_executable(CodingGame
-  src/prelude.cpp
-  src/file_manager.cpp
-  src/shader.cpp
-  src/block.cpp
-  src/vertex.cpp
-  src/texture.cpp
-  src/model.cpp
-  src/main.cpp
+	src/prelude.cpp
+	src/file_manager.cpp
+	src/shader.cpp 
+	src/block.cpp 
+	src/vertex.cpp 
+	src/texture.cpp 
+	src/model.cpp 
+	src/main.cpp
 )
 
 set_property(TARGET CodingGame PROPERTY CXX_STANDARD 17)
 set_property(TARGET CodingGame PROPERTY CXX_STANDARD_REQUIRED ON)
 
-file(COPY ${CMAKE_SOURCE_DIR}/src/shaders DESTINATION ${CMAKE_BINARY_DIR}/)
+file(COPY src/shaders DESTINATION ${CMAKE_BINARY_DIR}/)
 
 target_include_directories(CodingGame PRIVATE
-  ${CMAKE_SOURCE_DIR}/include
-  ${CMAKE_SOURCE_DIR}/contrib
+	${CMAKE_SOURCE_DIR}/include
+	${CMAKE_SOURCE_DIR}/contrib
 )
-
 target_link_libraries(CodingGame PRIVATE
-  glm::glm
-  OpenGL::GL
-  SDL3::SDL3           # vcpkg’s SDL3 target
-  GLEW::GLEW
+	SDL3::SDL3
+	OpenGL::GL
+	GLEW::GLEW
+	glm::glm
 )
 
-# Debug flags per toolchain
+# Debug flags
 if (MSVC)
-  target_compile_options(CodingGame PRIVATE $<$<CONFIG:Debug>:/Zi>)
-  target_link_options(CodingGame PRIVATE $<$<CONFIG:Debug>:/DEBUG:FULL>)
+	target_compile_options(CodingGame PRIVATE $<$<CONFIG:Debug>:/Zi>)
+	target_link_options(CodingGame PRIVATE $<$<CONFIG:Debug>:/DEBUG:FULL>)
 else()
-  target_compile_options(CodingGame PRIVATE $<$<CONFIG:Debug>:-ggdb>)
+	target_compile_options(CodingGame PRIVATE $<$<CONFIG:Debug>:-ggdb>)
 endif()
 
-# --- copy runtime DLLs next to the exe on Windows ---
-# (CMake 3.21+)
 if (WIN32)
-  add_custom_command(TARGET CodingGame POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E copy_if_different
-      $<TARGET_RUNTIME_DLLS:CodingGame> $<TARGET_FILE_DIR:CodingGame>
-    COMMAND_EXPAND_LISTS)
+	add_custom_command(TARGET CodingGame POST_BUILD
+		COMMAND ${CMAKE_COMMAND} -E copy_if_different
+			$<TARGET_RUNTIME_DLLS:CodingGame> $<TARGET_FILE_DIR:CodingGame>
+		COMMAND_EXPAND_LISTS)
 endif()

README.md

@@ -0,0 +1,29 @@
+
+
+# Project Description
+
+This is a basic future game engine for OpenGL 3D rendered games
+
+## Building on Windows
+
+In order to configure and run project on windows platform use following commands.
+
+Configuring:
+
+```console
+cmake -S . -B build `       
+   -G "Visual Studio 17 2022" -A x64 `
+   -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake `
+   -DVCPKG_TARGET_TRIPLET=x64-windows `
+   -DCMAKE_BUILD_TYPE=Debug
+```
+
+## Multi-GPU Devices
+
+If you want to use non-primary GPU on your device when launching the game specifically on Linux you should specify additional environment variables before running. For example in my case I have a hybrid gaming laptop with 2 GPUs AMD from CPU and NVIDIA discrete.
+
+The run command in that case would look following:
+
+```console
+__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia ./build/CodingGame
+```

WINDOWS.md

@@ -1,25 +0,0 @@
-
-# Setup VCPKG
-
-```console
-git clone https://github.com/microsoft/vcpkg C:\vcpkg
-C:\vcpkg\bootstrap-vcpkg.bat
-# install deps for 64-bit Windows
-C:\vcpkg\vcpkg install sdl3 glew glm --triplet x64-windows
-```
-
-# Configure
-
-```console
-cmake -S . -B build `
-  -G "Visual Studio 17 2022" -A x64 `
-  -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake `
-  -DVCPKG_TARGET_TRIPLET=x64-windows `
-  -DCMAKE_BUILD_TYPE=Debug
-```
-
-# Build
-
-```console
-cmake --build build --config Debug
-```

include/model.h

@@ -2,6 +2,7 @@
 #define MODEL_H_
 #include <vector>
 #include <string>
+#include <filesystem>
 #include <unordered_map>
 #include <glm/glm.hpp>
 #include <memory>
@@ -63,6 +64,8 @@ private:
     glm::vec3 m_diffuse { 0.8f, 0.8f, 0.8f };
     glm::vec3 m_specular { 1.0f, 1.0f, 1.0f };
     float m_shininess { 32.0f };
+    float m_opacity { 1.0f };
+    int m_illum { 2 };
 
     std::unique_ptr<Texture> m_diffuse_tex { nullptr };
 public:
@@ -76,12 +79,16 @@ public:
     inline const float GetSpecularWeight() const { return m_shininess; }
     inline const bool HasDiffuseTexture() const { return m_diffuse_tex != nullptr; }
     inline const Texture* GetDiffuseTexture() const { return m_diffuse_tex.get(); }
+    inline const float GetOpacity() const { return m_opacity; }
+    inline const int GetIllumination() const { return m_illum; }
 public:
     inline void SetAmbientColor(glm::vec3 ambient) { m_ambient = ambient; }
     inline void SetDiffuseColor(glm::vec3 diffuse) { m_diffuse = diffuse; }
     inline void SetSpecularColor(glm::vec3 specular) { m_specular = specular; }
     inline void SetSpecularWeight(float weight) { m_shininess = weight; }
     inline void SetDiffuseTexture(std::unique_ptr<Texture>&& texture) { m_diffuse_tex = std::move(texture); }
+    inline void SetOpacity(float opacity) { m_opacity = opacity; }
+    inline void SetIllumination(float illum) { m_illum = illum; }
 };
 
 class Mesh {
@@ -120,7 +127,7 @@ public:
     static Object LoadFile(const std::string& filename);
 
 private:
-    void LoadMaterials(const std::string& filename);
+    void LoadMaterials(const std::filesystem::path& filename);
 private:
     void AddMaterial(std::string name, std::shared_ptr<Material> material);
     std::shared_ptr<Material> GetMaterial(std::string name);

include/prelude.h

@@ -1,7 +1,11 @@
 #ifndef PRELUDE_H_
 #define PRELUDE_H_
-// #define GLEW_STATIC
+
+#ifndef WIN32
+#define GLEW_STATIC
+#endif
 #include <GL/glew.h>
+
 #include "SDL3/SDL.h"
 
 struct RenderContext {

src/main.bkp.cpp

@@ -1,229 +0,0 @@
-#include <iostream>
-#include <vector>
-#include <glm/glm.hpp>
-#include <glm/ext/matrix_transform.hpp>
-#include <glm/ext/matrix_clip_space.hpp>
-#include <GL/glew.h>
-#include <SDL3/SDL.h>
-
-#include "shader.h"
-#include "file_manager.h"
-#include "prelude.h"
-#include "block.h"
-#include "vertex.h"
-#include "model.h"
-
-#define WIDTH 1024
-#define HEIGHT 768
-
-int main() {
-    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS);
-
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 6);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
-
-    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
-    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 8);
-
-    SDL_Window *window = SDL_CreateWindow("OpenGL Test", WIDTH, HEIGHT, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE|SDL_WINDOW_ALWAYS_ON_TOP);
-
-    SDL_GLContext glcontext = SDL_GL_CreateContext(window);
-
-    glewExperimental = GL_TRUE;
-    if (GLEW_OK != glewInit()) {
-        fprintf(stderr, "Could not initialize GLEW!\n");
-        SDL_GL_DestroyContext(glcontext);
-        SDL_DestroyWindow(window);
-        exit(1);
-    }
-
-    glEnable(GL_DEBUG_OUTPUT);
-    glEnable(GL_DEPTH_TEST);
-    glDebugMessageCallback(MessageCallback, 0);
-
-    // brightness multipliers for faces
-    const float FACE_BRIGHTNESS[6] = {
-        1.0f,  // front
-        0.7f,  // right
-        0.5f,  // back
-        0.7f,  // left
-        1.2f,  // top
-        0.4f   // bottom
-    };
-
-    // position, normal, color
-    glm::vec4 cubeColor = {1.0f, 0.5f, 0.31f, 1.0f};
-    std::vector<Point> cubeVerts = {
-        // front face (z = 0, normal = +Z)
-        { {-0.5f, -0.5f, 0.5f}, {0.f, 0.f, 1.f}, cubeColor },
-        { {0.5f, -0.5f, 0.5f}, {0.f, 0.f, 1.f}, cubeColor },
-        { {0.5f, 0.5f, 0.5f}, {0.f, 0.f, 1.f}, cubeColor },
-        { {-0.5f, 0.5f, 0.5f}, {0.f, 0.f, 1.f}, cubeColor },
-
-        // back face (z = 1, normal = -Z)
-        { {-0.5f, -0.5f, -0.5f}, {0.f, 0.f, -1.f}, cubeColor },
-        { {0.5f, -0.5f, -0.5f}, {0.f, 0.f, -1.f}, cubeColor },
-        { {0.5f, 0.5f, -0.5f}, {0.f, 0.f, -1.f}, cubeColor },
-        { {-0.5f, 0.5f, -0.5f}, {0.f, 0.f, -1.f}, cubeColor },
-
-        // left face (x = 0, normal = -X)
-        { {-0.5f, -0.5f, -0.5f}, {-1.f, 0.f, 0.f}, cubeColor },
-        { {-0.5f, -0.5f, 0.5f}, {-1.f, 0.f, 0.f}, cubeColor },
-        { {-0.5f, 0.5f, 0.5f}, {-1.f, 0.f, 0.f}, cubeColor },
-        { {-0.5f, 0.5f, -0.5f}, {-1.f, 0.f, 0.f}, cubeColor },
-
-        // right face (x = 1, normal = +X)
-        { {0.5f, -0.5f, -0.5f}, {1.f, 0.f, 0.f}, cubeColor },
-        { {0.5f, -0.5f, 0.5f}, {1.f, 0.f, 0.f}, cubeColor },
-        { {0.5f, 0.5f, 0.5f}, {1.f, 0.f, 0.f}, cubeColor },
-        { {0.5f, 0.5f, -0.5f}, {1.f, 0.f, 0.f}, cubeColor },
-
-        // top face (y = 1, normal = +Y)
-        { {-0.5f, 0.5f, 0.5f}, {0.f, 1.f, 0.f}, cubeColor },
-        { {0.5f, 0.5f, 0.5f}, {0.f, 1.f, 0.f}, cubeColor },
-        { {0.5f, 0.5f, -0.5f}, {0.f, 1.f, 0.f}, cubeColor },
-        { {-0.5f, 0.5f, -0.5f}, {0.f, 1.f, 0.f}, cubeColor },
-
-        // bottom face (y = 0, normal = -Y)
-        { {-0.5f, -0.5f, 0.5f}, {0.f, -1.f, 0.f}, cubeColor },
-        { {0.5f, -0.5f, 0.5f}, {0.f, -1.f, 0.f}, cubeColor },
-        { {0.5f, -0.5f, -0.5f}, {0.f, -1.f, 0.f}, cubeColor },
-        { {-0.5f, -0.5f, -0.5f}, {0.f, -1.f, 0.f}, cubeColor },
-    };
-
-    std::vector<unsigned int> cubeIndices = {
-        0,1,2,  2,3,0,      // front
-        4,5,6,  6,7,4,      // back
-        8,9,10, 10,11,8,    // left
-        12,13,14, 14,15,12, // right
-        16,17,18, 18,19,16, // top
-        20,21,22, 22,23,20  // bottom
-    };
-
-    Vertices vertices;
-    for (auto &v : cubeVerts) vertices.PushVertex(v);
-    for (auto i : cubeIndices) vertices.PushIndex(i);
-    vertices.Upload();
-
-    Shader simpleShader;
-    simpleShader.init(
-        FileManager::read("./src/shaders/simple.vs"),
-        FileManager::read("./src/shaders/simple.fs")
-    );
-
-    int screenWidth = WIDTH, screenHeight = HEIGHT;
-
-    glm::vec3 cameraPosition(0.f, 0.f, 2.f);
-    glm::vec3 cameraViewDirection(0.f, 0.f, -1.f);
-    // glm::vec3 lightPosition(1.f, 3.5f, -2.f);
-    glm::vec3 lightPosition = cameraPosition;
-
-    glm::mat4 model(1.f);
-
-    glm::mat4 view = glm::lookAt(
-        cameraPosition,
-        cameraPosition + cameraViewDirection,
-        glm::vec3(0.f, 1.f, 0.f)
-    );
-
-    glm::mat4 projection = glm::perspective(
-        (float)M_PI_2,
-        (float)screenWidth / (float)screenHeight,
-        0.01f,
-        100.0f
-    );
-
-    float angle = 3.45f;
-    Uint64 lastTicks = SDL_GetTicks();
-
-    Object cube = Object::LoadFile("./assets/cube.obj");
-    Object monkey = Object::LoadFile("./assets/monkey.obj");
-
-    bool paused = false;
-
-    bool quit = false;
-    while (!quit) {
-        Uint64 currentTicks = SDL_GetTicks();
-        float deltaTime = (currentTicks - lastTicks) / 1000.0f; // seconds
-
-        lastTicks = currentTicks;
-
-        SDL_Event event;
-        while(SDL_PollEvent(&event)) {
-            switch (event.type) {
-                case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
-                case SDL_EVENT_QUIT:
-                    quit = true;
-                    break;
-                case SDL_EVENT_WINDOW_RESIZED:
-                    int width, height;
-                    if (SDL_GetWindowSize(window, &width, &height)) {
-                        glViewport(
-                            0,
-                            0,
-                            width,
-                            height);
-                    }
-                    break;
-                case SDL_EVENT_KEY_DOWN:
-                    switch (event.key.key) {
-                    case SDLK_SPACE:
-                        paused = !paused;
-                        break;
-                    // case SDLK_F5:
-                    //     reload_shaders(&context);
-                    //     break;
-                    default: break;
-                    };
-                    break;
-                default: break;
-            };
-        }
-
-        // update rotation
-        if (!paused) {
-            angle += glm::radians(45.0f) * deltaTime; // 72° per second
-            if (angle > glm::two_pi<float>()) {
-                angle -= glm::two_pi<float>(); // keep value small
-            }
-        }
-
-        // std::cout << "angle = " << angle << std::endl;
-
-        glClearColor(0x18/255.0f, 0x18/255.0f, 0x18/255.0f, 1);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-        // Triangle render
-        {
-            simpleShader.use();
-
-            model = glm::rotate(
-                glm::mat4(1.f),
-                angle,
-                glm::vec3(0.8f, -0.4f, 0.5f)
-            );
-
-            // lightPosition -= glm::vec3(0.05f, 0.f, 0.f) * deltaTime;
-
-            simpleShader.setMat4("u_model", model);
-            simpleShader.setMat4("u_view", view);
-            simpleShader.setMat4("u_projection", projection);
-
-            simpleShader.setVec3("lightColor", glm::vec3(1.0f, 1.0f, 1.0f));
-            simpleShader.setVec3("lightPos", lightPosition);
-            simpleShader.setVec3("viewPos", cameraPosition);
-            simpleShader.setFloat("ambientStrength", 0.2f);
-            simpleShader.setFloat("specularStrength", 0.5f);
-
-            vertices.Draw();
-        }
-        
-        SDL_GL_SwapWindow(window);
-    }
-
-    SDL_GL_DestroyContext(glcontext);
-    SDL_DestroyWindow(window);
-
-    return 0;
-}

src/main.cpp

@@ -1,6 +1,10 @@
 #include <iostream>
+
+// #ifdef WIN32
 #define _USE_MATH_DEFINES
 #include <cmath>
+// #endif
+
 #include <vector>
 #include <glm/glm.hpp>
 #include <glm/ext/quaternion_geometric.hpp>

src/model.cpp

@@ -86,7 +86,7 @@ Object::Object() {
     m_texCoords = std::vector<glm::vec2>();
 }
 
-void Object::LoadMaterials(const std::string& filename) {
+void Object::LoadMaterials(const std::filesystem::path& filename) {
     std::ifstream file(filename);
 
     std::string currentMaterialName;
@@ -142,6 +142,20 @@ void Object::LoadMaterials(const std::string& filename) {
             currentMaterial->SetDiffuseColor(glm::vec3(r, g, b));
             break;
         }
+        case MtlElement::D:
+        {
+            float d;
+            iss >> d;
+            currentMaterial->SetOpacity(d);
+            break;
+        }
+        case MtlElement::ILLUM:
+        {
+            int illum;
+            iss >> illum;
+            currentMaterial->SetIllumination(illum);
+            break;
+        }
         case MtlElement::MAP_KD:
         {
             std::string texturePath;
@@ -215,7 +229,7 @@ Object Object::LoadFile(const std::string& filename) {
             iss >> mtlFile;
             std::filesystem::path fullPath = filename;
             std::filesystem::path mtlPath = fullPath.replace_filename(mtlFile);
-            obj.LoadMaterials(mtlPath.u8string());
+            obj.LoadMaterials(mtlPath);
             std::cout << "loaded mtl at '" << mtlPath << "' with "
                 << obj.m_materials.size() << " materials" << std::endl;
             break;
@@ -325,7 +339,10 @@ void Object::Render(Shader& shader)
         auto material = GetMaterial(mesh.materialName);
         
         shader.setFloat("ambientStrength", 0.2f);
-        shader.setFloat("specularStrength", material->GetSpecularWeight());
+        shader.setFloat("shininess", material->GetSpecularWeight());
+        shader.setFloat("opacity", material->GetOpacity());
+        shader.setBool("useSpecular", material->GetIllumination() >= 2);
+        shader.setFloat("specularStrength", 1.0f);
         shader.setVec3("ambientColor", material->GetAmbientColor());
         shader.setVec3("diffuseColor", material->GetDiffuseColor());
         shader.setVec3("specularColor", material->GetSpecularColor());

src/prelude.cpp

@@ -6,7 +6,9 @@
 #include <errno.h>
 #include "prelude.h"
 
-// #define GLEW_STATIC
+#ifndef WIN32
+#define GLEW_STATIC
+#endif
 #include <GL/glew.h>
 
 #define SCREEN_WIDTH 1024

src/shaders/pbr.fs

@@ -0,0 +1,126 @@
+#version 410 core
+
+// Output color
+out vec4 FragColor;
+
+in vec3 vertexPos;
+in vec3 vertexNormal;
+in vec2 TexCoords;
+
+uniform vec3 lightPos;
+uniform vec3 viewPos;
+
+// From Object Renderer
+uniform vec3 ambientColor;
+uniform vec3 diffuseColor;
+uniform vec3 specularColor;   // used as F0 (base reflectance)
+
+uniform float ambientStrength;
+uniform float specularStrength; 
+uniform float shininess;      // mapped to roughness
+uniform bool useSpecular;
+
+uniform float opacity;
+
+uniform sampler2D diffuseTex;
+uniform bool useTexture;
+
+#define LIGHT_COLOR vec3(1.0, 1.0, 1.0)
+
+// ----------------------------------------------------------------------------
+// Helper functions for Cook-Torrance BRDF
+// ----------------------------------------------------------------------------
+
+// Normal Distribution Function (GGX/Trowbridge-Reitz)
+float DistributionGGX(vec3 N, vec3 H, float roughness)
+{
+    float a      = roughness * roughness;
+    float a2     = a * a;
+    float NdotH  = max(dot(N, H), 0.0);
+    float NdotH2 = NdotH * NdotH;
+
+    float num   = a2;
+    float denom = (NdotH2 * (a2 - 1.0) + 1.0);
+    denom = 3.14159265 * denom * denom;
+
+    return num / denom;
+}
+
+// Geometry function (Schlick-GGX)
+float GeometrySchlickGGX(float NdotV, float roughness)
+{
+    float r = (roughness + 1.0);
+    float k = (r * r) / 8.0; // remapped for direct lighting
+
+    float num   = NdotV;
+    float denom = NdotV * (1.0 - k) + k;
+
+    return num / denom;
+}
+
+// Smith's geometry function
+float GeometrySmith(vec3 N, vec3 V, vec3 L, float roughness)
+{
+    float NdotV = max(dot(N, V), 0.0);
+    float NdotL = max(dot(N, L), 0.0);
+    float ggx1 = GeometrySchlickGGX(NdotV, roughness);
+    float ggx2 = GeometrySchlickGGX(NdotL, roughness);
+    return ggx1 * ggx2;
+}
+
+// Fresnel term (Schlick's approximation)
+vec3 FresnelSchlick(float cosTheta, vec3 F0)
+{
+    return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
+}
+
+// ----------------------------------------------------------------------------
+void main()
+{
+    vec3 N = normalize(vertexNormal);
+    vec3 V = normalize(viewPos - vertexPos);
+    vec3 L = normalize(lightPos - vertexPos);
+    vec3 H = normalize(V + L);
+
+    // Texture or uniform color
+    vec3 albedo = (useTexture)
+        ? texture(diffuseTex, TexCoords).rgb
+        : diffuseColor;
+
+    // Map shininess to roughness (inverse relationship)
+    float roughness = clamp(1.0 - (shininess / 256.0), 0.05, 1.0);
+
+    // Base reflectivity (F0)
+    vec3 F0 = mix(vec3(0.04), specularColor, specularStrength);
+
+    // Cook-Torrance BRDF
+    float NDF = DistributionGGX(N, H, roughness);
+    float G   = GeometrySmith(N, V, L, roughness);
+    vec3  F   = FresnelSchlick(max(dot(H, V), 0.0), F0);
+
+    vec3 numerator    = NDF * G * F;
+    float denominator = 4.0 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001;
+    vec3 specular     = numerator / denominator;
+
+    // Energy conservation
+    vec3 kS = F;
+    vec3 kD = vec3(1.0) - kS;
+    kD *= (useSpecular ? 1.0 : 1.0); // keep diffuse always unless specular is off
+
+    float NdotL = max(dot(N, L), 0.0);
+
+    vec3 diffuse = kD * albedo / 3.14159265;
+    vec3 radiance = LIGHT_COLOR;
+
+    vec3 Lo = (diffuse + specular) * radiance * NdotL;
+
+    // Ambient (simple, not IBL)
+    vec3 ambient = ambientStrength * ambientColor * albedo;
+
+    vec3 result = ambient + Lo;
+
+    // Gamma correction
+    result = pow(result, vec3(1.0/2.2));
+
+    FragColor = vec4(result, opacity);
+}

src/shaders/simple.fs

@@ -17,7 +17,12 @@ uniform vec3 diffuseColor;
 uniform vec3 specularColor;
 
 uniform float ambientStrength;
+
 uniform float specularStrength;
+uniform float shininess;
+uniform bool useSpecular;
+
+uniform float opacity;
 
 uniform sampler2D diffuseTex;
 uniform bool useTexture;
@@ -33,8 +38,13 @@ void main()
     vec3 reflectDir = reflect(-lightDir, norm);
 
     // Phong components
-    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
-    vec3 specular = specularStrength * spec * specularColor; 
+    // float spec = pow(max(dot(viewDir, reflectDir), 0.0), clamp(shininess, 2, 256));
+    // vec3 specular = (useSpecular) ? specularStrength * spec * specularColor : vec3(0.0);
+
+    // Blinn Phong
+    vec3 halfDir = normalize(lightDir + viewDir);
+    float spec = pow(max(dot(norm, halfDir), 0.0), clamp(shininess, 2.0, 256.0));
+    vec3 specular = (useSpecular) ? specularStrength * spec * specularColor : vec3(0.0);
 
     float diff = max(dot(norm, lightDir), 0.0);
     vec3 diffuse = diff * diffuseColor;
@@ -46,5 +56,6 @@ void main()
         : diffuseColor;
 
     vec3 result = (ambient + diffuse + specular) * texColor;
-    FragColor = vec4(result, 1.0);
+
+    FragColor = vec4(result, opacity);
 }

src/texture.cpp

@@ -10,7 +10,7 @@ std::unique_ptr<Texture> Texture::LoadFile(const std::string& filename) {
     auto texture = std::make_unique<Texture>();
 
     int w, h, c;
-    unsigned char *data = stbi_load(filename.c_str(), &w, &h, &c, 0);
+    unsigned char *data = stbi_load(filename.c_str(), &w, &h, &c, 4);
     if (!data) {
         std::cerr << "ERROR: Failed to load texture under '" << filename << "'" << std::endl;
         std::exit(1);
@@ -26,7 +26,7 @@ std::unique_ptr<Texture> Texture::LoadFile(const std::string& filename) {
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
     // TODO: automatically detect values for this function
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
     glGenerateMipmap(GL_TEXTURE_2D);
 
     std::cout << "Loaded texture under '" << filename << "' with size of " << sizeof(data) << " bytes" << std::endl;