From 005fceafd96486a8ad2b50324372c8a4e4c783e3 Mon Sep 17 00:00:00 2001
From: Eero Holmala <eero.holmala@hotmail.com>
Date: Fri, 28 Apr 2023 17:44:09 +0300
Subject: [PATCH] App: WIP broken

---
 App/App/CMakeLists.txt |  2 +
 App/App/include/App.hh |  4 +-
 App/App/src/App.cpp    | 85 ++++++++++++++++++++++++++++++++++++++++++
 App/App/src/main.cpp   |  1 -
 4 files changed, 89 insertions(+), 3 deletions(-)

diff --git a/App/App/CMakeLists.txt b/App/App/CMakeLists.txt
index 62d8b9d..9886560 100644
--- a/App/App/CMakeLists.txt
+++ b/App/App/CMakeLists.txt
@@ -13,11 +13,13 @@ add_executable(App
 
 find_package(SDL2 CONFIG REQUIRED)
 find_package(OpenGL REQUIRED)
+find_package(GLEW REQUIRED)
 target_link_libraries(App PRIVATE 
   AppLib 
   SDL2::SDL2 
   SDL2::SDL2main
   OpenGL::GL
+  GLEW::GLEW
 )
 
 target_include_directories(App PUBLIC "${CMAKE_SOURCE_DIR}/App/include")
diff --git a/App/App/include/App.hh b/App/App/include/App.hh
index c6fa761..3f0f0d7 100644
--- a/App/App/include/App.hh
+++ b/App/App/include/App.hh
@@ -2,8 +2,8 @@
 
 #include "SDL2/SDL.h"
 // #include "SDL2/SDL_vulkan.h"
-#include <SDL2/SDL_opengl.h>
-#include <GL/gl.h>
+#include "SDL2/SDL_opengl.h"
+#include "GL/glew.h"
 
 #include "Logger.hh"
 #include "Controller.hh"
diff --git a/App/App/src/App.cpp b/App/App/src/App.cpp
index 61f3d00..4c2714f 100644
--- a/App/App/src/App.cpp
+++ b/App/App/src/App.cpp
@@ -8,10 +8,89 @@
     #define PLATFORM_SURFACE_EXTENSION_NAME VK_KHR_WIN32_SURFACE_EXTENSION_NAME
 #endif
 
+
+//TODO (Eero): https://github.com/theandrew168/sdl2-opengl-demo/blob/master/src/main.c
 namespace App
 {    
     App::App() : m_ReturnCode(0), m_WindowWidth(800), m_WindowHeight(600), m_Quit(false), m_VSync(false)
     {
+        float vertices[] = {
+            -0.5f, -0.5f, 0.0f,
+            0.5f, -0.5f, 0.0f,
+            0.0f, 0.5f, 0.0f
+        };
+
+    //         printf("OpenGL Vendor:   %s\n", glGetString(GL_VENDOR));
+    // printf("OpenGL Renderer: %s\n", glGetString(GL_RENDERER));
+    // printf("OpenGL Version:  %s\n", glGetString(GL_VERSION));
+    // printf("GLSL Version:    %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));
+        // Vertex Shader Part
+        unsigned int VBO;
+        glGenBuffers(1, &VBO);
+        glBindBuffer(GL_ARRAY_BUFFER, VBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+        const char *vertexShaderSource = "#version 330 core\n"
+            "layout (location = 0) in vec3 aPos;\n"
+            "void main()\n"
+            "{\n"
+            "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
+            "}\0";
+
+        unsigned int vertexShader;
+        vertexShader = glCreateShader(GL_VERTEX_SHADER);
+        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
+        glCompileShader(vertexShader);
+
+        int  success;
+        char infoLog[512];
+        glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
+        if(!success)
+        {
+            glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
+            std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
+        }
+
+        // Fragment Shader Part
+        unsigned int fragmentShader;
+        fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+        glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
+        glCompileShader(fragmentShader);
+        
+        
+        glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
+        if(!success) {
+            glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
+            std::cout << "ERROR::SHADER::FRAGMET::COMPILATION_FAILED\n" << infoLog << std::endl;
+        }
+
+        unsigned int shaderProgram;
+        shaderProgram = glCreateProgram();
+        glAttachShader(shaderProgram, vertexShader);
+        glAttachShader(shaderProgram, fragmentShader);
+        glLinkProgram(shaderProgram);
+
+        glUseProgram(shaderProgram);
+
+        // Oh yeah, and don't forget to delete the shader objects once we've linked them into the program object; we no longer need them anymore: 
+        glDeleteShader(vertexShader);
+        glDeleteShader(fragmentShader);  
+
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+        glEnableVertexAttribArray(0); 
+
+        
+
+        // // 0. copy our vertices array in a buffer for OpenGL to use
+        // glBindBuffer(GL_ARRAY_BUFFER, VBO);
+        // glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+        // // 1. then set the vertex attributes pointers
+        // glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+        // glEnableVertexAttribArray(0);  
+        // // 2. use our shader program when we want to render an object
+        // glUseProgram(shaderProgram);
+        // // 3. now draw the object 
+        // someOpenGLFunctionThatDrawsOurTriangle();  
+
         std::cout << "Eternity Engine" << std::endl;
         m_Logger = std::make_shared<Logger>();
         m_Controller = std::make_shared<Controller>();
@@ -81,6 +160,9 @@ namespace App
                 glClearColor(0.39f, 0.58f, 0.93f, 1.f);
                 // Clear color buffer
                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+                glUseProgram(shaderProgram);
+                glBindVertexArray(VAO);
+                // someOpenGLFunctionThatDrawsOurTriangle();
                 // Update window with OpenGL rendering
                 SDL_GL_SwapWindow(m_Window);
             }
@@ -92,6 +174,9 @@ namespace App
     
     App::~App()
     {
+        glDeleteVertexArrays(1, &VAO);
+        glDeleteBuffers(1, &VBO);
+        glDeleteProgram(shaderProgram);
         SDL_DestroyWindow(m_Window);
         SDL_Quit();
         m_Logger.reset();
diff --git a/App/App/src/main.cpp b/App/App/src/main.cpp
index 4a21f8c..fa8d7bb 100644
--- a/App/App/src/main.cpp
+++ b/App/App/src/main.cpp
@@ -1,5 +1,4 @@
 #include "App.hh"
-#include "Math.hh"
 
 #include <iostream>