Tesseract-Engine/src/Windows/RenderWindow.cpp

// RenderWindow.cpp

#include "RenderWindow.h"
#include <vector> // Add this line

#include <GL/glew.h>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include "imgui.h"

#include "gcml.h"


#include "Componenets/GameObject.h"
#include "Componenets/mesh.h"
#include "Componenets/transform.h"

extern std::vector<std::shared_ptr<GameObject>> g_GameObjects;

#define CAM_FOV 45.0f
#define CAM_NEAR_PLAIN 0.1f
#define CAM_FAR_PLAIN 1000.0f

// Include your AssetManager & Shader headers
#include "Engine/AssetManager.h"
#include "Rendering/Shader.h"

// Extern reference to our global (or extern) asset manager
extern AssetManager g_AssetManager;

extern int g_GPU_Triangles_drawn_to_screen;


// Example cube data (position + UVs)
static float g_CubeVertices[] =
    {
        // FRONT (z=+1)
        -1.f,
        -1.f,
        1.f,
        0.f,
        0.f,
        1.f,
        -1.f,
        1.f,
        1.f,
        0.f,
        1.f,
        1.f,
        1.f,
        1.f,
        1.f,
        -1.f,
        1.f,
        1.f,
        0.f,
        1.f,

        // BACK (z=-1)
        -1.f,
        -1.f,
        -1.f,
        1.f,
        0.f,
        1.f,
        -1.f,
        -1.f,
        0.f,
        0.f,
        1.f,
        1.f,
        -1.f,
        0.f,
        1.f,
        -1.f,
        1.f,
        -1.f,
        1.f,
        1.f,

        // LEFT (x=-1)
        -1.f,
        -1.f,
        -1.f,
        0.f,
        0.f,
        -1.f,
        -1.f,
        1.f,
        1.f,
        0.f,
        -1.f,
        1.f,
        1.f,
        1.f,
        1.f,
        -1.f,
        1.f,
        -1.f,
        0.f,
        1.f,

        // RIGHT (x=+1)
        1.f,
        -1.f,
        -1.f,
        1.f,
        0.f,
        1.f,
        -1.f,
        1.f,
        0.f,
        0.f,
        1.f,
        1.f,
        1.f,
        0.f,
        1.f,
        1.f,
        1.f,
        -1.f,
        1.f,
        1.f,

        // TOP (y=+1)
        -1.f,
        1.f,
        -1.f,
        0.f,
        0.f,
        1.f,
        1.f,
        -1.f,
        1.f,
        0.f,
        1.f,
        1.f,
        1.f,
        1.f,
        1.f,
        -1.f,
        1.f,
        1.f,
        0.f,
        1.f,

        // BOTTOM (y=-1)
        -1.f,
        -1.f,
        -1.f,
        1.f,
        0.f,
        1.f,
        -1.f,
        -1.f,
        0.f,
        0.f,
        1.f,
        -1.f,
        1.f,
        0.f,
        1.f,
        -1.f,
        -1.f,
        1.f,
        1.f,
        1.f,
};

static unsigned int g_CubeIndices[] =
    {
        // Front
        0, 1, 2, 2, 3, 0,
        // Back
        4, 5, 6, 6, 7, 4,
        // Left
        8, 9, 10, 10, 11, 8,
        // Right
        12, 13, 14, 14, 15, 12,
        // Top
        16, 17, 18, 18, 19, 16,
        // Bottom
        20, 21, 22, 22, 23, 20};

void RenderWindow::Show()
{
    
    ImGui::Begin("Editor");

    ImVec2 size = ImGui::GetContentRegionAvail();
    int w = static_cast<int>(size.x);
    int h = static_cast<int>(size.y);

    if (!m_Initialized)
    {
        InitGLResources();
        m_Initialized = true;
    }



    // If there's space, render to the FBO, then show it as an ImGui image

    if (w > 0 && h > 0)
    {
        if (w != m_LastWidth || h != m_LastHeight)
        {
            
            m_FBO.Create(w, h);
            m_LastWidth = w;
            m_LastHeight = h;
        }

        RenderSceneToFBO();

        ImGui::Image(m_FBO.GetTextureID(), size, ImVec2(0, 0), ImVec2(1, 1));
    }
    else
    {
        ImGui::Text("No space to render.");
    }

    ImGui::End();

}

void RenderWindow::InitGLResources()
{
    // ----------------------------------------------------
    // 1) Load SHADER from the asset manager
    // ----------------------------------------------------

    {
        Shader* shaderAsset = g_AssetManager.loadAsset<Shader*>(AssetType::SHADER, "assets/shaders/UnlitMaterial");
        if (!shaderAsset)
        {
            fprintf(stderr, "[RenderWindow] Failed to load shader via AssetManager.\n");
            return;
        }
        // Cast back to your Shader class
        m_ShaderPtr = static_cast<Shader *>(shaderAsset);
    }

    // ----------------------------------------------------
    // 2) Create VAO/VBO/EBO for the cube
    // ----------------------------------------------------
    glGenVertexArrays(1, &m_VAO);
    glBindVertexArray(m_VAO);

    glGenBuffers(1, &m_VBO);
    glBindBuffer(GL_ARRAY_BUFFER, m_VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(g_CubeVertices), g_CubeVertices, GL_STATIC_DRAW);

    glGenBuffers(1, &m_EBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_EBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(g_CubeIndices), g_CubeIndices, GL_STATIC_DRAW);

    // Position = location 0, UV = location 1
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,
                          5 * sizeof(float), (void *)0);
    glEnableVertexAttribArray(0);

    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE,
                          5 * sizeof(float), (void *)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    glBindVertexArray(0);

    // ----------------------------------------------------
    // 3) Load TEXTURE from the asset manager
    // ----------------------------------------------------
    {
        GLuint texAsset = g_AssetManager.loadAsset<GLuint>(AssetType::TEXTURE, "assets/textures/wood.png");
        if (!texAsset)
        {
            fprintf(stderr, "[RenderWindow] Failed to load texture.\n");
        }
        else
        {
            // Cast from void* to GLuint
            m_TextureID = texAsset;
        }
    }

    // ----------------------------------------------------
    // 4) Initialize GameObjects
    // ----------------------------------------------------

}

void RenderWindow::RenderSceneToFBO()
{

    

    m_RotationAngle += 0.001f; // spin per frame

    // Bind the FBO
    m_FBO.Bind();
    glViewport(0, 0, m_LastWidth, m_LastHeight);

    glEnable(GL_DEPTH_TEST);

    glClearColor(0.f, 0.f, 0.f, 1.f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // Use our loaded shader

    if (!m_ShaderPtr)
        return; // Can't render without a shader

    m_ShaderPtr->Use();
    GLuint programID = m_ShaderPtr->GetProgramID();

    // Define view and projection matrices once
    glm::mat4 view = glm::translate(glm::mat4(1.f), glm::vec3(0.f, 0.f, -5.f));
    float aspect = (m_LastHeight != 0) ? (float)m_LastWidth / (float)m_LastHeight : 1.0f;
    glm::mat4 proj = glm::perspective(glm::radians(CAM_FOV), aspect, CAM_NEAR_PLAIN, CAM_FAR_PLAIN);

    // Iterate over each GameObject and render it


    for (auto &obj : g_GameObjects)
    {   

        // -----------------------------------
        // 1) Build MVP from transform
        // -----------------------------------
        glm::mat4 model = glm::mat4(1.f);


        std::shared_ptr<TransformComponent> transform = obj->GetComponent<TransformComponent>();



        std::shared_ptr<MeshComponent> mesh = obj->GetComponent<MeshComponent>();

        if (!transform) {
            DEBUG_PRINT("Could not find Transform Component");
        }


        if (transform && mesh)
        {
            
            // Translate

            g_GPU_Triangles_drawn_to_screen = static_cast<int>(mesh->indexCount);

            model = glm::translate(model, transform->position);

            // Rotate around X, Y, Z

            //transform->rotation.x += m_RotationAngle;
            model = glm::rotate(model, glm::radians(transform->rotation.x), glm::vec3(1.f, 0.f, 0.f));
            model = glm::rotate(model, glm::radians(transform->rotation.y), glm::vec3(0.f, 1.f, 0.f));
            model = glm::rotate(model, glm::radians(transform->rotation.z), glm::vec3(0.f, 0.f, 1.f));

            // Scale
            model = glm::scale(model, transform->scale);



            // Compute MVP
            glm::mat4 mvp = proj * view * model;

            // Pass MVP to the shader
            GLint mvpLoc = glGetUniformLocation(programID, "uMVP");
            glUniformMatrix4fv(mvpLoc, 1, GL_FALSE, glm::value_ptr(mvp));

            // -----------------------------------
            // 2) Bind the object's texture
            // -----------------------------------
            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D, mesh->textureID);

            // Set the sampler uniform to texture unit 0
            GLint texLoc = glGetUniformLocation(programID, "uTexture");
            glUniform1i(texLoc, 0);

            // -----------------------------------
            // 3) Draw the object's mesh
            // -----------------------------------
            glBindVertexArray(mesh->vao);
            glDrawElements(GL_TRIANGLES, mesh->indexCount, GL_UNSIGNED_INT, nullptr);

            // Unbind for cleanliness
            glBindVertexArray(0);
            glBindTexture(GL_TEXTURE_2D, 0);
        }
    }

    // Cleanup
    glUseProgram(0);
    m_FBO.Unbind();
}