I am using the glfw-opengl4 demo to draw. I don't get any compile errors. But the windows are not drawing properly. Here is the Image

Code:

ImGuiLayer.h

#pragma once

#define NK_GLFW_GL4_IMPLEMENTATION
#define NK_UINT_DRAW_INDEX
#define NK_INCLUDE_FIXED_TYPES
#define NK_INCLUDE_STANDARD_IO
#define NK_INCLUDE_STANDARD_VARARGS
#define NK_INCLUDE_DEFAULT_ALLOCATOR
#define NK_INCLUDE_VERTEX_BUFFER_OUTPUT
#define NK_INCLUDE_FONT_BAKING
#define NK_INCLUDE_DEFAULT_FONT
#define NK_KEYSTATE_BASED_INPUT

#include "Atlas/Layer.h"

struct nk_context;
struct nk_image;

namespace atlas
{
    class CImGuiLayer : public CLayer
    {
    private:
            ...
        nk_context* ctx;
        struct nk_image* img;
    };
}

ImGuiLayer.cpp


#include "atpch.h"
#include "ImGuiLayer.h"

...

include "GLFW/glfw3.h"

include "glad/glad.h"

include "nuklear.h"

include "demo/glfw_opengl4/nuklear_glfw_gl4.h"

define MAX_VERTEX_BUFFER 512 * 1024

define MAX_ELEMENT_BUFFER 128 * 1024

...

void CImGuiLayer::OnAttach( )
{
    GLFWwindow* window = static_cast<GLFWwindow*>( m_Window->GetNativeWindow( ) );
    ctx = nk_glfw3_init( window, NK_GLFW3_INSTALL_CALLBACKS, MAX_VERTEX_BUFFER, MAX_ELEMENT_BUFFER );

    struct nk_font_atlas* atlas;
    nk_glfw3_font_stash_begin( &atlas );
    nk_glfw3_font_stash_end( );

    int tex_index = 0;
    enum
    {
        tex_width = 256, tex_height = 256
    };
    char pixels[ tex_width * tex_height * 4 ];
    memset( pixels, 128, sizeof( pixels ) );
    tex_index = nk_glfw3_create_texture( pixels, tex_width, tex_height );
    auto _img = nk_image_id( tex_index );

    img = new struct nk_image( );
    img->handle = _img.handle;
    img->w = _img.w;
    img->h = _img.h;
    for (size_t i = 0; i < 4; ++i)
        img->region[ i ] = _img.region[ i ];

}

void CImGuiLayer::OnDetach( )
{
    delete img;
    nk_glfw3_shutdown( );
}

CImGuiLayer::OnRender( double_t alphaTime, double_t deltaTime ) { nk_glfw3_new_frame( );

    enum
    {
        EASY, HARD
    };
    static int op = EASY;
    static float value = 0.6f;
    static int i = 20;

    if (nk_begin( ctx, "Show", nk_rect( 50, 50, 220, 220 ),
                  NK_WINDOW_BORDER | NK_WINDOW_MOVABLE | NK_WINDOW_CLOSABLE ))
    {
        /* fixed widget pixel width */
        nk_layout_row_static( ctx, 30, 80, 1 );
        if (nk_button_label( ctx, "button" ))
        {
            /* event handling */
        }

        /* fixed widget window ratio width */
        nk_layout_row_dynamic( ctx, 30, 2 );
        if (nk_option_label( ctx, "easy", op == ( int) EASY )) op = EASY;
        if (nk_option_label( ctx, "hard", op == ( int) HARD )) op = HARD;

        /* custom widget pixel width */
        nk_layout_row_begin( ctx, NK_STATIC, 30, 2 );
        {
            nk_layout_row_push( ctx, 50 );
            nk_label( ctx, "Volume:", NK_TEXT_LEFT );
            nk_layout_row_push( ctx, 110 );
            nk_slider_float( ctx, 0, &value, 1.0f, 0.1f );
        }
        nk_layout_row_end( ctx );
    }
    nk_end( ctx );

    /* Bindless Texture */
    if (nk_begin( ctx, "Texture", nk_rect( 250, 150, 230, 250 ),
                  NK_WINDOW_BORDER | NK_WINDOW_MOVABLE | NK_WINDOW_SCALABLE |
                  NK_WINDOW_MINIMIZABLE | NK_WINDOW_TITLE ))
    {
        struct nk_command_buffer* canvas = nk_window_get_canvas( ctx );
        struct nk_rect total_space = nk_window_get_content_region( ctx );
        nk_draw_image( canvas, total_space, img, nk_white );
    }
    nk_end( ctx );

    nk_glfw3_render( NK_ANTI_ALIASING_ON );

}

vurtun / nuklear