Hi,

I am trying to make a cross platform graphics engine where I could write a library test it on my desktop with windows 8 and use the same library with Android/Iphone.(Including OpenGL ES libs ofcourse). As far as I am aware Android uses EGL to render images within a window (Correct me if I am wrong ). A lot of sources keep saying that EGL can be done on windows other say you need WGL, some others say Windows 8 can not support OpenGL ES at all. I also have an Nvidia card and only OpenGL ES libraries that I found are from AMD. Does anyone know what is the best way to get through this problem??

Found this link a couple of days ago when a similar question was asked: http://www.g-truc.net/post-0457.html

You can create an ES compatible context the normal WGL way using the method described here: https://www.opengl.org/registry/specs/EXT/wgl_create_context_es2_profile.txt

Then you just use only OpenGL functions that are avail in your ES version, nothing more nothing less
OpenGL will work the same way on all platforms if you will be using same functions.

well almost... except for vendor specific bugs and slight differences between versions...

There are not many, but there are a few #ifdefs in our engine if you run it on "normal" GL instead of GLES. Mostly because of different enum names. Then some function which for some reason has an f for float on the end on GLES but not on GL.

There are also #ifdefs if you run on GLES for android, or GLES for iOS... (again different enum names)

Also the shader code had to be slightly modified before the opengl driver liked it.

Thank you everyone for your time and replies.

Found this link a couple of days ago when a similar question was asked: http://www.g-truc.net/post-0457.html

This very link I also found whilst researching, it said I cannot run EGL or WGL on Windows 8 ....

well its not that hard as you think. First of all decide which es version you target, then you need to get somekind of wrapper that creates opengl window on every platform you can do that writing different codes for different platforms or use some kind of libs that provide this.

Then you just use only OpenGL functions that are avail in your ES version, nothing more nothing less

OpenGL will work the same way on all platforms if you will be using same functions.

So for windows you dont link es version you can link normal opengl lib provided with windows...

I am planning on using OpenGL ES 2.0 ...How would I know which functions are supported in ES 2.0 and which are not if I am using openGL ... I mainly used Glut and glew before to run a small graphics engine on a pc but I can no longer use this in Android as android uses EGL, also the plan is making it compatible with ios in future. what is the most efficient approach you can suggest from your experience? What kind of libraries should I use ?

it said I cannot run EGL or WGL on Windows 8 ....

Think it says Windows RT, which only goes if you buy one of those Surface tablets with an ARM processor or a Windows Phone. If you have a desktop then it most definitely runs OpenGL as well as anything, a long as you have the Nvidia graphics card driver installed

it said I cannot run EGL or WGL on Windows 8 ....

Think it says Windows RT, which only goes if you buy one of those Surface tablets with an ARM processor or a Windows Phone. If you have a desktop then it most definitely runs OpenGL as well as anything, a long as you have the Nvidia graphics card driver installed

I apologize I did not read that carefully, yes you are correct.


I was trying to go to the basics and at least use opengl in a window (WIN32_API). I managed to create a blank window and supposedly an Opengl context. But I cannot understand how do you use the context, I could not even change the color...

#include <Windows.h>
#include <gl\GL.h>
#include <iostream>

#pragma comment(lib , "opengl32.lib")

bool InitMainWindow(HINSTANCE, int);

LRESULT CALLBACK MsgProc(HWND, UINT, WPARAM, LPARAM);

const int WIDTH = 800;
const int HEIGHT= 600;

HWND hwnd = NULL;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
	if (!InitMainWindow(hInstance, nCmdShow))
	return 1;

	MSG msg = { 0 };
	HDC hdc = GetDC(hwnd);

	while (WM_QUIT != msg.message)
	{
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}
	return 0;

}


bool InitMainWindow(HINSTANCE hInstance, int nCmdShow)
{
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(wcex);
	wcex.style = CS_HREDRAW | CS_VREDRAW;
	wcex.cbClsExtra = 0;
	wcex.cbWndExtra = 0;


	wcex.lpfnWndProc = MsgProc;
	wcex.hInstance = hInstance;
	wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);

	wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
	wcex.lpszClassName = "WIndow";
	wcex.lpszMenuName = NULL;
	wcex.hIconSm = LoadIcon(NULL, IDI_WINLOGO);

	if (!RegisterClassEx(&wcex))
	{
		return false;
	}

	hwnd = CreateWindow("WIndow", "Win32", WS_OVERLAPPEDWINDOW | WS_SYSMENU | WS_CAPTION
		, GetSystemMetrics(SM_CXSCREEN) / 2 - WIDTH / 2,
		GetSystemMetrics(SM_CYSCREEN) / 2 - HEIGHT / 2,
		WIDTH,
		HEIGHT,
		(HWND)NULL,
		(HMENU)NULL,
		hInstance,
		(LPVOID*)NULL
		);

	if (!hwnd)
		return false;


	ShowWindow(hwnd, nCmdShow);
	return true;

}

LRESULT CALLBACK MsgProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
	switch (msg)
	{
	case WM_CREATE:
	{
 		PIXELFORMATDESCRIPTOR pfd =
		{
			sizeof(PIXELFORMATDESCRIPTOR),
			1,
			PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,    //Flags
			PFD_TYPE_RGBA,            //The kind of framebuffer. RGBA or palette.
			32,                        //Colordepth of the framebuffer.
			0, 0, 0, 0, 0, 0,
			0,
			0,
			0,
			0, 0, 0, 0,
			24,                        //Number of bits for the depthbuffer
			8,                        //Number of bits for the stencilbuffer
			0,                        //Number of Aux buffers in the framebuffer.
			PFD_MAIN_PLANE,
			0,
			0, 0, 0
		};

		HDC ourWindowHandleToDeviceContext = GetDC(hwnd);

		int  letWindowsChooseThisPixelFormat;
		letWindowsChooseThisPixelFormat = ChoosePixelFormat(ourWindowHandleToDeviceContext, &pfd);
		SetPixelFormat(ourWindowHandleToDeviceContext, letWindowsChooseThisPixelFormat, &pfd);

		HGLRC ourOpenGLRenderingContext = wglCreateContext(ourWindowHandleToDeviceContext);
		bool value = wglMakeCurrent(ourWindowHandleToDeviceContext, ourOpenGLRenderingContext);

		
		while (1)
		{
			glClearColor(0.0f, 1.0f, 0.0f, 0.0f);
		}
		//MessageBoxA(0, (char*)glGetString(GL_VERSION), "OPENGL VERSION", 0);

		wglDeleteContext(ourOpenGLRenderingContext);
		PostQuitMessage(0);
	}
	break;

	case WM_DESTROY: //recieved destroy msg
		PostQuitMessage(0);
		return 0;
	}

	return DefWindowProc(hwnd, msg, wparam, lparam);


}