/* Copyright (c) 2011 Timothy Wall, All Rights Reserved
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package com.sun.jna.platform.win32;
import com.sun.jna.Function;
import com.sun.jna.Pointer;
import com.sun.jna.platform.win32.WinDef.HDC;
import com.sun.jna.platform.win32.WinDef.HGLRCByReference;
import com.sun.jna.platform.win32.WinDef.HWND;
import com.sun.jna.platform.win32.WinGDI.PIXELFORMATDESCRIPTOR;
/**
* opengl32 utility API.
*/
public abstract class OpenGL32Util {
/**
* Return a procedure function pointer
* @param procName the procedure name
* @return the function
*/
public static Function wglGetProcAddress(String procName) {
Pointer funcPointer = OpenGL32.INSTANCE.wglGetProcAddress("wglEnumGpusNV");
return (funcPointer == null) ? null : Function.getFunction(funcPointer);
}
/**
* Count GPUs
* @return the number of available GPUs
*/
public static int countGpusNV() {
// create a dummy window
HWND hWnd = User32Util.createWindow("Message", null, 0, 0, 0, 0, 0, null, null, null, null);
HDC hdc = User32.INSTANCE.GetDC(hWnd);
// set a compatible pixel format
PIXELFORMATDESCRIPTOR.ByReference pfd = new PIXELFORMATDESCRIPTOR.ByReference();
pfd.nVersion = 1;
pfd.dwFlags = WinGDI.PFD_DRAW_TO_WINDOW | WinGDI.PFD_SUPPORT_OPENGL | WinGDI.PFD_DOUBLEBUFFER;
pfd.iPixelType = WinGDI.PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 16;
pfd.iLayerType = WinGDI.PFD_MAIN_PLANE;
GDI32.INSTANCE.SetPixelFormat(hdc, GDI32.INSTANCE.ChoosePixelFormat(hdc, pfd), pfd);
// create the OpenGL context to get function address
WinDef.HGLRC hGLRC = OpenGL32.INSTANCE.wglCreateContext(hdc);
OpenGL32.INSTANCE.wglMakeCurrent(hdc, hGLRC);
Pointer funcPointer = OpenGL32.INSTANCE.wglGetProcAddress("wglEnumGpusNV");
Function fncEnumGpusNV = (funcPointer == null) ? null : Function.getFunction(funcPointer);
OpenGL32.INSTANCE.wglDeleteContext(hGLRC);
// destroy the window
User32.INSTANCE.ReleaseDC(hWnd, hdc);
User32Util.destroyWindow(hWnd);
// abort if the nVidia extensions are not present
if (fncEnumGpusNV == null) return 0;
// enumerate nVidia adapters
HGLRCByReference hGPU = new HGLRCByReference();
for (int i = 0; i < 16; i++) {
Boolean ok = (Boolean) fncEnumGpusNV.invoke(Boolean.class, new Object[] { Integer.valueOf(i), hGPU, });
if (!ok.booleanValue()) return i;
}
return 0;
}
}