Windows中设置OpenGL像素格式的两种方法

indows使用OpenGL必须设置OpenGL环境，将窗口连接到OpenGL。首先选择并设置相应像素格式，然后创建着色描述表并将其连接到设备描述表。本文介绍两种设置OpenGL环境的方法，主要是选择像素格式方法的不同。

HDC g_hDC = NULL;

HGLRC g_hRC = NULL;

 

#define METHOD_1

 

BOOL ConnectGL1 (HWND hWnd);

BOOL ConnectGL2 (HWND hWnd);         

 

#ifdef METHOD_1

#define ConnectGL ConnectGL1

#endif

 

#ifdef METHOD_2

#define ConnectGL ConnectGL2

#endif

 

BOOL  ConnectGL1 (HWND hWnd)

{

GLuint PixelFormat; 

 static PIXELFORMATDESCRIPTOR pfd = {

sizeof (PIXELFORMATDESCRIPTOR),

1,

PFD_DWAR_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,           //标志

PFD_TYEP_RGBA,                 //颜色模式

24,                                   //颜色位数

0, 0, 0, 0, 0, 0,

0,

0,

0,

0, 0, 0, 0,

32,                                  //深度位数

0,

0,

PFD_MAIN_PLANE,

0,

0, 0, 0

}; 

if ((g_hDC = GetDC (hWnd)) == NULL) return FALSE;

if ((PixelFormat = ChoosePixelFormat (g_hDC, &pfd)) == 0) return FALSE;                //选择相应像素格式

if (!SetPixelFormat (g_hDC, PixelFormat, &pfd)) return FALSE;                               //设置像素格式

if ((g_hRC = wglCreateContext (g_hDC)) == NULL) return FALSE;                          //创建着色描述表

if (!wglMakeCurrent (g_hDC, g_hRC)) return FALSE;                                           //将着色描述表连接到设备描述表

}

 

#define DESFLAGS PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER

BOOL ConnectGL2 (HWND hWnd)

{

GLuint PixelFormat, iPixelFormat, maxPixelFormat;

static PIXELFORMATDESCRIPTOR pfd;

 

if ((g_hDC = GetDC (hWnd)) == NULL) return FALSE;

maxPixelFormat = DescribePixelFormat (g_hDC, 1, sizeof (PIXELFORMATDESCRIPTOR), NULL);  //获取所支持的像素最大索引

for (iPixelFormat = 1; iPixelFormat <= maxPixelFormat; iPixelFormat++) {

DescribePixelFormat (g_hDC, iPixelFormat, sizeof (PIXELFORMATDESCRIPTOR), &pfd);

if ((pfd.dwFlags & DESFLAGS) == DESFLAGS) {

PixelFormat = iPixelFormat;

break;

}

}

 

if (!SetPixelFormat (g_hDC, PixelFormat, &pfd)) return FALSE;                               //设置像素格式

if ((g_hRC = wglCreateContext (g_hDC)) == NULL) return FALSE;                          //创建着色描述表

if (!wglMakeCurrent (g_hDC, g_hRC)) return FALSE;                                           //将着色描述表连接到设备描述表

}