int COpenGLDemoView::DrawGLScene()
{// Here's Where We Do All The Drawing
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The View
glTranslatef(1.1f*float(cos(rot/16.0f)),0.8f*float(sin(rot/20.0f)),-3.0f);
glRotatef(rot,1.0f,0.0f,0.0f); // Rotate On The X Axis
glRotatef(rot*1.2f,0.0f,1.0f,0.0f); // Rotate On The Y Axis
glRotatef(rot*1.4f,0.0f,0.0f,1.0f); // Rotate On The Z Axis
glTranslatef(-0.35f,-0.35f,0.1f); // Center On X, Y, Z Axis
glPrint("N"); // Draw A Skull And Crossbones Symbol
return TRUE;
}
int COpenGLDemoView::LoadGLTextures()
{//加载位图并转换为纹理
int Status=FALSE; // Status Indicator
AUX_RGBImageRec *TextureImage[1]; // Create Storage Space For The Texture
memset(TextureImage,0,sizeof(void *)*1); // Set The Pointer To NULL
// Load The Bitmap, Check For Errors, If Bitmap's Not Found Quit
if (TextureImage[0]=LoadBMP("Data/Lights.bmp"))
{
Status=TRUE; // Set The Status To TRUE
glGenTextures(1, &texture[0]); // Create The Texture
glBindTexture(GL_TEXTURE_2D, texture[0]);
gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP );
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP );
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
}
if (TextureImage[0]) // If Texture Exists
{
if (TextureImage[0]->data) // If Texture Image Exists
{
free(TextureImage[0]->data); // Free The Texture Image Memory
}
free(TextureImage[0]); // Free The Image Structure
}
return Status; // Return The Status
}
GLvoid COpenGLDemoView::BuildFont(GLvoid)
{
GLYPHMETRICSFLOAT gmf[256]; // Address Buffer For Font Storage
HFONT font; // Windows Font ID
base = glGenLists(256); // Storage For 256 Characters
font = CreateFont( -12, // Height Of Font
0, // Width Of Font
0, // Angle Of Escapement
0, // Orientation Angle
FW_BOLD, // Font Weight
FALSE, // Italic
FALSE, // Underline
FALSE, // Strikeout
SYMBOL_CHARSET, // Character Set Identifier
OUT_TT_PRECIS, // Output Precision
CLIP_DEFAULT_PRECIS, // Clipping Precision
ANTIALIASED_QUALITY, // Output Quality
FF_DONTCARE|DEFAULT_PITCH, // Family And Pitch
"Wingdings"); // Font Name
HDC hDC = ::GetDC(this->m_hWnd);
SelectObject(hDC, font); // Selects The Font We Created
wglUseFontOutlines( hDC, // Select The Current DC
0, // Starting Character
255, // Number Of Display Lists To Build
base, // Starting Display Lists
0.1f, // Deviation From The True Outlines
0.2f, // Font Thickness In The Z Direction
WGL_FONT_POLYGONS, // Use Polygons, Not Lines
gmf); // Address Of Buffer To Recieve Data
}
GLvoid COpenGLDemoView::glPrint(const char *text) // Custom GL "Print" Routine
{
if (text == NULL) // If There's No Text
return; // Do Nothing
glPushAttrib(GL_LIST_BIT); // Pushes The Display List Bits
glListBase(base); // Sets The Base Character to 32
glCallLists(strlen(text), GL_UNSIGNED_BYTE, text); // Draws The Display List Text
glPopAttrib(); // Pops The Display List Bits // Pops The Display List Bits
}
LoadGLTextures中的几行代码将为我们绘制在屏幕上的任何物体自动生成纹理坐标。GL_S和GL_T是纹理坐标。默认状态下，glTexGen被设置为提取物体此刻在屏幕上的x坐标和y坐标，并把它们转换为顶点坐标。你会发现到物体在z平面没有纹理，只显示一些斑纹。正面和反面都被赋予了纹理，这些都是由glTexGen函数产生的。(X(GL_S)用于从左到右映射纹理， Y(GL_T)用于从上到下映射纹理。
GL_TEXTURE_GEN_MODE允许我们选择我们想在S和T纹理坐标上使用的纹理映射模式。你有3种选择：
GL_EYE_LINEAR - 纹理会固定在屏幕上。它永远不会移动。物体将被赋予处于它通过的地区的那一块纹理。
GL_OBJECT_LINEAR - 这种就是我们使用的模式。纹理被固定于在屏幕上运动的物体上。
GL_SPHERE_MAP - 每个人都喜欢。创建一种有金属质感的物体。
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2007/08/27/871439.html，如需转载请自行联系原作者
