OpenGL纹理贴图,贴出来的图像是空白的,纯白色,为啥呀?
每次渲染时调用下面代码:(问题是显示出来的图片是空白的,这是为啥呢?
LPBYTE lpCurTexture ; // 指向位图数据,经检测是正确的
if ( lpCurTexture )
{
if ( this->texId == -1 )
{
glGenTextures( 1, &texId ); // `生成一个贴图对象`
}
//memset ( lpCurTexture, 0, 1000 ) ;
RECT rect;
GetClientRect(GetActiveWindow(),&rect);
glBindTexture( GL_TEXTURE_2D, texId ); // `使用g_TextureID贴图对象
glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGBA, this->sizeTexture.cx, \
this->sizeTexture.cy, 0, GL_RGBA, GL_UNSIGNED_BYTE, lpCurTexture ) ; glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glEnable ( GL_TEXTURE_2D ) ;
glMatrixMode( GL_PROJECTION );
glPushMatrix();
glLoadIdentity();
glOrtho ( 0, _WIDTH_(rect), 0, _HEIGHT_(rect), -1, 1 );
glMatrixMode( GL_MODELVIEW );
glPushMatrix();
glLoadIdentity();
glPushAttrib(0xfffffff) ;
glDepthFunc(GL_ALWAYS) ;
int left = texPos.x;
int right = texPos.x + this->sizeTexture.cx ;
int top = _HEIGHT_(rect) - texPos.y ;
int bottom = _HEIGHT_(rect) - ( texPos.y + this->sizeTexture.cy ) ;
glBindTexture(GL_TEXTURE_2D, texId);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); glVertex2i( left, bottom );
glTexCoord2f(1.0f, 0.0f); glVertex2i( right,bottom );
glTexCoord2f(1.0f, 1.0f); glVertex2i( right,top);
glTexCoord2f(0.0f, 1.0f); glVertex2i( left, top);
glEnd();
glPopAttrib () ;
glPopMatrix();
glColor3f(1.0,1.0,1.0);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glFlush();
}