OpengL动画问题

[leidafu]

本程序基于mfc对话框的在opengl中画几何字体，用到了glut包的函数，但是在onTimer中旋转字体时发现没有看到旋转的字体（动画只是一闪而过）。请大家帮忙修改下。谢谢。
OnCreate函数：
添加的代码：
// TODO: Add your specialized creation code here
UINT_PTR TimeToDraw = this->SetTimer(1,500,NULL);

OnTimer函数：
void CDrawTextOGLDlg::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
if (nIDEvent==1)
{
if (Rotate_Angle<360.0)
{
Rotate_Angle+=0.05;
}
else
Rotate_Angle = 0.0;

Invalidate(FALSE);
}
CDialog::OnTimer(nIDEvent);
}

OnPaint函数：
添加了：this->output(-0.7,0.0,0.0,"Hello World!");

Output函数：
void CDrawTextOGLDlg::output(GLfloat x, GLfloat y, GLfloat z, char *text)
{
char *p;

//make glClearColor function called before glClear
//glClearColor(0.0,1.0,0.0,0.0);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glEnable(GL_LINE_SMOOTH);
glLineWidth(7.0);

glRotatef(Rotate_Angle,0.0,0.0,1.0);
glTranslatef(x, y, z);
glScalef(.002,.002,.002);

glPushMatrix();
glColor4f(1.0f,0.0f,0.0f,1.0f);

for (p = text; *p; p++)
glutStrokeCharacter(GLUT_STROKE_ROMAN, *p);
glPopMatrix();

SwapBuffers(m_hdc);
}

[newsupman]

感觉opengl编程在不同的机器上总是有不同的效果 你这个问题我感觉首先得用双缓存技术把ontimer方法下产生的屏幕闪烁现象除去 你再试试

[zhucde]

应该是坐标不对,
被你移动过(x,y,z),然后再绕Z轴旋转一下后已经超出显示范围(此旋转是按照世界坐标轴来旋转, 你是否应该先重置一下,绕本地坐标轴来旋转?)

[leidafu]

多谢zhucde，是坐标问题，搞定了，下面是正确的代码：

void CDrawTextOGLDlg::output(GLfloat x, GLfloat y, GLfloat z, char *text)
{
char *p;

//make glClearColor function called before glClear
//glClearColor(0.0,1.0,0.0,0.0);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glEnable(GL_LINE_SMOOTH);
glLineWidth(7.0);

glRotatef(Rotate_Angle,0.0,1.0,0.0);

glPushMatrix();

glTranslatef(x, y, z);
glScalef(.002,.002,.002);

glPushMatrix();
glColor4f(1.0f,0.0f,0.0f,1.0f);

for (p = text; *p; p++)
glutStrokeCharacter(GLUT_STROKE_ROMAN, *p);
glPopMatrix();

glPopMatrix();

SwapBuffers(m_hdc);
}