dials

Use those 2 functions:


void Enter2DMode()
{
glPushAttrib(GL_LIGHTING_BIT|GL_DEPTH_BUFFER_BIT);
glDisable(GL_LIGHTING);
glDisable(GL_DEPTH_TEST);

//glEnable(GL_BLEND);
//glBlendFunc(GL_DST_ALPHA,GL_SRC_ALPHA);

glViewport(0, 0, window_width, window_height);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0, (GLdouble)window_width, (GLdouble)window_height, 0.0, -250.0, 250.0);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
}

void Leave2DMode()
{
//glDisable(GL_BLEND);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopAttrib();
}


Then draw the instruments, push the modelview matrix, rotate, etc. your needles, then pop the matrix

Height Map Editor | Eternal lands

Thanks for your post but it doesn't answer my question exactly, i need to know how to rotate the image and get it in the right place. Thanx anyway

I think they could be some confusion over my problem. I mean to create a texture from the needle image, bind it to a quad which will be made transparent so that it don't obsecure the background. It is THE QUAD i mean to rotate. I think you thought that i was trying to rotate the image in some way???? Sorry for the confusion.
So my question is:
1. How do i rotate the image in accordance with the speed for example?
2. How do i get it in the right place on the screen?

And also, is this a good or bad or rubbish way of doing a guage? How are guages implemented in simulators or games?? Mayb i can do a simplfied version of it??

[edited by - I_Pee_Freely on January 23, 2003 10:35:44 AM]

No, he was correct. Push model view matrix, rotate/translate your need into postion, then pop the model view matrix, and repeat until all needles are done.

try this...
1. Load a texture with the needle. the background should be transparent. (ie. black background, yellow needle)

2.use Raduprv''s code to enter ortho mode, then...

3.use glBlendFunc(GL_SRC_ALPHA, GL_ONE) & enable (GL_BLEND)

4.go into texture matrix, push matrix
glMatrixMode(GL_TEXTURE);
glPushMatrix();

5. rotate the needle (glRotated(20,0,0) or whatever)

6. DRAW it as a quad, or whatever.

7. pop the matrix

8. leave ortho mode.

That''s lovely. Thanks for all the help folks.