Hi all. I''m a newbie to OpenGl and have been trying to work out this problem for hours now. I''m using GLUT, as I don''t want to attempt Win 32 API. Following NeHe''s tutorial on rotation, I can''t seen to get it to work. I''m trying to rotate a triangle. //--------------------------------------------------------------------------- GLfloat rtri; //Declare variable for triangle void init ( void ) { glEnable ( GL_DEPTH_TEST ); glClearColor ( 0.0, 0.0, 0.0, 0.0 ); } void display (void) //needs to return a value of TRUE { glClear ( GL_COLOR_BUFFER_BIT / GL_DEPTH_BUFFER_BIT ); glLoadIdentity ( ); glPushMatrix ( ); glRotatef(rtri, 0.0f, 1.0f, 0.0f); //rotate triangle glTranslatef (-1.5f, 0.0f, -6.0f); //Translate triange glBegin(GL_TRIANGLES); //begin triangle glColor3f( 1.0f, 0.0f, 0.0f); glVertex3f(0.0f, 1.0f, 0.0f); glColor3f( 0.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f); glColor3f( 0.0f, 0.0f, 1.0f); glVertex3f(1.0f, -1.0f, 0.0f); glEnd( ); //end triangle glPopMatrix ( ); glutSwapBuffers ( ); rtri +=0.2f; //increase rotation variable for triangle return TRUE; //Keep rotation going } void reshape(int w, int h) { glViewport ( 0, 0, w, h ); glMatrixMode ( GL_PROJECTION ); glLoadIdentity ( ); if ( h==0 ) gluPerspective ( 80, ( float ) w, 1.0, 5000.0 ); else gluPerspective ( 80, ( float ) w / ( float ) h, 1.0, 5000.0 ); glMatrixMode ( GL_MODELVIEW ); glLoadIdentity ( ); } // Main Loop int main ( int argc, char** argv ) { glutInit ( &argc, argv ); glutInitDisplayMode ( GLUT_RGB / GLUT_DOUBLE ); glutInitWindowSize ( 250, 250 ); glutCreateWindow ( argv[0] ); init ( ); glutReshapeFunc ( reshape ); glutKeyboardFunc ( keyboard ); glutDisplayFunc ( display ); //When display function is changed, errors show here. glutMainLoop ( ); return 0; } *************************************************************** I know that void display (void) needs to change as it doesn''t return a value. But when i try changing it to return a bool, int or float errors appear in "GLUTDISPLAYFUNC( display );" [C++Error] triangle.cpp(84): Cannot convert ''int (*)(float)'' to ''void (*)()''. [C++Error] triangle.cpp(84): Type mismatch in parameter ''func'' in call to ''__stdcall glutDisplayFunc(void (*)())''. Anyone help, what am I doing wrong? Is there another way? Thanx --Ched-- chris@ched45.com

So, how would I rotate? Create another none GLUT function and call that for the rotation?

--Ched--
chris@ched45.com

I''ll give that ago. Thanx. I''m a newbie, trying to do some basic OpenGL over the summer ( I''m 16 ). I knew some C/C++ and wanted to do something that looked good :o).

Thanx again


--Ched--
chris@ched45.com

I know you mentioned that you didn''t want to mess with the Win32 API, but I think you should reconsider using it as base code.. When I started programming in OpenGL ( sheesh some 6-8 months ago.. lol ) I considered GLUT.. and several times since..

But using the code from say lesson 1, you can essientially ignore the win32 API and concentrate on the OpenGL stuff like DrawGLScene() and InitGLScene() and what not..

I don''t like GLUT at all.. don''t know why.. other than I don''t feel like I''m programming OpenGL... that''s silly ain''t it...



anyway, my 2 cents,

bosco()

I''ll give it a go.....even if its just a copy and paste job....lol. NeHe''s tutorials look great and I understand most of the stuff, but trying to convert to GLUT is kinda hard. Thanx for the advice

Thanx

--Ched--
chris@ched45.com

Yep and that''s why I advise learning NeHe''s stuff first.. most of my first work was just the way I explained.. Ignoring the Win 32 api code and learning opengl calls..

It''s amazing, because now that I am fimilar with everything, converting between the two seems like it will be a breeze.. as a matter of fact I''m gonna be doing some of that this weekend..


good luck and feel free to post here if you need help.. seems like there''s some really cool people watching the threads..


bosco()