Thread: OpenGL Transformations

I've managed to load an image and texture map it. I am now trying to rotate this object. When I rotate it, it looks funny and I'm not sure why.

Here are the relevant lines of code:

Code:

void initGL(void){
	glEnable(GL_TEXTURE_2D);
	glShadeModel(GL_SMOOTH);
	glClearColor(0.0f,0.0f,0.0f,0.0f);
	glClearDepth(1.0f);
	glEnable(GL_DEPTH_TEST);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0,640,480,0,-1,1);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}


void drawBox(void){

	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	glBindTexture(GL_TEXTURE_2D,tname);

	glPushMatrix();
	glRotatef(rcubex,1.0f,0.0f,0.0f);
//	glRotatef(rcubey,0.0f,1.0f,0.0f);
//	glRotatef(rcubez,0.0f,0.0f,1.0f);
	glBegin(GL_QUADS);

		//front
		glTexCoord2f(0,0);
		glVertex3f(270,190,0);
		glTexCoord2f(1,0);
		glVertex3f(370,190,0);
		glTexCoord2f(1,1);
		glVertex3f(370,290,0);
		glTexCoord2f(0,1);
		glVertex3f(270,290,0);

		//back
		glTexCoord2f(0,0);
		glVertex3f(270,190,100);
		glTexCoord2f(1,0);
		glVertex3f(370,190,100);
		glTexCoord2f(1,1);
		glVertex3f(370,290,100);
		glTexCoord2f(0,1);
		glVertex3f(270,290,100);

		//right
		glTexCoord2f(0,0);
		glVertex3f(370,190,0);
		glTexCoord2f(1,0);
		glVertex3f(370,190,100);
		glTexCoord2f(1,1);
		glVertex3f(370,290,100);
		glTexCoord2f(0,1);
		glVertex3f(370,290,0);

	glEnd();
	glPopMatrix();
	rcubex+= 0.3f;
	rcubey+= 0.2f;
	rcubez+= 0.4f;
}

I think it might have to do with what is in initGL()

I noticed you never set your prespective, a la glFrustrum or equivalent.

...and that will only work if your entire object lies between -1 and 1. This will work fine for 2D where everything can be at z = 0.0f or z = 1.0f and objects are normally on the x/y plane but it will not work for anything else.