int DrawGLScene(GLvoid)									// Here's Where We Do All The Drawing{	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer	glLoadIdentity();									// Reset The View	GLfloat x_m, y_m, z_m, u_m, v_m;  // You should initialize these to have some value (0.0f works fine)	GLfloat xtrans = -xpos;	GLfloat ztrans = -zpos;	GLfloat ytrans = -walkbias-0.25f;	GLfloat sceneroty = 360.0f - yrot;  // You don't need that "360.0f" there, but if it helps to visualize, then keep it, I suppose	glClearColor(0.5f,0.5f,0.5f,1.0f);			// We'll Clear To The Color Of The Fog ( Modified )        //  All this fog setup should go into your initialization code, unless these parameters are actually changed from draw to draw	glFogi(GL_FOG_MODE, fogMode[fogfilter]);		// Fog Mode	glFogfv(GL_FOG_COLOR, fogColor);			// Set Fog Color	glFogf(GL_FOG_DENSITY, 0.35f);				// How Dense Will The Fog Be	glHint(GL_FOG_HINT, GL_DONT_CARE);			// Fog Hint Value	glFogf(GL_FOG_START, 1.0f);				// Fog Start Depth	glFogf(GL_FOG_END, 5.0f);				// Fog End Depth	glEnable(GL_FOG);					// Enables GL_FOG        //  go ahead and initialize this here, instead of four lines later	int numtriangles;	glRotatef(lookupdown,1.0f,0,0);	glRotatef(sceneroty,0,1.0f,0);	glTranslatef(xtrans, ytrans, ztrans);	numtriangles = sector1.numtriangles;		// Process Each Triangle	for (int loop_m = 0; loop_m < numtriangles; loop_m++)	{                //  Moving this glBegin/glEnd pair to outside of the for loop                //  will speed things up and have absolutely no effect on                //  appearance.  With the primitive mode set to GL_TRIANGLES,                //  GL will automatically take groups of three vertices and                //  make a triangle, no need to stop and start again.                //  However, this is where you'll want to bind the needed texture.                //  This information is stored somewhere with the triangle in                //  your text file, and should be bound here.                //  Also, since you're performing the same operation on three                //  vertices stored in an array, why not make this a loop, as                //  well?  0-2 for the vertex array.		glBegin(GL_TRIANGLES);			glNormal3f( 0.0f, 0.0f, 1.0f);			x_m = sector1.triangle[loop_m].vertex[0].x;			y_m = sector1.triangle[loop_m].vertex[0].y;			z_m = sector1.triangle[loop_m].vertex[0].z;			u_m = sector1.triangle[loop_m].vertex[0].u;			v_m = sector1.triangle[loop_m].vertex[0].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);						x_m = sector1.triangle[loop_m].vertex[1].x;			y_m = sector1.triangle[loop_m].vertex[1].y;			z_m = sector1.triangle[loop_m].vertex[1].z;			u_m = sector1.triangle[loop_m].vertex[1].u;			v_m = sector1.triangle[loop_m].vertex[1].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);						x_m = sector1.triangle[loop_m].vertex[2].x;			y_m = sector1.triangle[loop_m].vertex[2].y;			z_m = sector1.triangle[loop_m].vertex[2].z;			u_m = sector1.triangle[loop_m].vertex[2].u;			v_m = sector1.triangle[loop_m].vertex[2].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);		glEnd();	}	return TRUE;										// Everything Went OK}

// Process Each TriangleglBegin(GL_TRIANGLES);	for (int loop_m = 0; loop_m < numtriangles; loop_m++)	{                unsigned int uiTextureNeededByThisTriangle = sector1.triangle[loop_m].textureID;                glBindTexture(GL_TEXTURE_2D, uiTextureNeededByThisTriangle);                //  As was mentioned before, a handy thing to do would be to                //  collect all the geometry that uses each texture, and render                //  in that order, because binding textures is a costly                //  operation. 		glNormal3f( 0.0f, 0.0f, 1.0f);                for (unsigned int ui = 0; ui < 3; ++ui)                {			x_m = sector1.triangle[loop_m].vertex[ui].x;			y_m = sector1.triangle[loop_m].vertex[ui].y;			z_m = sector1.triangle[loop_m].vertex[ui].z;			u_m = sector1.triangle[loop_m].vertex[ui].u;			v_m = sector1.triangle[loop_m].vertex[ui].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);					}	}glEnd( );