[SOURCE]
struct MCtri
{
	int		vi[3];			// Vertex index
	float	dist;			// Distance from camera
};

struct MCscene
{
	int		numVert;		// Number of verts
	float	*vert[3];		// Vertices
	int		numTri;			// Number of triangles
	MCtri	*tri;			// Trianges
	float	camPos[3];		// Camera position
};


// Compare function
int mcCompare(struct MCtri *elem1, struct MCtri *elem2)
{
   if ( elem1->dist < elem2->dist)									// If First Structure distance Is Less Than The Second
      return -1;													// Return -1
   else if (elem1->dist > elem2->dist)								// If First Structure distance Is Greater Than The Second
      return 1;														// Return 1
   else																// Otherwise (If The distance Is Equal)
      return 0;														// Return 0
}

// Calculate distance between two points in 3d
float mcDistance3d(float[3] ptA, float[3] ptB)
{
	float tempa = ptA[MC_X] - ptB[MC_X];
	float tempb = ptA[MC_Y] - ptB[MC_Y];
	float tempc = ptA[MC_Z] - ptB[MC_Z];
	return sqrt((tempa*tempa)+(tempb*tempb)+(tempc*tempc));
}

// Returns the smallest of a group of three numbers (same as min() found in <algorithm>)
float mcSmallest (float A, float B, float C)
{
	float smallest;
	if (A <= B)
	{
		if (A <= C) smallest = A;
		else smallest = C;
	}
	else if (B <= C) smallest = B;
	else smallest = C;
	return smallest;
}

void mcMeasureTriDist( MCscene *s )
{
	MCuint32 mc_t;
	float dist[3];

	for ( mc_t = 0; mc_t < s->numTri; mc_t++ )
	{
		dist[0] = mcDistance3d( s->camPos, s->tri[mc_t].vi[0]]);
		dist[1] = mcDistance3d( s->camPos, s->tri[mc_t].vi[1]]);
		dist[2] = mcDistance3d( s->camPos, s->tri[mc_t].vi[2]]);
		s->tri[mc_t].dist = mcSmallest( dist[0], dist[1], dist[2] );
	}
}

void mcRender( MCscene *s )
{
	// Measure distance to camera for each triangle
	mcMeasureTriDist(s);
	// Sort triangles from back to front
	qsort((void *) s->tri, s->numTri, sizeof(struct MCtri), (compfn)mcCompare );
	// Render each triangle
	for ( mc_t = 0; mc_t < s->numTri; mc_t++)
	{
		glBegin(GL_TRIANGLES);
			glVertex3fv( s->tri[mc_t].vi[0]] );
			glVertex3fv( s->tri[mc_t].vi[1]] );
			glVertex3fv( s->tri[mc_t].vi[2]] );
		glEnd();
	}
}
[/SOURCE]