GEEKING

CSG/sgCore/Core/GEO/TATOHOBJ.cpp

@@ -0,0 +1,73 @@
+#include "../sg.h"
+
+static BOOL tang_3d_pa(lpGEO_ARC a, BOOL flag_arc,
+                       lpD_POINT b, lpD_POINT p, short *kp);
+
+lpD_POINT tangent_to_hobj(hOBJ hobj, OBJTYPE type,
+                          lpD_POINT vp, lpD_POINT p)
+
+{
+GEO_OBJ   geo;
+
+  if(!true_geo_info(hobj, &type, &geo))
+		return NULL;
+  return tangent_to_geo_obj(type, &geo, vp, p);
+}
+
+lpD_POINT tangent_to_geo_obj(OBJTYPE type, void * geo,
+                          lpD_POINT vp, lpD_POINT p)
+
+{
+D_POINT   pp[2];
+short       kp;
+BOOL      flag_arc;
+
+  set_flag_el(&type, &flag_arc);
+
+  if(!tang_3d_pa((lpGEO_ARC)geo, FALSE, &curr_point, pp, &kp))
+		return NULL;
+
+  return test_cont(pp, kp, vp, type, geo, flag_arc, p);
+}
+
+static BOOL tang_3d_pa(lpGEO_ARC a, BOOL flag_arc,
+                       lpD_POINT b, lpD_POINT p, short *kp)
+
+
+{
+
+lpGEO_ARC  a2d = &el_geo1;
+sgFloat     xc, yc;
+short        i;
+
+	set_el_geo();
+	*kp = 0;
+
+	if(!test_wrd_arc(a, &flag_arc))
+		return FALSE;
+
+	trans_arc_to_acs(a, flag_arc, a2d, el_g_e, el_e_g);
+
+	o_hcncrd(el_g_e, b, p);
+
+	if(fabs(p->z) >= eps_d){
+		el_geo_err = EL_NO_ARC_PLANE;
+		return FALSE;
+	}
+	xc = p->x/2.;
+	yc = p->y/2.;
+	if(!(*kp = intersect_2d_cc(0., 0., a->r, xc, yc, hypot(xc, yc), p))){
+		el_geo_err = EL_NO_TANG;
+		return FALSE;
+	}
+
+	if(flag_arc)
+		if(!test_in_arrey(p, kp, OARC, TRUE, a2d)){
+			el_geo_err = EL_NO_TANG;
+			return FALSE;
+		}
+
+	for(i = 0; i < *kp; i++)
+    o_hcncrd(el_e_g, &p[i], &p[i]);
+  return TRUE;
+}