diff -urN wf-/Makefile wf/Makefile
--- wf-/Makefile	2015-12-20 00:00:00.000000000 +0900
+++ wf/Makefile	2016-01-03 00:00:00.000000000 +0900
@@ -4,15 +4,20 @@
 CFLAGS += -Wall -I/usr/X11R6/include
 #CFLAGS += -DDBG
 
-WF_OBJS = wf_ex.o data.o eye.o way.o d3.o x.o util.o key.o select.o
+OBJS = data.o eye.o way.o d3.o x.o util.o key.o select.o
+WF_OBJS = wf_ex.o $(OBJS)
+NT_OBJS = nt.o $(OBJS)
 
-all: wf_ex
+all: wf_ex nt
 
 wf_ex: $(WF_OBJS)
 	$(CC) -o $@ $(WF_OBJS) $(LIBS)
 
+nt: $(NT_OBJS)
+	$(CC) -o $@ $(NT_OBJS) $(LIBS)
+
 clean:
-	rm -f wf_ex
+	rm -f wf_ex nt
 	rm -f *.o *~
 
 # EOF
diff -urN wf-/data.c wf/data.c
--- wf-/data.c	2015-12-30 00:00:00.000000000 +0900
+++ wf/data.c	2016-01-03 00:00:00.000000000 +0900
@@ -9,6 +9,7 @@
 
 	switch(type){
 	CASE_RET(type_end);
+	CASE_RET(type_none);
 	CASE_RET(type_wire_frame);
 	CASE_RET(type_bar);
 	CASE_RET(type_cross);
@@ -16,6 +17,7 @@
 	CASE_RET(type_cube);
 	CASE_RET(type_circle);
 	CASE_RET(type_ball);
+	CASE_RET(type_arc);
 	CASE_RET(type_arr);
 	CASE_RET(type_op_data_set);
 	CASE_RET(type_slide);
@@ -27,12 +29,14 @@
 	CASE_RET(type_timeshift);
 	CASE_RET(type_rdiv);
 	CASE_RET(type_slide_way);
+	CASE_RET(type_slide_way_liss);
 	CASE_RET(type_rot_way);
 	CASE_RET(type_copy);
 	CASE_RET(type_copy_rot);
 	CASE_RET(type_copy_point_symmetry);
 	CASE_RET(type_copy_mirror);
 	CASE_RET(type_copy_timeshift);
+	CASE_RET(type_test_conv);
 	default: break;
 	}
 	return "???";
@@ -248,8 +252,8 @@
 
 		odr[i] = i;
 	}
-	odr[n] = 0;
-	odr[n+1] = odr[n+2] = -1;
+	odr[i++] = 0;
+	odr[i] = odr[i+1] = -1;
 	data_draw(&data, prm);
 }
 
@@ -269,6 +273,31 @@
 }
 
 static void
+arc_draw(struct arc *arc, prm_t *prm)
+{
+	int i, n = arc->n;
+	d3_t p[256*3];
+	int odr[256+2];
+	data_t data = {
+		type_wire_frame,
+		&(struct wire_frame){ n, p, odr, &p[n], &p[n*2] }
+	};
+
+	if(n > 256) ERR("n>256");
+
+	for(i=0; i<n; i++){
+		double deg = arc->dec_s + (arc->dec_e - arc->dec_s) * i / (n-1);
+		pos_t *pp = &p[i];
+		d3_set(pp, arc->r,0,0);
+		pos_rot(pp, &(line_t)LINE_Z, deg);
+
+		odr[i] = i;
+	}
+	odr[i] = odr[i+1] = -1;
+	data_draw(&data, prm);
+}
+
+static void
 arr_draw(data_t *data, prm_t *prm)
 {
 	for(; data->type!=type_end; data++){
@@ -282,12 +311,20 @@
 	op_data_draw(set->op, set->data, prm);
 }
 
+static void
+test_conv_draw(pos_t *p, prm_t *prm)
+{
+	if(!prm->skip_af){
+		affin_conv(&prm->af, p);
+	}
+}
+
 void
 data_draw(data_t *data, prm_t *prm)
 {
 #ifdef DBG
-	fprintf(stderr, "%s() type=%s\r\n",
-		__func__, type_str(data->type));
+	fprintf(stderr, "%s() data=%p ", __func__, data);
+	fprintf(stderr, "type=%s\r\n", type_str(data->type));
 #endif
 	switch(data->type){
 	case type_wire_frame:
@@ -311,14 +348,23 @@
 	case type_ball:
 		ball_draw(data->p, prm);
 		break;
+	case type_arc:
+		arc_draw(data->p, prm);
+		break;
 
 	case type_arr:
 		arr_draw(data->p, prm);
 		break;
 	case type_op_data_set:
 		op_data_set_draw(data->p, prm);
+		break;
+
+	case type_test_conv:
+		test_conv_draw(data->p, prm);
+		break;
 
 	case type_end:
+	case type_none:
 	default:
 		break;
 	}
@@ -418,6 +464,18 @@
 }
 
 static void
+op_data_slide_way_liss(struct slide_way_liss *swl, data_t *data, prm_t *prm)
+{
+	struct way_liss wl;
+	pos_t p;
+	data_t op = { type_slide, &p };
+
+	way_liss_init(&wl, &swl->ps, &swl->pe, &swl->sec, &swl->init_sec);
+	way_liss_get(&wl, prm->sec, &p);
+	op_data_draw(&op, data, prm);
+}
+
+static void
 op_data_rot_way(struct rot_way *rw, data_t *data, prm_t *prm)
 {
 	struct way way = rw->deg_way;
@@ -509,8 +567,9 @@
 	prm_t bak = *prm;
 
 #ifdef DBG
-	fprintf(stderr, "%s() op.type=%s data.type=%s\r\n",
-		__func__, type_str(op->type), type_str(data->type));
+	fprintf(stderr, "%s() op=%p data=%p ", __func__, op, data);
+	fprintf(stderr, "op.type=%s data.type=%s\r\n",
+		type_str(op->type), type_str(data->type));
 #endif
 	switch(op->type){
 	case type_arr:
@@ -545,6 +604,9 @@
 	case type_slide_way:
 		op_data_slide_way(op->p, data, prm);
 		break;
+	case type_slide_way_liss:
+		op_data_slide_way_liss(op->p, data, prm);
+		break;
 	case type_rot_way:
 		op_data_rot_way(op->p, data, prm);
 		break;
@@ -568,6 +630,10 @@
 		op_data_copy_timeshift(op->p, data, prm);
 		break;
 
+	case type_none:
+		data_draw(data, prm);
+		break;
+
 	case type_end:
 	default:
 		break;
diff -urN wf-/data.h wf/data.h
--- wf-/data.h	2015-12-30 00:00:00.000000000 +0900
+++ wf/data.h	2016-01-03 00:00:00.000000000 +0900
@@ -10,6 +10,8 @@
 } data_t;
 
 #define type_end			(-1)
+#define type_none			255
+
 #define type_wire_frame			0
 #define type_bar			1
 #define type_cross			2
@@ -17,6 +19,7 @@
 #define type_cube			4
 #define type_circle			5
 #define type_ball			6
+#define type_arc			7
 
 #define type_arr			10
 #define type_op_data_set		11
@@ -31,6 +34,7 @@
 #define type_rdiv			107
 
 #define type_slide_way			120
+#define type_slide_way_liss		121
 #define type_rot_way			130
 #define type_rdiv_way			131
 
@@ -40,6 +44,8 @@
 #define type_copy_mirror		203
 #define type_copy_timeshift		204
 
+#define type_test_conv			254
+
 
 struct wire_frame{
 	int n;		/* ex. n = 4 */
@@ -63,10 +69,21 @@
 	int n;
 };
 
+struct arc{
+	double r;
+	double dec_s, dec_e;
+	int n;
+};
+
 struct op_data_set{
 	data_t *op, *data;
 };
 
+struct slide_way_liss{
+	pos_t ps, pe;
+	d3_t sec, init_sec;
+};
+
 struct rot{
 	line_t l;
 	double deg;
diff -urN wf-/nt.c wf/nt.c
--- wf-/nt.c	1970-01-01 09:00:00.000000000 +0900
+++ wf/nt.c	2016-01-03 00:00:00.000000000 +0900
@@ -0,0 +1,44 @@
+#include "data.h"
+
+static double
+fz(double sec, int ac, char **av)
+{
+	double r = 30;
+	double sky_deg = 10;
+	pos_t p = {0,0,-r};
+	data_t data = { type_op_data_set, &(struct op_data_set){
+	  .op = &(data_t){ type_rot_way, &(struct rot_way){
+	    .l=LINE_Y,.deg_way=WAY_V2(-90-sky_deg,90+sky_deg, 10,10, 3) }},
+	  .data = &(data_t){ type_test_conv, &p }
+	}};
+
+	eye_t eye;
+	prm_t prm;
+
+	eye_init(&eye, 640, 480, ac, av);
+	d3_set(&eye.p, 0,0,0);
+	d3_set(&eye.t, 0,1,0);
+
+	eye.sec = sec;
+	prm_set_eye_update(&prm, &eye);
+	data_draw(&data, &prm);
+#ifdef DBG
+	printf("(%f %f %f)\n", p.x, p.y, p.z);
+#endif
+	return p.z;
+}
+
+int
+main(int ac, char **av)
+{
+	double l_sec = 0, r_sec = 5, sec = 2.5;
+
+	while(r_sec - l_sec > 5*0.0000001){
+		sec = (l_sec + r_sec) * 0.5;
+		if(fz(sec, ac, av) < 0) r_sec = sec;
+		else l_sec = sec;
+	}
+	printf("sec=%f,5-sec=%f\n", sec, 5-sec);
+	printf("%f:%f=%f:5\n", sec, 5-sec, sec*5/(5-sec));
+	return 0;
+}
diff -urN wf-/way.h wf/way.h
--- wf-/way.h	2015-12-30 00:00:00.000000000 +0900
+++ wf/way.h	2016-01-03 00:00:00.000000000 +0900
@@ -1,6 +1,7 @@
 #ifndef __INTERP_H__
 #define __INTERP_H__
 
+#include <stdio.h>
 #include "d3.h"
 
 /*
diff -urN wf-/wf_ex.c wf/wf_ex.c
--- wf-/wf_ex.c	2015-12-30 00:00:00.000000000 +0900
+++ wf/wf_ex.c	2016-01-03 00:00:00.000000000 +0900
@@ -196,7 +196,6 @@
 		data_t *rcube = &(data_t){ type_op_data_set, &(struct op_data_set){
 		  .op = &(data_t){ type_rdiv_way, &(struct rdiv_way){
 		    .n=4,
-		    //.rate_way={ .n=2, .vs=(double[]){-0.5,1.0}, .ts=(double[]){3,3}, .ps=NULL, .dg=3 } } },
 		    .rate_way=WAY_V2(-0.5,1.0, 3,3, 3) } },
 		  .data = &(data_t){ type_cube } }};
 
@@ -301,15 +300,29 @@
 		  .op = &(data_t){ type_arr, (data_t[]){
 		    { type_copy_timeshift, &(struct copy_timeshift){
 		      .n=10, .init_sec=0, .step_sec=-0.3, .init=D3_O, .step=D3_O } },
-		    { type_slide_way, &(struct way){ .n=2, .ps=(pos_t[]){{0,0,-20},{0,0,20}}, .ts=(double[]){5,5}, .vs=NULL, .dg=3} },
-		    { type_slide_way, &(struct way){ .n=2, .ps=(pos_t[]){{0,-20,0},{0,20,0}}, .ts=(double[]){4.5,4.5}, .vs=NULL, .dg=3} },
-		    { type_slide_way, &(struct way){ .n=2, .ps=(pos_t[]){{-20,0,0},{20,0,0}}, .ts=(double[]){3,3}, .vs=NULL, .dg=3} },
+		    { type_slide_way_liss, &(struct slide_way_liss){
+		      .ps={-20,-20,-20},.pe={20,20,20},.sec={5*2,4.5*2,3*2},.init_sec={0,0,0}} },
 		    { type_rot_way, &(struct rot_way){
 		      .l={D3_O,D3_I}, .deg_way=WAY_V2(0,360*2, 1,1, 3) } },
 		    { type_end } }},
 		  .data = &(data_t){ type_circle, &(struct circle){ .r=1,.n=10*4 } }
 		}};
 
+		double r = 30;
+		data_t *half_pipe = &(data_t){ type_op_data_set, &(struct op_data_set){
+		  .op = &(data_t){ type_zoom_and_slide, (d3_t[]){{0.1,0.1,0.1},{-30,-30,-10}} },
+		  .data = &(data_t){ type_arr, (data_t[]){
+		    { type_circle, &(struct circle){ .r=r*3, .n=360/10 } },
+		    { type_circle, &(struct circle){ .r=r*5, .n=360/10 } },
+		    { type_op_data_set, &(struct op_data_set){
+		      .op = &(data_t){ type_arr, (data_t[]){
+			{ type_copy_rot, &(struct copy_rot){ .n=360/10, .l=LINE_Z, .init_deg=0, .step_deg=10 } },
+		        { type_slide, &(d3_t){r*4,0,0} },
+			{ type_copy_rot, &(struct copy_rot){ .n=5, .l=LINE_Y, .init_deg=-90+30, .step_deg=30 } },
+			{ type_end } }},
+		      .data = &(data_t){ type_cross, (pos_t[]){{-1,0,-r},{1,0,-r}} } }},
+		    { type_end } }} }};
+
 		data.type = type_arr;
 		data.p = (data_t[]){
 			*axyz,
@@ -317,6 +330,7 @@
 			*cube, *cube3,
 			*cup, *ferris_wheel, *merry_go_round, *ship,
 			*exile, *lissajours,
+			*half_pipe,
 			{ type_end }
 		};
 	}