Feature for Curve objects in Blender; 'tapering'.

Next to the "BevOb" button you now have a "TaperOb" button to give a name
of a curve object which defines the width of extrusion of the 'BevObj'
along the curve. The TaperOb curve typically is horizontal, where the
height denotes the width.
Important rules;
- Only the firste curve in TaperObj is evaluated
- the first width is left, last width is right
- it scales the width of normal extrusions based on evaluating the taper
  curve; which means sharp corners in taper curve won't be easily visible

(That latter feature could be improved by extrusing based on the points
in the taper curve; this is a *lot* more work)

6 files changed, 86 insertions, 21 deletions

diff --git a/source/blender/blenkernel/intern/displist.c b/source/blender/blenkernel/intern/displist.c
index 07977a52a52..3b45ded0c74 100644
--- a/source/blender/blenkernel/intern/displist.c
+++ b/source/blender/blenkernel/intern/displist.c
@@ -1666,6 +1666,54 @@ void set_displist_onlyzero(int val)
 	dl_onlyzero= val;
 }
 
+/* taper rules:
+  - only 1 curve
+  - first point left, last point right
+  - based on subdivided points in original curve, not on points in taper curve (still)
+*/
+static float calc_taper(Object *taperobj, int cur, int tot)
+{
+	Curve *cu;
+	DispList *dl;
+	
+	if(taperobj==NULL) return 1.0;
+	
+	cu= taperobj->data;
+	dl= cu->disp.first;
+	if(dl==NULL) {
+		makeDispList(taperobj);
+		dl= cu->disp.first;
+	}
+	if(dl) {
+		float fac= ((float)cur)/(float)(tot-1);
+		float minx, dx, *fp;
+		int a;
+		
+		/* horizontal size */
+		minx= dl->verts[0];
+		dx= dl->verts[3*(dl->nr-1)] - minx;
+		if(dx>0.0) {
+		
+			fp= dl->verts;
+			for(a=0; a<dl->nr; a++, fp+=3) {
+				if( (fp[0]-minx)/dx >= fac) {
+					/* interpolate with prev */
+					if(a>0) {
+						float fac1= (fp[-3]-minx)/dx;
+						float fac2= (fp[0]-minx)/dx;
+						if(fac1!=fac2)
+							return fp[1]*(fac1-fac)/(fac1-fac2) + fp[-2]*(fac-fac2)/(fac1-fac2);
+					}
+					return fp[1];
+				}
+			}
+			return fp[-2];	// last y coord
+		}
+	}
+	
+	return 1.0;
+}
+
 void makeDispList(Object *ob)
 {
 	EditMesh *em = G.editMesh;
@@ -1888,14 +1936,18 @@ void makeDispList(Object *ob)
 
 						data= dl->verts;
 						bevp= (BevPoint *)(bl+1);
-						a= bl->nr;
-						while(a--) {	/* for each point of poly make a bevel piece */
-
+						for(a=0; a<bl->nr; a++) {	/* for each point of poly make a bevel piece */
+							float fac;
+							
+							/* returns 1.0 if no taper, of course */
+							fac= calc_taper(cu->taperobj, a, bl->nr);
+							
 							/* rotate bevel piece and write in data */
 							fp1= dlb->verts;
 							b= dlb->nr;
 
 							while(b--) {
+								
 								if(cu->flag & CU_3D) {
 								
 									vec[0]= fp1[1]+widfac;
@@ -1904,14 +1956,14 @@ void makeDispList(Object *ob)
 									
 									Mat3MulVecfl(bevp->mat, vec);
 									
-									data[0]= bevp->x+ vec[0];
-									data[1]= bevp->y+ vec[1];
-									data[2]= bevp->z+ vec[2];
+									data[0]= bevp->x+ fac*vec[0];
+									data[1]= bevp->y+ fac*vec[1];
+									data[2]= bevp->z+ fac*vec[2];
 								}
 								else {
-									data[0]= bevp->x+ (fp1[1]+widfac)*bevp->sina;
-									data[1]= bevp->y+ (fp1[1]+widfac)*bevp->cosa;
-									data[2]= bevp->z+ fp1[2];
+									data[0]= bevp->x+ fac*(fp1[1]+widfac)*bevp->sina;
+									data[1]= bevp->y+ fac*(fp1[1]+widfac)*bevp->cosa;
+									data[2]= bevp->z+ fac*fp1[2];
 								}
 
 								data+=3;
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index d1f6da37a7c..5b271daefdd 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -218,28 +218,29 @@ void unlink_object(Object *ob)
 	/* check all objects: parents en bevels */
 	obt= G.main->object.first;
 	while(obt) {
-		if(obt->id.lib==0) {
+		if(obt->id.lib==NULL) {
 			if(obt->parent==ob) {
-				obt->parent= 0;
+				obt->parent= NULL;
 				if(ob->type==OB_LATTICE) freedisplist(&obt->disp);
 			}
-			if(obt->track==ob) obt->track= 0;
+			if(obt->track==ob) obt->track= NULL;
 			if ELEM(obt->type, OB_CURVE, OB_FONT) {
 				cu= obt->data;
-				if(cu->bevobj==ob) cu->bevobj= 0;
-				if(cu->textoncurve==ob) cu->textoncurve= 0;
+				if(cu->bevobj==ob) cu->bevobj= NULL;
+				if(cu->taperobj==ob) cu->taperobj= NULL;
+				if(cu->textoncurve==ob) cu->textoncurve= NULL;
 			}
 			if(obt->type==OB_IKA) {
 				Ika *ika= obt->data;
 				Deform *def= ika->def;
 				
-				if(ika->parent==ob) ika->parent= 0;
+				if(ika->parent==ob) ika->parent= NULL;
 				a= ika->totdef;
 				while(a--) {
 					if(def->ob==ob) {
 						ika->totdef= 0;
 						MEM_freeN(ika->def);
-						ika->def= 0;
+						ika->def= NULL;
 						break;
 					}
 					def++;
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 4f10130c3b7..d72921f1c03 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -1781,6 +1781,7 @@ static void lib_link_curve(FileData *fd, Main *main)
 			for(a=0; a<cu->totcol; a++) cu->mat[a]= newlibadr_us(fd, cu->id.lib, cu->mat[a]);
 
 			cu->bevobj= newlibadr(fd, cu->id.lib, cu->bevobj);
+			cu->taperobj= newlibadr(fd, cu->id.lib, cu->taperobj);
 			cu->textoncurve= newlibadr(fd, cu->id.lib, cu->textoncurve);
 			cu->vfont= newlibadr_us(fd, cu->id.lib, cu->vfont);
 
@@ -4535,6 +4536,7 @@ static void expand_curve(FileData *fd, Main *mainvar, Curve *cu)
 	expand_doit(fd, mainvar, cu->key);
 	expand_doit(fd, mainvar, cu->ipo);
 	expand_doit(fd, mainvar, cu->bevobj);
+	expand_doit(fd, mainvar, cu->taperobj);
 	expand_doit(fd, mainvar, cu->textoncurve);
 }
 
diff --git a/source/blender/makesdna/DNA_curve_types.h b/source/blender/makesdna/DNA_curve_types.h
index 24a627ec6a4..59e91fa861b 100644
--- a/source/blender/makesdna/DNA_curve_types.h
+++ b/source/blender/makesdna/DNA_curve_types.h
@@ -110,7 +110,7 @@ typedef struct Curve {
 	
 	ListBase nurb;
 	ListBase disp;
-	struct Object *bevobj, *textoncurve;
+	struct Object *bevobj, *taperobj, *textoncurve;
 	struct Ipo *ipo;
 	Path *path;
 	struct Key *key;
diff --git a/source/blender/src/buttons_editing.c b/source/blender/src/buttons_editing.c
index 1a429f00f61..1d2dd031d59 100644
--- a/source/blender/src/buttons_editing.c
+++ b/source/blender/src/buttons_editing.c
@@ -1270,7 +1270,8 @@ static void editing_panel_curve_type(Object *ob, Curve *cu)
 		uiDefButF(block, NUM, B_MAKEDISP, "Ext1:",		760,70,150,19, &cu->ext1, 0.0, 5.0, 10, 0, "");
 		uiDefButF(block, NUM, B_MAKEDISP, "Ext2:",		760,50,150,19, &cu->ext2, 0.0, 2.0, 1, 0, "");
 		uiDefButS(block, NUM, B_MAKEDISP, "BevResol:",	760,30,150,19, &cu->bevresol, 0.0, 10.0, 0, 0, "");
-		uiDefIDPoinBut(block, test_obcurpoin_but, B_MAKEDISP, "BevOb:",		760,10,150,19, &cu->bevobj, "");
+		uiDefIDPoinBut(block, test_obcurpoin_but, B_MAKEDISP, "BevOb:",		760,10,150,19, &cu->bevobj, "Curve object name that defines the bevel shape");
+		uiDefIDPoinBut(block, test_obcurpoin_but, B_MAKEDISP, "TaperOb:",		760,-10,150,19, &cu->taperobj, "Curve object name that defines the taper (width)");
 
 		uiBlockBeginAlign(block);
 		uiBlockSetCol(block, TH_BUT_SETTING1);
diff --git a/source/blender/src/editobject.c b/source/blender/src/editobject.c
index 7927f809db0..959aa3b7e53 100644
--- a/source/blender/src/editobject.c
+++ b/source/blender/src/editobject.c
@@ -1175,7 +1175,7 @@ void exit_editmode(int freedata)	/* freedata==0 at render */
 					text_to_curve(base->object, 0);
 					makeDispList(base->object);
 				}
-				if(cu->bevobj== ob) {
+				if(cu->bevobj==ob || cu->taperobj==ob) {
 					makeDispList(base->object);
 				}
 			}
@@ -2142,6 +2142,7 @@ void copy_attr(short event)
 						cu1= base->object->data;
 						
 						cu1->bevobj= cu->bevobj;
+						cu1->taperobj= cu->taperobj;
 						cu1->width= cu->width;
 						cu1->bevresol= cu->bevresol;
 						cu1->ext1= cu->ext1;
@@ -3931,6 +3932,7 @@ void special_aftertrans_update(char mode, int flip, short canceled, int keyflags
 				cu= ob->data;
 				
 				if(cu->bevobj && (cu->bevobj->flag & SELECT) ) doit= 1;
+				else if(cu->taperobj && (cu->taperobj->flag & SELECT) ) doit= 1;
 				else if(cu->textoncurve) {
 					if(cu->textoncurve->flag & SELECT) doit= 1;
 					else if(ob->flag & SELECT) doit= 1;
@@ -3947,6 +3949,8 @@ void special_aftertrans_update(char mode, int flip, short canceled, int keyflags
 				
 				if(cu->bevobj && (cu->bevobj->flag & SELECT) ) 
 					makeDispList(ob);
+				else if(cu->taperobj && (cu->taperobj->flag & SELECT) ) 
+					makeDispList(ob);
 			}
 			
 			where_is_object(ob);	/* always do, for track etc. */
@@ -4561,8 +4565,8 @@ void transform(int mode)
 	if(mode=='w' && G.obedit==0) return;
 
 	if (G.obedit && G.obedit->type == OB_MESH) {
-               undo_push_mesh(transform_mode_to_string(mode));
-       }
+		undo_push_mesh(transform_mode_to_string(mode));
+	}
 
 	/* what data will be involved? */
 	if(G.obedit) {
@@ -6142,6 +6146,10 @@ void transform(int mode)
 	if(edge_creases) MEM_freeN(edge_creases);
 	
 	tottrans= 0;
+
+	/* undo after transform, since it's storing current situations */
+	//if(canceled==0 && G.obedit==NULL) 
+	//	BIF_write_undo(transform_mode_to_string(mode));
 }
 
 void std_rmouse_transform(void (*xf_func)(int))
@@ -6300,6 +6308,7 @@ void single_obdata_users(int flag)
 				case OB_FONT:
 					ob->data= cu= copy_curve(ob->data);
 					ID_NEW(cu->bevobj);
+					ID_NEW(cu->taperobj);
 					makeDispList(ob);
 					break;
 				case OB_LATTICE: