Hi, Taco:
In TeX's Packaging algorithm, TeX wraps lists into boxes. Knuth create
two functions, hpack (p,w,m) and vpack (p,w,m)=
vpackage(p,w,m,max_dimen) to solve this problem.
In the LuaTeX manual, (4.1.3.13), only node.hpack is given. maybe we
should also write something called node.vpack?
I wrote one for LuaTeX since I need it in my document project. I think
it will be useful to others too. The code is easy to write by
following yours and here is the patch:
y...@localhost ~/luatex $ svn diff
Index: src/texk/web2c/luatexdir/lua/lnodelib.c
===================================================================
--- src/texk/web2c/luatexdir/lua/lnodelib.c (revision 1985)
+++ src/texk/web2c/luatexdir/lua/lnodelib.c (working copy)
@@ -496,6 +496,32 @@
return 1;
}
+/* build a vbox */
+
+static int lua_nodelib_vpack(lua_State * L)
+{
+ halfword n, p;
+ char *s;
+ integer w = 0;
+ int m = 1;
+ n = *(check_isnode(L, 1));
+ if (lua_gettop(L) > 1) {
+ w = lua_tointeger(L, 2);
+ if (lua_gettop(L) > 2 && lua_type(L, 3) == LUA_TSTRING) {
+ s = (char *) lua_tostring(L, 3);
+ if (strcmp(s, "additional") == 0) {
+ m = 1;
+ } else {
+ m = lua_tonumber(L, 3);
+ }
+ }
+ }
+ p = vpackage(n, w, m, max_dimen);
+ lua_nodelib_push_fast(L, p);
+ return 1;
+}
+
+
/* create a hlist from a formula */
static int lua_nodelib_mlist_to_hlist(lua_State * L)
@@ -3202,6 +3228,7 @@
{"copy", lua_nodelib_copy},
{"copy_list", lua_nodelib_copy_list},
{"hpack", lua_nodelib_hpack},
+ {"vpack", lua_nodelib_vpack},
{"mlist_to_hlist", lua_nodelib_mlist_to_hlist},
{"family_font", lua_nodelib_mfont},
{"has_attribute", lua_nodelib_has_attribute},
btw, I think the original code buggy, shouldn't it be something like this?
y...@localhost ~/luatex $ svn diff
Index: src/texk/web2c/luatexdir/lua/lnodelib.c
===================================================================
--- src/texk/web2c/luatexdir/lua/lnodelib.c (revision 1985)
+++ src/texk/web2c/luatexdir/lua/lnodelib.c (working copy)
@@ -482,13 +482,24 @@
n = *(check_isnode(L, 1));
if (lua_gettop(L) > 1) {
w = lua_tointeger(L, 2);
- if (lua_gettop(L) > 2 && lua_type(L, 3) == LUA_TSTRING) {
- s = (char *) lua_tostring(L, 3);
- if (strcmp(s, "additional") == 0) {
- m = 1;
- } else {
+ if (lua_gettop(L) > 2){
+ if (lua_type(L, 3) == LUA_TSTRING) {
+ s = (char *) lua_tostring(L, 3);
+ if (strcmp(s, "additional") == 0)
+ m = 1;
+ else if (strcmp(s,"exactly") == 0)
+ m = 0;
+ else {
+ lua_pushstring(L, "3rd argument should be either
additional or exactly");
+ lua_error(L);
+ }
+ }
+
+ else if (lua_type(L, 3) == LUA_TNUMBER) {
m = lua_tonumber(L, 3);
- }
+ }else{
+ lua_pushstring(L, "incorrect 3rd argument");
+ }
}
}
p = hpack(n, w, m);
@@ -496,6 +507,42 @@
return 1;
}
+/* build a vbox */
+static int lua_nodelib_vpack(lua_State * L)
+{
+ halfword n, p;
+ char *s;
+ integer w = 0;
+ int m = 1;
+ n = *(check_isnode(L, 1));
+ if (lua_gettop(L) > 1) {
+ w = lua_tointeger(L, 2);
+ if (lua_gettop(L) > 2){
+ if (lua_type(L, 3) == LUA_TSTRING) {
+ s = (char *) lua_tostring(L, 3);
+ if (strcmp(s, "additional") == 0)
+ m = 1;
+ else if (strcmp(s,"exactly") == 0)
+ m = 0;
+ else {
+ lua_pushstring(L, "3rd argument should be either
additional or exactly");
+ lua_error(L);
+ }
+ }
+
+ else if (lua_type(L, 3) == LUA_TNUMBER) {
+ m = lua_tonumber(L, 3);
+ }else{
+ lua_pushstring(L, "incorrect 3rd argument");
+ }
+ }
+ }
+ p = vpackage(n, w, m, max_dimen);
+ lua_nodelib_push_fast(L, p);
+ return 1;
+}
+
+
/* create a hlist from a formula */
static int lua_nodelib_mlist_to_hlist(lua_State * L)
@@ -3202,6 +3249,7 @@
{"copy", lua_nodelib_copy},
{"copy_list", lua_nodelib_copy_list},
{"hpack", lua_nodelib_hpack},
+ {"vpack", lua_nodelib_vpack},
{"mlist_to_hlist", lua_nodelib_mlist_to_hlist},
{"family_font", lua_nodelib_mfont},
{"has_attribute", lua_nodelib_has_attribute},
y...@localhost ~/luatex $
Yue Wang
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