std::vector<menu> menus;
std::vector<title> titles;
};
-
+
class webdvd_window : public Gtk::Window
{
public:
}
}
- void generate_menu_dispatch(std::ostream &, int indent,
- int first_menu, int last_menu);
-
void webdvd_window::generate_dvd()
{
temp_file temp("webdvd-dvdauthor-");
// We generate code that uses registers in the following way:
//
- // g0: button destination (when jumping to menu 1), then scratch
+ // g0: scratch
// g1: current location
- // g2-g11: location history (g2 = most recent)
- // g12: location that last linked to a video
+ // g12: location that last jumped to a video
//
// All locations are divided into two bitfields: the least
// significant 10 bits are a page/menu number and the most
static const int button_mult = dvd::reg_s8_button_mult;
static const int menu_mask = button_mult - 1;
static const int button_mask = (1 << dvd::reg_bits) - button_mult;
- static const int location_bias = button_mult + 1;
file <<
"<dvdauthor>\n"
if (menu_num == 0)
{
- // This is the first (title) menu, which needs to include
- // initialisation and dispatch code.
-
+ // This is the first (title) menu, displayed when the
+ // disc is first played.
file <<
" <pgc entry='title'>\n"
" <pre>\n"
- // Has the location been set yet?
+ // Initialise the current location if it is not set
+ // (all general registers are initially 0).
" if (g1 eq 0)\n"
- " {\n"
- // Initialise the current location to first button on
- // this menu.
- " g1 = " << location_bias << ";\n"
- " }\n"
- " else\n"
- " {\n"
- // Has the user selected a link?
- " if (g0 ne 0)\n"
- " {\n"
- // First update the history.
- // Does link go to the last page in the history?
- " if (((g0 ^ g2) & " << menu_mask
- << ") == 0)\n"
- // It does; we treat this as going back and pop the old
- // location off the history stack into the current
- // location. Clear the free stack slot.
- " {\n"
- " g1 = g2; g2 = g3; g3 = g4; g4 = g5;\n"
- " g5 = g6; g6 = g7; g7 = g8; g8 = g9;\n"
- " g9 = g10; g10 = g11; g11 = 0;\n"
- " }\n"
- " else\n"
- // Link goes to some other page, so push current
- // location onto the history stack and set the current
- // location to be exactly the target location.
- " {\n"
- " g11 = g10; g10 = g9; g9 = g8; g8 = g7;\n"
- " g7 = g6; g6 = g5; g5 = g4; g4 = g3;\n"
- " g3 = g2; g2 = g1; g1 = g0;\n"
- " }\n"
- " }\n"
- // Find the target page number.
- " g0 = g1 & " << menu_mask << ";\n";
- // There seems to be no way to perform a computed jump,
- // so we generate all possible jumps and a binary search
- // to select the correct one.
- generate_menu_dispatch(file, 12,
- 0, contents_.menus.size() - 1);
- file <<
- " }\n";
+ " g1 = " << 1 + button_mult << ";\n";
}
- else // menu_num != 0
+ else
{
file <<
" <pgc>\n"
" <pre>\n";
}
+ // When a title finishes or the user presses the menu
+ // button, this always jumps to the titleset's root menu.
+ // We want to return the user to the last menu they used.
+ // So we arrange for each titleset's root menu to return
+ // to the vmgm title menu and then dispatch from there to
+ // whatever the correct menu is. We determine the correct
+ // menu by looking at the menu part of g1.
+
+ file << " g0 = g1 & " << menu_mask << ";\n";
+
+ // There is a limit of 128 VM instructions in each PGC.
+ // Therefore in each menu's <pre> section we generate
+ // jumps to menus with numbers greater by 512, 256, 128,
+ // ..., 1 where (a) such a menu exists, (b) this menu
+ // number is divisible by twice that increment and (c) the
+ // correct menu is that or a later menu. Thus each menu
+ // has at most 10 such conditional jumps and is reachable
+ // by at most 10 jumps from the title menu. This chain of
+ // jumps might take too long on some players; this has yet
+ // to be investigated.
+
+ for (std::size_t menu_incr = (menu_mask + 1) / 2;
+ menu_incr != 0;
+ menu_incr /= 2)
+ {
+ if (menu_num + menu_incr < contents_.menus.size()
+ && (menu_num & (menu_incr * 2 - 1)) == 0)
+ {
+ file <<
+ " if (g0 ge " << 1 + menu_num + menu_incr
+ << ")\n"
+ " jump menu " << 1 + menu_num + menu_incr
+ << ";\n";
+ }
+ }
+
file <<
- // Clear link indicator and highlight the
- // appropriate link/button.
- " g0 = 0; s8 = g1 & " << button_mask << ";\n"
+ // Highlight the appropriate button.
+ " s8 = g1 & " << button_mask << ";\n"
" </pre>\n"
- " <vob file='"
- << menu.vob_temp->get_name() << "'/>\n";
+ " <vob file='" << menu.vob_temp->get_name() << "'/>\n";
for (std::size_t button_num = 0;
button_num != menu.entries.size();
++button_num)
{
- file << " <button> "
- // Update current location.
- " g1 = "
- << location_bias + button_num * button_mult + menu_num
- << ";";
+ file << " <button> ";
- // Jump to appropriate resource.
if (menu.entries[button_num].first == dvd_contents::menu_pgc)
{
- file << " g0 = "
- << location_bias + menu.entries[button_num].second
- << "; jump menu 1;";
+ int dest_menu_num = menu.entries[button_num].second;
+
+ // Look for a button on the new menu that links
+ // back to this one. If there is one, set that to
+ // be the highlighted button; otherwise, use the
+ // first button.
+ const std::vector<dvd_contents::pgc_ref> &
+ dest_menu_entries =
+ contents_.menus[dest_menu_num].entries;
+ dvd_contents::pgc_ref this_pgc(
+ dvd_contents::menu_pgc, menu_num);
+ std::size_t dest_button_num = dest_menu_entries.size();
+ while (dest_button_num != 0
+ && dest_menu_entries[--dest_button_num] != this_pgc)
+ ;
+
+ file << "g1 = "
+ << (1 + dest_menu_num
+ + (1 + dest_button_num) * button_mult)
+ << "; jump menu " << 1 + dest_menu_num << ";";
}
else
{
assert(menu.entries[button_num].first
== dvd_contents::title_pgc);
- file << " jump title "
+
+ file << "g1 = "
+ << 1 + menu_num + (1 + button_num) * button_mult
+ << "; jump title "
<< 1 + menu.entries[button_num].second << ";";
}
" </menus>\n"
" <titles>\n"
" <pgc>\n"
- // Record calling page/menu.
+ // Record calling location.
" <pre> g12 = g1; </pre>\n"
<< contents_.titles[title_num].vob_list <<
- // If page/menu location has not been changed during the
- // video, change the location to be the following
- // link/button when returning to it. In any case,
- // return to a page/menu.
+ // If the menu location has not been changed during
+ // the title, set the location to be the following
+ // button in the menu. In any case, return to some
+ // menu.
" <post> if (g1 eq g12) g1 = g1 + " << button_mult
<< "; call menu; </post>\n"
" </pgc>\n"
}
}
- void generate_menu_dispatch(std::ostream & file, int indent,
- int first_menu, int last_menu)
- {
- if (first_menu == last_menu)
- {
- if (first_menu == 0)
- {
- // This dispatch code is generated *on* the first menu
- // so don't create an infinite loop.
- }
- else
- {
- file << std::setw(indent) << ""
- << "jump menu " << 1 + first_menu << ";\n";
- }
- }
- else // first_menu != last_menu
- {
- if (first_menu == 0 && last_menu == 1)
- {
- // dvdauthor doesn't allow empty blocks or null
- // statements so when selecting between the first 2
- // menus we don't use an "else" part. We must use
- // braces so that a following "else" will match the
- // right "if".
- file << std::setw(indent) << "" << "{\n"
- << std::setw(indent) << "" << "if (g0 eq 2)\n"
- << std::setw(indent + 2) << "" << "jump menu 2;\n"
- << std::setw(indent) << "" << "}\n";
- }
- else
- {
- int middle = (first_menu + last_menu) / 2;
- file << std::setw(indent) << "" << "if (g0 le " << 1 + middle
- << ")\n";
- generate_menu_dispatch(file, indent + 2,
- first_menu, middle);
- file << std::setw(indent) << "" << "else\n";
- generate_menu_dispatch(file, indent + 2,
- middle + 1, last_menu);
- }
- }
- }
-
const video::frame_params & lookup_frame_params(const char * str)
{
assert(str);
projects / videolink.git / commitdiff