4.3 Queuable technologies

The queuable technologiess functionality was first introduced in Tech hotkeys and is probably one of the most clever things ever implemented. As any player from before Definitive Edition knows, it is possible to queue units but not technollogies. However, the units tab has a field called “Initiates technology” that at least can be used to keep track of the buildings required to age up. Most actual units whose production we can queue have this field disabled, all except for the Trebuchet.

That’s the idea: creating a bunch of copies of the Trebuchet, that can be queued but also can be assigned a technology to research upon completion. Assigning each unit the icon, position in the menu, cost and research time of the technology it represents, we can mimic the idea of researching techs when in reality we are creating units. Moreover, this trick allows to have technologies with zero research time but that have to be manually clicked. Definitive Edition claims to have Loom research instantly for Goths when actually it has to take at least one second in order not to be an instantaneous technology (see the section on the Techs Tab for more information on this). The Community Patch really has Loom with zero research time.

Actual implementation​

Appart from actually going over all techs in the game, copying the cost and research time, and having to modify civilization bonuses that affect research time or research cost, there are a number of issues that we have to solve:

• We need new technologies that “make available” the queuabe version when the requirements of the technology are met. For example, technology 816 researches automatically once you reach Feudal Age and its only effect is to activate the queuabe version of Bloodlines.
• Thechnologies are programmed into the Technology Tree of civilizations by simply disabling the tech. For the queuable technologies, we also need to disable the techs that make the queuable version available. Effect 258, the Frank Technology Tree, has technology 816 disabled.
• The queuable technology is actually a unit that should disappear as soon as it has triggered the tech. This is easy to do by setting the hit points of all the queuable techs to -1.
• Since for all intends and purposes, the queuable techs are units, it is perfectly possible to queue more than one or to shift-click them in a group of buildings. With this you are paying the cost of several techs but only getting the effect once. To solve this we introduce another resource into the cost, a hidden resource of which the player only has one unit. This way, once the player clicks once in the tech, it consumes the single unit of the resource and prevents from researching a technology more than once. We have to create a new resource per technology in order to have this.
• Once the technology has been researched, the icon doesn’t disapear, as the game treats it like a unit. Therefore, we have to program the effect of every technology to also disable the unit that created it.
• Additionally, we instruct the technology to move the button to position 255. This effectively hides the button and is implemented as a security measure for scenarios that may want to research technologies using triggers.
• We need also to disable the button field in the Techs Tab so it doesn’t show in game. This is the only part of the original technology we should modify as the AI still researches technollogies in this fashion. Leaving the research time and cost intact allows to competitively play against AI.

Issues​

The main issue with this functionality is that the icon of the technology doesn’t hide during the research of the technology, giving the impression that the technology is not in progress. We managed to fix this on the Community Patch by modifying the patch.

Another issue that may occur is that, if the building has the gather point set to itself, the technology will appear garrisoned after completion. Regardless of this, its effects are applied.

A more obscure issue​

Technologies researched through units don’t seem to always register as researched technologies for other technologies that have them as required techs. Let’s see the example of Thalassocracy. The basic tech, 624, turns Docks into Harbors. Since Harbors shoot arrows, they are affected by Blacksmith upgrades, Ballistics, Chemistry, etc.

This effects are added through additional techs that have both Thalassocracy and the corresponding technology as required technologies. However, if this technologies are researched with queueable techs, they don’t always register as researched (depending on the order they are researched) and thus Harbors don’t benefit from all upgrades.

A similiar thing could happen with techs that require a previous technology and a new age to be available. Depending on the order things are done, the new technology may be available or not.

This is solved with dummy technologies. Creating technologies without effect whose only prerequisite is the technology they stand for, (technology 78 is an example of this). Since these technologies depend only on one, even if it comes from a queuable tech, it is researched. All the addons on Thalassocracy don’t depend directly on the actual technologies but on dummy version to ensure they are researched. Similarly, all blacksmith technologies that are conected through ages have a dummy version.

In game behavior​

With all this explanation of the implementation, let's see how all the pieces work in game.

1. When the requisites of the technology are met (age, previous technology) the actual technology is enabled and the "make available" version is activated. Humans don't see the actual technology, as the button is hidden, but AIs do. In the corresponding building, a trebuchet-like unit appears in the position of the technology.
2. When the unit is created, it dies instantly but triggers the actual technology. Appart from it's effects, this technology hides and disables the unit.
3. If needed, a dummy version of the technology is triggered to enable future technologies.

Scenario Editor use​

Since now all technologies of the game are hidden and handled through units, if you want to control them in the scenario, you have to be aware of their implementation. Here are some tips:

• If you want to research a technolgy using triggers, research the actual one. It will take care of hidding the button of the unit.
• If you want to enable a technology for the player to research, use a trigger to research the "make available" version.
• If you want to disable a technology for a civilization, disable the "make available" version. The section of the editor where you can disable technologies only uses the actual ones, which may be useful if you expect to use AI players.
• Unique technologiess and unique units upgrades use all the same three technologies.
• The effect to research technologies allows to input a number. Some of the useful values you can use with queuable techs are the following. For more information, see here.
  • 0. Research the technology.
  • 2. Disable technology.
  • 3. Enable a technology for researching through triggers.

Both versions of the technologies are accessible through the triggers menu.