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Difference between revisions of "HOWTO-Engines"
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Dreammaster (talk | contribs) m (Made changes to reflect changed way to register engines) |
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# Add a new directory <tt>engines/quux/</tt> | # Add a new directory <tt>engines/quux/</tt> | ||
# Add <tt>engines/quux/ | # Add <tt>engines/quux/configure.engine</tt> (looking at configure.engine files of existing engines should make it clear what you have to do). | ||
# Add <tt>engines/quux/module.mk</tt> (Again, just check out what is done for the existing engines). | |||
# Add <tt>engines/quux/quux.h</tt> and <tt>engines/quux/quux.cpp</tt>; this will contain your Engine subclass (or at least parts of it). | # Add <tt>engines/quux/quux.h</tt> and <tt>engines/quux/quux.cpp</tt>; this will contain your Engine subclass (or at least parts of it). | ||
# Add <tt>engines/quux/detection.cpp</tt>; It will contain the plugin interface code (more on that in the next section). | # Add <tt>engines/quux/detection.cpp</tt>; It will contain the plugin interface code (more on that in the next section). | ||
That's it. The difficult part is of course writing the Engine subclass. More on that in the next section! | That's it. The difficult part is of course writing the Engine subclass. More on that in the next section! | ||
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|inter.cpp, logic.cpp, script.cpp || Game logic, resp. script/bytecode interpreter | |inter.cpp, logic.cpp, script.cpp || Game logic, resp. script/bytecode interpreter | ||
|} | |} | ||
Additionally, the files saved by each engine should be consistent. | |||
* '''Saves''': These should be named <targetid>.### (where ### is the slot id) or <gameid>.###. The latter should be used when the saves can be shared across all game variants. | |||
* '''Other files''': These should be named <targetid>-<filename> or <gameid>-<filename>. Again the latter when the files can be shared acress all variants of the game (an example for these type of files would be when a minigame saves a high score record). | |||
Here, only use the <gameid> scheme if you are '''absolutely''' sure that such files can be shared across '''all''' (that is every game platform, every game language, every game patch version, every game release, etc.) versions. If you are not sure whether this is the case, then stick to the <targetid> based scheme. | |||
=== Subclassing MetaEngine === | === Subclassing MetaEngine === | ||
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=== Example: engines/quux/quux.h === | === Example: engines/quux/quux.h === | ||
< | <syntaxhighlight lang="cpp"> | ||
#ifndef QUUX_H | #ifndef QUUX_H | ||
#define QUUX_H | #define QUUX_H | ||
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#endif | #endif | ||
</ | </syntaxhighlight> | ||
=== Example: engines/quux/quux.cpp === | === Example: engines/quux/quux.cpp === | ||
< | <syntaxhighlight lang="cpp"> | ||
#include "common/scummsys.h" | #include "common/scummsys.h" | ||
| Line 162: | Line 169: | ||
#include "common/debug-channels.h" | #include "common/debug-channels.h" | ||
#include "common/error.h" | #include "common/error.h" | ||
#include " | #include "gui/EventRecorder.h" | ||
#include "common/file.h" | #include "common/file.h" | ||
#include "common/fs.h" | #include "common/fs.h" | ||
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QuuxEngine::QuuxEngine(OSystem *syst) | QuuxEngine::QuuxEngine(OSystem *syst) | ||
: Engine(syst) { | : Engine(syst), _console(nullptr) { | ||
// Put your engine in a sane state, but do nothing big yet; | // Put your engine in a sane state, but do nothing big yet; | ||
// in particular, do not load data from files; rather, if you | // in particular, do not load data from files; rather, if you | ||
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// Do not initialize graphics here | // Do not initialize graphics here | ||
// Do not initialize audio devices here | |||
// However this is the place to specify all default directories | // However this is the place to specify all default directories | ||
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} // End of namespace Quux | } // End of namespace Quux | ||
</ | </syntaxhighlight> | ||
=== Example: engines/quux/detection.cpp === | === Example: engines/quux/detection.cpp === | ||
The following example implements a custom MetaEngine instead of using the AdvancedMetaEngine. | The following example implements a custom MetaEngine instead of using the AdvancedMetaEngine. | ||
< | <syntaxhighlight lang="cpp"> | ||
#include "quux/quux.h" | #include "quux/quux.h" | ||
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REGISTER_PLUGIN_STATIC(QUUX, PLUGIN_TYPE_ENGINE, QuuxMetaEngine); | REGISTER_PLUGIN_STATIC(QUUX, PLUGIN_TYPE_ENGINE, QuuxMetaEngine); | ||
#endif | #endif | ||
</ | </syntaxhighlight> | ||
=== Example: engines/quux/module.mk === | === Example: engines/quux/module.mk === | ||
< | <syntaxhighlight lang="make"> | ||
MODULE := engines/quux | MODULE := engines/quux | ||
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# Include common rules | # Include common rules | ||
include $(srcdir)/rules.mk | include $(srcdir)/rules.mk | ||
</ | </syntaxhighlight> | ||
=== Example: engines/quux/configure.engine === | |||
<syntaxhighlight lang="bash"> | |||
# This file is included from the main "configure" script | |||
# add_engine [name] [desc] [build-by-default] [subengines] [base games] [deps] | |||
add_engine quux "Quux" no | |||
</syntaxhighlight> | |||