added initial support for building our 4 adventure engines as loadable modules; right now only work on OS X; once we add more build rules, other systems with dlopen() should work, too (e.g. Linux); Windows support may come later. This is still very much WIP

svn-id: r10304

1 files changed, 27 insertions, 2 deletions

diff --git a/base/plugins.h b/base/plugins.h
index 8257bf1a53..d79ff0c5d9 100644
--- a/base/plugins.h
+++ b/base/plugins.h
@@ -37,11 +37,13 @@ struct TargetSettings;
  */
 class Plugin {
 public:
-	virtual void loadPlugin()		{}
+	virtual ~Plugin()				{}
+
+	virtual bool loadPlugin()		{ return true; }
 	virtual void unloadPlugin()		{}
 
 	virtual const char *getName() const = 0;
-	virtual int getVersion() const = 0;
+	virtual int getVersion() const	{ return 0; }	// TODO!
 	
 	virtual int countTargets() const;
 	virtual const TargetSettings *getTargets() const = 0;
@@ -51,6 +53,27 @@ public:
 };
 
 
+/**
+ * The REGISTER_PLUGIN is a convenience macro meant to ease writing
+ * the plugin interface for our modules. In particular, using it
+ * makes it possible to compile the very same code in a module
+ * both as a static and a dynamic plugin.
+ *
+ * @todo	add some means to query the plugin API version etc.
+ * @todo	on Windows, we might need __declspec(dllexport) ?
+ */
+#ifndef DYNAMIC_MODULES
+#define REGISTER_PLUGIN(name,targetListFactory,engineFactory)
+#else
+#define REGISTER_PLUGIN(name,targetListFactory,engineFactory) \
+	extern "C" { \
+		const char *PLUGIN_name() { return name; } \
+		const TargetSettings *PLUGIN_getTargetList() { return targetListFactory(); } \
+		Engine *PLUGIN_createEngine(GameDetector *detector, OSystem *syst) { return engineFactory(detector, syst); } \
+	}
+#endif
+
+
 /** List of plugins. */
 typedef ScummVM::List<Plugin *> PluginList;
 
@@ -65,6 +88,8 @@ class PluginManager {
 protected:
 	PluginList _plugins;
 	
+	bool tryLoadPlugin(Plugin *plugin);
+	
 public:
 	PluginManager();
 	~PluginManager();