Difference between revisions of "HOWTO-Engines"

HOWTO-Engines (view source)

Revision as of 13:21, 12 February 2006

2,284 bytes added , 13:21, 12 February 2006

Added code for a minimal example "engine"

Fingolfin

1,079

edits

@@ Line 26: / Line 26: @@
 Important note: Use a C++ namespace for all your work, e.g. "namespace Quux" in this case.
+=== Subclassing Engine ===
+TODO: We should probably give some sample code, maybe even provide a full (empty) Engine demo class. Maybe even provide a real mini engine project somewhere on our site which demonstrates using events, drawing, etc. ? Not sure whether this would be worth the effort, though.
+TODO: At the very least, describe the plugin interface: I.e. which functions *must* be implemented, and what they are supposed to do. Once again, sample code would be nice.
+=== Example: engines/quux/quux.h ===
+<pre>
+#ifndef QUUX_H
+#define QUUX_H
+#include "base/engine.h"
+namespace Quux {
+class QuuxEngine : public Engine {
+public:
+	QuuxEngine(OSystem *syst);
+	~QuuxEngine();
+	virtual int init(GameDetector &detector);
+	virtual int go();
+};
+} // End of namespace Quux
+#endif
+</pre>
+=== Example: engines/quux/quux.cpp ===
+<pre>
+#include "common/stdafx.h"
+#include "backends/fs/fs.h"
+#include "base/gameDetector.h"
+#include "base/plugins.h"
+#include "quux/quux.h"
+static const GameSettings quux_setting[] = {
+	{ "quux", "Quux the Example Module", 0 },
+	{ "quuxcd", "Quux the Example Module (CD version)", 0 },
+	{ 0, 0, 0 }
+};
+GameList Engine_QUUX_gameList() {
+	GameList games;
+	const GameSettings *g = quux_setting;
+	while (g->gameid) {
+		games.push_back(*g);
+		g++;
+	}
+	return games;
+}
+DetectedGameList Engine_QUUX_detectGames(const FSList &fslist) {
+	DetectedGameList detectedGames;
+	// Iterate over all files in the given directory
+	for (FSList::const_iterator file = fslist.begin(); file != fslist.end(); ++file) {
+		if (!file->isDirectory()) {
+			const char *gameName = file->displayName().c_str();
+			if (0 == scumm_stricmp("README", gameName)) {
+				// You could check the contents of the file now if you need to.
+				detectedGames.push_back(quux_setting[0]);
+				break;
+			}
+		}
+	}
+	return detectedGames;
+}
+Engine *Engine_QUUX_create(GameDetector *detector, OSystem *syst) {
+	// At this point you may want to perform a sanity check on the
+	// values in 'detecetor'.
+	return new Quux::QuuxEngine(syst);
+}
+REGISTER_PLUGIN(QUUX, "Quux the Example Module")
+namespace Quux {
+QuuxEngine::QuuxEngine(OSystem *syst)
+ : Engine(syst) {
+	// Put your engine in a sane state, but do nothing big yet;
+	// in particular, do not load data from files; rather, if you
+	// need to do such things, do them from init().
+	printf("QuuxEngine::QuuxEngine\n");
+}
+QuuxEngine::~QuuxEngine() {
+	// Dispose your resources here
+	printf("QuuxEngine::~QuuxEngine\n");
+}
+int QuuxEngine::init(GameDetector &detector) {
+	// Additional setup.
+	printf("QuuxEngine::init\n");
+	return 0;
+}
+int QuuxEngine::go() {
+	// Your main even loop should be (invoked from) here.
+	printf("QuuxEngine::go: Hello, World!\n");
+	return 0;
+}
+} // End of namespace Quux
+</pre>
@@ Line 46: / Line 165: @@
 include $(srcdir)/common.rules
 </pre>
-=== Subclassing Engine ===
-TODO: We should probably give some sample code, maybe even provide a full (empty) Engine demo class. Maybe even provide a real mini engine project somewhere on our site which demonstrates using events, drawing, etc. ? Not sure whether this would be worth the effort, though.
-TODO: At the very least, describe the plugin interface: I.e. which functions *must* be implemented, and what they are supposed to do. Once again, sample code would be nice.