(svn r10444) -Codechange: switch to c++ classes and inheritance for sound/music/video drivers, using self-registration based on the blitter-model.

1 files changed, 198 insertions, 2 deletions

diff --git a/src/driver.h b/src/driver.h
index 6a504362c..d10f18688 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -5,11 +5,207 @@
 #ifndef DRIVER_H
 #define DRIVER_H
 
-void LoadDriver(int driver, const char *name);
+#include "debug.h"
+#include "helpers.hpp"
+#include "string.h"
+#include <string>
+#include <map>
 
 bool GetDriverParamBool(const char* const* parm, const char* name);
 int GetDriverParamInt(const char* const* parm, const char* name, int def);
 
-char *GetDriverList(char *p, const char *last);
+class Driver {
+public:
+	virtual bool CanProbe() = 0;
+
+	virtual const char *Start(const char * const *parm) = 0;
+
+	virtual void Stop() = 0;
+
+	virtual ~Driver() { }
+
+	enum Type {
+		DT_BEGIN = 0,
+		DT_SOUND = 0,
+		DT_MUSIC,
+		DT_VIDEO,
+		DT_END,
+	};
+};
+
+DECLARE_POSTFIX_INCREMENT(Driver::Type);
+
+
+class DriverFactoryBase {
+private:
+	Driver::Type type;
+	char *name;
+	typedef std::map<std::string, DriverFactoryBase *> Drivers;
+
+	static Drivers &GetDrivers()
+	{
+		static Drivers &s_drivers = *new Drivers();
+		return s_drivers;
+	}
+
+	static Driver **GetActiveDriver(Driver::Type type)
+	{
+		static Driver *s_driver[3] = { NULL, NULL, NULL };
+		return &s_driver[type];
+	}
+
+	static const char *GetDriverTypeName(Driver::Type type)
+	{
+		static const char *driver_type_name[] = { "sound", "music", "video" };
+		return driver_type_name[type];
+	}
+
+protected:
+	/**
+	 * Register a driver internally, based on its name.
+	 * @param name the name of the driver.
+	 * @note an assert() will be trigger if 2 driver with the same name try to register.
+	 */
+	void RegisterDriver(const char *name, Driver::Type type)
+	{
+		/* Don't register nameless Drivers */
+		if (name == NULL) return;
+
+		this->name = strdup(name);
+		this->type = type;
+
+		/* Prefix the name with driver type to make it unique */
+		char buf[32];
+		strecpy(buf, GetDriverTypeName(type), lastof(buf));
+		strecpy(buf + 5, name, lastof(buf));
+
+		std::pair<Drivers::iterator, bool> P = GetDrivers().insert(Drivers::value_type(buf, this));
+		assert(P.second);
+	}
+
+public:
+	DriverFactoryBase() :
+		name(NULL)
+	{}
+
+	virtual ~DriverFactoryBase() { if (this->name != NULL) GetDrivers().erase(this->name); free(this->name); }
+
+	/**
+	 * Find the requested driver and return its class.
+	 * @param name the driver to select.
+	 * @post Sets the driver so GetCurrentDriver() returns it too.
+	 */
+	static Driver *SelectDriver(const char *name, Driver::Type type)
+	{
+		if (GetDrivers().size() == 0) return NULL;
+
+		if (*name == '\0') {
+			/* Probe for this driver */
+			Drivers::iterator it = GetDrivers().begin();
+			for (; it != GetDrivers().end(); ++it) {
+				DriverFactoryBase *d = (*it).second;
+
+				/* Check driver type */
+				if (d->type != type) continue;
+
+				Driver *newd = d->CreateInstance();
+				if (!newd->CanProbe()) {
+					DEBUG(driver, 1, "Skipping probe of driver '%s'", d->name);
+				} else {
+					const char *err = newd->Start(NULL);
+					if (err == NULL) {
+						DEBUG(driver, 1, "Successfully probed %s driver '%s'", GetDriverTypeName(type), d->name);
+						delete *GetActiveDriver(type);
+						*GetActiveDriver(type) = newd;
+						return newd;
+					}
+
+					DEBUG(driver, 1, "Probing %s driver '%s' failed with error: %s", GetDriverTypeName(type), d->name, err);
+				}
+
+				delete newd;
+			}
+			error("Couldn't find any suitable %s driver", GetDriverTypeName(type));
+		} else {
+			char *parm;
+			char buffer[256];
+			const char *parms[32];
+
+			/* Extract the driver name and put parameter list in parm */
+			strecpy(buffer, name, lastof(buffer));
+			parm = strchr(buffer, ':');
+			parms[0] = NULL;
+			if (parm != NULL) {
+				uint np = 0;
+				/* Tokenize the parm. */
+				do {
+					*parm++ = '\0';
+					if (np < lengthof(parms) - 1)
+						parms[np++] = parm;
+					while (*parm != '\0' && *parm != ',')
+						parm++;
+				} while (*parm == ',');
+				parms[np] = NULL;
+			}
+
+			/* Find this driver */
+			Drivers::iterator it = GetDrivers().begin();
+			for (; it != GetDrivers().end(); ++it) {
+				DriverFactoryBase *d = (*it).second;
+
+				/* Check driver type */
+				if (d->type != type) continue;
+
+				/* Check driver name */
+				if (strcasecmp(buffer, d->name) != 0) continue;
+
+				/* Found our driver, let's try it */
+				Driver *newd = d->CreateInstance();
+
+				const char *err = newd->Start(parms);
+				if (err != NULL) {
+					delete newd;
+					error("Unable to load driver '%s'. The error was: %s", d->name, err);
+				}
+
+				DEBUG(driver, 1, "Successfully loaded %s driver '%s'", GetDriverTypeName(type), d->name);
+				delete *GetActiveDriver(type);
+				*GetActiveDriver(type) = newd;
+				return newd;
+			}
+			error("No such %s driver: %s\n", GetDriverTypeName(type), buffer);
+		}
+	}
+
+	/**
+	 * Build a human readable list of available drivers, grouped by type.
+	 */
+	static char *GetDriversInfo(char *p, const char *last)
+	{
+		for (Driver::Type type = Driver::DT_BEGIN; type != Driver::DT_END; type++) {
+			p += snprintf(p, last - p, "List of %s drivers:\n", GetDriverTypeName(type));
+
+			Drivers::iterator it = GetDrivers().begin();
+			for (; it != GetDrivers().end(); it++) {
+				DriverFactoryBase *d = (*it).second;
+				if (d->type == type) p += snprintf(p, last - p, "%18s: %s\n", d->name, d->GetDescription());
+			}
+
+			p += snprintf(p, last - p, "\n");
+		}
+
+		return p;
+	}
+
+	/**
+	 * Get a nice description of the driver-class.
+	 */
+	virtual const char *GetDescription() = 0;
+
+	/**
+	 * Create an instance of this driver-class.
+	 */
+	virtual Driver *CreateInstance() = 0;
+};
 
 #endif /* DRIVER_H */