(svn r10190) -Codechange: merged renderer and blitter to one single class API: blitter

-Codechange: introduced a hierachy of blitters to avoid a lot of code duplication
 Note: this allows much easier adding other types of video-drivers, like OpenGL

src/blitter/factory.hpp

@@ -0,0 +1,121 @@
+/* $Id$ */
+
+#ifndef BLITTER_FACTORY_HPP
+#define BLITTER_FACTORY_HPP
+
+#include "base.hpp"
+#include <string>
+#include <map>
+
+/**
+ * The base factory, keeping track of all blitters.
+ */
+class BlitterFactoryBase {
+private:
+	char *name;
+	typedef std::map<std::string, BlitterFactoryBase *> Blitters;
+
+	static Blitters &GetBlitters()
+	{
+		static Blitters &s_blitters = *new Blitters();
+		return s_blitters;
+	}
+
+	static Blitter **GetActiveBlitter()
+	{
+		static Blitter *s_blitter = NULL;
+		return &s_blitter;
+	}
+
+protected:
+	/**
+	 * Register a blitter internally, based on his name.
+	 * @param name the name of the blitter.
+	 * @note an assert() will be trigger if 2 blitters with the same name try to register.
+	 */
+	void RegisterBlitter(const char *name)
+	{
+		/* Don't register nameless Blitters */
+		if (name == NULL) return;
+
+		this->name = strdup(name);
+		std::pair<Blitters::iterator, bool> P = GetBlitters().insert(Blitters::value_type(name, this));
+		assert(P.second);
+	}
+
+public:
+	BlitterFactoryBase() :
+		name(NULL)
+	{}
+
+	virtual ~BlitterFactoryBase() { if (this->name != NULL) GetBlitters().erase(this->name); free(this->name); }
+
+	/**
+	 * Find the requested blitter and return his class.
+	 * @param name the blitter to select.
+	 * @post Sets the blitter so GetCurrentBlitter() returns it too.
+	 */
+	static Blitter *SelectBlitter(const char *name)
+	{
+		if (GetBlitters().size() == 0) return NULL;
+
+		Blitters::iterator it = GetBlitters().begin();
+		for (; it != GetBlitters().end(); it++) {
+			BlitterFactoryBase *b = (*it).second;
+			if (strcasecmp(name, b->name) == 0) {
+				Blitter *newb = b->CreateInstance();
+				*GetActiveBlitter() = newb;
+				return newb;
+			}
+		}
+		return NULL;
+	}
+
+	/**
+	 * Get the current active blitter (always set by calling SelectBlitter).
+	 */
+	static Blitter *GetCurrentBlitter()
+	{
+		return *GetActiveBlitter();
+	}
+
+
+	static char *GetBlittersInfo(char *p, const char *last)
+	{
+		p += snprintf(p, last - p, "List of blitters:\n");
+		Blitters::iterator it = GetBlitters().begin();
+		for (; it != GetBlitters().end(); it++) {
+			BlitterFactoryBase *b = (*it).second;
+			p += snprintf(p, last - p, "%18s: %s\n", b->name, b->GetDescription());
+		}
+		p += snprintf(p, last - p, "\n");
+
+		return p;
+	}
+
+	/**
+	 * Get a nice description of the blitter-class.
+	 */
+	virtual const char *GetDescription() = 0;
+
+	/**
+	 * Create an instance of this Blitter-class.
+	 */
+	virtual Blitter *CreateInstance() = 0;
+};
+
+/**
+ * A template factory, so ->GetName() works correctly. This because else some compiler will complain.
+ */
+template <class T>
+class BlitterFactory: public BlitterFactoryBase {
+public:
+	BlitterFactory() { this->RegisterBlitter(((T *)this)->GetName()); }
+
+	/**
+	 * Get the long, human readable, name for the Blitter-class.
+	 */
+	const char *GetName();
+};
+
+#endif /* BLITTER_FACTORY_HPP */