support for music streaming

client/SDLRWwrapper.cpp

@@ -0,0 +1,85 @@
+#include "StdInc.h"
+#include "SDLRWwrapper.h"
+#include "../lib/filesystem/CInputStream.h"
+#include <SDL_rwops.h>
+
+static inline CInputStream* get_stream(SDL_RWops* context)
+{
+	return static_cast<CInputStream*>(context->hidden.unknown.data1);
+}
+
+static Sint64 impl_size(SDL_RWops* context)
+{
+    return get_stream(context)->getSize();
+}
+
+static Sint64 impl_seek(SDL_RWops* context, Sint64 offset, int whence)
+{
+	auto stream = get_stream(context);
+	switch (whence)
+	{
+	case RW_SEEK_SET:
+		return stream->seek(offset);
+		break;
+	case RW_SEEK_CUR:
+		return stream->seek(stream->tell() + offset);
+		break;
+	case RW_SEEK_END:
+		return stream->seek(stream->getSize() + offset);
+		break;
+	default:
+		return -1;
+	}
+
+}
+
+static std::size_t impl_read(SDL_RWops* context, void *ptr, size_t size, size_t maxnum)
+{
+    auto stream = get_stream(context);
+    auto oldpos = stream->tell();
+
+    auto count = stream->read(static_cast<ui8*>(ptr), size*maxnum);
+
+	if (count != 0 && count != size*maxnum)
+	{
+		// if not a whole amount of objects of size has been read, we need to seek
+		stream->seek(oldpos + size * (count / size));
+	}
+
+    return count / size;
+}
+
+static std::size_t impl_write(SDL_RWops* context, const void *ptr, size_t size, size_t num)
+{
+	// writing is not supported
+    return 0;
+}
+
+static int impl_close(SDL_RWops* context)
+{
+	if (context == nullptr)
+		return 0;
+
+    delete get_stream(context);
+    SDL_FreeRW(context);
+    return 0;
+}
+
+
+SDL_RWops* MakeSDLRWops(std::unique_ptr<CInputStream> in)
+{
+	SDL_RWops* result = SDL_AllocRW();
+	if (!result)
+		return nullptr;
+
+	result->size  = &impl_size;
+	result->seek  = &impl_seek;
+	result->read  = &impl_read;
+	result->write = &impl_write;
+	result->close = &impl_close;
+
+	result->type = SDL_RWOPS_UNKNOWN;
+	result->hidden.unknown.data1 = in.release();
+
+	return result;
+}