Text Capture & Unicode

Authoring Inform 7
1 
Include Text Capture by Eric Eve.

There is a room.


When play begins:
	start capturing text;
	say "[unicode 301]";
	stop capturing text;
	say "[captured text]";
	say "[unicode 301]";

Text Capture (by Eric Eve) doesn’t handle unicode, consequently i’m trying to adapt it, but unfortunately, i don’t have a clear idea of what I’m doing. I know that I should use glk_stream_open_memory_uni rather than glk_stream_open_memory, but I don’t really understand the mystical aspect of some opcodes (@push, @pull, @copy) nor have a good grasp at how arrays (bytes, words, multiplications and additions) work.

So here is a pale attempt (vaguely copied from Casting in IndexedText.i6t.

Include (-

#ifndef IT_MemoryBufferSize;
Constant IT_MemoryBufferSize = 512;
#endif;

Constant IT_Memory_NoBuffers = 2;

#ifndef IT_Memory_NoBuffers;
Constant IT_Memory_NoBuffers = 1;
#endif;

#ifdef TARGET_ZCODE;
Array IT_MemoryBuffer -> IT_MemoryBufferSize*IT_Memory_NoBuffers; ! Where characters are bytes
#ifnot;
Array IT_MemoryBuffer --> (IT_MemoryBufferSize+2)*IT_Memory_NoBuffers; ! Where characters are words
#endif;

Global RawBufferAddress = IT_MemoryBuffer;
Global RawBufferSize = IT_MemoryBufferSize;

Global old_stream = 0;

[ StartCapture i  buffx buff str;   
	if (capture_active > 0) return;
	old_stream = glk_stream_get_current();
	
	buffx = (IT_MemoryBufferSize + 2)*WORDSIZE;
	buff = RawBufferAddress;
	
	str = glk_stream_open_memory_uni(buff, RawBufferSize, filemode_Write, 0);
	glk_stream_set_current(str);
	
	capture_active = 1;
];

[ EndCapture  results buffx buff;
	buffx = (IT_MemoryBufferSize + 2)*WORDSIZE;
	buff = RawBufferAddress;
	
	if (capture_active == 0) return;
	print (char) 255; !add end of string marker
	results = buff + buffx - 2*WORDSIZE;
	glk_stream_close(glk_stream_get_current(), results);
	set_cur_stream(old_stream);      
	capture_active = 0;
];

-).

Include (-

[ PrintCapture i j ch;
	j = captured_text-->0;
	for (i=WORDSIZE:i<(j+WORDSIZE):i++){
		ch = captured_text->i;
		if(ch== 0 or 255) break;
		else if(ch ~= 10 || i>WORDSIZE) {
			if (unicode_gestalt_ok) glk_put_char_uni(ch);
		}
	}
];

-).

I would highly appreciate any sort of help. Thanks