/* med-buff.c: MED buffer handling routines, by Teijo Kinnunen 1990 */
#include <math.h> /* min(), abs() */
#include "med.h"

static UBYTE *buffer, bufftracks, bufflines;
static UBYTE markblock, marktrack, markline;
extern UWORD soittolohko,currtrk,soittorivi,lohkoja;
extern void __asm PaivitaNaytto(register __d0 BOOL);
extern struct Lohko *lohko[];

void FreeBuffer()
{
	if(!buffer) return;
	FreeMem((void *)buffer, bufftracks * bufflines * 3);
	bufftracks = bufflines = 0;
	buffer = NULL;
}

BOOL AllocBuffer(UBYTE tracks,UBYTE lines) /* FALSE = ok, TRUE = error */
{
	FreeBuffer(); /* free the previous buffer */
	if(!(buffer = AllocMem(tracks * lines * 3,MEMF_PUBLIC))) return(TRUE);
	bufftracks = tracks;
	bufflines = lines;
	return(FALSE);
}

void CutCopyPaste(UBYTE block,UBYTE startline,UBYTE lines,UBYTE starttrack,
	UBYTE tracks,UBYTE op) /* op: 0 = copy, 1 = cut, 2 = paste, 3 = swap */
{
	UBYTE ntrks = lohko[block]->numtracks; /* tracks in the block */
	UBYTE *p1 = &lohko[block]->music[startline * ntrks * 3 +
				starttrack * 3],*p2,linecnt,trkcnt,swb;
	UBYTE *linep1,*linep2;
	if(starttrack + tracks > ntrks) tracks = ntrks - starttrack;
	if(startline + lines > 64) lines = 64 - startline;
	if((op == 0 || op == 1) && AllocBuffer(tracks,lines)) { Ilmoita("No memory!!"); return; }
	else if(op >= 2) {
		if(lines > bufflines) lines = bufflines;
		if(tracks > bufftracks) tracks = bufftracks;
	}
	if(!(p2 = buffer)) { Ilmoita("The buffer is empty."); return; }
	for(linecnt = 0; linecnt < lines; linecnt++) {
		linep1 = p1; linep2 = p2;
		for(trkcnt = 0; trkcnt < tracks; trkcnt++) {
			if(op == 0 || op == 1) { /* cut/copy */
				*p2=*p1; *(p2+1)=*(p1+1); *(p2+2)=*(p1+2);
				if(op == 1) *p1 = *(p1+1) = *(p1+2) = 0;
			} else if(op == 2) { /* paste */
				*p1=*p2; *(p1+1)=*(p2+1); *(p1+2)=*(p2+2);
			} else if(op == 3) { /* swap */
				swb = *p1; *p1 = *p2; *p2 = swb;
				swb=*(p1+1); *(p1+1)=*(p2+1); *(p2+1)=swb;
				swb=*(p1+2); *(p1+2)=*(p2+2); *(p2+2)=swb;
			}
			p1 += 3; p2 += 3; /* advance pointers one note */
		}
		p1 = linep1 + 3 * ntrks; /* advance blockptr one line */
		p2 = linep2 + 3 * bufftracks; /* advance buffptr 1 line */
	}
}

void SetMark()
{
	markblock = (UBYTE)soittolohko;
	markline = (UBYTE)soittorivi;
	marktrack = (UBYTE)currtrk;
}

void HandleMark(UBYTE code)
{
	UBYTE block = soittolohko,line = soittorivi,track = currtrk;
	if(markblock != soittolohko && code != 0x34) {
		Ilmoita("Only one block at a time!!"); return;
	}
	if(code == 0x34) CutCopyPaste((UBYTE)block,(UBYTE)line,
		bufflines,(UBYTE)currtrk,bufftracks,2);
	else	CutCopyPaste((UBYTE)block,(UBYTE)min(markline,line),
		(UBYTE)(abs(markline-line)+1),(UBYTE)min(marktrack,track),
		(UBYTE)(abs(marktrack - track) + 1),
		(UBYTE)(code == 0x32 ? 1 : 0));
	PaivitaNaytto(TRUE);
}

void ExpandBlock(UWORD block)
{
	UBYTE linecnt,prevblk = (UBYTE)lohkoja,tracks;
	if(lohkoja >= 100) {
		Ilmoita("Too many blocks!!"); return;
	}
	tracks = lohko[block]->numtracks;
	NewBlockHere(block+1,tracks);
	if(lohkoja != prevblk+1 || lohko[block+1]->numtracks != tracks) {
		Ilmoita("Out of memory!!"); return; }
	for(linecnt = 0; linecnt < 64; linecnt++) {
		if(linecnt & 0x1) /* clear odd-numbered lines */
			memset(&lohko[block+1]->music[linecnt * 3 * tracks],
				0,3 * tracks);
		else	memcpy(&lohko[block+1]->music[linecnt * 3 * tracks],
				&lohko[block]->music[(32 + linecnt / 2) *
				3 * tracks], 3 * tracks);
	}
	for(linecnt = 63; linecnt; linecnt--) {
		if(linecnt & 0x1)
			memset(&lohko[block]->music[linecnt * 3 * tracks],
				0,3 * tracks);
		else	memcpy(&lohko[block]->music[linecnt * 3 * tracks],
			&lohko[block]->music[(linecnt / 2) * 3 * tracks],
			3 * tracks);
	}
	PaivitaNaytto(TRUE);
	TulostaLohkoJaSoitin();
}

void ShrinkBlock(UWORD block)
{
	UBYTE linecnt,tracks = lohko[block]->numtracks;
	if(!lohko[block+1]) { Ilmoita("There's no second block."); return; }
	if(tracks != lohko[block+1]->numtracks) {
		Ilmoita("Not the same number of tracks!!"); return; }
	for(linecnt = 0; linecnt < 64; linecnt++) {
		if(linecnt < 32)	memcpy(&lohko[block]->music[
			linecnt * 3 * tracks],&lohko[block]->music[
			linecnt * 6 * tracks],3 * tracks);
		else	memcpy(&lohko[block]->music[linecnt * 3 * tracks],
				&lohko[block+1]->music[(linecnt - 32) *
				6 * tracks], 3 * tracks);
	}
	PaivitaNaytto(TRUE);
	TulostaLohkoJaSoitin();
}