#include <stdio.h>

#define	VERTICAL		480		
#define	HORIZONTAL		640		

#define	ARC_RES			64		

#define	SET_PIXEL		0x0F	
#define	CLEAR_PIXEL		0x00	
#define	FLIP_PIXEL		0x8F	

#define	MOUSE_LEFT		0x01	
#define	MOUSE_RIGHT		0x02	
#define	MOUSE_CENTER	0x04	

#define	LINE			0x01	
#define	BOX				0x02	
#define	CIRCLE			0x03	
#define	TEXT			0x04	
#define	ARC				0x05	
#define	GROUP			0x06	
#define	ACOPY			0x07	
#define	RCOPY			0x08	

unsigned char drawing[32000];	
unsigned dtop = 0, dpos;		


#define	PBYTES	11				
int grid = 0,					
	snap = 0,					
	tscale = 100,				
	xbase = 0,					
	ybase = 0;					
char tick = 1;					

char pixel = SET_PIXEL,			
	cursor_flag = 0,			
	edit = -1,					
	font[4608],					
	dfile[65],					
	ffile[65],					
	ifile[65],					
	vmode;						

unsigned mousex = -1, mousey = -1;	


unsigned sine[] = {
	    0,  1608,  3216,  4821,  6424,  8022,  9616, 11204,
	12785, 14359, 15924, 17479, 19024, 20557, 22078, 23586,
	25079, 26557, 28020, 29465, 30893, 32302, 33692, 35062,
	36410, 37736, 39040, 40320, 41575, 42806, 44011, 45190,
	46341, 47464, 48559, 49624, 50660, 51665, 52639, 53581,
	54491, 55368, 56212, 57022, 57797, 58538, 59243, 59913,
	60547, 61144, 61705, 62228, 62714, 63162, 63571, 63943,
	64276, 64571, 64826, 65043, 65220, 65358, 65457, 65516 };

extern FILE *get_file();	

main(argc, argv)
	int argc;
	char *argv[];
{
	int i, j, select;
	char *ptr;
	FILE *fp;

	concat(dfile, "MICROCAD.DWG");
	concat(ffile, "MICROCAD.FNT");
	*ifile = 0;

	for(i=1; i < argc; ++i) {
		ptr = argv[i];
		switch((toupper(*ptr++) << 8) | toupper(*ptr++)) {
			case 'F=' :		
				concat(ffile, ptr, ".FNT");
				break;
			case '/D' :		
			case '-D' :
				edit = 0;
				break;
			case '?' << 8:	
			case '/?' :
			case '-?' :
				abort("\nUse: MICROCAD [drawing file] [F=font file] [/Display]\n\nCopyright 1992-1993 Dave Dunfield\nAll rights reserved.\n");
			default:		/* Assume drawing filename */
				concat(dfile, argv[i], ".DWG"); } }


	fp = fopen(ffile, "qrbv");
	fread(font, sizeof(font), 1,fp);
	fclose(fp);

	if(fp = fopen(dfile, "rbv")) {
		fread(&grid, PBYTES,1, fp);
		dtop = fread(drawing, sizeof(drawing),1, fp);
		fclose(fp); }

	zero_drawing(dtop);

	if(!init_video())
		abort("VGA required!");

	if(!edit) {
		grid = 0;
		tick = 1;
		redraw();
		get_key();
		video_mode(vmode);
		return; }

	if(!init_mouse())
		abort("MOUSE required!");

	redraw();

	if(!fp) {
		message();
		printf("New drawing: '%s'", dfile); }

	for(;;) {
		if((i=mouse_status()) & MOUSE_LEFT) {	
			message();
			printf("A)rc B)ox C)ircle D)up E)rase F)unc L)ine M)ove R)edraw S)etup T)ext U)ndo");
			select = get_key(); }
		else if(j = test_key())
			select = j;
		else if(!(i & MOUSE_RIGHT))				
			continue;
		switch(toupper(select)) {
			case 'A' :		
				draw_arc();
				break;
			case 'B' :		
				draw_box();
				break;
			case 'C' :		
				draw_circle();
				break;
			case 'D' :		
				copy();
				break;
			case 'E' :		
				erase();
				break;
			case 'F' :		
				function();
				break;
			case 'L' :		
				draw_line();
				break;
			case 'M' :		
				move();
				break;
			case 'R' :		
				redraw();
				break;
			case 'T' :		
				draw_text();
				break;
			case 'U' :		
				undo();
				break;
			case 'S' :		
				message();
				printf("B)ase-markers C)ursor-base G)rid S)nap T)ext-scale");
				switch(toupper(get_key())) {
					case 'B' :		
						tick = tick ? 0 : 1;
						redraw();
						continue;
					case 'C' :		
						i = xbase;
						j = ybase;
						xbase = ybase = 0;
						if(!wait_for_left("Select cursor base point")) {
							xbase = mousex;
							ybase = mousey;
							goto exit; }
						xbase = i;
						ybase = j;
						continue;
					case 'G' :		
						grid = get_value("Grid spacing (0 to remove)?");
						redraw();
						continue;
					case 'S' :		
						snap = get_value("Snap spacing (0 to remove)?");
						goto exit;
					case 'T' :		
						tscale = get_value("Text scale (100 = 1:1)?");
					exit:
						message();
						continue; }
			default:
				message(); 
				printf("Unknown command!"); } }
}


function()
{
	FILE *fp;
	
	message();
	printf("F)ont I)nsert L)oad Q)uit S)ave");
	switch(toupper(get_key())) {
		case 'I' :		
			insert();
			return;
		case 'F' :		
			if(fp = get_file("font", ffile, ".FNT", "rbv")) {
				fread(font, sizeof(font), 1,fp);
				fclose(fp);
				redraw(); }
			return;
		case 'L' :		
			if(fp = get_file("drawing", dfile, ".DWG", "rbv")) {
				fread(&grid, PBYTES,1, fp);
				zero_drawing(fread(drawing, sizeof(drawing),1, fp));
				fclose(fp);
				redraw(); }
			return;
		case 'S' :		
			if(fp = get_file("drawing", dfile, ".DWG", "wbv")) {
				fwrite(&grid, PBYTES, 1,fp);
				if(dtop)
					fwrite(drawing, dtop,1, fp);
				fclose(fp);
				message(); }
			return;
		case 'Q' :		
			video_mode(vmode);
			exit(0); }

		message();
		printf("Unknown command!");
}


insert()
{
	unsigned i, dsave, base, size, minx, miny, x, y;
	char buffer[PBYTES];
	FILE *fp;

	if(!(fp = get_file("drawing", ifile, ".DWG", "rbv")))
		return;

	dsave = dtop;
	drawing[dtop++] = GROUP;
	draw(0);	
	draw(0);	
	draw(0);	

	fread(buffer, PBYTES,1, fp);
	size = fread(&drawing[base = dpos = dtop], sizeof(drawing) - dtop,1, fp);
	fclose(fp);

	minx = miny = 32767;
	while(drawing[dpos]) {
		i = dpos++;
		minx = min(x = dvalue(), minx);
		miny = min(y = dvalue(), miny);
		dpos = i;
		skip_object(); }
	
	dpos = base;
	while(x = drawing[i = dpos]) {
		dtop = ++dpos;
		draw(dvalue() - minx);
		draw(dvalue() - miny);
		
		if(x == ACOPY) {
			drawing[i] = RCOPY;
			draw((dvalue()+base) - i); }
		dpos = i;
		skip_object(); }

	dtop = dsave + 1;
	draw(0);
	draw(0);
	draw(size);

	message();
	printf("INSERT: Selection insertion point");
	pixel = FLIP_PIXEL;
newbox:
	dpos = dsave;
	draw_object(x = mousex, y=mousey);
	while(!((i = mouse_status()) & MOUSE_LEFT)) {
		if(i & MOUSE_RIGHT) {
			dpos = dsave;
			draw_object(x, y);
			zero_drawing(dsave);
			message();
			return; }
		if((x != mousex) || (y != mousey)) {
			dpos = dsave;
			draw_object(x, y);
			goto newbox; } }

	dpos = dsave;
	pixel = SET_PIXEL;
	dtop = dsave + 1;
	draw(x);
	draw(y);
	dtop = base + size;
	redraw();
}


draw_line()
{
	int x, y, x1, y1, s;
	if(wait_for_left("LINE: From point?"))
		return;
	gotoxy(30, 0); printf(" To point?");
	x = mousex;
	y = mousey;
again:
	pixel = FLIP_PIXEL;
newline:
	line(x, y, x1 = mousex, y1 = mousey);
	while(!((s = mouse_status()) & MOUSE_LEFT)) {
		if(s & MOUSE_RIGHT) {
			line(x, y, x1, y1);
			pixel = SET_PIXEL;
			message();
			return; }
		if((mousex != x1) || (mousey != y1)) {
			line(x, y, x1, y1);
			goto newline; } }
	pixel = SET_PIXEL;
	drawing[dpos = dtop++] = LINE;
	draw(x);
	draw(y);
	draw(x1 - x);
	draw(y1 - y);
	draw_object(0, 0);
	x = x1;
	y = y1;
	goto again;
}


draw_box()
{
	int x, y, x1, y1, s;
	if(wait_for_left("BOX: First corner?"))
		return;
	gotoxy(30, 0); printf(" Second corner?");
	x = mousex;
	y = mousey;
	pixel = FLIP_PIXEL;
newbox:
	box(x, y, x1 = mousex, y1 = mousey);
	while(!((s = mouse_status()) & MOUSE_LEFT)) {
		if(s & MOUSE_RIGHT) {
			box(x, y, x1, y1);
			message();
			return; }
		if((mousex != x1) || (mousey != y1)) {
			box(x, y, x1, y1);
			goto newbox; } }
	pixel = SET_PIXEL;
	message();
	drawing[dpos = dtop++] = BOX;
	draw(x);
	draw(y);
	draw(x1 - x);
	draw(y1 - y);
	draw_object(0, 0);
}

draw_circle()
{
	int x, y, r, r1, a, b, s;
	if(wait_for_left("CIRCLE: Select center point"))
		return;
	x = mousex;
	y = mousey;
	pixel = FLIP_PIXEL;
	r = 1;
newcircle:
	circle(x, y, r);
	while(!((s = mouse_status()) & MOUSE_LEFT)) {
		if(s & MOUSE_RIGHT) {
			circle(x, y, r);
			message();
			return; }
		a = abs(mousex - x);
		b = abs(mousey - y);
		if((r1 = sqrt((a*a) + (b*b))) != r) {
			gotoxy(40, 0); printf("Radius=%-3u", r1);
			circle(x, y, r);
			r = r1;
			goto newcircle; } }
	pixel = SET_PIXEL;
	message();
	drawing[dpos = dtop++] = CIRCLE;
	draw(x);
	draw(y);
	draw(r);
	draw_object(0, 0);
}


draw_arc()
{
	int x, y, r, v1, v2, x1, y1, s;

	if(wait_for_left("ARC: Select center point"))
		return;
	x = mousex;
	y = mousey;
	if(wait_for_left("ARC: Select starting point"))
		return;
	x1 = abs(mousex - x);
	y1 = abs(mousey - y);
	r = sqrt((x1*x1) + (y1*y1));
	v1 = find_vector(x, y, r, mousex, mousey);
	message();
	printf("ARC: Select ending point");
	pixel = FLIP_PIXEL;
newarc:
	v2 = find_vector(x, y, r, x1=mousex, y1=mousey);
	arc(x, y, r, v1, v2);
	while(!((s = mouse_status()) & MOUSE_LEFT)) {
		if(s & MOUSE_RIGHT) {
			arc(x, y, r, v1, v2);
			message();
			return; }
		if((mousex != x1) || (mousey != y1)) {
			arc(x, y, r, v1, v2);
			goto newarc; } }
	pixel = SET_PIXEL;
	message();
	drawing[dpos = dtop++] = ARC;
	draw(x);
	draw(y);
	draw(r);
	draw(v1);
	draw(v2);
	draw_object(0, 0);
}


draw_text()
{
	unsigned i, x, y;
	char buffer[80], *ptr;

	message();
	printf("String?");
	fgets(ptr = buffer, sizeof(buffer)-1, stdin);
	message();
	if(*buffer) {
		printf("TEXT: Select position");
		pixel = FLIP_PIXEL;
	newtext:
		text(buffer, x = mousex, y = mousey, tscale);
		while(!((i = mouse_status()) & MOUSE_LEFT)) {
			if(i & MOUSE_RIGHT) {					
				text(buffer, x, y, tscale);
				pixel = SET_PIXEL;
				message();
				return; }
			if((x != mousex) || (y != mousey)) {	
				text(buffer, x, y, tscale);
				goto newtext; } }

		pixel = SET_PIXEL;
		message();
		drawing[dpos = dtop++] = TEXT;
		draw(mousex);
		draw(mousey);
		draw(tscale);
		do
			drawing[dtop++] = *ptr;
		while(*ptr++);
		draw_object(0, 0); }
}


draw_cursor()
{
	char s;

	s = pixel;
	pixel = FLIP_PIXEL;
	line(max(0, mousex-3), mousey, min(HORIZONTAL-1,mousex+3), mousey);
	line(mousex, max(0,mousey-3), mousex, min(VERTICAL-1,mousey+3));
	pixel = s;
}


redraw()
{
	int x, y;

	video_mode(0x11);
	dpos = cursor_flag = 0;
	pixel = SET_PIXEL;
	while(!draw_object(0, 0));
	if(grid) {
		for(y = 0; y < VERTICAL; y += grid)
			for(x=0; x < HORIZONTAL; x += grid)
				set_pixel(x, y); }
}


undo()
{
	unsigned dlast;
	dpos = dlast = 0;
	while(drawing[dpos]) {
		dlast = dpos;
		if(skip_object())
			return; }
	dpos = dlast;
	pixel = CLEAR_PIXEL;
	draw_object(0, 0);
	pixel = SET_PIXEL;
	zero_drawing(dlast);
	message();
}


erase()
{
	unsigned e, d, i, x, y;

	if(select_object("ERASE")) {
		d = dtop;
		e = dpos;		
		while(i = drawing[dpos]) {
			if(i == ACOPY) {
				i = dpos++;
				x = dvalue();
				y = dvalue();
				if(dvalue() == e) {	
					dtop = e + 1;
					draw(x);
					draw(y);
					e = i; }
				dpos = i; }
			skip_object(); }

		dpos = e;
		skip_object();
		x = dpos - e;
		while(i = drawing[dpos]) {
			if(i == ACOPY) {
				i = dpos;
				dpos += 5;
				if((y = dvalue()) > e) {
					dtop = dpos - 2;
					draw(y - x); }
				dpos = i; }
			skip_object(); }

	/* Remove the selected entry */
		dpos = e;
		skip_object();
		while(dpos < d)
			drawing[e++] = drawing[dpos++];
		zero_drawing(e); }
}

move()
{
	unsigned psave, i, x, y, sx, sy;
	if(select_object("MOVE")) {
		psave = dpos;
		++dpos;
		sx = dvalue();
		sy = dvalue();
		message();
		printf("MOVE: Select new position");
		pixel = FLIP_PIXEL;
newmove:
		dpos = psave;
		draw_object((x = mousex) - sx, (y = mousey) - sy);
		while(!((i = mouse_status()) & MOUSE_LEFT)) {
			if(i & MOUSE_RIGHT) {					
				dpos = psave;
				draw_object(x - sx, y - sy);
				goto skipmove; }
			if((x != mousex) || (y != mousey)) {	
				dpos = psave;
				draw_object(x - sx, y - sy);