/* TECO for DOS  Copyright (C) 1986-1991 Matt Fichtenbaum					*/
/* Based on Ultrix TECO (C) 1986-1990 GenRad Inc., Concord, MA 01742		*/
/* These programs may be copied if this copyright notice is included and	*/
/* only on a "not for sale or profit" basis									*/

/* te_mouse.c: mouse-driver interface routines */
/* 02/05/91  21.15 */
/* mod for horizontal split screen  08/28/91  20.21 */

/* mouse driver */
/* implements nFM command, as follows */
/*  n,1FM: set mouse mode: 0: off, >0: on, bit 0: displayed, */
/*		   bit 1: mouse active during command execution */
/*  2FM:   character position of mouse */
/*  3FM:   buffer in which mouse is */
/*  4FM:   absolute screen y coordinate */
/*  5FM:   absolute screen x coordinate */
/*  Q`X:   left mouse button macro */
/*  Q'Y:   right mouse buttom macro */
/*  all but 1FM are read-only */

#include<dos.h>
#include "te_defs.h"

#define Mousepointer_and mousepointer[0]
#define Mousepointer_xor mousepointer[1]

long fm_vals[5] = { 0, 0, 0, 0, 0 };			/* mouse control parameters */
unsigned char mousepointer[2] = { 0x0, 0xc0 };
extern unsigned char mousepointer[];
void do_mouse(void);
long setup_mouse(long);
void clear_mouse(void);
void set_mouse_range(void);
void display_mouse(unsigned short mouse_disp_func);
static unsigned short install_mouse_ptr(unsigned short pointer_on);
long xy_to_dot(long x, long y, long *p);
void _far _loadds mouse_handler();

void do_mouse()
{
	if (!(ez_val & EZ_MOUSE)) ERROR(E_IFC);					/* bit must be set in EZ */
	if (!esp->flag1 || esp->val1 < 1 || esp->val1 > 5 ||
		(esp->flag2 && esp->val1 > 1)) ERROR(E_IMO);		/* invalid mouse function */
	if (esp->flag2)					/* enable/disable/hide mouse */
	{
		esp->val1 = setup_mouse(esp->val2);	/* call routine to do work */
		if (!esp->val1 && !colonflag)  ERROR(E_NOM);	/* error if no mouse support */
		esp->flag2 = 0;				/* consume write argument */
		esp->flag1 = colonflag;		/* return value only if asked */
		colonflag = 0;
	}
	else esp->val1 = fm_vals[esp->val1 - 1];	/* return value - esp->flag1 is already set */
	esp->op = OP_START;
}

long setup_mouse(long func)
{
	union REGS r;
	struct SREGS s;
	long retval = -1L;
	void (_far _loadds *handler_p)() = mouse_handler;

	if (fm_ctrl < 0) return(0L);		/* no mouse support available */
	if ((func & MOUSE_IS_ENABLED) && !(fm_ctrl & MOUSE_IS_ENABLED))		/* turn mouse on, was off */
	{
		if (reset_mouse() == 0)
		{
			fm_ctrl = -1;				/* mark no support available */
			retval = 0;					/* return failure */
		}

		set_mouse_range();					/* set maximum x, y */

		r.x.ax = 0x0c;						/* install our event handler */
		r.x.cx = 0x1f;						/* motion or either button pressed */
		r.x.dx = FP_OFF(handler_p);
		s.es = FP_SEG(handler_p);
		int86x(0x33, &r, &r, &s);
		r.x.ax = 0x04;						/* set present position */
		r.x.cx = fm_x;
		r.x.dx = fm_y;
		int86(0x33, &r, &r);

		display_mouse((func & MOUSE_IS_INVISIBLE) ? MOUSE_HIDE : MOUSE_SHOW);
	}
	else if (!(func & MOUSE_IS_ENABLED) && (fm_ctrl & MOUSE_IS_ENABLED))	/* turn mouse off, was on */
	{
		(void) reset_mouse;
		display_mouse(MOUSE_HIDE);				/* remove from display */
		func = 0;								/* clear all of fm_ctrl */
	}
	else if (func < 0) ERROR(E_IMO);			/* can't write it negative */
	fm_ctrl = func;								/* save last op */
	display_mouse( ((func & 3) == 1) ? MOUSE_SHOW : MOUSE_HIDE);	/* show if on and visible; hide otherwise */
	return(retval);
}


/* routine to reset mouse driver (inactivate our event routine) */
/* returns mouse status code */
short reset_mouse()
{
	union REGS r;

	r.x.ax = 0;							/* reset mouse */
	int86(0x33, &r, &r);
	return(r.x.ax);
}

/* routine to set range of mouse position */
void set_mouse_range()
{
	union REGS r;

	r.x.ax = 0x07;						/* set minimum, maximum x */
	r.x.cx = 0;
	r.x.dx = (term_cols - 1) << 3;
	int86(0x33, &r, &r);

	r.x.ax = 0x08;						/* set minimum, maximum y */
	r.x.cx = 0;
	r.x.dx = (term_rows - WN_scroll - 1) << 3;
	int86(0x33, &r, &r);
}


/* routine to clear mouse (called when EZ mouse bit set to 0) */

void clear_mouse(void)
{
	if (fm_ctrl > 0)
	{
		display_mouse(MOUSE_HIDE);
		reset_mouse();
		fm_ctrl = 0;
	}
}


/* routine to control display of mouse pointer */
/* call with argument: */
/*  MOUSE_HIDE: disable display, MOUSE_SHOW: enable display, */
/*  MOUSE_RDCMD: begin command read-in (show mouse), */
/*  MOUSE_NORDCMD: end command read-in (hide mouse unless MOUSE_WHILE_EXEC set */

static unsigned short mouse_disp_sw = 0;		/* bit 0: off/on,  bit 1: suspend/resume */

void display_mouse(unsigned short mouse_disp_func)
{
	unsigned short temp_sw = mouse_disp_sw;

	switch (mouse_disp_func)
	{
		case MOUSE_HIDE:	temp_sw &= ~1;										break;	/* off */
		case MOUSE_SHOW:	temp_sw |= ((fm_ctrl & MOUSE_WHILE_EXEC) ? 3 : 1);	break;	/* on */
		case MOUSE_RDCMD:	temp_sw |= 2;										break;	/* resume */
		case MOUSE_NORDCMD: if (!(fm_ctrl & MOUSE_WHILE_EXEC)) temp_sw &= ~2; 	break;	/* suspend */
		case MOUSE_SUSPEND:	temp_sw |= 4;										break;	/* suspend for screen update */
		case MOUSE_RESUME:	temp_sw &= ~4;										break;
	}
	if (temp_sw == 3 && mouse_disp_sw != 3) install_mouse_ptr(1);		/* new */
	else if (temp_sw != 3 && mouse_disp_sw == 3) install_mouse_ptr(0);	/* remove */
	mouse_disp_sw = temp_sw;
}
/* routine to install or remove mouse pointer */
/* always remove, then install if arg nonzero */
/* returns previous state of pointer */

static unsigned char saved_attributes = 0;
static unsigned char _far *saved_loc = 0;
static unsigned short saved_state = 0;

static unsigned short install_mouse_ptr(unsigned short pointer_on)
{
	unsigned short temp_state = saved_state;	/* return previous state */

#pragma check_pointer(off)
	saved_state = pointer_on;			/* save new pointer state */
	if (saved_loc != 0)					/* remove existing pointer */
	{
		*saved_loc = saved_attributes;
		saved_loc = 0;
	}
	if (pointer_on)
	{
		saved_loc = ((unsigned char _far *) video_buffer) + 1 + 2 * (term_cols * fm_y + fm_x);
		saved_attributes = *saved_loc;
		*saved_loc = (saved_attributes & Mousepointer_and) ^ Mousepointer_xor;
	}
	return(temp_state);
#pragma check_pointer ()
}
/* mouse event processor */
/* this routine is called by the keyboard processing routine when a mouse event occurs */
/* it returns the mouse char if a button pressed, else 0 */

#define MOUSE_KEYL 1
#define MOUSE_KEYR 2
#define MOUSE_KEYM 4

static unsigned short last_mouse_event = 0;
static unsigned short last_fm_x, last_fm_y;

unsigned short do_mouse_event()
{
	unsigned short return_val = 0;
	union REGS r;

	r.x.ax = 0x03;						/* what happened? */
	int86(0x33, &r, &r);
	fm_y = r.x.dx >> 3;					/* update coordinates */
	fm_x = r.x.cx >> 3;
	if (mouse_disp_sw == 3 && (fm_x != last_fm_x || fm_y != last_fm_y))
		install_mouse_ptr(1);			/* if motion & display, update pointer */
	last_fm_x = fm_x;
	last_fm_y = fm_y;

	if (r.x.bx & (MOUSE_KEYL | MOUSE_KEYR) & ~last_mouse_event)	/* if mouse button pushed */
	{
		if ((fm_dot = xy_to_dot(fm_x, fm_y, &fm_buff)) != -2)		/* get a pointer from screen position */
		{
			if (r.x.bx & MOUSE_KEYL & ~last_mouse_event) return_val = KEY_MOUSEL;
			else if (r.x.bx & MOUSE_KEYR & ~last_mouse_event) return_val = KEY_MOUSER;
		}
	}
	last_mouse_event = r.x.bx;			/* save this event */
	return(return_val);
}


/* mouse event handler */
/* called by mouse driver when button pushed or mouse moves */

unsigned short mouse_event_flag = 0;

#pragma check_stack(off)
void _far _loadds mouse_handler()
{
	if (mouse_disp_sw == 3) mouse_event_flag = 1;
}
#pragma check_stack()