* Copyright (c) 1992, 1993

/* $NetBSD: screen.c,v 1.34 2021/05/02 12:50:46 rillig Exp $ */

/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek and Darren F. Provine.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)screen.c 8.1 (Berkeley) 5/31/93
*/

/*
* Tetris screen control.
*/

#include <sys/cdefs.h>
#include <sys/ioctl.h>

#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <term.h>
#include <termios.h>
#include <unistd.h>

#ifndef sigmask
#define sigmask(s) (1 << ((s) - 1))
#endif

#include "screen.h"
#include "tetris.h"

static cell curscreen[B_SIZE]; /* 1 => standout (or otherwise marked) */
static int curscore;
static int isset; /* true => terminal is in game mode */
static struct termios oldtt;
static void (*tstp)(int);

static void scr_stop(int);
static void stopset(int) __dead;

/*
* Routine used by tputs().
*/
int
put(int c)
{

return (putchar(c));
}

/*
* putstr() is for unpadded strings (either as in termcap(5) or
* simply literal strings); putpad() is for padded strings with
* count=1. (See screen.h for putpad().)
*/
#define putstr(s) (void)fputs(s, stdout)

static void
moveto(int r, int c)
{
char *buf;

buf = tiparm(cursor_address, r, c);
if (buf != NULL)
putpad(buf);
}

static void
setcolor(int c)
{
char *buf;
char monochrome[] = "\033[0m";
if (nocolor == 1)
return;
if (set_a_foreground == NULL)
return;

if (c == 0 || c == 7)
buf = monochrome;
else
buf = tiparm(set_a_foreground, c);
if (buf != NULL)
putpad(buf);
}

/*
* Set up from termcap.
*/
void
scr_init(void)
{

setupterm(NULL, 0, NULL);
if (clear_screen == NULL)
stop("cannot clear screen");
if (cursor_address == NULL || cursor_up == NULL)
stop("cannot do random cursor positioning");
}

/* this foolery is needed to modify tty state `atomically' */
static jmp_buf scr_onstop;

static void
stopset(int sig)
{
sigset_t set;

(void) signal(sig, SIG_DFL);
(void) kill(getpid(), sig);
sigemptyset(&set);
sigaddset(&set, sig);
(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
longjmp(scr_onstop, 1);
}

static void
scr_stop(int sig)
{
sigset_t set;

scr_end();
(void) kill(getpid(), sig);
sigemptyset(&set);
sigaddset(&set, sig);
(void) sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0);
scr_set();
scr_msg(key_msg, 1);
}

/*
* Set up screen mode.
*/
void
scr_set(void)
{
struct winsize ws;
struct termios newtt;
sigset_t nsigset, osigset;
void (*ttou)(int);

sigemptyset(&nsigset);
sigaddset(&nsigset, SIGTSTP);
sigaddset(&nsigset, SIGTTOU);
(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
(void) signal(SIGTSTP, SIG_IGN);
if ((ttou = signal(SIGTTOU, stopset)) == SIG_IGN)
(void) signal(SIGTTOU, SIG_IGN);
/*
* At last, we are ready to modify the tty state. If
* we stop while at it, stopset() above will longjmp back
* to the setjmp here and we will start over.
*/
(void) setjmp(scr_onstop);
(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
Rows = 0, Cols = 0;
if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
Rows = ws.ws_row;
Cols = ws.ws_col;
}
if (Rows == 0)
Rows = lines;
if (Cols == 0)
Cols = columns;
if (Rows < MINROWS || Cols < MINCOLS) {
(void) fprintf(stderr,
"the screen is too small: must be at least %dx%d, ",
MINCOLS, MINROWS);
stop(""); /* stop() supplies \n */
}
Offset = (Rows - D_LAST + D_FIRST - 2) / 2;
if (tcgetattr(0, &oldtt) < 0)
stop("tcgetattr() fails");
newtt = oldtt;
newtt.c_lflag &= ~(ICANON|ECHO);
newtt.c_oflag &= ~OXTABS;
if (tcsetattr(0, TCSADRAIN, &newtt) < 0)
stop("tcsetattr() fails");
ospeed = cfgetospeed(&newtt);
(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);

/*
* We made it. We are now in screen mode, modulo TIstr
* (which we will fix immediately).
*/
const char *tstr;
if ((tstr = enter_ca_mode) != NULL)
putstr(tstr);
if ((tstr = cursor_invisible) != NULL)
putstr(tstr);
if (tstp != SIG_IGN)
(void) signal(SIGTSTP, scr_stop);
if (ttou != SIG_IGN)
(void) signal(SIGTTOU, ttou);

isset = 1;
(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
scr_clear();
}

/*
* End screen mode.
*/
void
scr_end(void)
{
sigset_t nsigset, osigset;

sigemptyset(&nsigset);
sigaddset(&nsigset, SIGTSTP);
sigaddset(&nsigset, SIGTTOU);
(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);
/* move cursor to last line */
const char *tstr;
if ((tstr = cursor_to_ll) != NULL)
putstr(tstr);
else
moveto(Rows - 1, 0);
/* exit screen mode */
if ((tstr = exit_ca_mode) != NULL)
putstr(tstr);
if ((tstr = cursor_normal) != NULL)
putstr(tstr);
(void) fflush(stdout);
(void) tcsetattr(0, TCSADRAIN, &oldtt);
isset = 0;
/* restore signals */
(void) signal(SIGTSTP, tstp);
(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
}

void
stop(const char *why)
{

if (isset)
scr_end();
(void) fprintf(stderr, "aborting: %s\n", why);
exit(1);
}

/*
* Clear the screen, forgetting the current contents in the process.
*/
void
scr_clear(void)
{

putpad(clear_screen);
curscore = -1;
memset((char *)curscreen, 0, sizeof(curscreen));
}

#if vax && !__GNUC__
typedef int regcell; /* pcc is bad at `register char', etc */
#else
typedef cell regcell;
#endif

/*
* Update the screen.
*/
void
scr_update(void)
{
cell *bp, *sp;
regcell so, cur_so = 0;
int i, ccol, j;
sigset_t nsigset, osigset;
static const struct shape *lastshape;

sigemptyset(&nsigset);
sigaddset(&nsigset, SIGTSTP);
(void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);

/* always leave cursor after last displayed point */
curscreen[D_LAST * B_COLS - 1] = -1;

if (score != curscore) {
if (cursor_home)
putpad(cursor_home);
else
moveto(0, 0);
setcolor(0);
(void) printf("Score: %d", score);
curscore = score;
}

/* draw preview of nextpattern */
if (showpreview && (nextshape != lastshape)) {
static int r=5, c=2;
int tr, tc, t;

lastshape = nextshape;

/* clean */
putpad(exit_standout_mode);
moveto(r-1, c-1); putstr(" ");
moveto(r, c-1); putstr(" ");
moveto(r+1, c-1); putstr(" ");
moveto(r+2, c-1); putstr(" ");

moveto(r-3, c-2);
putstr("Next shape:");

/* draw */
setcolor(nextshape->color);
putpad(enter_standout_mode);
moveto(r, 2*c);
putstr(" ");
for(i=0; i<3; i++) {
t = c + r*B_COLS;
t += nextshape->off[i];

tr = t / B_COLS;
tc = t % B_COLS;

moveto(tr, 2*tc);
putstr(" ");
}
putpad(exit_standout_mode);
}

bp = &board[D_FIRST * B_COLS];
sp = &curscreen[D_FIRST * B_COLS];
for (j = D_FIRST; j < D_LAST; j++) {
ccol = -1;
for (i = 0; i < B_COLS; bp++, sp++, i++) {
if (*sp == (so = *bp))
continue;
*sp = so;
if (i != ccol) {
if (cur_so && move_standout_mode) {
putpad(exit_standout_mode);
cur_so = 0;
}
moveto(RTOD(j + Offset), CTOD(i));
}
if (enter_standout_mode) {
if (so != cur_so) {
setcolor(so);
putpad(so ?
enter_standout_mode :
exit_standout_mode);
cur_so = so;
}
#ifdef DEBUG
char buf[3];
snprintf(buf, sizeof(buf), "%d%d", so, so);
putstr(buf);
#else
putstr(" ");
#endif
} else
putstr(so ? "XX" : " ");
ccol = i + 1;
/*
* Look ahead a bit, to avoid extra motion if
* we will be redrawing the cell after the next.
* Motion probably takes four or more characters,
* so we save even if we rewrite two cells
* `unnecessarily'. Skip it all, though, if
* the next cell is a different color.
*/
#define STOP (B_COLS - 3)
if (i > STOP || sp[1] != bp[1] || so != bp[1])
continue;
if (sp[2] != bp[2])
sp[1] = -1;
else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
sp[2] = -1;
sp[1] = -1;
}
}
}
if (cur_so)
putpad(exit_standout_mode);
(void) fflush(stdout);
(void) sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
}

/*
* Write a message (set!=0), or clear the same message (set==0).
* (We need its length in case we have to overwrite with blanks.)
*/
void
scr_msg(char *s, int set)
{

if (set || clr_eol == NULL) {
int l = strlen(s);

moveto(Rows - 2, ((Cols - l) >> 1) - 1);
if (set)
putstr(s);
else
while (--l >= 0)
(void) putchar(' ');
} else {
moveto(Rows - 2, 0);
putpad(clr_eol);
}
}