/* $Id: screen-display.c,v 1.2 2007-11-21 13:11:41 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <string.h>

#include "tmux.h"

/*
 * Screen display modification functions. These alter the displayed portion
 * of the screen.
 */

/* Create a region of lines. */
void
screen_display_make_lines(struct screen *s, u_int py, u_int ny)
{
	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
		fatalx("bad value");
	screen_make_lines(s, screen_y(s, py), ny);
}

/* Free a region of lines. */
void
screen_display_free_lines(struct screen *s, u_int py, u_int ny)
{
	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
		fatalx("bad value");
	screen_free_lines(s, screen_y(s, py), ny);
}

/* Move a set of lines. */
void
screen_display_move_lines(struct screen *s, u_int dy, u_int py, u_int ny)
{
	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
		fatalx("bad value");
	if (!screen_in_y(s, dy) || !screen_in_y(s, dy + ny - 1) || dy == py)
		fatalx("bad value");
	screen_move_lines(s, screen_y(s, dy), screen_y(s, py), ny);
}

/* Fill a set of lines. */
void
screen_display_fill_lines(
    struct screen *s, u_int py, u_int ny, u_char data, u_char attr, u_char colr)
{
	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
		fatalx("bad value");
	screen_fill_lines(s, screen_y(s, py), ny, data, attr, colr);
}

/* Fill a set of cellss. */
void
screen_display_fill_cells(struct screen *s,
    u_int px, u_int py, u_int nx, u_char data, u_char attr, u_char colr)
{
	if (nx == 0 || !screen_in_x(s, px) || !screen_in_y(s, py))
		fatalx("bad value");
	screen_fill_cells(
	    s, screen_x(s, px), screen_y(s, py), nx, data, attr, colr);
}

/* Fill entire screen. */
void
screen_display_fill_screen(
    struct screen *s, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_lines(s, 0, screen_size_y(s), data, attr, colr);
}

/* Fill end of screen from cursor. */
void
screen_display_fill_cursor_eos(
    struct screen *s, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_cursor_eol(s, data, attr, colr);
	if (s->cy != screen_last_y(s)) {
		screen_display_fill_lines(
		    s, s->cy, screen_size_y(s) - s->cy, data, attr, colr);
	}
}

/* Fill beginning of screen from cursor. */
void
screen_display_fill_cursor_bos(
    struct screen *s, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_lines(s, 0, s->cy, data, attr, colr);
}

/* Fill a single line. */
void
screen_display_fill_line(
    struct screen *s, u_int py, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_lines(s, py, 1, data, attr, colr);
}

/* Fill cursor to beginning of line. */
void
screen_display_fill_cursor_bol(
    struct screen *s, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_cells(s, 0, s->cy, s->cx, data, attr, colr);
}

/* Fill cursor to end of line. */
void
screen_display_fill_cursor_eol(
    struct screen *s, u_char data, u_char attr, u_char colr)
{
	screen_display_fill_cells(
	    s, s->cx, s->cy, screen_size_x(s) - s->cx, data, attr, colr);
}

/* Set character at cursor. */
void
screen_display_cursor_set(struct screen *s, u_char ch)
{
	u_int	px, py;

	px = screen_x(s, s->cx);
	py = screen_y(s, s->cy);

	s->grid_data[py][px] = ch;
	s->grid_attr[py][px] = s->attr;
	s->grid_colr[py][px] = s->colr;
}

/* Move cursor up and scroll if necessary. */
void
screen_display_cursor_up(struct screen *s)
{
	if (s->cy == s->rupper)
		screen_display_scroll_region_down(s);
	else if (s->cy > 0)
		s->cy--;
}

/* Move cursor down and scroll if necessary. */
void
screen_display_cursor_down(struct screen *s)
{
	if (s->cy == s->rlower)
		screen_display_scroll_region_up(s);
	else if (s->cy < screen_last_y(s))
		s->cy++;
}

/* Scroll region up. */
void
screen_display_scroll_region_up(struct screen *s)
{
	u_int	sy;
	
	/*
	 * If the region is the entire screen, this is easy-peasy. Allocate
	 * a new line and adjust the history size.
	 * XXX1 should this be done somewhere else?
	 */
	if (s->rupper == 0 && s->rlower == screen_last_y(s)) {
		sy = screen_size_y(s) + s->hsize;

		if (s->hsize == s->hlimit) {
			/*
			 * If the limit is hit, shift the whole thing up.
			 * XXX this is inefficient, is there a better way?
			 */
			screen_move_lines(s, 0, 1, sy - 1);
		} else {
			s->hsize++;

			s->grid_data = xrealloc(
			    s->grid_data, sy + 1, sizeof *s->grid_data);
			s->grid_attr = xrealloc(
			    s->grid_attr, sy + 1, sizeof *s->grid_attr);
			s->grid_colr = xrealloc(
			    s->grid_colr, sy + 1, sizeof *s->grid_colr);
		}
		screen_display_make_lines(s, screen_last_y(s), 1);
		return;
	}

	/* 
	 * Scroll scrolling region up:
	 * 	- delete rupper
	 *	- move rupper + 1 to rlower to rupper
	 *	- make new line at rlower
	 *
	 * Example: region is 12 to 24.
	 *	rlower = 24, rupper = 12
	 *	screen_free_lines(s, 12, 1);
	 *	screen_move_lines(s, 12, 13, 12);
	 *	screen_make_lines(s, 24, 1);
	 */

	screen_display_free_lines(s, s->rupper, 1);

	if (s->rupper != s->rlower) {
		screen_display_move_lines(s, 
		    s->rupper, s->rupper + 1, s->rlower - s->rupper);
	}

	screen_display_make_lines(s, s->rlower, 1);
}

/* Scroll region down. */
void
screen_display_scroll_region_down(struct screen *s)
{
	/* 
	 * Scroll scrolling region down:
	 * 	- delete rlower
	 *	- move rupper to rlower - 1 to rupper + 1
	 *	- make new line at rupper
	 *
	 * Example: region is 12 to 24.
	 *	rlower = 24, rupper = 12
	 *	screen_free_lines(s, 24, 1);
	 *	screen_move_lines(s, 13, 12, 12);
	 *	screen_make_lines(s, 12, 1);
	 */

	screen_display_free_lines(s, s->rlower, 1);

	if (s->rupper != s->rlower) {
		screen_display_move_lines(s,
		    s->rupper + 1, s->rupper, s->rlower - s->rupper);
	}

	screen_display_make_lines(s, s->rupper, 1);
}

/* Insert lines. */
void
screen_display_insert_lines(struct screen *s, u_int py, u_int ny)
{
	if (!screen_in_y(s, py))
		fatalx("bad value");
	if (ny == 0)
		fatalx("bad value");

	if (py + ny > screen_last_y(s))
		ny = screen_last_y(s) - py;

	/*
	 * Insert range of ny lines at py:
	 *	- Free ny lines from end of screen.
	 *	- Move from py to end of screen - ny to py + ny.
	 *	- Create ny lines at py.
	 *
	 * Example: insert 2 lines at 4.
	 *	sy = 10, py = 4, ny = 2
	 *	screen_free_lines(s, 8, 2);	- delete lines 8,9
	 *	screen_move_lines(s, 6, 4, 4);	- move 4,5,6,7 to 6,7,8,9
	 *	screen_make_lines(s, 4, 2);	- make lines 4,5
	 */

	screen_display_free_lines(s, screen_size_y(s) - ny, ny);

	if (py != screen_last_y(s)) {
		screen_display_move_lines(
		    s, py + ny, py, screen_size_y(s) - py - ny);
	}

	screen_display_make_lines(s, py, ny);
}

/* Insert lines in region. */
void
screen_display_insert_lines_region(struct screen *s, u_int py, u_int ny)
{
	if (!screen_in_region(s, py))
		fatalx("bad value");
	if (ny == 0)
		fatalx("bad value");

	if (py + ny > s->rlower)
		ny = s->rlower - py;

	/*
	 * Insert range of ny lines at py:
	 *	- Free ny lines from end of screen.
	 *	- Move from py to end of screen - ny to py + ny.
	 *	- Create ny lines at py.
	 *
	 * Example: insert 2 lines at 4.
	 *	ryu = 11, ryl = 16, py = 13, ny = 2
	 *	screen_free_lines(s, 15, 2);	- delete lines 15,16
	 *	screen_move_lines(s, 13, 15, 2);- move 13,14 to 15,16
	 *	screen_make_lines(s, 13, 2);	- make lines 13,14
	 */

	screen_display_free_lines(s, (s->rlower + 1) - ny, ny);

	if (py != s->rlower) {
		screen_display_move_lines(
		    s, py + ny, py, (s->rlower + 1) - py - ny);
	}

	screen_display_make_lines(s, py, ny);
}

/* Delete lines. */
void
screen_display_delete_lines(struct screen *s, u_int py, u_int ny)
{
	if (!screen_in_y(s, py))
		fatalx("bad value");
	if (ny == 0)
		fatalx("bad value");

	if (py + ny > screen_last_y(s))
		ny = screen_last_y(s) - py;

	/*
	 * Delete range of ny lines at py:
	 * 	- Free ny lines at py.
	 *	- Move from py + ny to end of screen to py.
	 *	- Free and recreate last ny lines.
	 *
	 * Example: delete lines 3,4.
	 *	sy = 10, py = 3, ny = 2
	 *	screen_free_lines(s, 3, 2);	- delete lines 3,4
	 *	screen_move_lines(s, 3, 5, 5);	- move 5,6,7,8,9 to 3
	 *	screen_make_lines(s, 8, 2);	- make lines 8,9
	 */

	screen_display_free_lines(s, py, ny);

	if (py != screen_last_y(s)) {
		screen_display_move_lines(
		    s, py, py + ny, screen_size_y(s) - py - ny);
	}

	screen_display_make_lines(s, screen_size_y(s) - ny, ny);
}

/* Delete lines inside scroll region. */
void
screen_display_delete_lines_region(struct screen *s, u_int py, u_int ny)
{
	if (!screen_in_region(s, py))
		fatalx("bad value");
	if (ny == 0)
		fatalx("bad value");

	if (py + ny > s->rlower)
		ny = s->rlower - py;

	/*
	 * Delete range of ny lines at py:
	 * 	- Free ny lines at py.
	 *	- Move from py + ny to end of region to py.
	 *	- Free and recreate last ny lines.
	 *
	 * Example: delete lines 13,14.
	 *	ryu = 11, ryl = 16, py = 13, ny = 2
	 *	screen_free_lines(s, 13, 2);	- delete lines 13,14
	 *	screen_move_lines(s, 15, 16, 2);- move 15,16 to 13
	 *	screen_make_lines(s, 15, 16);	- make lines 15,16
	 */

	screen_display_free_lines(s, py, ny);

	if (py != s->rlower) {
		screen_display_move_lines(
		    s, py, py + ny, (s->rlower + 1) - py - ny);
	}

	screen_display_make_lines(s, (s->rlower + 1) - ny, ny);
}

/* Insert characters. */
void
screen_display_insert_characters(struct screen *s, u_int px, u_int py, u_int nx)
{
	u_int	mx;

	if (!screen_in_x(s, px) || !screen_in_y(s, py))
		fatalx("bad value");

	if (px + nx > screen_last_x(s))
		nx = screen_last_x(s) - px;

	py = screen_y(s, py);

	/*
	 * Inserting a range of nx at px.
	 *
	 * - Move sx - (px + nx) from px to px + nx.
	 * - Clear the range at px.
	 */

	if (px + nx != screen_last_x(s)) {
		mx = screen_last_x(s) - (px + nx);
		memmove(&s->grid_data[py][px + nx], &s->grid_data[py][px], mx);
		memmove(&s->grid_attr[py][px + nx], &s->grid_attr[py][px], mx);
		memmove(&s->grid_colr[py][px + nx], &s->grid_colr[py][px], mx);
	}
	memset(&s->grid_data[py][px], SCREEN_DEFDATA, nx);
	memset(&s->grid_attr[py][px], SCREEN_DEFATTR, nx);
	memset(&s->grid_colr[py][px], SCREEN_DEFCOLR, nx);
}

/* Delete characters. */
void
screen_display_delete_characters(struct screen *s, u_int px, u_int py, u_int nx)
{
	u_int	mx;

	if (!screen_in_x(s, px) || !screen_in_y(s, py))
		fatalx("bad value");

	if (px + nx > screen_last_x(s))
		nx = screen_last_x(s) - px;

	py = screen_y(s, py);

	/*
	 * Deleting the range from px to px + nx.
	 *
	 * - Move sx - (px + nx) from px + nx to px.
	 * - Clear the range from the last x - (rx - lx)  to the last x.
	 */

	if (px + nx != screen_last_x(s)) {
		mx = screen_last_x(s) - (px + nx);
		memmove(&s->grid_data[py][px], &s->grid_data[py][px + nx], mx);
		memmove(&s->grid_attr[py][px], &s->grid_attr[py][px + nx], mx);
		memmove(&s->grid_colr[py][px], &s->grid_colr[py][px + nx], mx);
	}

	memset(&s->grid_data[py][screen_size_x(s) - nx], SCREEN_DEFDATA, nx);
	memset(&s->grid_attr[py][screen_size_x(s) - nx], SCREEN_DEFATTR, nx);
	memset(&s->grid_colr[py][screen_size_x(s) - nx], SCREEN_DEFCOLR, nx);
}