/*
   Copyright (C) 2002-2010 Karl J. Runge <runge@karlrunge.com> 
   All rights reserved.

This file is part of x11vnc.

x11vnc is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

x11vnc is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with x11vnc; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA
or see <http://www.gnu.org/licenses/>.

In addition, as a special exception, Karl J. Runge
gives permission to link the code of its release of x11vnc with the
OpenSSL project's "OpenSSL" library (or with modified versions of it
that use the same license as the "OpenSSL" library), and distribute
the linked executables.  You must obey the GNU General Public License
in all respects for all of the code used other than "OpenSSL".  If you
modify this file, you may extend this exception to your version of the
file, but you are not obligated to do so.  If you do not wish to do
so, delete this exception statement from your version.
*/

/* -- xinerama.c -- */

#include "x11vnc.h"
#include "xwrappers.h"
#include "blackout_t.h"
#include "scan.h"

/*
 * routines related to xinerama and blacking out rectangles
 */

/* blacked-out region (-blackout, -xinerama) */

#define BLACKR_MAX 100
blackout_t blackr[BLACKR_MAX];	/* hardwired max blackouts */
tile_blackout_t *tile_blackout;
int blackouts = 0;

void initialize_blackouts_and_xinerama(void);
void push_sleep(int n);
void push_black_screen(int n);
void refresh_screen(int push);
void zero_fb(int x1, int y1, int x2, int y2);


static void initialize_blackouts(char *list);
static void blackout_tiles(void);
static void initialize_xinerama (void);


/*
 * Take a comma separated list of geometries: WxH+X+Y and register them as
 * rectangles to black out from the screen.
 */
static void initialize_blackouts(char *list) {
	char *p, *blist = strdup(list);
	int x, y, X, Y, h, w, t;

	p = strtok(blist, ", \t");
	while (p) {
		if (!strcmp("noptr", p)) {
			blackout_ptr = 1;
			rfbLog("pointer will be blocked from blackout "
			    "regions\n");
			p = strtok(NULL, ", \t");
			continue;
		}
		if (! parse_geom(p, &w, &h, &x, &y, dpy_x, dpy_y)) {
			if (*p != '\0') {
				rfbLog("skipping invalid geometry: %s\n", p);
			}
			p = strtok(NULL, ", \t");
			continue;
		}
		w = nabs(w);
		h = nabs(h);
		x = nfix(x, dpy_x);
		y = nfix(y, dpy_y);
		X = x + w;
		Y = y + h;
		X = nfix(X, dpy_x+1);
		Y = nfix(Y, dpy_y+1);
		if (x > X) {
			t = X; X = x; x = t;
		}
		if (y > Y) {
			t = Y; Y = y; y = t;
		}
		if (x < 0 || x > dpy_x || y < 0 || y > dpy_y ||
		    X < 0 || X > dpy_x || Y < 0 || Y > dpy_y ||
		    x == X || y == Y) {
			rfbLog("skipping invalid blackout geometry: %s x="
			    "%d-%d,y=%d-%d,w=%d,h=%d\n", p, x, X, y, Y, w, h);
		} else {
			rfbLog("blackout rect: %s: x=%d-%d y=%d-%d\n", p,
			    x, X, y, Y);

			/*
			 * note that the black out is x1 <= x but x < x2
			 * for the region. i.e. the x2, y2 are outside
			 * by 1 pixel. 
			 */
			blackr[blackouts].x1 = x;
			blackr[blackouts].y1 = y;
			blackr[blackouts].x2 = X;
			blackr[blackouts].y2 = Y;
			blackouts++;
			if (blackouts >= BLACKR_MAX) {
				rfbLog("too many blackouts: %d\n", blackouts);
				break;
			}
		}
		p = strtok(NULL, ", \t");
	}
	free(blist);
}

/*
 * Now that all blackout rectangles have been constructed, see what overlap
 * they have with the tiles in the system.  If a tile is touched by a
 * blackout, record information.
 */
static void blackout_tiles(void) {
	int tx, ty;
	int debug_bo = 0;
	if (! blackouts) {
		return;
	}
	if (getenv("DEBUG_BLACKOUT") != NULL) {
		debug_bo = 1;
	}

	/* 
	 * to simplify things drop down to single copy mode, etc...
	 */
	single_copytile = 1;
	/* loop over all tiles. */
	for (ty=0; ty < ntiles_y; ty++) {
		for (tx=0; tx < ntiles_x; tx++) {
			sraRegionPtr tile_reg, black_reg;
			sraRect rect;
			sraRectangleIterator *iter;
			int n, b, x1, y1, x2, y2, cnt;

			/* tile number and coordinates: */
			n = tx + ty * ntiles_x;
			x1 = tx * tile_x;
			y1 = ty * tile_y;
			x2 = x1 + tile_x;
			y2 = y1 + tile_y;
			if (x2 > dpy_x) {
				x2 = dpy_x;
			}
			if (y2 > dpy_y) {
				y2 = dpy_y;
			}

			/* make regions for the tile and the blackouts: */
			black_reg = (sraRegionPtr) sraRgnCreate();
			tile_reg  = (sraRegionPtr) sraRgnCreateRect(x1, y1,
			    x2, y2);

			tile_blackout[n].cover = 0;
			tile_blackout[n].count = 0;

			/* union of blackouts */
			for (b=0; b < blackouts; b++) {
				sraRegionPtr tmp_reg = (sraRegionPtr)
				    sraRgnCreateRect(blackr[b].x1,
				    blackr[b].y1, blackr[b].x2, blackr[b].y2);

				sraRgnOr(black_reg, tmp_reg);
				sraRgnDestroy(tmp_reg);
			}

			if (! sraRgnAnd(black_reg, tile_reg)) {
				/*
				 * no intersection for this tile, so we
				 * are done.
				 */
				sraRgnDestroy(black_reg);
				sraRgnDestroy(tile_reg);
				continue;
			}

			/*
			 * loop over rectangles that make up the blackout
			 * region:
			 */
			cnt = 0;
			iter = sraRgnGetIterator(black_reg);
			while (sraRgnIteratorNext(iter, &rect)) {

				/* make sure x1 < x2 and y1 < y2 */
				if (rect.x1 > rect.x2) {
					int tmp = rect.x2;
					rect.x2 = rect.x1;
					rect.x1 = tmp;
				}
				if (rect.y1 > rect.y2) {
					int tmp = rect.y2;
					rect.y2 = rect.y1;
					rect.y1 = tmp;
				}

				/* store coordinates */
				tile_blackout[n].bo[cnt].x1 = rect.x1;
				tile_blackout[n].bo[cnt].y1 = rect.y1;
				tile_blackout[n].bo[cnt].x2 = rect.x2;
				tile_blackout[n].bo[cnt].y2 = rect.y2;

				/* note if the tile is completely obscured */
				if (rect.x1 == x1 && rect.y1 == y1 &&
				    rect.x2 == x2 && rect.y2 == y2) {
					tile_blackout[n].cover = 2;
					if (debug_bo) {
 						fprintf(stderr, "full: %d=%d,%d"
						    "  (%d-%d)  (%d-%d)\n",
						    n, tx, ty, x1, x2, y1, y2);
					}
				} else {
					tile_blackout[n].cover = 1;
					if (debug_bo) {
						fprintf(stderr, "part: %d=%d,%d"
						    "  (%d-%d)  (%d-%d)\n",
						    n, tx, ty, x1, x2, y1, y2);
					}
				}

				if (++cnt >= BO_MAX) {
					rfbLog("too many blackout rectangles "
					    "for tile %d=%d,%d.\n", n, tx, ty);
					break;
				}
			}
			sraRgnReleaseIterator(iter);

			sraRgnDestroy(black_reg);
			sraRgnDestroy(tile_reg);

			tile_blackout[n].count = cnt;
			if (debug_bo && cnt > 1) {
 				rfbLog("warning: multiple region overlaps[%d] "
				    "for tile %d=%d,%d.\n", cnt, n, tx, ty);
			}
		}
	}
}

static int did_xinerama_clip = 0;

void check_xinerama_clip(void) {
#if LIBVNCSERVER_HAVE_LIBXINERAMA
	int n, k, i, ev, er, juse = -1;
	int score[32], is = 0;
	XineramaScreenInfo *x;

	if (!clip_str || !dpy) {
		return;
	}
	if (sscanf(clip_str, "xinerama%d", &k) == 1) {
		;
	} else if (sscanf(clip_str, "screen%d", &k) == 1) {
		;
	} else {
		return;
	}

	free(clip_str);
	clip_str = NULL;

	if (! XineramaQueryExtension(dpy, &ev, &er)) {
		return;
	}
	if (! XineramaIsActive(dpy)) {
		return;
	}
	x = XineramaQueryScreens(dpy, &n);
	if (k < 0 || k >= n) {
		XFree_wr(x);
		return;
	}
	for (i=0; i < n; i++) {
		score[is++] = nabs(x[i].x_org) + nabs(x[i].y_org);
		if (is >= 32) {
			break;
		}
	}
	for (i=0; i <= k; i++) {
		int j, jmon = 0, mon = -1, mox = -1;
		for (j=0; j < is; j++) {
			if (mon < 0 || score[j] < mon) {
				mon = score[j];
				jmon = j;
			}
			if (mox < 0 || score[j] > mox) {
				mox = score[j];
			}
		}
		juse = jmon;
		score[juse] = mox+1+i;
	}

	if (juse >= 0 && juse < n) {
		char str[64];
		sprintf(str, "%dx%d+%d+%d", x[juse].width, x[juse].height,
		    x[juse].x_org, x[juse].y_org);
		clip_str = strdup(str);
		did_xinerama_clip = 1;
	} else {
		clip_str = strdup("");
	}
	XFree_wr(x);
	if (!quiet) {
		rfbLog("set -clip to '%s' for xinerama%d\n", clip_str, k);
	}
#endif
}

static void initialize_xinerama (void) {
#if !LIBVNCSERVER_HAVE_LIBXINERAMA
	if (!raw_fb_str) {
		rfbLog("Xinerama: Library libXinerama is not available to determine\n");
		rfbLog("Xinerama: the head geometries, consider using -blackout\n");
		rfbLog("Xinerama: if the screen is non-rectangular.\n");
	}
#else
	XineramaScreenInfo *sc, *xineramas;
	sraRegionPtr black_region, tmp_region;
	sraRectangleIterator *iter;
	sraRect rect;
	char *bstr, *tstr;
	int ev, er, i, n, rcnt;

	RAWFB_RET_VOID

	X_LOCK;
	if (! XineramaQueryExtension(dpy, &ev, &er)) {
		if (verbose) {
			rfbLog("Xinerama: disabling: display does not support it.\n");
		}
		xinerama = 0;
		xinerama_present = 0;
		X_UNLOCK;
		return;
	}
	if (! XineramaIsActive(dpy)) {
		/* n.b. change to XineramaActive(dpy, window) someday */
		if (verbose) {
			rfbLog("Xinerama: disabling: not active on display.\n");
		}
		xinerama = 0;
		xinerama_present = 0;
		X_UNLOCK;
		return;
	}
	xinerama_present = 1;
	rfbLog("\n");
	rfbLog("Xinerama is present and active (e.g. multi-head).\n");

	/* n.b. change to XineramaGetData() someday */
	xineramas = XineramaQueryScreens(dpy, &n);
	rfbLog("Xinerama: number of sub-screens: %d\n", n);

	if (! use_xwarppointer && ! got_noxwarppointer && n > 1) {
		rfbLog("Xinerama: enabling -xwarppointer mode to try to correct\n");
		rfbLog("Xinerama: mouse pointer motion. XTEST+XINERAMA bug.\n");
		rfbLog("Xinerama: Use -noxwarppointer to force XTEST.\n");
		use_xwarppointer = 1;
	}

	if (n == 1) {
		rfbLog("Xinerama: no blackouts needed (only one sub-screen)\n");
		rfbLog("\n");
		XFree_wr(xineramas);
		X_UNLOCK;
		return;		/* must be OK w/o change */
	}

	black_region = sraRgnCreateRect(0, 0, dpy_x, dpy_y);

	sc = xineramas;
	for (i=0; i<n; i++) {
		int x, y, w, h;
		
		x = sc->x_org;
		y = sc->y_org;
		w = sc->width;
		h = sc->height;

		rfbLog("Xinerama: sub-screen[%d]  %dx%d+%d+%d\n", i, w, h, x, y);

		tmp_region = sraRgnCreateRect(x, y, x + w, y + h);

		sraRgnSubtract(black_region, tmp_region);
		sraRgnDestroy(tmp_region);
		sc++;
	}
	XFree_wr(xineramas);
	X_UNLOCK;


	if (sraRgnEmpty(black_region)) {
		rfbLog("Xinerama: no blackouts needed (screen fills"
		    " rectangle)\n");
		rfbLog("\n");
		sraRgnDestroy(black_region);
		return;
	}
	if (did_xinerama_clip) {
		rfbLog("Xinerama: no blackouts due to -clip xinerama.\n");
		return;
	}

	/* max len is 10000x10000+10000+10000 (23 chars) per geometry */
	rcnt = (int) sraRgnCountRects(black_region);
	bstr = (char *) malloc(30 * (rcnt+1));
	tstr = (char *) malloc(30);
	bstr[0] = '\0';

	iter = sraRgnGetIterator(black_region);
	while (sraRgnIteratorNext(iter, &rect)) {
		int x, y, w, h;

		/* make sure x1 < x2 and y1 < y2 */
		if (rect.x1 > rect.x2) {
			int tmp = rect.x2;
			rect.x2 = rect.x1;
			rect.x1 = tmp;
		}
		if (rect.y1 > rect.y2) {
			int tmp = rect.y2;
			rect.y2 = rect.y1;
			rect.y1 = tmp;
		}
		x = rect.x1;
		y = rect.y1;
		w = rect.x2 - x;
		h = rect.y2 - y;
		sprintf(tstr, "%dx%d+%d+%d,", w, h, x, y);
		strcat(bstr, tstr);
	}
	sraRgnReleaseIterator(iter);
	initialize_blackouts(bstr);
	rfbLog("\n");

	free(bstr);
	free(tstr);
#endif
}

void initialize_blackouts_and_xinerama(void) {

	blackouts = 0;
	blackout_ptr = 0;

	if (blackout_str != NULL) {
		initialize_blackouts(blackout_str);
	}
	if (xinerama) {
		initialize_xinerama();
	}
	if (blackouts) {
		blackout_tiles();
		/* schedule a copy_screen(), now is too early. */
		do_copy_screen = 1;
	}
}

void push_sleep(int n) {
	int i;
	for (i=0; i<n; i++) {
		rfbPE(-1);
		if (i != n-1 && defer_update) {
			usleep(defer_update * 1000);
		}
	}
}

/*
 * try to forcefully push a black screen to all connected clients
 */
void push_black_screen(int n) {
	int Lx = dpy_x, Ly = dpy_y;
	if (!screen) {
		return;
	}
#ifndef NO_NCACHE
	if (ncache > 0) {
		Ly = dpy_y * (1+ncache);
	}
#endif
	zero_fb(0, 0, Lx, Ly);
	mark_rect_as_modified(0, 0, Lx, Ly, 0);
	push_sleep(n);
}

void refresh_screen(int push) {
	int i;
	if (!screen) {
		return;
	}
	mark_rect_as_modified(0, 0, dpy_x, dpy_y, 0);
	for (i=0; i<push; i++) {
		rfbPE(-1);
	}
}

/*
 * Fill the framebuffer with zero for the prescribed rectangle
 */
void zero_fb(int x1, int y1, int x2, int y2) {
	int pixelsize = bpp/8;
	int line, fill = 0, yfac = 1;
	char *dst;

#ifndef NO_NCACHE
	if (ncache > 0) {
		yfac = 1+ncache;
		if (ncache_xrootpmap) {
			yfac++;
		}
	}
#endif
	
	if (x1 < 0 || x2 <= x1 || x2 > dpy_x) {
		return;
	}
	if (y1 < 0 || y2 <= y1 || y2 > yfac * dpy_y) {
		return;
	}
	if (! main_fb) {
		return;
	}

	dst = main_fb + y1 * main_bytes_per_line + x1 * pixelsize;
	line = y1;
	while (line++ < y2) {
		memset(dst, fill, (size_t) (x2 - x1) * pixelsize);
		dst += main_bytes_per_line;
	}
}