xref: /openbsd/lib/libcurses/base/lib_overlay.c (revision c7ef0cfc)
1 /* $OpenBSD: lib_overlay.c,v 1.4 2023/10/17 09:52:08 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright 2020 Thomas E. Dickey                                          *
5  * Copyright 1998-2013,2016 Free Software Foundation, Inc.                  *
6  *                                                                          *
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8  * copy of this software and associated documentation files (the            *
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12  * copies of the Software, and to permit persons to whom the Software is    *
13  * furnished to do so, subject to the following conditions:                 *
14  *                                                                          *
15  * The above copyright notice and this permission notice shall be included  *
16  * in all copies or substantial portions of the Software.                   *
17  *                                                                          *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
21  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
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24  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
25  *                                                                          *
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31 
32 /****************************************************************************
33  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
34  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
35  ****************************************************************************/
36 
37 /*
38 **	lib_overlay.c
39 **
40 **	The routines overlay(), copywin(), and overwrite().
41 **
42 */
43 
44 #include <curses.priv.h>
45 
46 MODULE_ID("$Id: lib_overlay.c,v 1.4 2023/10/17 09:52:08 nicm Exp $")
47 
48 static int
overlap(const WINDOW * const src,WINDOW * const dst,int const flag)49 overlap(const WINDOW *const src, WINDOW *const dst, int const flag)
50 {
51     int rc = ERR;
52 
53     T((T_CALLED("overlap(%p,%p,%d)"), (const void *) src, (void *) dst, flag));
54 
55     if (src != 0 && dst != 0) {
56 	int sx1, sy1, sx2, sy2;
57 	int dx1, dy1, dx2, dy2;
58 
59 	_nc_lock_global(curses);
60 
61 	T(("src : begy %ld, begx %ld, maxy %ld, maxx %ld",
62 	   (long) src->_begy,
63 	   (long) src->_begx,
64 	   (long) src->_maxy,
65 	   (long) src->_maxx));
66 	T(("dst : begy %ld, begx %ld, maxy %ld, maxx %ld",
67 	   (long) dst->_begy,
68 	   (long) dst->_begx,
69 	   (long) dst->_maxy,
70 	   (long) dst->_maxx));
71 
72 	sx1 = src->_begx;
73 	sy1 = src->_begy;
74 	sx2 = sx1 + src->_maxx;
75 	sy2 = sy1 + src->_maxy;
76 
77 	dx1 = dst->_begx;
78 	dy1 = dst->_begy;
79 	dx2 = dx1 + dst->_maxx;
80 	dy2 = dy1 + dst->_maxy;
81 
82 	if (dx2 >= sx1 && dx1 <= sx2 && dy2 >= sy1 && dy1 <= sy2) {
83 	    int sminrow = max(sy1, dy1) - sy1;
84 	    int smincol = max(sx1, dx1) - sx1;
85 	    int dminrow = max(sy1, dy1) - dy1;
86 	    int dmincol = max(sx1, dx1) - dx1;
87 	    int dmaxrow = min(sy2, dy2) - dy1;
88 	    int dmaxcol = min(sx2, dx2) - dx1;
89 
90 	    rc = copywin(src, dst,
91 			 sminrow, smincol,
92 			 dminrow, dmincol,
93 			 dmaxrow, dmaxcol,
94 			 flag);
95 	}
96 	_nc_unlock_global(curses);
97     }
98     returnCode(rc);
99 }
100 
101 /*
102 **
103 **	overlay(win1, win2)
104 **
105 **
106 **	overlay() writes the overlapping area of win1 behind win2
107 **	on win2 non-destructively.
108 **
109 **/
110 
111 NCURSES_EXPORT(int)
overlay(const WINDOW * win1,WINDOW * win2)112 overlay(const WINDOW *win1, WINDOW *win2)
113 {
114     T((T_CALLED("overlay(%p,%p)"), (const void *) win1, (void *) win2));
115     returnCode(overlap(win1, win2, TRUE));
116 }
117 
118 /*
119 **
120 **	overwrite(win1, win2)
121 **
122 **
123 **	overwrite() writes the overlapping area of win1 behind win2
124 **	on win2 destructively.
125 **
126 **/
127 
128 NCURSES_EXPORT(int)
overwrite(const WINDOW * win1,WINDOW * win2)129 overwrite(const WINDOW *win1, WINDOW *win2)
130 {
131     T((T_CALLED("overwrite(%p,%p)"), (const void *) win1, (void *) win2));
132     returnCode(overlap(win1, win2, FALSE));
133 }
134 
135 NCURSES_EXPORT(int)
copywin(const WINDOW * src,WINDOW * dst,int sminrow,int smincol,int dminrow,int dmincol,int dmaxrow,int dmaxcol,int over)136 copywin(const WINDOW *src, WINDOW *dst,
137 	int sminrow, int smincol,
138 	int dminrow, int dmincol,
139 	int dmaxrow, int dmaxcol,
140 	int over)
141 {
142     int rc = ERR;
143 
144     T((T_CALLED("copywin(%p, %p, %d, %d, %d, %d, %d, %d, %d)"),
145        (const void *) src,
146        (void *) dst,
147        sminrow, smincol,
148        dminrow, dmincol,
149        dmaxrow, dmaxcol, over));
150 
151     if (src != 0
152 	&& dst != 0
153 	&& dmaxrow >= dminrow
154 	&& dmaxcol >= dmincol) {
155 	attr_t bk;
156 	attr_t mask;
157 
158 	_nc_lock_global(curses);
159 
160 	bk = AttrOf(dst->_nc_bkgd);
161 	mask = ~(attr_t) ((bk & A_COLOR) ? A_COLOR : 0);
162 
163 	/* make sure rectangle exists in source */
164 	if ((sminrow + dmaxrow - dminrow) <= (src->_maxy + 1) &&
165 	    (smincol + dmaxcol - dmincol) <= (src->_maxx + 1)) {
166 
167 	    T(("rectangle exists in source"));
168 
169 	    /* make sure rectangle fits in destination */
170 	    if (dmaxrow <= dst->_maxy && dmaxcol <= dst->_maxx) {
171 		int sx, sy, dx, dy;
172 		bool copied = FALSE;
173 
174 		T(("rectangle fits in destination"));
175 
176 		for (dy = dminrow, sy = sminrow;
177 		     dy <= dmaxrow;
178 		     sy++, dy++) {
179 		    bool touched;
180 
181 		    if (dy < 0 || sy < 0)
182 			continue;
183 
184 		    touched = FALSE;
185 		    for (dx = dmincol, sx = smincol;
186 			 dx <= dmaxcol;
187 			 sx++, dx++) {
188 
189 			if (dx < 0 || sx < 0)
190 			    continue;
191 			copied = TRUE;
192 
193 			if (over) {
194 			    if ((CharOf(src->_line[sy].text[sx]) != L(' ')) &&
195 				(!CharEq(dst->_line[dy].text[dx],
196 					 src->_line[sy].text[sx]))) {
197 				dst->_line[dy].text[dx] =
198 				    src->_line[sy].text[sx];
199 				SetAttr(dst->_line[dy].text[dx],
200 					((AttrOf(src->_line[sy].text[sx]) &
201 					  mask) | bk));
202 				touched = TRUE;
203 			    }
204 			} else {
205 			    if (!CharEq(dst->_line[dy].text[dx],
206 					src->_line[sy].text[sx])) {
207 				dst->_line[dy].text[dx] =
208 				    src->_line[sy].text[sx];
209 				touched = TRUE;
210 			    }
211 			}
212 		    }
213 		    if (touched) {
214 			touchline(dst, dminrow, (dmaxrow - dminrow + 1));
215 		    }
216 		}
217 		T(("finished copywin"));
218 		if (copied)
219 		    rc = OK;
220 	    }
221 	}
222 	_nc_unlock_global(curses);
223     }
224     returnCode(rc);
225 }
226