PolyTxt.c revision 9c019ec5 
1/*
2
3Copyright 1986, 1998  The Open Group
4
5Permission to use, copy, modify, distribute, and sell this software and its
6documentation for any purpose is hereby granted without fee, provided that
7the above copyright notice appear in all copies and that both that
8copyright notice and this permission notice appear in supporting
9documentation.
10
11The above copyright notice and this permission notice shall be included in
12all copies or substantial portions of the Software.
13
14THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
17OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
18AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
19CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20
21Except as contained in this notice, the name of The Open Group shall not be
22used in advertising or otherwise to promote the sale, use or other dealings
23in this Software without prior written authorization from The Open Group.
24
25*/
26
27#ifdef HAVE_CONFIG_H
28#include <config.h>
29#endif
30#include "Xlibint.h"
31
32int
33XDrawText(
34    register Display *dpy,
35    Drawable d,
36    GC gc,
37    int x,
38    int y,
39    XTextItem *items,
40    int nitems)
41{
42    register int i;
43    register XTextItem *item;
44    int length = 0;
45    register xPolyText8Req *req;
46
47    LockDisplay(dpy);
48    FlushGC(dpy, gc);
49    GetReq (PolyText8, req);
50    req->drawable = d;
51    req->gc = gc->gid;
52    req->x = x;
53    req->y = y;
54
55    item = items;
56    for (i=0; i < nitems; i++) {
57	if (item->font)
58	    length += 5;  /* a 255 byte, plus size of Font id */
59        if (item->delta)
60        {
61	    if (item->delta > 0)
62	    {
63	      length += SIZEOF(xTextElt) * ((item->delta + 126) / 127);
64	    }
65            else
66            {
67   	      length += SIZEOF(xTextElt) * ((-item->delta + 127) / 128);
68 	    }
69        }
70	if (item->nchars > 0)
71	{
72	    length += SIZEOF(xTextElt) * ((item->nchars + 253) / 254 - 1);
73	    if (!item->delta) length += SIZEOF(xTextElt);
74	    length += item->nchars;
75     	}
76	item++;
77    }
78
79    req->length += (length + 3)>>2;  /* convert to number of 32-bit words */
80
81
82    /*
83     * If the entire request does not fit into the remaining space in the
84     * buffer, flush the buffer first.   If the request does fit into the
85     * empty buffer, then we won't have to flush it at the end to keep
86     * the buffer 32-bit aligned.
87     */
88
89    if (dpy->bufptr + length > dpy->bufmax)
90    	_XFlush (dpy);
91
92    item = items;
93    for (i=0; i< nitems; i++) {
94
95	if (item->font) {
96            /* to mark a font shift, write a 255 byte followed by
97	       the 4 bytes of font ID, big-end first */
98	    register unsigned char *f;
99	    BufAlloc (unsigned char *, f, 5);
100
101	    f[0] = 255;
102	    f[1] = (item->font & 0xff000000) >> 24;
103	    f[2] = (item->font & 0x00ff0000) >> 16;
104	    f[3] = (item->font & 0x0000ff00) >> 8;
105	    f[4] =  item->font & 0x000000ff;
106
107            /* update GC shadow */
108	    gc->values.font = item->font;
109	    }
110
111	{
112	    int nbytes = SIZEOF(xTextElt);
113	    int PartialNChars = item->nchars;
114	    int PartialDelta = item->delta;
115            /* register xTextElt *elt; */
116	    int FirstTimeThrough = True;
117 	    char *CharacterOffset = item->chars;
118            char *tbuf = NULL;
119
120	    while((PartialDelta < -128) || (PartialDelta > 127))
121            {
122	    	int nb = SIZEOF(xTextElt);
123
124	    	BufAlloc (char *, tbuf, nb);
125	    	*tbuf = 0;    /*   elt->len  */
126	    	if (PartialDelta > 0 )
127		{
128		    *(tbuf+1) = 127;  /* elt->delta  */
129		    PartialDelta = PartialDelta - 127;
130		}
131		else
132		{
133		    /* -128 = 0x8, need to be careful of signed chars... */
134		    *((unsigned char *)(tbuf+1)) = 0x80;  /* elt->delta */
135		    PartialDelta = PartialDelta + 128;
136		}
137	    }
138	    if (PartialDelta)
139            {
140                BufAlloc (char *, tbuf , nbytes);
141	        *tbuf = 0;      /* elt->len */
142		*(tbuf+1) = PartialDelta;    /* elt->delta  */
143	    }
144	    while(PartialNChars > 254)
145            {
146		nbytes = 254;
147	    	if (FirstTimeThrough)
148		{
149		    FirstTimeThrough = False;
150		    if (!item->delta)
151 		    {
152			nbytes += SIZEOF(xTextElt);
153	   		BufAlloc (char *, tbuf, nbytes);
154		        *(tbuf+1) = 0;     /* elt->delta */
155		    }
156		    else
157		    {
158			char *DummyChar;
159		        BufAlloc(char *, DummyChar, nbytes);
160		    }
161		}
162		else
163		{
164 		    nbytes += SIZEOF(xTextElt);
165	   	    BufAlloc (char *, tbuf, nbytes);
166		    *(tbuf+1) = 0;   /* elt->delta */
167		}
168		/* watch out for signs on chars */
169		*(unsigned char *)tbuf = 254;  /* elt->len */
170                memcpy (tbuf+2 , CharacterOffset, 254);
171		PartialNChars = PartialNChars - 254;
172		CharacterOffset += 254;
173
174	    }
175	    if (PartialNChars)
176            {
177		nbytes = PartialNChars;
178	    	if (FirstTimeThrough)
179		{
180		    FirstTimeThrough = False;
181		    if (!item->delta)
182 		    {
183			nbytes += SIZEOF(xTextElt);
184	   		BufAlloc (char *, tbuf, nbytes);
185			*(tbuf+1) = 0;   /*  elt->delta  */
186		    }
187		    else
188		    {
189			char *DummyChar;
190		        BufAlloc(char *, DummyChar, nbytes);
191		    }
192		}
193		else
194		{
195 		    nbytes += SIZEOF(xTextElt);
196	   	    BufAlloc (char *, tbuf, nbytes);
197		    *(tbuf+1) = 0;   /* elt->delta  */
198		}
199	    	*tbuf = PartialNChars;   /*  elt->len  */
200                memcpy (tbuf+2 , CharacterOffset, (size_t) PartialNChars);
201	    }
202	}
203    item++;
204    }
205
206    /* Pad request out to a 32-bit boundary */
207
208    if (length &= 3) {
209	char *pad;
210	/*
211	 * BufAlloc is a macro that uses its last argument more than
212	 * once, otherwise I'd write "BufAlloc (char *, pad, 4-length)"
213	 */
214	length = 4 - length;
215	BufAlloc (char *, pad, length);
216	/*
217	 * if there are 3 bytes of padding, the first byte MUST be 0
218	 * so the pad bytes aren't mistaken for a final xTextElt
219	 */
220	*pad = 0;
221        }
222
223    /*
224     * If the buffer pointer is not now pointing to a 32-bit boundary,
225     * we must flush the buffer so that it does point to a 32-bit boundary
226     * at the end of this routine.
227     */
228
229    if ((dpy->bufptr - dpy->buffer) & 3)
230       _XFlush (dpy);
231    UnlockDisplay(dpy);
232    SyncHandle();
233    return 0;
234    }
235