[occt.git] / src / Xw / Xw_draw_segment.cxx

// Copyright (c) 1999-2012 OPEN CASCADE SAS
//
// The content of this file is subject to the Open CASCADE Technology Public
// License Version 6.5 (the "License"). You may not use the content of this file
// except in compliance with the License. Please obtain a copy of the License
// at http://www.opencascade.org and read it completely before using this file.
//
// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
//
// The Original Code and all software distributed under the License is
// distributed on an "AS IS" basis, without warranty of any kind, and the
// Initial Developer hereby disclaims all such warranties, including without
// limitation, any warranties of merchantability, fitness for a particular
// purpose or non-infringement. Please see the License for the specific terms
// and conditions governing the rights and limitations under the License.


#define S3593		/*GG_130398
OPTIMISATION MFT
			Activer le clipping de maniere optionnelle
*/

#include <Xw_Extension.h>

	/* ifdef then trace on */
#ifdef TRACE
#define TRACE_DRAW_SEGMENT
#endif

static XW_EXT_SEGMENT *pseglist ;
static int BeginSegments = False ;

/*
   STATUS Xw_draw_segment (awindow,x1,y1,x2,y2):
   XW_EXT_WINDOW *awindow
   float x1,y1		First point Coordinates defined in User Space
   float x2,y2		Second point Coordinates defined in User Space

	Display segment in current QG set by set_line_attrib .
	Note that segments can be buffered depending of the DisplayMode context
	and Flush at Xw_flush time .

	returns SUCCESS always

*/

#ifdef XW_PROTOTYPE
XW_STATUS Xw_draw_segment (void* awindow,float x1,float y1,float x2,float y2)
#else
XW_STATUS Xw_draw_segment (awindow,x1,y1,x2,y2)
void *awindow;
float x1,y1,x2,y2 ;
#endif /*XW_PROTOTYPE*/
{
XW_EXT_WINDOW *pwindow = (XW_EXT_WINDOW*)awindow;
XW_EXT_BUFFER *pbuffer ;
int status ;
int nseg,bindex;
int ix1,iy1,ix2,iy2 ;

	if( !Xw_isdefine_window(pwindow) ) {
	   /*ERROR*Bad EXT_WINDOW Address*/
	   Xw_set_error(24,"Xw_draw_segment",pwindow) ;
	   return (XW_ERROR) ;
	}

	bindex = _BINDEX ;
	pbuffer = &_BUFFER(bindex) ;
        for( pseglist = pbuffer->pseglist ; pseglist ;
                        pseglist = (XW_EXT_SEGMENT*)pseglist->link ) {
            if( pseglist->nseg < MAXSEGMENTS ) break ;
        }
             
        if( !pseglist ) {
            pseglist = Xw_add_segment_structure(pbuffer) ;
	}


	if( !pseglist ) return XW_ERROR ;

//OCC186
	ix1 = PXPOINT(x1, pwindow->xratio) ;
	iy1 = PYPOINT(y1, pwindow->attributes.height, pwindow->yratio) ;
	ix2 = PXPOINT(x2, pwindow->xratio) ;
	iy2 = PYPOINT(y2, pwindow->attributes.height, pwindow->yratio) ;
//OCC186

	nseg = pseglist->nseg ;

#ifdef S3593
	if( pwindow->clipflag ) {
#endif
	  status = Xw_clip_segment(pwindow,ix1,iy1,ix2,iy2,
					&pseglist->rsegments[nseg]);
	  if( status < 0 ) return (XW_SUCCESS);
#ifdef S3593
	} else {
	  pseglist->rsegments[nseg].x1 = ix1 ;
	  pseglist->rsegments[nseg].y1 = iy1 ;
	  pseglist->rsegments[nseg].x2 = ix2 ;
	  pseglist->rsegments[nseg].y2 = iy2 ;
	}
#endif
	pseglist->nseg++ ;

	if( bindex > 0 ) {
	    pbuffer->isempty = False ;
	    if( ix1 < ix2 ) {
	      pbuffer->rxmin = min(pbuffer->rxmin,ix1) ;
	      pbuffer->rxmax = max(pbuffer->rxmax,ix2) ;
	    } else {
	      pbuffer->rxmin = min(pbuffer->rxmin,ix2) ;
	      pbuffer->rxmax = max(pbuffer->rxmax,ix1) ;
	    }
	    if( iy1 < iy2 ) {
	      pbuffer->rymin = min(pbuffer->rymin,iy1) ;
	      pbuffer->rymax = max(pbuffer->rymax,iy2) ;
	    } else {
	      pbuffer->rymin = min(pbuffer->rymin,iy2) ;
	      pbuffer->rymax = max(pbuffer->rymax,iy1) ;
	    }
	} else if( !BeginSegments ) {
	    int index = pwindow->lineindex ;
	    Xw_draw_pixel_segments(pwindow,pseglist,pwindow->qgline[index].gc) ;
	    pseglist->nseg = 0 ;
	}

#ifdef  TRACE_DRAW_SEGMENT
if( Xw_get_trace() > 2 ) {
    printf(" Xw_draw_segment(%lx,%f,%f,%f,%f\n",(long ) pwindow,x1,y1,x2,y2) ;
}
#endif

	return (XW_SUCCESS);
}

#ifdef XW_PROTOTYPE
void Xw_draw_pixel_segments(XW_EXT_WINDOW* pwindow,XW_EXT_SEGMENT *pseglist,GC gc)
#else
void Xw_draw_pixel_segments(pwindow,pseglist,gc)
XW_EXT_WINDOW *pwindow;
XW_EXT_SEGMENT *pseglist;
GC gc ;
#endif /*XW_PROTOTYPE*/
{

	if( pseglist->isupdated ) {
	  XDrawSegments(_DISPLAY,_DRAWABLE,gc,
			pseglist->usegments,pseglist->nseg) ;
	} else {
	  XDrawSegments(_DISPLAY,_DRAWABLE,gc,
			pseglist->rsegments,pseglist->nseg) ;
	}

#ifdef  TRACE_DRAW_SEGMENT
if( Xw_get_trace() > 2 ) {
    printf(" %d = Xw_draw_pixel_segments(%lx,%lx,%lx\n",pseglist->nseg,(long ) pwindow,(long ) pseglist,(long ) gc) ;
}
#endif
}

/*
   STATUS Xw_begin_segments (awindow,nsegment):
   XW_EXT_WINDOW *awindow
   int nsegment           Not used


        Begin a set of segments which must be filled by Xw_draw_segment and
                                     closed by Xw_close_segments 

        returns ERROR if bad extended window address 
        returns SUCCESS if successful

*/
 
#ifdef XW_PROTOTYPE
XW_STATUS Xw_begin_segments(void* awindow,int nsegment)
#else
XW_STATUS Xw_begin_segments(awindow,nsegment)
void *awindow ;
int nsegment ;
#endif /*XW_PROTOTYPE*/
{
XW_EXT_WINDOW *pwindow = (XW_EXT_WINDOW*)awindow ;
 
        if( !Xw_isdefine_window(pwindow) ) {
            /*ERROR*Bad EXT_WINDOW Address*/
            Xw_set_error(24,"Xw_begin_segments",pwindow) ;
            return (XW_ERROR) ;
        }    

        if( BeginSegments ) Xw_close_segments(pwindow);
	
	BeginSegments = True;
 
#ifdef  TRACE_DRAW_LINE
if( Xw_get_trace() > 2 ) {
    printf(" Xw_begin_segments(%x,%d)\n",pwindow,nsegment) ;
}
#endif
        return (XW_SUCCESS) ;
}

/*
   STATUS Xw_close_segments (awindow):
   XW_EXT_WINDOW *awindow

        Close the set of segments 

        returns ERROR if bad extended window address 
        returns SUCCESS successful

*/
 
#ifdef XW_PROTOTYPE
XW_STATUS Xw_close_segments(void* awindow)
#else
XW_STATUS Xw_close_segments(awindow)
void *awindow ;
#endif /*XW_PROTOTYPE*/
{
XW_EXT_WINDOW *pwindow = (XW_EXT_WINDOW*)awindow ;
XW_EXT_BUFFER *pbuffer ;
int bindex ;
 
	bindex = _BINDEX ; 
	pbuffer = &_BUFFER(bindex) ;
        if( BeginSegments && !bindex ) {
	  int index = pwindow->lineindex ;
	  for( pseglist = pbuffer->pseglist ; pseglist ;
				pseglist = (XW_EXT_SEGMENT*)pseglist->link ) {
	    if( pseglist->nseg ) {
              Xw_draw_pixel_segments(pwindow,pseglist,
						pwindow->qgline[index].gc) ;
	      pseglist->nseg = 0 ;
	    } else break ;
	  }
        }
 
	BeginSegments = False; 

#ifdef  TRACE_DRAW_SEGMENT
if( Xw_get_trace() > 2 ) {
    printf(" Xw_close_segments(%lx)\n",(long ) pwindow) ;
}
#endif
        return (XW_SUCCESS) ;
}
 
#ifdef XW_PROTOTYPE
XW_EXT_SEGMENT* Xw_add_segment_structure(XW_EXT_BUFFER* pbuflist )
#else
XW_EXT_SEGMENT* Xw_add_segment_structure(pbuflist )
XW_EXT_BUFFER *pbuflist ;
#endif /*XW_PROTOTYPE*/
/*
        Create and Insert at end one Extended segment structure in the
        segment List

        returns Extended segment address if successful
                or NULL if Bad Allocation
*/
{
XW_EXT_SEGMENT *pseg ;

	pseg = (XW_EXT_SEGMENT*) Xw_malloc(sizeof(XW_EXT_SEGMENT)) ;
        if( pseg ) {
            pseg->link = pbuflist->pseglist ;
            pseg->isupdated = False ;
            pseg->nseg = 0 ;
	    pbuflist->pseglist = pseg ;
        } else {
	    /*ERROR*EXT_SEGMENT Allocation failed*/
	    Xw_set_error(35,"Xw_add_segment_structure",NULL) ;
        }

        return (pseg) ;
}

#ifdef XW_PROTOTYPE
XW_STATUS Xw_del_segment_structure(XW_EXT_BUFFER* pbuflist)
#else
XW_STATUS Xw_del_segment_structure(pbuflist)
XW_EXT_BUFFER *pbuflist ;
#endif /*XW_PROTOTYPE*/
/*
        Remove ALL Extended segment structure in the
        segment List

        SUCCESS always
*/
{
XW_EXT_SEGMENT *pseg,*qseg ;

      	for( pseg = pbuflist->pseglist ; pseg ; pseg = qseg ) {
            qseg = (XW_EXT_SEGMENT*)pseg->link ;
            Xw_free(pseg) ;
        }
	pbuflist->pseglist = NULL ;
	
	return (XW_SUCCESS) ;
}

#define MINXCOORD -32768
#define MAXXCOORD 32767 
#define MINYCOORD -32768
#define MAXYCOORD 32767 

#ifdef XW_PROTOTYPE
int Xw_clip_segment (XW_EXT_WINDOW* pwindow,int x1,int y1,int x2,int y2,XSegment* pseg)
#else
int Xw_clip_segment (pwindow,x1,y1,x2,y2,pseg)
XW_EXT_WINDOW *pwindow;
int x1,y1,x2,y2;
XSegment *pseg;	
#endif /*XW_PROTOTYPE*/
/*
	Clip a segment when one coord is < MINCOORD or > MAXCOORD.
	Returns the clipped segment and a clip bit-mask status :

	  0   Nothing is clipped
	  1   X first point is clipped on MAX
	  2   X first point is clipped on MIN
	  4   Y first point is clipped on MAX
	  8   Y first point is clipped on MIN
	  16  X second point is clipped on MAX
	  32  X second point is clipped on MIN
	  64  Y second point is clipped on MAX
	  128 Y second point is clipped on MIN
	  -1 segment is out of space.
*/
{
int xx1 = x1,yy1 = y1,xx2 = x2,yy2 = y2;
int status = 0;

	if( xx1 > MAXXCOORD ) {
	  if( xx2 < MAXXCOORD ) {
	    float rap = (float)(yy2 - yy1)/(xx2 - xx1);
	    yy1 += (int)((MAXXCOORD - xx1) * rap); 
	    xx1 = MAXXCOORD;
	    status |= 1;
	  } else return -1;
	} else if( xx1 < MINXCOORD ) { 
	  if( xx2 > MINXCOORD ) {
	    float rap = (float)(yy2 - yy1)/(xx2 - xx1);
	    yy1 += (int)((MINXCOORD - xx1) * rap); 
	    xx1 = MINXCOORD;
	    status |= 2;
	  } else return -1;
	} 

        if( yy1 > MAXYCOORD ) {
	  if( yy2 < MAXYCOORD ) {
	    float rap = (float)(xx2 - xx1)/(yy2 - yy1);
	    xx1 += (int)((MAXYCOORD - yy1) * rap); 
	    yy1 = MAXYCOORD;
	    status |= 4;
	  } else return -1;
	} else if( yy1 < MINYCOORD ) { 
	  if( yy2 > MINYCOORD ) {
	    float rap = (float)(xx2 - xx1)/(yy2 - yy1);
	    xx1 += (int)((MINYCOORD - yy1) * rap); 
	    yy1 = MINYCOORD;
	    status |= 8;
	  } else return -1;
	}

	if( xx2 > MAXXCOORD ) {
	  float rap = (float)(yy2 - yy1)/(xx2 - xx1);
	  yy2 = yy1 + (int)((MAXXCOORD - xx1) * rap); 
	  xx2 = MAXXCOORD;
	  status |= 16;
	} else if( xx2 < MINXCOORD ) { 
	  float rap = (float)(yy2 - yy1)/(xx2 - xx1);
	  yy2 = yy1 + (int)((MINXCOORD - xx1) * rap); 
	  xx2 = MINXCOORD;
	  status |= 32;
	} 

        if( yy2 > MAXYCOORD ) {
	  float rap = (float)(xx2 - xx1)/(yy2 - yy1);
	  xx2 = xx1 + (int)((MAXYCOORD - yy1) * rap); 
	  yy2 = MAXYCOORD;
	  status |= 64;
	} else if( yy2 < MINYCOORD ) { 
	  float rap = (float)(xx2 - xx1)/(yy2 - yy1);
	  xx2 = xx1 + (int)((MINYCOORD - yy1) * rap); 
	  yy2 = MINYCOORD;
	  status |= 128;
	}

	pseg->x1 = xx1;
	pseg->y1 = yy1;
	pseg->x2 = xx2;
	pseg->y2 = yy2;

  	return status;
}
Commit	Line	Data
b311480e	1	// Copyright (c) 1999-2012 OPEN CASCADE SAS
	2	//
	3	// The content of this file is subject to the Open CASCADE Technology Public
	4	// License Version 6.5 (the "License"). You may not use the content of this file
	5	// except in compliance with the License. Please obtain a copy of the License
	6	// at http://www.opencascade.org and read it completely before using this file.
	7	//
	8	// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
	9	// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
	10	//
	11	// The Original Code and all software distributed under the License is
	12	// distributed on an "AS IS" basis, without warranty of any kind, and the
	13	// Initial Developer hereby disclaims all such warranties, including without
	14	// limitation, any warranties of merchantability, fitness for a particular
	15	// purpose or non-infringement. Please see the License for the specific terms
	16	// and conditions governing the rights and limitations under the License.
	17
7fd59977	18
7fd59977	19	#define S3593 /*GG_130398
b311480e	20	OPTIMISATION MFT
7fd59977	21	Activer le clipping de maniere optionnelle
	22	*/
	23
	24	#include <Xw_Extension.h>
	25
	26	/* ifdef then trace on */
	27	#ifdef TRACE
	28	#define TRACE_DRAW_SEGMENT
	29	#endif
	30
	31	static XW_EXT_SEGMENT *pseglist ;
	32	static int BeginSegments = False ;
	33
	34	/*
	35	STATUS Xw_draw_segment (awindow,x1,y1,x2,y2):
	36	XW_EXT_WINDOW *awindow
	37	float x1,y1 First point Coordinates defined in User Space
	38	float x2,y2 Second point Coordinates defined in User Space
	39
	40	Display segment in current QG set by set_line_attrib .
	41	Note that segments can be buffered depending of the DisplayMode context
	42	and Flush at Xw_flush time .
	43
	44	returns SUCCESS always
	45
	46	*/
	47
	48	#ifdef XW_PROTOTYPE
	49	XW_STATUS Xw_draw_segment (void* awindow,float x1,float y1,float x2,float y2)
	50	#else
	51	XW_STATUS Xw_draw_segment (awindow,x1,y1,x2,y2)
	52	void *awindow;
	53	float x1,y1,x2,y2 ;
	54	#endif /XW_PROTOTYPE/
	55	{
	56	XW_EXT_WINDOW pwindow = (XW_EXT_WINDOW)awindow;
	57	XW_EXT_BUFFER *pbuffer ;
	58	int status ;
	59	int nseg,bindex;
	60	int ix1,iy1,ix2,iy2 ;
	61
	62	if( !Xw_isdefine_window(pwindow) ) {
	63	/ERRORBad EXT_WINDOW Address*/
	64	Xw_set_error(24,"Xw_draw_segment",pwindow) ;
	65	return (XW_ERROR) ;
	66	}
	67
	68	bindex = _BINDEX ;
	69	pbuffer = &_BUFFER(bindex) ;
	70	for( pseglist = pbuffer->pseglist ; pseglist ;
	71	pseglist = (XW_EXT_SEGMENT*)pseglist->link ) {
	72	if( pseglist->nseg < MAXSEGMENTS ) break ;
	73	}
	74
	75	if( !pseglist ) {
	76	pseglist = Xw_add_segment_structure(pbuffer) ;
	77	}
	78
	79
	80	if( !pseglist ) return XW_ERROR ;
	81
	82	//OCC186
	83	ix1 = PXPOINT(x1, pwindow->xratio) ;
	84	iy1 = PYPOINT(y1, pwindow->attributes.height, pwindow->yratio) ;
85	ix2 = PXPOINT(x2, pwindow->xratio) ;
86	iy2 = PYPOINT(y2, pwindow->attributes.height, pwindow->yratio) ;
87	//OCC186
88
89	nseg = pseglist->nseg ;
90
91	#ifdef S3593
92	if( pwindow->clipflag ) {
93	#endif
94	status = Xw_clip_segment(pwindow,ix1,iy1,ix2,iy2,
95	&pseglist->rsegments[nseg]);
96	if( status < 0 ) return (XW_SUCCESS);
97	#ifdef S3593
98	} else {
99	pseglist->rsegments[nseg].x1 = ix1 ;
100	pseglist->rsegments[nseg].y1 = iy1 ;
101	pseglist->rsegments[nseg].x2 = ix2 ;
102	pseglist->rsegments[nseg].y2 = iy2 ;
103	}
104	#endif
105	pseglist->nseg++ ;
106
107	if( bindex > 0 ) {
108	pbuffer->isempty = False ;
109	if( ix1 < ix2 ) {
110	pbuffer->rxmin = min(pbuffer->rxmin,ix1) ;
111	pbuffer->rxmax = max(pbuffer->rxmax,ix2) ;
112	} else {
113	pbuffer->rxmin = min(pbuffer->rxmin,ix2) ;
114	pbuffer->rxmax = max(pbuffer->rxmax,ix1) ;
115	}
116	if( iy1 < iy2 ) {
117	pbuffer->rymin = min(pbuffer->rymin,iy1) ;
118	pbuffer->rymax = max(pbuffer->rymax,iy2) ;
119	} else {
120	pbuffer->rymin = min(pbuffer->rymin,iy2) ;
121	pbuffer->rymax = max(pbuffer->rymax,iy1) ;
122	}
123	} else if( !BeginSegments ) {
124	int index = pwindow->lineindex ;
125	Xw_draw_pixel_segments(pwindow,pseglist,pwindow->qgline[index].gc) ;
126	pseglist->nseg = 0 ;
127	}
128
129	#ifdef TRACE_DRAW_SEGMENT
130	if( Xw_get_trace() > 2 ) {
131	printf(" Xw_draw_segment(%lx,%f,%f,%f,%f\n",(long ) pwindow,x1,y1,x2,y2) ;
132	}
133	#endif
134
135	return (XW_SUCCESS);
136	}
137
138	#ifdef XW_PROTOTYPE
139	void Xw_draw_pixel_segments(XW_EXT_WINDOW* pwindow,XW_EXT_SEGMENT *pseglist,GC gc)
140	#else
141	void Xw_draw_pixel_segments(pwindow,pseglist,gc)
142	XW_EXT_WINDOW *pwindow;
143	XW_EXT_SEGMENT *pseglist;
144	GC gc ;
145	#endif /XW_PROTOTYPE/
146	{
147
148	if( pseglist->isupdated ) {
149	XDrawSegments(_DISPLAY,_DRAWABLE,gc,
150	pseglist->usegments,pseglist->nseg) ;
151	} else {
152	XDrawSegments(_DISPLAY,_DRAWABLE,gc,
153	pseglist->rsegments,pseglist->nseg) ;
154	}
155
156	#ifdef TRACE_DRAW_SEGMENT
157	if( Xw_get_trace() > 2 ) {
158	printf(" %d = Xw_draw_pixel_segments(%lx,%lx,%lx\n",pseglist->nseg,(long ) pwindow,(long ) pseglist,(long ) gc) ;
159	}
160	#endif
161	}
162
163	/*
164	STATUS Xw_begin_segments (awindow,nsegment):
165	XW_EXT_WINDOW *awindow
166	int nsegment Not used
167
168
169	Begin a set of segments which must be filled by Xw_draw_segment and
170	closed by Xw_close_segments
171
172	returns ERROR if bad extended window address
173	returns SUCCESS if successful
174
175	*/
176
177	#ifdef XW_PROTOTYPE
178	XW_STATUS Xw_begin_segments(void* awindow,int nsegment)
179	#else
180	XW_STATUS Xw_begin_segments(awindow,nsegment)
181	void *awindow ;
182	int nsegment ;
183	#endif /XW_PROTOTYPE/
184	{
185	XW_EXT_WINDOW pwindow = (XW_EXT_WINDOW)awindow ;
186
187	if( !Xw_isdefine_window(pwindow) ) {
188	/ERRORBad EXT_WINDOW Address*/
189	Xw_set_error(24,"Xw_begin_segments",pwindow) ;
190	return (XW_ERROR) ;
191	}
192
193	if( BeginSegments ) Xw_close_segments(pwindow);
194
195	BeginSegments = True;
196
197	#ifdef TRACE_DRAW_LINE
198	if( Xw_get_trace() > 2 ) {
199	printf(" Xw_begin_segments(%x,%d)\n",pwindow,nsegment) ;
200	}
201	#endif
202	return (XW_SUCCESS) ;
203	}
204
205	/*
206	STATUS Xw_close_segments (awindow):
207	XW_EXT_WINDOW *awindow
208
209	Close the set of segments
210
211	returns ERROR if bad extended window address
212	returns SUCCESS successful
213
214	*/
215
216	#ifdef XW_PROTOTYPE
217	XW_STATUS Xw_close_segments(void* awindow)
218	#else
219	XW_STATUS Xw_close_segments(awindow)
220	void *awindow ;
221	#endif /XW_PROTOTYPE/
222	{
223	XW_EXT_WINDOW pwindow = (XW_EXT_WINDOW)awindow ;
224	XW_EXT_BUFFER *pbuffer ;
225	int bindex ;
226
227	bindex = _BINDEX ;
228	pbuffer = &_BUFFER(bindex) ;
229	if( BeginSegments && !bindex ) {
230	int index = pwindow->lineindex ;
231	for( pseglist = pbuffer->pseglist ; pseglist ;
232	pseglist = (XW_EXT_SEGMENT*)pseglist->link ) {
233	if( pseglist->nseg ) {
234	Xw_draw_pixel_segments(pwindow,pseglist,
235	pwindow->qgline[index].gc) ;
236	pseglist->nseg = 0 ;
237	} else break ;
238	}
239	}
240
241	BeginSegments = False;
242
243	#ifdef TRACE_DRAW_SEGMENT
244	if( Xw_get_trace() > 2 ) {
245	printf(" Xw_close_segments(%lx)\n",(long ) pwindow) ;
246	}
247	#endif
248	return (XW_SUCCESS) ;
249	}
250
251	#ifdef XW_PROTOTYPE
252	XW_EXT_SEGMENT* Xw_add_segment_structure(XW_EXT_BUFFER* pbuflist )
253	#else
254	XW_EXT_SEGMENT* Xw_add_segment_structure(pbuflist )
255	XW_EXT_BUFFER *pbuflist ;
256	#endif /XW_PROTOTYPE/
257	/*
258	Create and Insert at end one Extended segment structure in the
259	segment List
260
261	returns Extended segment address if successful
262	or NULL if Bad Allocation
263	*/
264	{
265	XW_EXT_SEGMENT *pseg ;
266
267	pseg = (XW_EXT_SEGMENT*) Xw_malloc(sizeof(XW_EXT_SEGMENT)) ;
268	if( pseg ) {
269	pseg->link = pbuflist->pseglist ;
270	pseg->isupdated = False ;
271	pseg->nseg = 0 ;
272	pbuflist->pseglist = pseg ;
273	} else {
274	/ERROREXT_SEGMENT Allocation failed*/
275	Xw_set_error(35,"Xw_add_segment_structure",NULL) ;
276	}
277
278	return (pseg) ;
279	}
280
281	#ifdef XW_PROTOTYPE
282	XW_STATUS Xw_del_segment_structure(XW_EXT_BUFFER* pbuflist)
283	#else
284	XW_STATUS Xw_del_segment_structure(pbuflist)
285	XW_EXT_BUFFER *pbuflist ;
286	#endif /XW_PROTOTYPE/
287	/*
288	Remove ALL Extended segment structure in the
289	segment List
290
291	SUCCESS always
292	*/
293	{
294	XW_EXT_SEGMENT pseg,qseg ;
295
296	for( pseg = pbuflist->pseglist ; pseg ; pseg = qseg ) {
297	qseg = (XW_EXT_SEGMENT*)pseg->link ;
298	Xw_free(pseg) ;
299	}
300	pbuflist->pseglist = NULL ;
301
302	return (XW_SUCCESS) ;
303	}
304
305	#define MINXCOORD -32768
306	#define MAXXCOORD 32767
307	#define MINYCOORD -32768
308	#define MAXYCOORD 32767
309
310	#ifdef XW_PROTOTYPE
311	int Xw_clip_segment (XW_EXT_WINDOW* pwindow,int x1,int y1,int x2,int y2,XSegment* pseg)
312	#else
313	int Xw_clip_segment (pwindow,x1,y1,x2,y2,pseg)
314	XW_EXT_WINDOW *pwindow;
315	int x1,y1,x2,y2;
316	XSegment *pseg;
317	#endif /XW_PROTOTYPE/
318	/*
319	Clip a segment when one coord is < MINCOORD or > MAXCOORD.
320	Returns the clipped segment and a clip bit-mask status :
321
322	0 Nothing is clipped
323	1 X first point is clipped on MAX
324	2 X first point is clipped on MIN
325	4 Y first point is clipped on MAX
326	8 Y first point is clipped on MIN
327	16 X second point is clipped on MAX
328	32 X second point is clipped on MIN
329	64 Y second point is clipped on MAX
330	128 Y second point is clipped on MIN
331	-1 segment is out of space.
332	*/
333	{
334	int xx1 = x1,yy1 = y1,xx2 = x2,yy2 = y2;
335	int status = 0;
336
337	if( xx1 > MAXXCOORD ) {
338	if( xx2 < MAXXCOORD ) {
339	float rap = (float)(yy2 - yy1)/(xx2 - xx1);
340	yy1 += (int)((MAXXCOORD - xx1) * rap);
341	xx1 = MAXXCOORD;
342	status \|= 1;
343	} else return -1;
344	} else if( xx1 < MINXCOORD ) {
345	if( xx2 > MINXCOORD ) {
346	float rap = (float)(yy2 - yy1)/(xx2 - xx1);
347	yy1 += (int)((MINXCOORD - xx1) * rap);
348	xx1 = MINXCOORD;
349	status \|= 2;
350	} else return -1;
351	}
352
353	if( yy1 > MAXYCOORD ) {
354	if( yy2 < MAXYCOORD ) {
355	float rap = (float)(xx2 - xx1)/(yy2 - yy1);
356	xx1 += (int)((MAXYCOORD - yy1) * rap);
357	yy1 = MAXYCOORD;
358	status \|= 4;
359	} else return -1;
360	} else if( yy1 < MINYCOORD ) {
361	if( yy2 > MINYCOORD ) {
362	float rap = (float)(xx2 - xx1)/(yy2 - yy1);
363	xx1 += (int)((MINYCOORD - yy1) * rap);
364	yy1 = MINYCOORD;
365	status \|= 8;
366	} else return -1;
367	}
368
369	if( xx2 > MAXXCOORD ) {
370	float rap = (float)(yy2 - yy1)/(xx2 - xx1);
371	yy2 = yy1 + (int)((MAXXCOORD - xx1) * rap);
372	xx2 = MAXXCOORD;
373	status \|= 16;
374	} else if( xx2 < MINXCOORD ) {
375	float rap = (float)(yy2 - yy1)/(xx2 - xx1);
376	yy2 = yy1 + (int)((MINXCOORD - xx1) * rap);
377	xx2 = MINXCOORD;
378	status \|= 32;
379	}
380
381	if( yy2 > MAXYCOORD ) {
382	float rap = (float)(xx2 - xx1)/(yy2 - yy1);
383	xx2 = xx1 + (int)((MAXYCOORD - yy1) * rap);
384	yy2 = MAXYCOORD;
385	status \|= 64;
386	} else if( yy2 < MINYCOORD ) {
387	float rap = (float)(xx2 - xx1)/(yy2 - yy1);
388	xx2 = xx1 + (int)((MINYCOORD - yy1) * rap);
389	yy2 = MINYCOORD;
390	status \|= 128;
391	}
392
393	pseg->x1 = xx1;
394	pseg->y1 = yy1;
395	pseg->x2 = xx2;
396	pseg->y2 = yy2;
397
398	return status;
399	}