1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/* This file contains the bezier2 and bezier3 methods, which are GNU
extensions to libplot. Each of them draws an object: a quadratic and a
cubic Bezier path segment, respectively. */
#include "sys-defines.h"
#include "extern.h"
int
#ifdef _HAVE_PROTOS
_API_fbezier2 (R___(Plotter *_plotter) double x0, double y0, double x1, double y1, double x2, double y2)
#else
_API_fbezier2 (R___(_plotter) x0, y0, x1, y1, x2, y2)
S___(Plotter *_plotter;)
double x0, y0, x1, y1, x2, y2;
#endif
{
int prev_num_segments;
plPoint p0, p1, p2;
if (!_plotter->data->open)
{
_plotter->error (R___(_plotter)
"fbezier2: invalid operation");
return -1;
}
if (_plotter->drawstate->path != (plPath *)NULL
&& (_plotter->drawstate->path->type != PATH_SEGMENT_LIST
||
(_plotter->drawstate->path->type == PATH_SEGMENT_LIST
&& _plotter->drawstate->path->primitive)))
/* There's a simple path under construction (so that endsubpath() must
not have been invoked), and it contains a closed primitive
(box/circle/ellipse). So flush out the whole compound path. (It
may include other, previously drawn simple paths.) */
_API_endpath (S___(_plotter));
/* if new segment not contiguous, move to its starting point (first
flushing out the compound path under construction, if any) */
if (x0 != _plotter->drawstate->pos.x
|| y0 != _plotter->drawstate->pos.y)
{
if (_plotter->drawstate->path)
_API_endpath (S___(_plotter));
_plotter->drawstate->pos.x = x0;
_plotter->drawstate->pos.y = y0;
}
p0.x = x0; p0.y = y0;
p1.x = x1; p1.y = y1;
p2.x = x2; p2.y = y2;
if (_plotter->drawstate->path == (plPath *)NULL)
/* begin a new path, of segment list type */
{
_plotter->drawstate->path = _new_plPath ();
prev_num_segments = 0;
_add_moveto (_plotter->drawstate->path, p0);
}
else
prev_num_segments = _plotter->drawstate->path->num_segments;
/* Trivial case: if linemode is "disconnected", just plot a line segment
from (x0,y0) to (x2,y2). Only the endpoints will appear on the
display. */
if (!_plotter->drawstate->points_are_connected)
_add_line (_plotter->drawstate->path, p2);
/* Another trivial case: treat a zero-length arc as a line segment */
else if (x0 == x2 && y0 == y2)
_add_line (_plotter->drawstate->path, p2);
else
/* standard (non-trivial) case */
{
/* if segment buffer is occupied by a single arc, replace arc by a
polyline if that's called for (Plotter-dependent) */
if (_plotter->data->have_mixed_paths == false
&& _plotter->drawstate->path->num_segments == 2)
{
_maybe_replace_arc (S___(_plotter));
if (_plotter->drawstate->path->num_segments > 2)
prev_num_segments = 0;
}
/* add new quadratic Bezier segment to the path buffer */
if (_plotter->data->allowed_quad_scaling == AS_ANY)
/* add as a primitive element, since it's allowed */
_add_bezier2 (_plotter->drawstate->path, p1, p2);
else if (_plotter->data->allowed_cubic_scaling == AS_ANY)
/* add quadratic Bezier as a cubic Bezier, since it's allowed */
{
/* (control points need to be computed) */
plPoint p, pc, pd;
p.x = x2;
p.y = y2;
pc.x = (2.0 * x1 + x0) / 3.0;
pc.y = (2.0 * y1 + y0) / 3.0;
pd.x = (2.0 * x1 + x2) / 3.0;
pd.y = (2.0 * y1 + y2) / 3.0;
_add_bezier3 (_plotter->drawstate->path, pc, pd, p);
}
else
/* add quadratic Bezier segment as a polygonal approximation */
_add_bezier2_as_lines (_plotter->drawstate->path, p1, p2);
}
/* move to endpoint */
_plotter->drawstate->pos = p2;
/* pass all the newly added segments to the Plotter-specific function
maybe_paint_segments(), since some Plotters plot paths in real time,
i.e., prepaint them, rather than waiting until endpath() is called */
_plotter->maybe_prepaint_segments (R___(_plotter) prev_num_segments);
/* If the path is getting too long (and it doesn't have to be filled),
flush it out by invoking endpath(), and begin a new one. `Too long'
is Plotter-dependent; some don't do this flushing at all. */
if ((_plotter->drawstate->path->num_segments
>= _plotter->data->max_unfilled_path_length)
&& (_plotter->drawstate->fill_type == 0)
&& _plotter->path_is_flushable (S___(_plotter)))
_API_endpath (S___(_plotter));
return 0;
}
int
#ifdef _HAVE_PROTOS
_API_fbezier3 (R___(Plotter *_plotter) double x0, double y0, double x1, double y1, double x2, double y2, double x3, double y3)
#else
_API_fbezier3 (R___(_plotter) x0, y0, x1, y1, x2, y2, x3, y3)
S___(Plotter *_plotter;)
double x0, y0, x1, y1, x2, y2, x3, y3;
#endif
{
int prev_num_segments;
plPoint p0, p1, p2, p3;
if (!_plotter->data->open)
{
_plotter->error (R___(_plotter)
"fbezier3: invalid operation");
return -1;
}
if (_plotter->drawstate->path != (plPath *)NULL
&& (_plotter->drawstate->path->type != PATH_SEGMENT_LIST
||
(_plotter->drawstate->path->type == PATH_SEGMENT_LIST
&& _plotter->drawstate->path->primitive)))
/* There's a simple path under construction (so that endsubpath() must
not have been invoked), and it contains a closed primitive
(box/circle/ellipse). So flush out the whole compound path. (It
may include other, previously drawn simple paths.) */
_API_endpath (S___(_plotter));
/* if new segment not contiguous, move to its starting point (first
flushing out the compound path under construction, if any) */
if (x0 != _plotter->drawstate->pos.x
|| y0 != _plotter->drawstate->pos.y)
{
if (_plotter->drawstate->path)
_API_endpath (S___(_plotter));
_plotter->drawstate->pos.x = x0;
_plotter->drawstate->pos.y = y0;
}
p0.x = x0; p0.y = y0;
p1.x = x1; p1.y = y1;
p2.x = x2; p2.y = y2;
p3.x = x3; p3.y = y3;
if (_plotter->drawstate->path == (plPath *)NULL)
/* begin a new path, of segment list type */
{
_plotter->drawstate->path = _new_plPath ();
prev_num_segments = 0;
_add_moveto (_plotter->drawstate->path, p0);
}
else
prev_num_segments = _plotter->drawstate->path->num_segments;
/* Trivial case: if linemode is "disconnected", just plot a line segment
from (x0,y0) to (x2,y2). Only the endpoints will appear on the
display. */
if (!_plotter->drawstate->points_are_connected)
_add_line (_plotter->drawstate->path, p3);
/* Another trivial case: treat a zero-length arc as a line segment */
else if (x0 == x3 && y0 == y3)
_add_line (_plotter->drawstate->path, p3);
else
/* standard (non-trivial) case */
{
/* if segment buffer is occupied by a single arc, replace arc by a
polyline if that's called for (Plotter-dependent) */
if (_plotter->data->have_mixed_paths == false
&& _plotter->drawstate->path->num_segments == 2)
{
_maybe_replace_arc (S___(_plotter));
if (_plotter->drawstate->path->num_segments > 2)
prev_num_segments = 0;
}
/* add new cubic Bezier segment to the segment buffer */
if (_plotter->data->allowed_cubic_scaling == AS_ANY)
/* add as a primitive element, since it's allowed */
_add_bezier3 (_plotter->drawstate->path, p1, p2, p3);
else
/* add cubic Bezier segment as a polygonal approximation */
_add_bezier3_as_lines (_plotter->drawstate->path, p1, p2, p3);
}
/* move to endpoint */
_plotter->drawstate->pos = p3;
/* pass all the newly added segments to the Plotter-specific function
maybe_paint_segments(), since some Plotters plot paths in real time,
i.e., prepaint them, rather than waiting until endpath() is called */
_plotter->maybe_prepaint_segments (R___(_plotter) prev_num_segments);
/* If the path is getting too long (and it doesn't have to be filled),
flush it out by invoking endpath(), and begin a new one. `Too long'
is Plotter-dependent; some don't do this flushing at all. */
if ((_plotter->drawstate->path->num_segments
>= _plotter->data->max_unfilled_path_length)
&& (_plotter->drawstate->fill_type == 0)
&& _plotter->path_is_flushable (S___(_plotter)))
_API_endpath (S___(_plotter));
return 0;
}
|
