1 /* ADG - Automatic Drawing Generation
2 * Copyright (C) 2007,2008,2009 Nicola Fontana <ntd at entidi.it>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
24 * @short_description: The basic model representing a generic path
26 * The #AdgPath model is a virtual path: in a few words, it is a
27 * simple conceptual #cairo_path_t struct. This class implements
28 * methods to manipulate the underlying cairo path.
30 * Although some of the provided methods are clearly based on the
31 * original cairo path manipulation API, their behavior could be
32 * sligthly different. This is intentional, because the ADG provides
33 * additional path manipulation algorithms, sometime quite complex,
34 * and a more restrictive filter on the path quality is required.
35 * Also, the ADG is designed to be used by technicians while cairo
36 * targets a broader range of developers.
38 * As an example, following the rule of the less surprise, some
39 * cairo functions guess the current point when it is not defined,
40 * while the #AdgPath methods trigger a warning without other effect.
41 * Furthermore, after a cairo_path_close_path() call a MOVE_TO
42 * primitive to the starting point of the segment is automatically
43 * added by cairo while in the ADG, after an adg_path_close(), the
44 * current point is simply unset.
48 #include "adg-path-private.h"
54 static void finalize (GObject
*object
);
55 static void changed (AdgModel
*model
);
56 static void clear_cairo_path (AdgPath
*path
);
57 static cairo_path_t
* get_cairo_path (AdgPath
*path
);
58 static cairo_path_t
* get_cpml_path (AdgPath
*path
);
59 static GArray
* arc_to_curves (GArray
*array
,
60 const cairo_path_data_t
*src
);
61 static void append_primitive_valist (AdgPath
*path
,
62 cairo_path_data_type_t type
,
65 static cairo_path_data_t
*
66 create_nodes_valist (cairo_path_data_type_t type
,
69 static void clear_operation (AdgPath
*path
);
70 static gboolean
append_operation (AdgPath
*path
,
73 static void do_operation (AdgPath
*path
,
74 cairo_path_data_t
*data
);
75 static void do_chamfer (AdgPath
*path
,
76 CpmlPrimitive
*current
);
79 G_DEFINE_TYPE(AdgPath
, adg_path
, ADG_TYPE_MODEL
);
83 adg_path_class_init(AdgPathClass
*klass
)
85 GObjectClass
*gobject_class
;
86 AdgModelClass
*model_class
;
88 gobject_class
= (GObjectClass
*) klass
;
89 model_class
= (AdgModelClass
*) klass
;
91 g_type_class_add_private(klass
, sizeof(AdgPathPrivate
));
93 gobject_class
->finalize
= finalize
;
95 model_class
->changed
= changed
;
99 adg_path_init(AdgPath
*path
)
101 AdgPathPrivate
*priv
= G_TYPE_INSTANCE_GET_PRIVATE(path
, ADG_TYPE_PATH
,
104 priv
->cp_is_valid
= FALSE
;
105 priv
->path
= g_array_new(FALSE
, FALSE
, sizeof(cairo_path_data_t
));
106 priv
->cairo_path
.status
= CAIRO_STATUS_INVALID_PATH_DATA
;
107 priv
->cairo_path
.data
= NULL
;
108 priv
->cairo_path
.num_data
= 0;
109 priv
->operation
.operator = ADG_OPERATOR_NONE
;
115 finalize(GObject
*object
)
118 GObjectClass
*object_class
;
120 path
= (AdgPath
*) object
;
121 object_class
= (GObjectClass
*) adg_path_parent_class
;
123 g_array_free(path
->priv
->path
, TRUE
);
124 clear_cairo_path(path
);
125 clear_operation(path
);
127 if (object_class
->finalize
!= NULL
)
128 object_class
->finalize(object
);
135 * Creates a new path model. The path must be constructed in the @callback
136 * function: AdgPath will cache and reuse the cairo_copy_path() returned by
137 * the cairo context after the @callback call.
139 * Return value: the new model
144 return (AdgModel
*) g_object_new(ADG_TYPE_PATH
, NULL
);
149 * adg_path_get_cairo_path:
152 * Gets a pointer to the cairo path structure of @path. The return value
153 * is owned by @path and must be considered read-only.
155 * This function also converts %CAIRO_PATH_ARC_TO primitives, not
156 * recognized by cairo, into approximated Bézier curves. The conversion
157 * is cached so any furter request is O(1). This cache is cleared
158 * whenever @path is modified (by adding a new primitive or by calling
162 * <title>TODO</title>
164 * <listitem>Actually, the arcs are approximated to Bézier using the
165 * hardcoded max angle of PI/2. This should be customizable
166 * by adding, for instance, a property to the #AdgPath class
167 * with a default value of PI/2.</listitem>
171 * Return value: a pointer to the internal cairo path or %NULL on errors
174 adg_path_get_cairo_path(AdgPath
*path
)
176 g_return_val_if_fail(ADG_IS_PATH(path
), NULL
);
178 return get_cairo_path(path
);
182 * adg_path_get_cpml_path:
185 * Gets a pointer to the cairo path structure of @path. The return
186 * value is owned by @path and must not be freed.
188 * This function is similar to adg_path_get_cairo_path() but with
189 * two important differences: firstly the arc primitives are not
190 * expanded to Bézier curves and secondly the returned path is
191 * not read-only. This means it is allowed to modify the returned
192 * path as long as its size is retained and its data contains a
195 * Keep in mind any changes to @path makes the value returned by
196 * this function useless, as it is likely to contain plain garbage.
198 * Return value: a pointer to the internal cpml path or %NULL on errors
201 adg_path_get_cpml_path(AdgPath
*path
)
203 g_return_val_if_fail(ADG_IS_PATH(path
), NULL
);
205 clear_cairo_path(path
);
207 return get_cpml_path(path
);
211 * adg_path_dup_cpml_path:
214 * Gets a duplicate of the cairo path structure of @path. The return
215 * value should be freed with g_free(). The returned #cairo_path_t
216 * struct also contains the #cairo_path_data_t array in the same
217 * chunk of memory, so a g_free() to the returned pointer also frees
220 * Although quite similar to adg_path_get_cpml_path(), the use case
221 * of this method is different: being a duplicate, modifying the
222 * returned path does not modify @path itsself.
224 * Return value: a newly allocated #cairo_path_t pointer to be freed
225 * with g_free() or %NULL on errors
228 adg_path_dup_cpml_path(AdgPath
*path
)
230 cairo_path_t
*cpml_path
;
231 gsize head_size
, data_size
;
233 g_return_val_if_fail(ADG_IS_PATH(path
), NULL
);
235 head_size
= sizeof(cairo_path_t
);
236 data_size
= sizeof(cairo_path_data_t
) * path
->priv
->path
->len
;
238 /* Both the cairo_path_t struct and the cairo_path_data_t array
239 * are stored in the same chunk of memory, so only a single
240 * g_free() is needed */
241 cpml_path
= g_malloc(head_size
+ data_size
);
242 cpml_path
->status
= CAIRO_STATUS_SUCCESS
;
243 cpml_path
->data
= (cairo_path_data_t
*) ((gchar
*) cpml_path
+ head_size
);
244 cpml_path
->num_data
= path
->priv
->path
->len
;
245 memcpy(cpml_path
->data
, path
->priv
->path
->data
, data_size
);
251 * adg_path_get_current_point:
253 * @x: return value for x coordinate of the current point
254 * @y: return value for y coordinate of the current point
256 * Gets the current point of @path, which is conceptually the
257 * final point reached by the path so far.
259 * If there is no defined current point, @x and @y will both be set
260 * to 0 and a warning will be triggered. It is possible to check this
261 * in advance with adg_path_has_current_point().
263 * Most #AdgPath methods alter the current point and most of them
264 * expect a current point to be defined otherwise will fail triggering
265 * a warning. Check the description of every method for specific details.
268 adg_path_get_current_point(AdgPath
*path
, gdouble
*x
, gdouble
*y
)
270 g_return_if_fail(ADG_IS_PATH(path
));
272 if (path
->priv
->cp_is_valid
) {
273 *x
= path
->priv
->cp
.x
;
274 *y
= path
->priv
->cp
.y
;
277 g_return_if_reached();
282 * adg_path_has_current_point:
285 * Returns whether a current point is defined on @path.
286 * See adg_path_get_current_point() for details on the current point.
288 * Return value: whether a current point is defined
291 adg_path_has_current_point(AdgPath
*path
)
293 g_return_val_if_fail(ADG_IS_PATH(path
), FALSE
);
295 return path
->priv
->cp_is_valid
;
302 * Releases the internal memory hold by @path and resets its status,
303 * so that after this call @path contains an empty path.
306 adg_path_clear(AdgPath
*path
)
308 g_return_if_fail(ADG_IS_PATH(path
));
310 g_array_set_size(path
->priv
->path
, 0);
311 clear_cairo_path(path
);
312 clear_operation(path
);
319 * @type: a #cairo_data_type_t value
320 * @...: point data, specified as #AdgPair pointers
322 * Generic method to append a primitive to @path. The number of #AdgPair
323 * structs depends on @type: there is no way with this function to
324 * reserve more cairo_path_data_t structs than what is needed by the
327 * This function accepts also the special %CAIRO_PATH_ARC_TO primitive.
329 * If @path has no current point while the requested primitive needs it,
330 * a warning message will be triggered without other effect.
333 adg_path_append(AdgPath
*path
, cairo_path_data_type_t type
, ...)
337 va_start(var_args
, type
);
338 adg_path_append_valist(path
, type
, var_args
);
343 * adg_path_append_valist:
345 * @type: a #cairo_data_type_t value
346 * @var_args: point data, specified as #AdgPair pointers
348 * va_list version of adg_path_append().
351 adg_path_append_valist(AdgPath
*path
, cairo_path_data_type_t type
,
356 g_return_if_fail(ADG_IS_PATH(path
));
360 case CAIRO_PATH_CLOSE_PATH
:
361 g_return_if_fail(path
->priv
->cp_is_valid
);
365 case CAIRO_PATH_MOVE_TO
:
369 case CAIRO_PATH_LINE_TO
:
370 g_return_if_fail(path
->priv
->cp_is_valid
);
374 case CAIRO_PATH_ARC_TO
:
375 g_return_if_fail(path
->priv
->cp_is_valid
);
379 case CAIRO_PATH_CURVE_TO
:
380 g_return_if_fail(path
->priv
->cp_is_valid
);
385 g_assert_not_reached();
389 append_primitive_valist(path
, type
, length
, var_args
);
393 * adg_path_append_cairo_path:
395 * @cairo_path: the #cairo_path_t path to append
397 * Appends a whole cairo path to @path.
400 adg_path_append_cairo_path(AdgPath
*path
, const cairo_path_t
*cairo_path
)
402 g_return_if_fail(ADG_IS_PATH(path
));
404 clear_cairo_path(path
);
405 path
->priv
->path
= g_array_append_vals(path
->priv
->path
,
407 cairo_path
->num_data
);
414 * @x: the new x coordinate
415 * @y: the new y coordinate
417 * Begins a new segment. After this call the current point will be (@x, @y).
420 adg_path_move_to(AdgPath
*path
, gdouble x
, gdouble y
)
427 adg_path_append(path
, CAIRO_PATH_MOVE_TO
, &p
);
433 * @x: the new x coordinate
434 * @y: the new y coordinate
436 * Adds a line to @path from the current point to position (@x, @y).
437 * After this call the current point will be (@x, @y).
439 * If @path has no current point before this call, this function will
440 * trigger a warning without other effect.
443 adg_path_line_to(AdgPath
*path
, gdouble x
, gdouble y
)
450 adg_path_append(path
, CAIRO_PATH_LINE_TO
, &p
);
456 * @x1: the x coordinate of an intermediate point
457 * @y1: the y coordinate of an intermediate point
458 * @x2: the x coordinate of the end of the arc
459 * @y2: the y coordinate of the end of the arc
461 * Adds an arc to the path from the current point to (@x2, @y2),
462 * passing throught (@x1, @y1). After this call the current point
463 * will be (@x2, @y2).
465 * If @path has no current point before this call, this function will
466 * trigger a warning without other effect.
469 adg_path_arc_to(AdgPath
*path
, gdouble x1
, gdouble y1
, gdouble x2
, gdouble y2
)
478 adg_path_append(path
, CAIRO_PATH_ARC_TO
, &p
[0], &p
[1]);
484 * @x1: the x coordinate of the first control point
485 * @y1: the y coordinate of the first control point
486 * @x2: the x coordinate of the second control point
487 * @y2: the y coordinate of the second control point
488 * @x3: the x coordinate of the end of the curve
489 * @y3: the y coordinate of the end of the curve
491 * Adds a cubic Bézier curve to the path from the current point to
492 * position (@x3, @y3), using (@x1, @y1) and (@x2, @y2) as the
493 * control points. After this call the current point will be (@x3, @y3).
495 * If @path has no current point before this call, this function will
496 * trigger a warning without other effect.
499 adg_path_curve_to(AdgPath
*path
, gdouble x1
, gdouble y1
,
500 gdouble x2
, gdouble y2
, gdouble x3
, gdouble y3
)
511 adg_path_append(path
, CAIRO_PATH_CURVE_TO
, &p
[0], &p
[1], &p
[2]);
518 * Adds a line segment to the path from the current point to the
519 * beginning of the current segment, (the most recent point passed
520 * to an adg_path_move_to()), and closes this segment.
521 * After this call the current point will be unset.
523 * The behavior of adg_path_close() is distinct from simply calling
524 * adg_line_to() with the coordinates of the segment starting point.
525 * When a closed segment is stroked, there are no caps on the ends.
526 * Instead, there is a line join connecting the final and initial
527 * primitive of the segment.
529 * If @path has no current point before this call, this function will
530 * trigger a warning without other effect.
533 adg_path_close(AdgPath
*path
)
535 adg_path_append(path
, CAIRO_PATH_CLOSE_PATH
);
541 * @xc: x position of the center of the arc
542 * @yc: y position of the center of the arc
543 * @r: the radius of the arc
544 * @start: the start angle, in radians
545 * @end: the end angle, in radians
547 * A more usual way to add an arc to @path. After this call, the current
548 * point will be the computed end point of the arc. The arc will be
549 * rendered in increasing angle, accordling to @start and @end. This means
550 * if @start is less than @end, the arc will be rendered in clockwise
551 * direction (accordling to the default cairo coordinate system) while if
552 * @start is greather than @end, the arc will be rendered in couterclockwise
555 * By explicitely setting the whole arc data, the start point could be
556 * different from the current point. In this case, if @path has no
557 * current point before the call a %CAIRO_PATH_MOVE_TO to the start
558 * point of the arc will be automatically prepended to the arc.
559 * If @path has a current point, a %CAIRO_PATH_LINE_TO to the start
560 * point of the arc will be used instead of the moveto.
563 adg_path_arc(AdgPath
*path
, gdouble xc
, gdouble yc
, gdouble r
,
564 gdouble start
, gdouble end
)
566 AdgPair center
, p
[3];
568 g_return_if_fail(ADG_IS_PATH(path
));
573 cpml_vector_from_angle(&p
[0], start
, r
);
574 cpml_vector_from_angle(&p
[1], (end
-start
) / 2, r
);
575 cpml_vector_from_angle(&p
[2], end
, r
);
577 cpml_pair_add(&p
[0], ¢er
);
578 cpml_pair_add(&p
[1], ¢er
);
579 cpml_pair_add(&p
[2], ¢er
);
581 if (!path
->priv
->cp_is_valid
)
582 adg_path_append(path
, CAIRO_PATH_MOVE_TO
, &p
[0]);
583 else if (p
[0].x
!= path
->priv
->cp
.x
|| p
[0].y
!= path
->priv
->cp
.y
)
584 adg_path_append(path
, CAIRO_PATH_LINE_TO
, &p
[0]);
586 adg_path_append(path
, CAIRO_PATH_ARC_TO
, &p
[1], &p
[2]);
592 * @delta1: the distance from the intersection point of the current primitive
593 * @delta2: the distance from the intersection point of the next primitive
595 * A binary operator that generates a chamfer between two primitives.
596 * The first primitive involved is the current primitive, the second will
597 * be the next primitive appended to @path after this call. The second
598 * primitive is required: if the chamfer operation is not properly
599 * terminated not providing the second primitive, any API accessing the
600 * path in reading mode will raise a warning.
602 * The chamfer operation requires two lengths: @delta1 specifies the
603 * "quantity" to trim on the first primitive while @delta2 is the same
604 * applied on the second primitive. The term "quantity" means the length
605 * of the portion to cut out from the original primitive (that is the
606 * primitive as would be without the chamfer).
609 adg_path_chamfer(AdgPath
*path
, gdouble delta1
, gdouble delta2
)
611 g_return_if_fail(ADG_IS_PATH(path
));
613 if (!append_operation(path
, ADG_OPERATOR_CHAMFER
, delta1
, delta2
))
622 * Dumps the data content of @path to stdout in a human readable format.
625 adg_path_dump(AdgPath
*path
)
628 cairo_path_t
*cairo_path
;
630 g_return_if_fail(ADG_IS_PATH(path
));
632 cairo_path
= get_cairo_path(path
);
634 g_return_if_fail(cairo_path
!= NULL
);
636 if (!cpml_segment_from_cairo(&segment
, cairo_path
)) {
637 g_warning("Invalid path data to dump!\n");
640 cpml_segment_dump(&segment
);
641 } while (cpml_segment_next(&segment
));
647 changed(AdgModel
*model
)
649 AdgModelClass
*model_class
= (AdgModelClass
*) adg_path_parent_class
;
651 adg_path_clear((AdgPath
*) model
);
653 if (model_class
->changed
!= NULL
)
654 model_class
->changed(model
);
658 clear_cairo_path(AdgPath
*path
)
660 cairo_path_t
*cairo_path
= &path
->priv
->cairo_path
;
662 if (cairo_path
->data
== NULL
)
665 g_free(cairo_path
->data
);
667 cairo_path
->status
= CAIRO_STATUS_INVALID_PATH_DATA
;
668 cairo_path
->data
= NULL
;
669 cairo_path
->num_data
= 0;
672 static cairo_path_t
*
673 get_cairo_path(AdgPath
*path
)
675 cairo_path_t
*cairo_path
;
678 const cairo_path_data_t
*p_src
;
681 /* Check for cached result */
682 cairo_path
= &path
->priv
->cairo_path
;
683 if (cairo_path
->data
!= NULL
)
686 src
= path
->priv
->path
;
687 dst
= g_array_sized_new(FALSE
, FALSE
, sizeof(cairo_path_data_t
), src
->len
);
689 /* Cycle the path and convert arcs to Bézier curves */
690 for (i
= 0; i
< src
->len
; i
+= p_src
->header
.length
) {
691 p_src
= (const cairo_path_data_t
*) src
->data
+ i
;
693 if (p_src
->header
.type
== CAIRO_PATH_ARC_TO
)
694 dst
= arc_to_curves(dst
, p_src
);
696 dst
= g_array_append_vals(dst
, p_src
, p_src
->header
.length
);
699 cairo_path
->status
= CAIRO_STATUS_SUCCESS
;
700 cairo_path
->num_data
= dst
->len
;
701 cairo_path
->data
= (cairo_path_data_t
*) g_array_free(dst
, FALSE
);
706 static cairo_path_t
*
707 get_cpml_path(AdgPath
*path
)
709 cairo_path_t
*cpml_path
= &path
->priv
->cpml_path
;
711 cpml_path
->status
= CAIRO_STATUS_SUCCESS
;
712 cpml_path
->data
= (cairo_path_data_t
*) path
->priv
->path
->data
;
713 cpml_path
->num_data
= path
->priv
->path
->len
;
719 arc_to_curves(GArray
*array
, const cairo_path_data_t
*src
)
724 /* Build the arc primitive: the arc origin is supposed to be the previous
725 * point (src-1): this means a primitive must exist before the arc */
727 arc
.org
= (cairo_path_data_t
*) (src
-1);
728 arc
.data
= (cairo_path_data_t
*) src
;
730 if (cpml_arc_info(&arc
, NULL
, NULL
, &start
, &end
)) {
733 cairo_path_data_t
*curves
;
735 n_curves
= ceil(fabs(end
-start
) / M_PI_2
);
736 curves
= g_new(cairo_path_data_t
, n_curves
* 4);
737 segment
.data
= curves
;
738 cpml_arc_to_curves(&arc
, &segment
, n_curves
);
740 array
= g_array_append_vals(array
, curves
, n_curves
* 4);
749 append_primitive_valist(AdgPath
*path
, cairo_path_data_type_t type
,
750 int length
, va_list var_args
)
752 AdgPathPrivate
*priv
;
753 cairo_path_data_t
*nodes
;
756 nodes
= create_nodes_valist(type
, length
, var_args
);
758 /* Execute any pending operation */
759 do_operation(path
, nodes
);
761 /* Append the nodes to the internal path array */
762 priv
->path
= g_array_append_vals(priv
->path
, nodes
, length
);
764 nodes
= (cairo_path_data_t
*) priv
->path
->data
+ priv
->path
->len
- length
;
766 /* Set the last primitive for subsequent binary operations */
767 priv
->last
.org
= priv
->cp_is_valid
? nodes
- 1 : NULL
;
768 priv
->last
.segment
= NULL
;
769 priv
->last
.data
= nodes
;
771 /* Save the last point as the current point, if applicable */
772 priv
->cp_is_valid
= length
> 1;
774 cpml_pair_from_cairo(&priv
->cp
, &nodes
[length
-1]);
776 /* Invalidate cairo_path: should be recomputed */
777 clear_cairo_path(path
);
780 static cairo_path_data_t
*
781 create_nodes_valist(cairo_path_data_type_t type
, int length
, va_list var_args
)
783 cairo_path_data_t
*node
, *nodes
;
785 node
= nodes
= g_new(cairo_path_data_t
, length
);
787 /* Append the header item */
788 node
->header
.type
= type
;
789 node
->header
.length
= length
;
791 /* Append the data items (that is, the AdgPair points) */
794 cpml_pair_to_cairo(va_arg(var_args
, AdgPair
*), node
);
801 clear_operation(AdgPath
*path
)
803 AdgOperation
*operation
= &path
->priv
->operation
;
805 if (operation
->operator == ADG_OPERATOR_NONE
)
808 g_warning("An operation is still active while clearing the path "
809 "(operator `%d')", operation
->operator);
810 operation
->operator = ADG_OPERATOR_NONE
;
814 append_operation(AdgPath
*path
, AdgOperator
operator, ...)
816 AdgOperation
*operation
;
819 if (!path
->priv
->cp_is_valid
) {
820 g_warning("Operation requested but path has no current primitive "
821 "(operator `%d')", operator);
825 operation
= &path
->priv
->operation
;
826 va_start(var_args
, operator);
828 if (operation
->operator != ADG_OPERATOR_NONE
) {
829 /* TODO: this is a rude semplification, as a lot of operators can
830 * and may cohexist. As an example, a fillet followed by a
831 * polar chamfer is not difficult to compute */
832 g_warning("Operation requested but another operation is yet active"
833 "(operators: new `%d', old `%d')",
834 operator, operation
->operator);
840 case ADG_OPERATOR_CHAMFER
:
841 operation
->data
.chamfer
.delta1
= va_arg(var_args
, double);
842 operation
->data
.chamfer
.delta2
= va_arg(var_args
, double);
845 case ADG_OPERATOR_FILLET
:
846 operation
->data
.fillet
.radius
= va_arg(var_args
, double);
849 case ADG_OPERATOR_NONE
:
854 g_warning("Operation not recognized (operator `%d')", operator);
859 operation
->operator = operator;
866 do_operation(AdgPath
*path
, cairo_path_data_t
*data
)
868 AdgPathPrivate
*priv
;
869 AdgOperator
operator;
870 CpmlPrimitive current
;
871 cairo_path_data_t current_org
;
874 operator = priv
->operation
.operator;
875 current
.segment
= NULL
;
876 current
.org
= ¤t_org
;
878 cpml_pair_to_cairo(&priv
->cp
, ¤t_org
);
882 case ADG_OPERATOR_NONE
:
885 case ADG_OPERATOR_CHAMFER
:
886 do_chamfer(path
, ¤t
);
890 g_warning("Operation not implemented (operator `%d')", operator);
897 do_chamfer(AdgPath
*path
, CpmlPrimitive
*current
)
899 AdgPathPrivate
*priv
;
901 gdouble delta1
, delta2
;
904 cairo_path_data_t line
[2];
908 delta1
= priv
->operation
.data
.chamfer
.delta1
;
909 len1
= cpml_primitive_length(last
);
911 if (delta1
>= len1
) {
912 g_warning("Chamfer too big for the last primitive (%lf >= %lf)",
917 delta2
= priv
->operation
.data
.chamfer
.delta2
;
918 len2
= cpml_primitive_length(current
);
920 if (delta2
>= len2
) {
921 g_warning("Chamfer too big for the current primitive (%lf >= %lf)",
926 /* Change the end point of the last primitive */
927 cpml_primitive_pair_at(last
, &pair
, 1. - delta1
/ len1
);
928 cpml_pair_to_cairo(&pair
, cpml_primitive_get_point(last
, -1));
930 /* Change the start point of the current primitive */
931 cpml_primitive_pair_at(current
, &pair
, delta2
/ len2
);
932 cpml_pair_to_cairo(&pair
, cpml_primitive_get_point(current
, 0));
934 /* Add the chamfer line */
935 line
[0].header
.type
= CAIRO_PATH_LINE_TO
;
936 line
[0].header
.length
= 2;
937 line
[1].point
.x
= pair
.x
;
938 line
[1].point
.y
= pair
.y
;
939 priv
->path
= g_array_append_vals(priv
->path
, line
, 2);
941 priv
->operation
.operator = ADG_OPERATOR_NONE
;