arc autogap
- From: Grégoire Dooms <dooms info ucl ac be>
- To: discussions about usage and development of dia <dia-list gnome org>
- Subject: arc autogap
- Date: Mon, 16 May 2005 17:30:01 +0200
Hi,
I finally upload this patch for arc autogap.
This is a partial and buggy implementation.
A first working step is adding a new way of handling arcs with the
modify tool:
keep center and radius and change only the angle of one of the endpoints.
This can be done by holding shift while moving a green handle.
This code combined with a bisection search on the end angle should do it.
It is implemented and only works in a few cases. I have no time to debug
this currently.
As Lars suggested, I release the code as is so someone can fix it before me.
All the best,
--
Grégoire Dooms
? arcs_autogap.diff
? multiple_arcs.dia
? app/Diagram1.dia
? app/Diagram1.dia.autosave
? objects/standard/arc_modified.c
Index: app/modify_tool.c
===================================================================
RCS file: /cvs/gnome/dia/app/modify_tool.c,v
retrieving revision 1.53
diff -u -r1.53 modify_tool.c
--- app/modify_tool.c 6 Apr 2005 19:43:55 -0000 1.53
+++ app/modify_tool.c 16 May 2005 15:22:31 -0000
@@ -36,6 +36,7 @@
#include "prop_text.h"
#include "gtk/gtk.h"
+
static DiaObject *click_select_object(DDisplay *ddisp, Point *clickedpoint,
GdkEventButton *event);
static int do_if_clicked_handle(DDisplay *ddisp, ModifyTool *tool,
@@ -76,6 +77,18 @@
return (Tool *)tool;
}
+ModifierKeys gdk_event_to_dia_ModifierKeys(guint event_state){
+ ModifierKeys mod = MODIFIER_NONE;
+ if (event_state & GDK_SHIFT_MASK)
+ mod |= MODIFIER_SHIFT;
+ /* Used intenally do not propagate
+ * if (event_state & GDK_CONTROL_MASK)
+ mod | MODIFIER_CONTROL;
+ */
+ return mod;
+}
+
+
void
free_modify_tool(Tool *tool)
{
@@ -518,7 +531,7 @@
/* Handle undo */
objchange = tool->object->ops->move_handle(tool->object, tool->handle,
&to, connectionpoint,
- HANDLE_MOVE_USER, 0);
+ HANDLE_MOVE_USER, gdk_event_to_dia_ModifierKeys(event->state));
if (objchange != NULL) {
undo_object_change(ddisp->diagram, tool->object, objchange);
}
@@ -652,7 +665,7 @@
object_add_updates(tool->object, ddisp->diagram);
objchange = tool->object->ops->move_handle(tool->object, tool->handle,
&tool->last_to, NULL,
- HANDLE_MOVE_USER_FINAL,0);
+
HANDLE_MOVE_USER_FINAL,gdk_event_to_dia_ModifierKeys(event->state));
if (objchange != NULL) {
undo_object_change(ddisp->diagram, tool->object, objchange);
}
Index: lib/geometry.h
===================================================================
RCS file: /cvs/gnome/dia/lib/geometry.h,v
retrieving revision 1.26
diff -u -r1.26 geometry.h
--- lib/geometry.h 17 Mar 2005 18:43:02 -0000 1.26
+++ lib/geometry.h 16 May 2005 15:22:31 -0000
@@ -326,6 +326,17 @@
}
#endif
+G_INLINE_FUNC const Point *closest_to(const Point *to, const Point *p1, const Point *p2);
+#ifdef G_CAN_INLINE
+G_INLINE_FUNC const Point *
+closest_to(const Point *to, const Point *p1, const Point *p2)
+{
+ if (distance_point_point(to,p1) < distance_point_point(to,p2))
+ return p1;
+ return p2;
+}
+#endif
+
G_INLINE_FUNC real distance_point_point_manhattan(const Point *p1,
const Point *p2);
#ifdef G_CAN_INLINE
Index: objects/standard/arc.c
===================================================================
RCS file: /cvs/gnome/dia/objects/standard/arc.c,v
retrieving revision 1.39
diff -u -r1.39 arc.c
--- objects/standard/arc.c 21 May 2004 15:48:35 -0000 1.39
+++ objects/standard/arc.c 16 May 2005 15:22:34 -0000
@@ -60,6 +60,7 @@
};
+/* updates both endpoints and arc->curve_distance */
static ObjectChange* arc_move_handle(Arc *arc, Handle *handle,
Point *to, ConnectionPoint *cp,
HandleMoveReason reason, ModifierKeys modifiers);
@@ -83,6 +84,9 @@
static void arc_save(Arc *arc, ObjectNode obj_node, const char *filename);
static DiaObject *arc_load(ObjectNode obj_node, int version, const char *filename);
+static int arc_compute_midpoint(Arc *arc, const Point * ep0, const Point * ep1 , Point * midpoint);
+static void calculate_arc_object_edge(Arc *arc, real ang_start, real ang_end, DiaObject *obj, Point *target);
+static void arc_get_point_at_angle(Arc *arc, Point* point, real angle);
static ObjectTypeOps arc_type_ops =
{
@@ -243,8 +247,151 @@
arc->curve_distance*dx/dist;
}
}
+/** returns the number of intersection the circle has with the horizontal line at y=horiz
+ * if 1 point intersects then *int1 is that point
+ * if 2 points intersect then *int1 and *int2 are these points
+ */
+static int
+arc_circle_intersects_horiz(const Arc *arc, real horiz, Point *int1, Point *int2){
+ /* inject y=horiz into r^2 = (x-x_c)^2 + (y-y_c)^2
+ * this is r^2 = (x-x_c)^2 + (horiz-y_c)^2
+ * translate to x^2 + b*x + c = 0
+ * b = -2 x_c
+ * c = x_c^2 - r^2 + (horiz-y_c)^2
+ * and solve classically */
+ real b, c, delta;
+ b = -2.0 * arc->center.x;
+ c = arc->center.x * arc->center.x + (horiz - arc->center.y) * (horiz - arc->center.y) - arc->radius *
arc->radius;
+ delta = b*b - 4 * c;
+ if (delta < 0)
+ return 0;
+ else if (delta == 0){
+ int1->x = -b/2;
+ int1->y = horiz;
+ return 1;
+ }
+ else {
+ int1->x = (sqrt(delta)-b)/2;
+ int1->y = horiz;
+ int2->x = (-sqrt(delta)-b)/2;
+ int2->y = horiz;
+ return 2;
+ }
+}
+/** returns the number of intersection the circle has with the vertical line at x=vert
+ * if 1 point intersects then *int1 is that point
+ * if 2 points intersect then *int1 and *int2 are these points
+ */
+static int
+arc_circle_intersects_vert(const Arc *arc, real vert, Point *int1, Point *int2){
+ /* inject x=vert into r^2 = (x-x_c)^2 + (y-y_c)^2
+ * this is r^2 = (vert-x_c)^2 + (y-y_c)^2
+ * translate to y^2 + b*y + c = 0 and solve classically */
+ real b, c, delta;
+ b = -2*arc->center.y;
+ c = arc->center.y * arc->center.y + (vert - arc->center.x) * (vert - arc->center.x) - arc->radius *
arc->radius;
+ delta = b*b - 4 * c;
+ if (delta < 0)
+ return 0;
+ else if (delta == 0){
+ int1->y = -b/2;
+ int1->x = vert;
+ return 1;
+ }
+ else {
+ int1->y = (sqrt(delta)-b)/2;
+ int1->x = vert;
+ int2->y = (-sqrt(delta)-b)/2;
+ int2->x = vert;
+ return 2;
+ }
+}
+
+
+
+static real
+arc_compute_curve_distance(const Arc *arc, const Point *start, const Point *end, const Point *mid)
+{
+ Point a,b;
+ real tmp,cd;
+ b = *mid;
+ point_sub(&b, start);
+
+ a = *end;
+ point_sub(&a, start);
+
+ tmp = point_dot(&a,&b);
+ cd =
+ sqrt(fabs(point_dot(&b,&b) - tmp*tmp/point_dot(&a,&a)));
+
+ if (a.x*b.y - a.y*b.x < 0)
+ cd = - cd;
+ return cd;
+}
+
+/** rotates p around the center by an angle given in radians
+ * a positive angle is ccw on the screen*/
+static void
+rotate_point_around_point(Point *p, const Point *center, real angle)
+{
+ real radius;
+ real a;
+ point_sub(p,center);
+ radius = point_len(p);
+ a = -atan2(p->y,p->x); /* y axis points down*/
+ a += angle;
+ p->x = cos(a); p->y = -sin(a);/* y axis points down*/
+ point_scale(p,radius);
+ point_add(p,center);
+}
+
+
+/* finds the point intersecting the full circle
+ * on the vector defined by the center and Point *to
+ * that point is returned in Point *best if 1 is returned */
+static int
+arc_find_radial(const Arc *arc, const Point *to, Point *best)
+{
+ Point tmp;
+ tmp = *to;
+ point_sub(&tmp, &arc->center);
+ point_normalize(&tmp);
+ point_scale(&tmp,arc->radius);
+ point_add(&tmp, &arc->center);
+ *best = tmp;
+ return 1;
+
+}
+
+/* finds the closest point intersecting the full circle
+ * at any position on the vertical and horizontal lines going through Point to
+ * that point is returned in Point *best if 1 is returned */
+static int
+arc_find_closest_vert_horiz(const Arc *arc, const Point *to, Point *best){
+ Point i1,i2;
+ int nh,nv;
+ nh = arc_circle_intersects_horiz(arc, to->y, &i1, &i2);
+ if (nh==2){
+ *best = *closest_to(to,&i1,&i2);
+ }
+ else if (nh==1) {
+ *best = i1;
+ }
+ nv = arc_circle_intersects_vert(arc, to->x, &i1, &i2);
+ if (nv==2){
+ Point tmp;
+ tmp = *closest_to(to,&i1,&i2);
+ *best = *closest_to(to,&tmp,best);
+ }
+ else if (nv==1) {
+ *best = *closest_to(to,&i1,best);
+ }
+ if (nv|nh)
+ return 1;
+ return 0;
+}
static ObjectChange*
arc_move_handle(Arc *arc, Handle *handle,
Point *to, ConnectionPoint *cp,
@@ -253,26 +400,40 @@
assert(arc!=NULL);
assert(handle!=NULL);
assert(to!=NULL);
-
if (handle->id == HANDLE_MIDDLE) {
- Point a,b;
- real tmp;
-
- b = *to;
- point_sub(&b, &arc->connection.endpoints[0]);
-
- a = arc->connection.endpoints[1];
- point_sub(&a, &arc->connection.endpoints[0]);
-
- tmp = point_dot(&a,&b);
- arc->curve_distance =
- sqrt(fabs(point_dot(&b,&b) - tmp*tmp/point_dot(&a,&a)));
-
- if (a.x*b.y - a.y*b.x < 0)
- arc->curve_distance = -arc->curve_distance;
+ printf("curve_dist: %.2f \n",arc->curve_distance);
+ arc->curve_distance = arc_compute_curve_distance(arc, &arc->connection.endpoints[0],
&arc->connection.endpoints[1], to);
+ printf("curve_dist: %.2f \n",arc->curve_distance);
} else {
- connection_move_handle(&arc->connection, handle->id, to, cp, reason, modifiers);
+ Point best;
+ printf("Modifiers: %d \n",modifiers);
+ if (modifiers & MODIFIER_SHIFT)
+ /* if(arc->end_arrow.type == ARROW_NONE)*/
+ {
+ printf("SHIFT USED, to at %.2f %.2f ",to->x,to->y);
+ if (arc_find_radial(arc, to, &best)){
+ /* needs to move two handles at the same time
+ * compute pos of middle handle */
+ Point midpoint;
+ int ok;
+ if (handle == (&arc->connection.endpoint_handles[0]))
+ ok = arc_compute_midpoint(arc, &best , &arc->connection.endpoints[1], &midpoint);
+ else
+ ok = arc_compute_midpoint(arc, &arc->connection.endpoints[0], &best , &midpoint);
+ if (!ok)
+ return NULL;
+ connection_move_handle(&arc->connection, handle->id, &best, cp, reason, modifiers);
+ /* recompute curve distance equiv. move middle handle */
+ arc->curve_distance = arc_compute_curve_distance(arc, &arc->connection.endpoints[0],
&arc->connection.endpoints[1], &midpoint);
+ printf("curve_dist: %.2f \n",arc->curve_distance);
+ }
+ else {
+ printf("NO best\n");
+ }
+ } else {
+ connection_move_handle(&arc->connection, handle->id, to, cp, reason, modifiers);
+ }
}
arc_update_data(arc);
@@ -297,27 +458,139 @@
return NULL;
}
+static int
+arc_compute_midpoint(Arc *arc, const Point * ep0, const Point * ep1 , Point * midpoint)
+{
+ real angle;
+ Point midpos;
+ Point *oep0, *oep1;
+
+ oep0 = &arc->connection.endpoints[0];
+ oep1 = &arc->connection.endpoints[1];
+
+ /* angle is total delta of angle of both endpoints */
+ angle = -atan2(ep0->y - arc->center.y, ep0->x - arc->center.x); /* angle of new */
+ angle -= -atan2(oep0->y - arc->center.y, oep0->x - arc->center.x); /* minus angle of old */
+ angle += -atan2(ep1->y - arc->center.y, ep1->x - arc->center.x); /* plus angle of new */
+ angle -= -atan2(oep1->y - arc->center.y, oep1->x - arc->center.x); /* minus angle of old */
+ if (!finite(angle)){
+ return 0;
+ }
+ if (angle < -1 * M_PI){
+ printf("angle: %.2f ",angle);
+ angle += 2*M_PI;
+ printf("angle: %.2f ",angle);
+ }
+ if (angle > 1 * M_PI){
+ printf("angle: %.2f ",angle);
+ angle -= 2*M_PI;
+ printf("angle: %.2f ",angle);
+ }
+
+ midpos = arc->middle_handle.pos;
+ /*rotate middle handle by half the angle */
+ printf("\nmidpos before: %.2f %.2f \n",midpos.x, midpos.y);
+ rotate_point_around_point(&midpos, &arc->center, angle/2);
+ printf("\nmidpos after : %.2f %.2f \n",midpos.x, midpos.y);
+ *midpoint = midpos;
+ return 1;
+}
+/** updates point to the point on the arc at angle angle */
+void arc_get_point_at_angle(Arc *arc, Point* point, real angle)
+{
+ Point vec;
+ vec.x = cos(angle/180.0*M_PI);
+ vec.y = sin(angle/180.0*M_PI);
+ point_copy(point,&arc->center);
+ point_add_scaled(point,&vec,arc->radius);
+}
+static void
+calculate_arc_object_edge(Arc *arc, real ang_start, real ang_end, DiaObject *obj, Point *target)
+{
+#define MAXITER 25
+#ifdef TRACE_DIST
+ real trace[MAXITER];
+ real disttrace[MAXITER];
+#endif
+ real mid1, mid2, mid3;
+ real dist;
+ int i = 0;
+
+ mid1 = ang_start;
+ mid2 = (ang_start + ang_end)/2;
+ mid3 = ang_end;
+
+ /* If the other end is inside the object */
+ arc_get_point_at_angle(arc,target,mid3);
+ dist = obj->ops->distance_from(obj, target );
+ if (dist < 0.001){
+ arc_get_point_at_angle(arc,target,mid1);
+ return ;
+ }
+ do {
+ arc_get_point_at_angle(arc, target, mid2);
+ dist = obj->ops->distance_from(obj, target);
+ if (dist < 0.0000001) {
+ mid1 = mid2;
+ } else {
+ mid3 = mid2;
+ }
+ mid2 = (mid1 + mid3) / 2;
+
+#ifdef TRACE_DIST
+ trace[i] = mid2;
+ disttrace[i] = dist;
+#endif
+ i++;
+ } while (i < MAXITER && (dist < 0.0000001 || dist > 0.001));
+
+#ifdef TRACE_DIST
+ if (i == MAXITER) {
+ for (i = 0; i < MAXITER; i++) {
+ printf("%d: %f, %f: %f\n", i, trace[i].x, trace[i].y, disttrace[i]);
+ }
+ printf("i = %d, dist = %f\n", i, dist);
+ }
+#endif
+ arc_get_point_at_angle(arc,target,mid2);
+ return ;
+}
static void
arc_draw(Arc *arc, DiaRenderer *renderer)
{
DiaRendererClass *renderer_ops = DIA_RENDERER_GET_CLASS (renderer);
Point *endpoints;
- real width;
+ Point gaptmp[3];
+ ConnectionPoint *start_cp, *end_cp;
assert(arc != NULL);
assert(renderer != NULL);
endpoints = &arc->connection.endpoints[0];
+ gaptmp[0] = endpoints[0];
+ gaptmp[1] = endpoints[1];
+ start_cp = arc->connection.endpoint_handles[0].connected_to;
+ end_cp = arc->connection.endpoint_handles[1].connected_to;
+
+ if (connpoint_is_autogap(start_cp))
+ calculate_arc_object_edge(arc, arc->angle1, arc->angle2, start_cp->object, &gaptmp[0]);
+ if (connpoint_is_autogap(end_cp))
+ calculate_arc_object_edge(arc, arc->angle2, arc->angle1, end_cp->object, &gaptmp[1]);
+
+ /* compute new middle_point */
+ arc_compute_midpoint(arc, &gaptmp[0], &gaptmp[1], &gaptmp[2]);
+
renderer_ops->set_linewidth(renderer, arc->line_width);
renderer_ops->set_linestyle(renderer, arc->line_style);
renderer_ops->set_dashlength(renderer, arc->dashlength);
renderer_ops->set_linecaps(renderer, LINECAPS_BUTT);
/* Special case when almost line: */
- if (fabs(arc->curve_distance) <= 0.0001) {
+ if (fabs(arc->curve_distance) <= 0.01) {
+ printf("drawing like a line\n");
renderer_ops->draw_line_with_arrows(renderer,
- &endpoints[0], &endpoints[1],
+ &gaptmp[0], &gaptmp[1],
arc->line_width,
&arc->arc_color,
&arc->start_arrow,
@@ -326,15 +599,13 @@
}
renderer_ops->draw_arc_with_arrows(renderer,
- &arc->connection.endpoints[0],
- &arc->connection.endpoints[1],
- &arc->middle_handle.pos,
+ &gaptmp[0],
+ &gaptmp[1],
+ &gaptmp[2],
arc->line_width,
&arc->arc_color,
&arc->start_arrow,
&arc->end_arrow);
- width = 2*arc->radius;
-
}
static DiaObject *
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