Allow removing spline points.

src/modify.cpp

@@ -8,8 +8,8 @@
 #include "solvespace.h"
 
 //-----------------------------------------------------------------------------
-// Replace a point-coincident constraint on oldpt with that same constraint
-// on newpt. Useful when splitting or tangent arcing.
+// Replace constraints on oldpt with the same constraints on newpt.
+// Useful when splitting, tangent arcing, or removing bezier points.
 //-----------------------------------------------------------------------------
 void GraphicsWindow::ReplacePointInConstraints(hEntity oldpt, hEntity newpt) {
     int i;
@@ -23,6 +23,27 @@ void GraphicsWindow::ReplacePointInConstraints(hEntity oldpt, hEntity newpt) {
     }
 }
 
+//-----------------------------------------------------------------------------
+// Remove constraints on hpt. Useful when removing bezier points.
+//-----------------------------------------------------------------------------
+void GraphicsWindow::RemoveConstraintsForPointBeingDeleted(hEntity hpt) {
+    SK.constraint.ClearTags();
+    for(int i = 0; i < SK.constraint.n; i++) {
+        Constraint *c = &(SK.constraint.elem[i]);
+        if(c->ptA.v == hpt.v || c->ptB.v == hpt.v) {
+            c->tag = 1;
+            (SS.deleted.constraints)++;
+            if(c->type != Constraint::POINTS_COINCIDENT &&
+               c->type != Constraint::HORIZONTAL &&
+               c->type != Constraint::VERTICAL)
+            {
+                (SS.deleted.nonTrivialConstraints)++;
+            }
+        }
+    }
+    SK.constraint.RemoveTagged();
+}
+
 //-----------------------------------------------------------------------------
 // Let's say that A is coincident with B, and B is coincident with C. This
 // implies that A is coincident with C; but if we delete B, then both
@@ -67,9 +88,12 @@ void GraphicsWindow::FixConstraintsForPointBeingDeleted(hEntity hpt) {
             c->tag = 1;
         }
     }
-    // These would get removed anyways when we regenerated, but do it now;
-    // that way subsequent calls of this function (if multiple coincident
-    // points are getting deleted) will work correctly.
+    // Remove constraints without waiting for regeneration; this way
+    // if another point takes the place of the deleted one (e.g. when
+    // removing control points of a bezier) the constraint doesn't
+    // spuriously move. Similarly, subsequent calls of this function
+    // (if multiple coincident points are getting deleted) will work
+    // correctly.
     SK.constraint.RemoveTagged();
 
     // If more than one point was constrained coincident with hpt, then

src/mouse.cpp

@@ -567,6 +567,18 @@ void GraphicsWindow::MouseRightUp(double x, double y) {
         }
         if(gs.comments > 0 || gs.points > 0) {
             AddContextMenuItem("Snap to Grid", CMNU_SNAP_TO_GRID);
+
+            if(gs.points == 1) {
+                hRequest hr = gs.point[0].request();
+                if(hr.v != 0) {
+                    Request *r = SK.GetRequest(hr);
+                    int index = r->IndexOfPoint(gs.point[0]);
+                    if((r->type == Request::CUBIC && (index > 1 && index < r->extraPoints + 2)) ||
+                            r->type == Request::CUBIC_PERIODIC) {
+                        AddContextMenuItem("Remove Spline Point", CMNU_REMOVE_SPLINE_PT);
+                    }
+                }
+            }
         }
 
         if(gs.points == 1) {
@@ -675,6 +687,36 @@ void GraphicsWindow::MouseRightUp(double x, double y) {
             MenuEdit(MNU_SNAP_TO_GRID);
             break;
 
+        case CMNU_REMOVE_SPLINE_PT: {
+            hRequest hr = gs.point[0].request();
+            Request *r = SK.GetRequest(hr);
+
+            int index = r->IndexOfPoint(gs.point[0]);
+            if(r->extraPoints == 0) oops();
+
+            SS.UndoRemember();
+            Entity *e = SK.GetEntity(r->h.entity(0));
+
+            // First, fix point-coincident constraints involving this point.
+            // Then, remove all other constraints, since they would otherwise
+            // jump to an adjacent one and mess up the bezier after generation.
+            FixConstraintsForPointBeingDeleted(e->point[index]);
+            RemoveConstraintsForPointBeingDeleted(e->point[index]);
+
+            for(int i = index; i < MAX_POINTS_IN_ENTITY - 1; i++) {
+                if(e->point[i + 1].v == 0) break;
+                Entity *p0 = SK.GetEntity(e->point[i]);
+                Entity *p1 = SK.GetEntity(e->point[i + 1]);
+                ReplacePointInConstraints(p1->h, p0->h);
+                p0->PointForceTo(p1->PointGetNum());
+            }
+            r->extraPoints--;
+            SS.MarkGroupDirtyByEntity(gs.point[0]);
+            SS.ScheduleGenerateAll();
+            ClearSelection();
+            break;
+        }
+
         case CMNU_GROUP_INFO: {
             hGroup hg;
             if(gs.entities == 1) {

src/request.cpp

@@ -184,6 +184,18 @@ std::string Request::DescriptionString(void) {
     return ssprintf("r%03x-%s", h.v, s);
 }
 
+int Request::IndexOfPoint(hEntity he) {
+    if(type == DATUM_POINT) {
+        return (he.v == h.entity(0).v) ? 0 : -1;
+    }
+    for(int i = 0; i < MAX_POINTS_IN_ENTITY; i++) {
+        if(he.v == h.entity(i + 1).v) {
+            return i;
+        }
+    }
+    return -1;
+}
+
 hParam Request::AddParam(IdList<Param,hParam> *param, hParam hp) {
     Param pa = {};
     pa.h = hp;

src/sketch.h

@@ -299,6 +299,7 @@ public:
     void Generate(EntityList *entity, ParamList *param);
 
     std::string DescriptionString(void);
+    int IndexOfPoint(hEntity he);
 
     void Clear(void) {}
 };

src/ui.h

@@ -601,6 +601,7 @@ public:
     hEntity SplitCircle(hEntity he, Vector pinter);
     hEntity SplitCubic(hEntity he, Vector pinter);
     void ReplacePointInConstraints(hEntity oldpt, hEntity newpt);
+    void RemoveConstraintsForPointBeingDeleted(hEntity hpt);
     void FixConstraintsForRequestBeingDeleted(hRequest hr);
     void FixConstraintsForPointBeingDeleted(hEntity hpt);
 
@@ -678,6 +679,7 @@ public:
         CMNU_OTHER_ANGLE      = 0x131,
         CMNU_DEL_COINCIDENT   = 0x132,
         CMNU_SNAP_TO_GRID     = 0x140,
+        CMNU_REMOVE_SPLINE_PT = 0x141,
         CMNU_FIRST_STYLE      = 0x40000000
     };
     void ContextMenuListStyles(void);