Replace convenience #defines with const auto references.

These are nicer as they are scoped, and so it's clear where they
can be used.

src/constraint.cpp

@@ -121,7 +121,7 @@ void Constraint::MenuConstrain(Command id) {
     c.workplane = SS.GW.ActiveWorkplane();
 
     SS.GW.GroupSelection();
-#define gs (SS.GW.gs)
+    auto const &gs = SS.GW.gs;
 
     switch(id) {
         case Command::DISTANCE_DIA:

src/describescreen.cpp

@@ -19,13 +19,13 @@ void TextWindow::ScreenEditTtfText(int link, uint32_t v) {
     SS.TW.edit.request = hr;
 }
 
-#define gs (SS.GW.gs)
 void TextWindow::ScreenSetTtfFont(int link, uint32_t v) {
     int i = (int)v;
     if(i < 0) return;
     if(i >= SS.fonts.l.n) return;
 
     SS.GW.GroupSelection();
+    auto const &gs = SS.GW.gs;
     if(gs.entities != 1 || gs.n != 1) return;
 
     Entity *e = SK.entity.FindByIdNoOops(gs.entity[0]);
@@ -57,6 +57,7 @@ void TextWindow::DescribeSelection() {
     int i;
     Printf(false, "");
 
+    auto const &gs = SS.GW.gs;
     if(gs.n == 1 && (gs.points == 1 || gs.entities == 1)) {
         e = SK.GetEntity(gs.points == 1 ? gs.point[0] : gs.entity[0]);
 

src/export.cpp

@@ -26,7 +26,7 @@ void SolveSpaceUI::ExportSectionTo(const std::string &filename) {
     double d;
 
     SS.GW.GroupSelection();
-#define gs (SS.GW.gs)
+    auto const &gs = SS.GW.gs;
     if((gs.n == 0 && g->activeWorkplane.v != Entity::FREE_IN_3D.v)) {
         Entity *wrkpl = SK.GetEntity(g->activeWorkplane);
         origin = wrkpl->WorkplaneGetOffset();

src/group.cpp

@@ -13,8 +13,6 @@ const hParam   Param::NO_PARAM = { 0 };
 
 const hGroup Group::HGROUP_REFERENCES = { 1 };
 
-#define gs (SS.GW.gs)
-
 //-----------------------------------------------------------------------------
 // The group structure includes pointers to other dynamically-allocated
 // memory. This clears and frees them all.
@@ -83,6 +81,7 @@ void Group::MenuGroup(Command id) {
     }
 
     SS.GW.GroupSelection();
+    auto const &gs = SS.GW.gs;
 
     switch(id) {
         case Command::GROUP_3D:

src/groupmesh.cpp

@@ -7,8 +7,6 @@
 //-----------------------------------------------------------------------------
 #include "solvespace.h"
 
-#define gs (SS.GW.gs)
-
 void Group::AssembleLoops(bool *allClosed,
                           bool *allCoplanar,
                           bool *allNonZeroLen)
@@ -513,6 +511,7 @@ void Group::DrawMesh(DrawMeshAs how, Canvas *canvas) {
 
             std::vector<uint32_t> faces;
             SS.GW.GroupSelection();
+            auto const &gs = SS.GW.gs;
             if(gs.faces > 0) faces.push_back(gs.face[0].v);
             if(gs.faces > 1) faces.push_back(gs.face[1].v);
             canvas->DrawFaces(displayMesh, faces, hcf);

src/solvespace.cpp

@@ -570,7 +570,7 @@ void SolveSpaceUI::MenuFile(Command id) {
 
 void SolveSpaceUI::MenuAnalyze(Command id) {
     SS.GW.GroupSelection();
-#define gs (SS.GW.gs)
+    auto const &gs = SS.GW.gs;
 
     switch(id) {
         case Command::STEP_DIM:

src/textwin.cpp

@@ -448,11 +448,11 @@ done:
     va_end(vl);
 }
 
-#define gs (SS.GW.gs)
 void TextWindow::Show() {
     if(SS.GW.pending.operation == GraphicsWindow::Pending::NONE) SS.GW.ClearPending();
 
     SS.GW.GroupSelection();
+    auto const &gs = SS.GW.gs;
 
     // Make sure these tests agree with test used to draw indicator line on
     // main list of groups screen.
@@ -963,6 +963,7 @@ void TextWindow::Paint() {
     // The line to indicate the column of radio buttons that indicates the
     // active group.
     SS.GW.GroupSelection();
+    auto const &gs = SS.GW.gs;
     // Make sure this test agrees with test to determine which screen is drawn
     if(!SS.GW.pending.description && gs.n == 0 && gs.constraints == 0 &&
         shown.screen == Screen::LIST_OF_GROUPS)
@@ -1023,34 +1024,31 @@ void TextWindow::MouseEvent(bool leftClick, bool leftDown, double x, double y) {
             break;
         }
     }
-    if(r >= rows || c >= MAX_COLS) {
+    if(r < rows && c < MAX_COLS) {
         SetMousePointerToHand(false);
-        goto done;
-    }
 
-    hoveredRow = r;
-    hoveredCol = c;
+        hoveredRow = r;
+        hoveredCol = c;
 
-#define META (meta[r][c])
-    if(leftClick) {
-        if(META.link && META.f) {
-            (META.f)(META.link, META.data);
-            Show();
-            InvalidateGraphics();
-        }
-    } else {
-        if(META.link) {
-            SetMousePointerToHand(true);
-            if(META.h) {
-                (META.h)(META.link, META.data);
+        const auto &item = meta[r][c];
+        if(leftClick) {
+            if(item.link && item.f) {
+                (item.f)(item.link, item.data);
+                Show();
+                InvalidateGraphics();
             }
         } else {
-            SetMousePointerToHand(false);
+            if(item.link) {
+                SetMousePointerToHand(true);
+                if(item.h) {
+                    (item.h)(item.link, item.data);
+                }
+            } else {
+                SetMousePointerToHand(false);
+            }
         }
     }
-#undef META
 
-done:
     if((!ps.Equals(&(SS.GW.hover))) ||
         prevHoveredRow != hoveredRow ||
         prevHoveredCol != hoveredCol)