Add catenary brush

core/src/main/java/com/boydti/fawe/config/BBC.java

@@ -128,6 +128,8 @@ public enum BBC {
     BRUSH_HEIGHT_INVALID("Invalid height map file (%s0)", "WorldEdit.Brush"),
     BRUSH_SMOOTH("Note: Use the blend brush if you want to smooth overhangs or caves.", "WorldEdit.Brush"),
     BRUSH_SPLINE("Click to add a point, click the same spot to finish", "WorldEdit.Brush"),
+    BRUSH_LINE_PRIMARY("Added point %s0, click another position to create the line", "WorldEdit.Brush"),
+    BRUSH_LINE_SECONDARY("Created pline", "WorldEdit.Brush"),
     BRUSH_SPLINE_PRIMARY_2("Added position, Click the same spot to join!", "WorldEdit.Brush"),
     BRUSH_SPLINE_SECONDARY_ERROR("Not enough positions set!", "WorldEdit.Brush"),
     BRUSH_SPLINE_SECONDARY("Created spline", "WorldEdit.Brush"),

core/src/main/java/com/boydti/fawe/object/brush/CatenaryBrush.java

@@ -0,0 +1,74 @@
+package com.boydti.fawe.object.brush;
+
+import com.boydti.fawe.config.BBC;
+import com.boydti.fawe.object.brush.visualization.VisualExtent;
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.MaxChangedBlocksException;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.command.tool.brush.Brush;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import java.util.Arrays;
+import java.util.List;
+
+public class CatenaryBrush implements Brush, ResettableTool {
+
+    private final boolean shell, select;
+    private final double slack;
+    private Vector pos1;
+
+    public CatenaryBrush(boolean shell, boolean select, double lengthFactor) {
+        this.shell = shell;
+        this.select = select;
+        this.slack = lengthFactor;
+    }
+
+    @Override
+    public void build(EditSession editSession, Vector pos2, final Pattern pattern, double size) throws MaxChangedBlocksException {
+        boolean visual = (editSession.getExtent() instanceof VisualExtent);
+        if (pos1 == null || pos2.equals(pos1)) {
+            if (!visual) {
+                pos1 = pos2;
+                BBC.BRUSH_LINE_PRIMARY.send(editSession.getPlayer(), pos2);
+            }
+            return;
+        }
+        Vector vertex = getVertex(pos1, pos2, slack);
+        List<Vector> nodes = Arrays.asList(pos1, vertex, pos2);
+        editSession.drawSpline(pattern, nodes, 0, 0, 0, 10, size, !shell);
+        if (!visual) {
+            BBC.BRUSH_LINE_SECONDARY.send(editSession.getPlayer());
+            if (!select) {
+                pos1 = null;
+                return;
+            } else {
+                pos1 = pos2;
+            }
+        }
+    }
+
+    @Override
+    public boolean reset() {
+        pos1 = null;
+        return true;
+    }
+
+public Vector getVertex(Vector pos1, Vector pos2, double lenPercent) {
+    double len = pos1.distance(pos2) * lenPercent;
+
+    double dy = pos2.getY() - pos1.getY();
+    double dx = pos2.getX() - pos1.getX();
+    double dz = pos2.getZ() - pos1.getZ();
+    double h = Math.sqrt(dx * dx + dz * dz);
+
+    double t = Math.sqrt(len * len - dy * dy) / h;
+    double z = 0.001;
+    for (; Math.sinh(z) < t*z; z += 0.001); // close enough
+
+    double a = (h / 2) / z;
+    double p = (h - a * Math.log((len + dy) / (len - dy)))/2;
+    double q = (dy - len * Math.cosh(z) / Math.sinh(z)) / 2;
+    double y = a * 1 + q;
+
+    return pos1.add(pos2.subtract(pos1).multiply(p / h).add(0, y, 0)).round();
+}
+}

core/src/main/java/com/boydti/fawe/object/brush/LineBrush.java

@@ -1,5 +1,6 @@
 package com.boydti.fawe.object.brush;
 
+import com.boydti.fawe.config.BBC;
 import com.boydti.fawe.object.brush.visualization.VisualExtent;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.MaxChangedBlocksException;
@@ -22,11 +23,15 @@ public class LineBrush implements Brush, ResettableTool {
     public void build(EditSession editSession, Vector position, final Pattern pattern, double size) throws MaxChangedBlocksException {
         boolean visual = (editSession.getExtent() instanceof VisualExtent);
         if (pos1 == null) {
-            if (!visual) pos1 = position;
+            if (!visual) {
+                pos1 = position;
+                BBC.BRUSH_LINE_PRIMARY.send(editSession.getPlayer(), position);
+            }
             return;
         }
         editSession.drawLine(pattern, pos1, position, size, !shell, flat);
         if (!visual) {
+            BBC.BRUSH_LINE_SECONDARY.send(editSession.getPlayer());
             if (!select) {
                 pos1 = null;
                 return;

core/src/main/java/com/sk89q/worldedit/command/BrushCommands.java

@@ -27,6 +27,7 @@ import com.boydti.fawe.object.FaweLimit;
 import com.boydti.fawe.object.FawePlayer;
 import com.boydti.fawe.object.brush.BlendBall;
 import com.boydti.fawe.object.brush.BrushSettings;
+import com.boydti.fawe.object.brush.CatenaryBrush;
 import com.boydti.fawe.object.brush.CircleBrush;
 import com.boydti.fawe.object.brush.CommandBrush;
 import com.boydti.fawe.object.brush.CopyPastaBrush;
@@ -84,6 +85,7 @@ import com.sk89q.worldedit.function.mask.Mask;
 import com.sk89q.worldedit.function.pattern.Pattern;
 import com.sk89q.worldedit.session.ClipboardHolder;
 import com.sk89q.worldedit.util.command.InvalidUsageException;
+import com.sk89q.worldedit.util.command.binding.Range;
 import com.sk89q.worldedit.util.command.binding.Switch;
 import com.sk89q.worldedit.util.command.parametric.Optional;
 import java.awt.Color;
@@ -245,7 +247,25 @@ public class BrushCommands extends MethodCommands {
                 .setFill(fill);
     }
 
-    // final double tension, final double bias, final double continuity, final double quality
+    @Command(
+            aliases = {"catenary", "cat", "gravityline", "saggedline"},
+            usage = "<pattern> [length-factor=1.2] [size=0]",
+            desc = "Create a hanging line between two points",
+            help = "Create a hanging line between two points.\n" +
+                    "The length-factor controls how long the line is\n" +
+                    "The -h flag creates only a shell\n" +
+                    "The -s flag selects the clicked point after drawing\n",
+            min = 1,
+            max = 3
+    )
+    @CommandPermissions("worldedit.brush.spline")
+    public BrushSettings catenaryBrush(Player player, EditSession editSession, LocalSession session, Pattern fill, @Optional("1.2") @Range(min=1) double lengthFactor, @Optional("0") double radius, @Switch('h') boolean shell, @Switch('s') boolean select, CommandContext context) throws WorldEditException {
+        worldEdit.checkMaxBrushRadius(radius);
+        return get(context)
+                .setBrush(new CatenaryBrush(shell, select, lengthFactor))
+                .setSize(radius)
+                .setFill(fill);
+    }
 
     @Command(
             aliases = {"sspl", "sspline", "surfacespline"},
@@ -254,7 +274,7 @@ public class BrushCommands extends MethodCommands {
             help = "Create a spline on the surface\n" +
                     "Video: https://www.youtube.com/watch?v=zSN-2jJxXlM",
             min = 0,
-            max = 2
+            max = 6
     )
     @CommandPermissions("worldedit.brush.surfacespline") // 0, 0, 0, 10, 0,
     public BrushSettings surfaceSpline(Player player, EditSession editSession, LocalSession session, Pattern fill, @Optional("0") double radius, @Optional("0") double tension, @Optional("0") double bias, @Optional("0") double continuity, @Optional("10") double quality, CommandContext context) throws WorldEditException {