tweaked line particle display and chunk display app

src/main/java/carpet/script/utils/ShapeDispatcher.java

@@ -546,14 +546,13 @@ public class ShapeDispatcher
             super.init(options);
             from = vecFromValue(options.get("from"));
             to = vecFromValue(options.get("to"));
-            if (from.equals(to)) throw new InternalExpressionException("Box dimensions are invalid - cannot draw a zero-size boxes");
         }
 
         @Override
         public Consumer<ServerPlayerEntity> alternative()
         {
             ParticleEffect particle = replacementParticle();
-            double density = Math.max(2.0, from.distanceTo(to) /50) / (a+0.1);
+            double density = Math.max(2.0, from.distanceTo(to) /50/ (a+0.1)) ;
             return p ->
             {
                 if (p.dimension == shapeDimension)
@@ -629,7 +628,6 @@ public class ShapeDispatcher
             super.init(options);
             from = vecFromValue(options.get("from"));
             to = vecFromValue(options.get("to"));
-            if (from.equals(to)) throw new InternalExpressionException("Line dimensions are invalid - cannot draw a zero-length lines");
         }
 
         @Override
@@ -1276,13 +1274,33 @@ public class ShapeDispatcher
 
     public static int drawParticleLine(List<ServerPlayerEntity> players, ParticleEffect particle, Vec3d from, Vec3d to, double density)
     {
-        if (isStraight(from, to, density)) return drawOptimizedParticleLine(players, particle, from, to, density);
-        double lineLengthSq = from.squaredDistanceTo(to);
-        if (lineLengthSq == 0) return 0;
-        Vec3d incvec = to.subtract(from).multiply(2*density/MathHelper.sqrt(lineLengthSq));
+        double distance = from.squaredDistanceTo(to);
+        if (distance == 0) return 0;
         int pcount = 0;
+        if (distance < 100)
+        {
+            Random rand = players.get(0).getServerWorld().random;
+            int particles = (int)(distance/density)+1;
+            Vec3d towards = to.subtract(from);
+            for (int i = 0; i < particles; i++)
+            {
+                Vec3d at = from.add(towards.multiply( rand.nextDouble()));
+                for (ServerPlayerEntity player : players)
+                {
+                    player.getServerWorld().spawnParticles(player, particle, true,
+                            at.x, at.y, at.z, 1,
+                            0.0, 0.0, 0.0, 0.0);
+                    pcount ++;
+                }
+            }
+            return pcount;
+        }
+
+        if (isStraight(from, to, density)) return drawOptimizedParticleLine(players, particle, from, to, density);
+        Vec3d incvec = to.subtract(from).multiply(2*density/MathHelper.sqrt(distance));
+
         for (Vec3d delta = new Vec3d(0.0,0.0,0.0);
-             delta.lengthSquared()<lineLengthSq;
+             delta.lengthSquared()<distance;
              delta = delta.add(incvec.multiply(Expression.randomizer.nextFloat())))
         {
             for (ServerPlayerEntity player : players)

src/main/resources/assets/carpet/scripts/chunk_display.sc

@@ -1,3 +1,4 @@
+global_update_interval = 100;
 global_chunk_colors = m(
     // loaded ticking
 	l(3,                   l(0xAAdd0000,  0x66990000)), // lime, green
@@ -126,6 +127,9 @@ __chunk_visualizer_tick(p) ->
 	if (!global_running, return());
 	show_activity = (p~'holds':0 == 'redstone_torch');
 	yval = setup:'plot_center':1+16;
+	base_update = global_update_interval;
+	random_component = ceil(0.4*base_update);
+	duration_max = ceil(1.5*base_update);
 	in_dimension( setup:'plot_dimension',
 		l(sx, sy, sz) = setup:'source_center';
 		l(px, py, pz) = setup:'plot_center';
@@ -160,10 +164,10 @@ __chunk_visualizer_tick(p) ->
 				l(cached_status, expiry) = global_status_cache:source_pos;
 				changed = (status != cached_status);
 				if ( changed || (expiry < now),
-                    global_status_cache:source_pos = l(status, now+100+floor(rand(40)));
+                    global_status_cache:source_pos = l(status, now+base_update+floor(rand(random_component)));
 					bpos = l(dx/2, yval, dz/2);
 					bcol = global_chunk_colors:status:((dx+dz)%2);
-					shapes += l('box', 150, 'from', bpos, 'to', bpos + l(0.5,0,0.5),
+					shapes += l('box', duration_max, 'from', bpos, 'to', bpos + l(0.5,0,0.5),
 					    'color', 0xffffff00, 'fill', bcol+128, 'follow', p, 'snap', 'xz');
 					if (changed,
 					    pbcol = global_chunk_colors:cached_status:((dx+dz)%2);