play with incremental rendering

src/kiri/stack.js

@@ -44,6 +44,16 @@
             this.show();
             for (let i=0, s=this.slices, len=s.length; i<len; i++) {
                 s[i].visible = i >= newMin && i <= newMax;
+                if (s[i].visible) this.lastVis = s[i];
+            }
+        }
+
+        setLastFraction(frac = 1) {
+            for (let mesh of this.lastVis.children) {
+                let geo = mesh.geometry;
+                let pos = geo.attributes.position;
+                let len = frac === 1 ? Infinity : Math.round(pos.count * frac);
+                geo.setDrawRange(0, len);
             }
         }
 

src/kiri/stacks.js

@@ -52,6 +52,10 @@
         return stacks[name];
     }
 
+    function getStacks() {
+        return Object.entries(stacks);
+    }
+
     function getLabels() {
         return Object.keys(DYN);
     }
@@ -139,16 +143,24 @@
         max = newMax;
     }
 
+    function setFraction(frac) {
+        Object.values(stacks).forEach(stack => {
+            stack.obj.setLastFraction(frac);
+        });
+    }
+
     KIRI.stacks = {
         clear,
         create,
         rotate,
         remove,
         getStack,
+        getStacks,
         getRange,
         setRange,
         getLabels,
         setVisible,
+        setFraction,
         setFreeMem
     };