Prep Attribute class for partial update (#3091)

visgl · May 15, 2019 · 9ffe6df · 9ffe6df
1 parent 73e167d
commit 9ffe6df
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Showing 2 changed files with 40 additions and 23 deletions.
diff --git a/modules/core/src/lib/attribute.js b/modules/core/src/lib/attribute.js
@@ -171,6 +171,11 @@ export default class Attribute extends BaseAttribute {
 
       this.constant = false;
       this.value = new ArrayType(this.size * allocCount);
+
+      if (this.buffer && this.buffer.byteLength < this.value.byteLength) {
+        this.buffer.reallocate(this.value.byteLength);
+      }
+
       state.needsUpdate = true;
       state.allocedInstances = allocCount;
       return true;
@@ -186,16 +191,24 @@ export default class Attribute extends BaseAttribute {
 
     const state = this.userData;
 
-    const {update} = state;
+    const {update, noAlloc} = state;
 
     let updated = true;
     if (update) {
       // Custom updater - typically for non-instanced layers
       update.call(context, this, {data, props, numInstances, bufferLayout});
-      this.update({
-        value: this.value,
-        constant: this.constant
-      });
+      if (noAlloc || this.constant || !this.buffer) {
+        // Full update
+        this.update({
+          value: this.value,
+          constant: this.constant
+        });
+      } else {
+        // Only update the changed part of the attribute
+        this.buffer.subData({
+          data: this.value.subarray(0, numInstances * this.size)
+        });
+      }
       this._checkAttributeArray();
     } else {
       updated = false;

diff --git a/modules/core/src/lib/base-attribute.js b/modules/core/src/lib/base-attribute.js
@@ -76,24 +76,7 @@ export default class BaseAttribute {
 
       // Create buffer if needed
       if (!constant && this.gl) {
-        // Move accessor fields to accessor object
-        const props = {
-          ...opts,
-          id: this.id,
-          target: this.target,
-          accessor: {
-            type: this.type
-          }
-        };
-        if (Number.isFinite(props.divisor)) {
-          props.accessor.divisor = props.divisor;
-        }
-        delete props.divisor;
-        if (Number.isFinite(props.size)) {
-          props.accessor.size = props.size;
-        }
-        delete props.size;
-        this.buffer = this.buffer || new Buffer(this.gl, props);
+        this.buffer = this.buffer || this._createBuffer(opts);
         this.buffer.setData({data: value});
         this.type = this.buffer.accessor.type;
       }
@@ -120,6 +103,27 @@ export default class BaseAttribute {
     return null;
   }
 
+  _createBuffer(opts) {
+    // Move accessor fields to accessor object
+    const props = Object.assign({}, opts, {
+      id: this.id,
+      target: this.target,
+      accessor: {
+        type: this.type
+      }
+    });
+    if (Number.isFinite(props.divisor)) {
+      props.accessor.divisor = props.divisor;
+    }
+    delete props.divisor;
+    if (Number.isFinite(props.size)) {
+      props.accessor.size = props.size;
+    }
+    delete props.size;
+
+    return new Buffer(this.gl, props);
+  }
+
   // Sets all accessor props except type
   // TODO - store on `this.accessor`
   _setAccessor(opts) {