Shader attribute tests

modules/core/src/lib/attribute-manager.js

@@ -212,7 +212,6 @@ export default class AttributeManager {
   }
 
   // Ensure all attribute buffers are updated from props or data.
-  /* eslint-disable complexity */
   update({data, numInstances, transitions, props = {}, buffers = {}, context = {}} = {}) {
     // keep track of whether some attributes are updated
     let updated = false;

modules/core/src/lib/base-attribute.js

@@ -61,8 +61,12 @@ export default class BaseAttribute {
 
       const size = this.size || opts.size || 0;
       if (constant && value.length !== size) {
+        // NOTE(Tarek): Assuming float constants.
+        // This is all we currently use, but we'll
+        // have to update this if we start using int
+        // attributes (WebGL 2-only)
         this.value = new Float32Array(size);
-        const index = this.offset / 4;
+        const index = this.offset / 4; // Always 4 bytes/element (float, int or uint)
         for (let i = 0; i < this.size; ++i) {
           this.value[i] = value[index + i];
         }

test/modules/core/lib/attribute.spec.js

@@ -69,6 +69,41 @@ test('Attribute#getUpdateTriggers', t => {
   t.end();
 });
 
+test('Attribute#shaderAttributes', t => {
+  const update = () => {};
+
+  const attribute = new Attribute(gl, {
+    id: 'positions',
+    update,
+    size: 3,
+    shaderAttributes: {
+      positions: {},
+      instancePositions: {
+        divisor: 1
+      }
+    }
+  });
+  t.ok(attribute.shaderAttributes.positions, 'Shader attribute created');
+  t.equals(
+    attribute.shaderAttributes.positions.size,
+    3,
+    'Shader attribute inherits pointer properties'
+  );
+  t.ok(attribute.shaderAttributes.instancePositions, 'Multiple shader attributes created');
+  t.equals(
+    attribute.shaderAttributes.instancePositions.size,
+    3,
+    'Multiple shader attributes inherit pointer properties'
+  );
+  t.equals(
+    attribute.shaderAttributes.instancePositions.divisor,
+    1,
+    'Shader attribute defines pointer properties'
+  );
+
+  t.end();
+});
+
 // t.ok(attribute.allocate(attributeName, allocCount), 'Attribute.allocate function available');
 // t.ok(attribute._setExternalBuffer(attributeName, buffer, numInstances), 'Attribute._setExternalBuffer function available');
 // t.ok(attribute._analyzeBuffer(attributeName, numInstances), 'Attribute._analyzeBuffer function available');