Added support for a new model layout property: allow-density-reduction

Author: JoshuaJMoore

3d-style/data/bucket/model_bucket.ts

@@ -342,6 +342,7 @@ class ModelBucket implements Bucket {
     ): string {
         const layer = this.layers[0];
         const modelIdProperty = layer.layout.get('model-id');
+        const modelAllowDensityReductionProperty = layer.layout.get('model-allow-density-reduction');
         assert(modelIdProperty);
 
         const modelId = modelIdProperty.evaluate(evaluationFeature, {}, this.canonical);
@@ -371,14 +372,16 @@ class ModelBucket implements Bucket {
                 if (point.x < 0 || point.x >= EXTENT || point.y < 0 || point.y >= EXTENT) {
                     continue; // Clip on tile borders to prevent duplicates
                 }
-                // reduce density
-                const tileToLookup = (this.lookupDim - 1.0) / EXTENT;
-                const lookupIndex = this.lookupDim * ((point.y * tileToLookup) | 0) + (point.x * tileToLookup) | 0;
-                if (this.lookup) {
-                    if (this.lookup[lookupIndex] !== 0) {
-                        continue;
+                if (modelAllowDensityReductionProperty) {
+                     // reduce density
+                    const tileToLookup = (this.lookupDim - 1.0) / EXTENT;
+                    const lookupIndex = this.lookupDim * ((point.y * tileToLookup) | 0) + (point.x * tileToLookup) | 0;
+                    if (this.lookup) {
+                        if (this.lookup[lookupIndex] !== 0) {
+                            continue;
+                        }
+                        this.lookup[lookupIndex] = 1;
                     }
-                    this.lookup[lookupIndex] = 1;
                 }
                 this.instanceCount++;
                 const i = instancedDataArray.length;

3d-style/style/style_layer/model_style_layer_properties.ts

@@ -19,11 +19,13 @@ import type {StylePropertySpecification} from '../../../src/style-spec/style-spe
 export type LayoutProps = {
     "visibility": DataConstantProperty<"visible" | "none">;
     "model-id": DataDrivenProperty<string>;
+    "model-allow-density-reduction": DataConstantProperty<boolean>;
 };
 let layout: Properties<LayoutProps>;
 export const getLayoutProperties = (): Properties<LayoutProps> => layout || (layout = new Properties({
     "visibility": new DataConstantProperty(styleSpec["layout_model"]["visibility"]),
     "model-id": new DataDrivenProperty(styleSpec["layout_model"]["model-id"]),
+    "model-allow-density-reduction": new DataConstantProperty(styleSpec["layout_model"]["model-allow-density-reduction"]),
 }));
 
 export type PaintProps = {

src/style-spec/reference/v8.json

@@ -1578,6 +1578,22 @@
             "vector"
           ]
         }]
+    },
+    "model-allow-density-reduction": {
+      "type": "boolean",
+      "default": true,
+      "doc": "If true, the models will be reduced in density based on the zoom level. This is useful for large datasets that may be slow to render.",
+      "sdk-support": {
+        "basic functionality": {
+          "js": "0.10.0",
+          "android": "2.0.1",
+          "ios": "2.0.0"
+        }
+      },
+      "expression": {
+        "interpolated": false
+      },
+      "property-type": "data-constant"
     }
   },
   "layout_clip": {

src/style-spec/types.ts

@@ -1066,6 +1066,7 @@ export type ModelLayerSpecification = {
     "layout"?: {
         "visibility"?: "visible" | "none" | ExpressionSpecification,
         "model-id"?: DataDrivenPropertyValueSpecification<string>
+        "model-allow-density-reduction"?: PropertyValueSpecification<boolean>,
     },
     "paint"?: {
         "model-opacity"?: DataDrivenPropertyValueSpecification<number>,