Add ability to set near clip offset. Relevant for orthographic

projection only.

GitOrigin-RevId: 3e8f61ac029282b2723fbcec7451e7014eda4c46

Author: alexey-romanov

debug/3d-playground.html

@@ -115,6 +115,7 @@
 
     this.mapProjection = 'globe';
     this.orthographicProjectionAtLowPitch = false;
+    this.nearClipOffset = 0;
     this.buildingExtrusion = "extrusion";
     this.enableBuildings = true;
 
@@ -264,6 +265,11 @@
     camera.addInput(demo3d, 'orthographicProjectionAtLowPitch').on('change', (ev) => {
         map.setCamera({'camera-projection': ev.value ? 'orthographic' : 'perspective'});
     });
+    camera.addInput(demo3d, 'nearClipOffset', {min:-1000.0, max:1000.0}).on('change', (ev) => {
+        map.setNearClipOffset(ev.value);
+    });
+
+
 
     // Sky
     const sky = gui.addFolder({title:'Sky', expanded:false});

src/geo/transform.ts

@@ -214,6 +214,7 @@ class Transform {
     _pixelsPerMercatorPixel: number;
     _nearZ: number;
     _farZ: number;
+    _nearClipOffset: number;
     _mercatorScaleRatio: number;
     _isCameraConstrained: boolean;
 
@@ -243,6 +244,7 @@ class Transform {
         this._pitch = 0;
         this._nearZ = 0;
         this._farZ = 0;
+        this._nearClipOffset = 0;
         this._unmodified = true;
         this._edgeInsets = new EdgeInsets();
         this._projMatrixCache = {};
@@ -286,6 +288,7 @@ class Transform {
         clone._pitch = this._pitch;
         clone._nearZ = this._nearZ;
         clone._farZ = this._farZ;
+        clone._nearClipOffset = this._nearClipOffset;
         clone._averageElevation = this._averageElevation;
         clone._orthographicProjectionAtLowPitch = this._orthographicProjectionAtLowPitch;
         clone._unmodified = this._unmodified;
@@ -308,6 +311,16 @@ class Transform {
         this._updateCameraOnTerrain();
         this._calcMatrices();
     }
+
+    get nearClipOffset(): number {
+        return this._nearClipOffset;
+    }
+
+    set nearClipOffset(offset: number) {
+        this._nearClipOffset = offset;
+        this._calcMatrices();
+    }
+
     get depthOcclusionForSymbolsAndCircles(): boolean {
         return this.projection.name !== 'globe' && !this.isOrthographic;
     }
@@ -2407,7 +2420,7 @@ class Transform {
             top += offset.y;
             bottom += offset.y;
 
-            cameraToClip = this._camera.getCameraToClipOrthographic(left, right, bottom, top, this._nearZ, this._farZ);
+            cameraToClip = this._camera.getCameraToClipOrthographic(left, right, bottom, top, this._nearZ + this._nearClipOffset, this._farZ);
 
             const mixValue =
                 this.pitch >= OrthographicPitchTranstionValue ? 1.0 : this.pitch / OrthographicPitchTranstionValue;

src/ui/map.ts

@@ -3975,6 +3975,37 @@ export class Map extends Camera {
         return this._triggerCameraUpdate(camera);
     }
 
+    /**
+     * Returns the map's near clip offset. Relevant for orthographic projection only.
+     *
+     * @memberof Map#
+     * @returns {number} The map's current near clip offset.
+     * @experimental
+     *
+     * @example
+     * map.getNearClipOffset();
+     */
+    getNearClipOffset(): number { return this.transform.nearClipOffset; }
+
+    /**
+     * Sets the map's camera near clip offset value. Relevant for orthographic projection only.
+     *
+     * @memberof Map#
+     * @param {number} offset The near clip offset to set.
+     * @returns {Map} Returns itself to allow for method chaining.
+     * @experimental
+     *
+     * @example
+     * map.setNearClipOffset(30)
+     */
+    setNearClipOffset(offset: number): this {
+        const needsUpdate = this.transform.nearClipOffset !== offset;
+
+        this.transform.nearClipOffset = offset;
+
+        return this._update(needsUpdate);
+    }
+
     _triggerCameraUpdate(camera: CameraSpecification): this {
         return this._update(this.transform.setOrthographicProjectionAtLowPitch(camera['camera-projection'] === 'orthographic'));
     }