Implement altitudeMode support in Camera logic. Use elevation model height as a fall-back in RenderContext.

Author: EMaksymenko

worldwind/src/main/java/gov/nasa/worldwind/geom/Camera.java

@@ -108,9 +108,8 @@ public Matrix4 computeViewingTransform(Matrix4 result) {
                     Logger.logMessage(Logger.ERROR, "Camera", "computeViewingTransform", "missingResult"));
         }
 
-        // TODO interpret altitude mode other than absolute
         // Transform by the local cartesian transform at the camera's position.
-        this.wwd.getGlobe().geographicToCartesianTransform(this.position.latitude, this.position.longitude, this.position.altitude, result);
+        this.geographicToCartesianTransform(this.position, this.altitudeMode, result);
 
         // Transform by the heading, tilt and roll.
         result.multiplyByRotation(0, 0, 1, -this.heading); // rotate clockwise about the Z axis
@@ -166,6 +165,7 @@ public Camera setFromLookAt(LookAt lookAt) {
         this.modelview.multiplyByMatrix(this.origin);
 
         this.position.set(this.originPos);
+        this.altitudeMode = WorldWind.ABSOLUTE; // Calculated position is absolute
         this.heading = this.modelview.extractHeading(lookAt.roll); // disambiguate heading and roll
         this.tilt = this.modelview.extractTilt();
         this.roll = lookAt.roll; // roll passes straight through
@@ -193,9 +193,8 @@ public Camera setFromLookAt(LookAt lookAt) {
     }
 
     protected Matrix4 lookAtToViewingTransform(LookAt lookAt, Matrix4 result) {
-        // TODO interpret altitude mode other than absolute
         // Transform by the local cartesian transform at the look-at's position.
-        this.wwd.getGlobe().geographicToCartesianTransform(lookAt.position.latitude, lookAt.position.longitude, lookAt.position.altitude, result);
+        this.geographicToCartesianTransform(lookAt.position, lookAt.altitudeMode, result);
 
         // Transform by the heading and tilt.
         result.multiplyByRotation(0, 0, 1, -lookAt.heading); // rotate clockwise about the Z axis
@@ -211,4 +210,23 @@ protected Matrix4 lookAtToViewingTransform(LookAt lookAt, Matrix4 result) {
         return result;
     }
 
+    protected void geographicToCartesianTransform(Position position, @WorldWind.AltitudeMode int altitudeMode, Matrix4 result) {
+        switch (altitudeMode) {
+            case WorldWind.ABSOLUTE:
+                this.wwd.getGlobe().geographicToCartesianTransform(
+                    position.latitude, position.longitude, position.altitude * this.wwd.getVerticalExaggeration(), result);
+                break;
+            case WorldWind.CLAMP_TO_GROUND:
+                this.wwd.getGlobe().geographicToCartesianTransform(
+                    position.latitude, position.longitude, this.wwd.getGlobe().getElevationAtLocation(
+                            position.latitude, position.longitude) * this.wwd.getVerticalExaggeration(), result);
+                break;
+            case WorldWind.RELATIVE_TO_GROUND:
+                this.wwd.getGlobe().geographicToCartesianTransform(
+                    position.latitude, position.longitude, (position.altitude + this.wwd.getGlobe().getElevationAtLocation(
+                            position.latitude, position.longitude)) * this.wwd.getVerticalExaggeration(), result);
+                break;
+        }
+    }
+
 }

worldwind/src/main/java/gov/nasa/worldwind/render/RenderContext.java

@@ -363,14 +363,17 @@ public Vec3 geographicToCartesian(double latitude, double longitude, double alti
         switch (altitudeMode) {
             case WorldWind.ABSOLUTE:
                 if (this.globe != null) {
-                    return this.globe.geographicToCartesian(latitude, longitude, altitude * this.verticalExaggeration, result);
+                    return this.globe.geographicToCartesian(latitude, longitude,
+                            altitude * this.verticalExaggeration, result);
                 }
             case WorldWind.CLAMP_TO_GROUND:
                 if (this.terrain != null && this.terrain.surfacePoint(latitude, longitude, result)) {
                     return result; // found a point on the terrain
                 } else if (this.globe != null) {
-                    // TODO use elevation model height as a fallback
-                    return this.globe.geographicToCartesian(latitude, longitude, 0, result);
+                    // Use elevation model height as a fallback
+                    return this.globe.geographicToCartesian(latitude, longitude,
+                            this.globe.getElevationAtLocation(latitude, longitude)
+                                    * this.verticalExaggeration, result);
                 }
             case WorldWind.RELATIVE_TO_GROUND:
                 if (this.terrain != null && this.terrain.surfacePoint(latitude, longitude, result)) {
@@ -382,8 +385,10 @@ public Vec3 geographicToCartesian(double latitude, double longitude, double alti
                     }
                     return result; // found a point relative to the terrain
                 } else if (this.globe != null) {
-                    // TODO use elevation model height as a fallback
-                    return this.globe.geographicToCartesian(latitude, longitude, altitude, result);
+                    // Use elevation model height as a fallback
+                    return this.globe.geographicToCartesian(latitude, longitude,
+                            (altitude + this.globe.getElevationAtLocation(latitude, longitude))
+                                    * this.verticalExaggeration, result);
                 }
         }
 

worldwind/src/main/java/gov/nasa/worldwind/shape/OmnidirectionalSightline.java

@@ -85,10 +85,6 @@ public class OmnidirectionalSightline extends AbstractRenderable implements Attr
 
     private Vec3 centerPoint = new Vec3();
 
-    private Vec3 scratchPoint = new Vec3();
-
-    private Vec3 scratchVector = new Vec3();
-
     private int pickedObjectId;
 
     private Color pickColor = new Color();
@@ -383,33 +379,9 @@ protected void doRender(RenderContext rc) {
     }
 
     protected boolean determineCenterPoint(RenderContext rc) {
-        double lat = this.position.latitude;
-        double lon = this.position.longitude;
-        double alt = this.position.altitude;
-
-        switch (this.altitudeMode) {
-            case WorldWind.ABSOLUTE:
-                if (rc.globe != null) {
-                    rc.globe.geographicToCartesian(lat, lon, alt * rc.verticalExaggeration, this.centerPoint);
-                }
-                break;
-            case WorldWind.CLAMP_TO_GROUND:
-                if (rc.terrain != null && rc.terrain.surfacePoint(lat, lon, this.scratchPoint)) {
-                    this.centerPoint.set(this.scratchPoint); // found a point on the terrain
-                }
-                break;
-            case WorldWind.RELATIVE_TO_GROUND:
-                if (rc.terrain != null && rc.terrain.surfacePoint(lat, lon, this.scratchPoint)) {
-                    this.centerPoint.set(this.scratchPoint); // found a point on the terrain
-                    if (alt != 0) { // Offset along the normal vector at the terrain surface point.
-                        rc.globe.geographicToCartesianNormal(lat, lon, this.scratchVector);
-                        this.centerPoint.x += this.scratchVector.x * alt;
-                        this.centerPoint.y += this.scratchVector.y * alt;
-                        this.centerPoint.z += this.scratchVector.z * alt;
-                    }
-                }
-                break;
-        }
+        rc.geographicToCartesian(
+                this.position.latitude, this.position.longitude, this.position.altitude,
+                this.altitudeMode, this.centerPoint);
 
         return this.centerPoint.x != 0
             && this.centerPoint.y != 0