Add configurable draw order for surface renderables.

Author: EMaksymenko

worldwind/src/commonMain/kotlin/earth/worldwind/formats/kml/KmlToRenderableConverter.kt

@@ -120,7 +120,9 @@ internal class KmlToRenderableConverter {
         val surfaceImage = SurfaceImage(
             sector = groundOverlay.latLonBox?.toSector() ?: return emptyList(),
             imageSource = groundOverlay.icon?.toImageSource() ?: return emptyList(),
-        )
+        ).apply {
+            zOrder = groundOverlay.drawOrder.toDouble()
+        }
         return listOf(surfaceImage)
     }
 
@@ -166,6 +168,7 @@ internal class KmlToRenderableConverter {
         isFollowTerrain = lineString.tessellate == true
         pathType = getPathTypeBy(altitudeMode, isFollowTerrain)
         maximumIntermediatePoints = 0 // Disable intermediate point for performance reasons
+        zOrder = lineString.drawOrder.toDouble()
 
         name?.let { displayName = it }
 

worldwind/src/commonMain/kotlin/earth/worldwind/layer/ShowTessellationLayer.kt

@@ -7,6 +7,7 @@ import earth.worldwind.render.program.BasicShaderProgram
 
 class ShowTessellationLayer: AbstractLayer("Terrain Tessellation") {
     override var isPickEnabled = false
+    var zOrder = 1.0 // z-order after surface textures
     var color = Color()
         set(value) {
             field.copy(value)
@@ -19,6 +20,6 @@ class ShowTessellationLayer: AbstractLayer("Terrain Tessellation") {
         val program = rc.getShaderProgram(BasicShaderProgram.KEY) { BasicShaderProgram() }
         val pool = rc.getDrawablePool(DrawableTessellation.KEY)
         val drawable = DrawableTessellation.obtain(pool).set(program, color, opacity)
-        rc.offerSurfaceDrawable(drawable, 1.0 /*z-order after surface textures*/)
+        rc.offerSurfaceDrawable(drawable, zOrder)
     }
 }

worldwind/src/commonMain/kotlin/earth/worldwind/layer/heatmap/ElevationHeatmapLayer.kt

@@ -8,6 +8,7 @@ import earth.worldwind.render.RenderContext
 open class ElevationHeatmapLayer: AbstractLayer("Elevation Heatmap") {
     override var isPickEnabled = false // Elevation Heatmap is not pickable
     override var opacity = 0.5f // Elevation Heatmap is semi-transparent by default
+    var zOrder = 0.0
     /**
      * RGB colors for five thresholds of heatmap
      */
@@ -41,6 +42,6 @@ open class ElevationHeatmapLayer: AbstractLayer("Elevation Heatmap") {
         drawable.opacity = opacity
         drawable.offset = rc.globe.offset
         drawable.program = rc.getShaderProgram(ElevationHeatmapProgram.KEY) { ElevationHeatmapProgram() }
-        rc.offerSurfaceDrawable(drawable, 0.0)
+        rc.offerSurfaceDrawable(drawable, zOrder)
     }
 }

worldwind/src/commonMain/kotlin/earth/worldwind/render/AbstractRenderable.kt

@@ -6,6 +6,7 @@ abstract class AbstractRenderable @JvmOverloads constructor(override var display
     override var isEnabled = true
     override var isPickEnabled = true
     override var pickDelegate: Any? = null
+    override var zOrder = 0.0
     private var userProperties: MutableMap<Any, Any>? = null
 
     @Suppress("UNCHECKED_CAST")

worldwind/src/commonMain/kotlin/earth/worldwind/render/Renderable.kt

@@ -5,6 +5,7 @@ interface Renderable {
     var isEnabled: Boolean
     var isPickEnabled: Boolean
     var pickDelegate: Any?
+    var zOrder: Double
     fun <T> getUserProperty(key: Any): T?
     fun putUserProperty(key: Any, value: Any): Any?
     fun removeUserProperty(key: Any): Any?

worldwind/src/commonMain/kotlin/earth/worldwind/shape/DirectionalSightline.kt

@@ -243,6 +243,6 @@ open class DirectionalSightline @JvmOverloads constructor(
         drawable.program = rc.getShaderProgram(SightlineProgram.KEY) { SightlineProgram() }
 
         // Enqueue a drawable for processing on the OpenGL thread.
-        rc.offerSurfaceDrawable(drawable, 0.0 /*z-order*/)
+        rc.offerSurfaceDrawable(drawable, zOrder)
     }
 }

worldwind/src/commonMain/kotlin/earth/worldwind/shape/Ellipse.kt

@@ -367,8 +367,8 @@ open class Ellipse @JvmOverloads constructor(
 
         // Enqueue the drawable for processing on the OpenGL thread.
         if (isSurfaceShape) {
-            rc.offerSurfaceDrawable(drawable, zOrder = 0.0)
-            rc.offerSurfaceDrawable(drawableLines, zOrder = 0.0)
+            rc.offerSurfaceDrawable(drawable, zOrder)
+            rc.offerSurfaceDrawable(drawableLines, zOrder)
         } else {
             rc.offerShapeDrawable(drawableLines, cameraDistance)
             rc.offerShapeDrawable(drawable, cameraDistance)

worldwind/src/commonMain/kotlin/earth/worldwind/shape/OmnidirectionalSightline.kt

@@ -187,6 +187,6 @@ open class OmnidirectionalSightline @JvmOverloads constructor(
         drawable.program = rc.getShaderProgram(SightlineProgram.KEY) { SightlineProgram() }
 
         // Enqueue a drawable for processing on the OpenGL thread.
-        rc.offerSurfaceDrawable(drawable, 0.0 /*z-order*/)
+        rc.offerSurfaceDrawable(drawable, zOrder)
     }
 }

worldwind/src/commonMain/kotlin/earth/worldwind/shape/Path.kt

@@ -181,7 +181,7 @@ open class Path @JvmOverloads constructor(
         drawState.enableDepthWrite = activeAttributes.isDepthWrite
 
         // Enqueue the drawable for processing on the OpenGL thread.
-        if (isSurfaceShape) rc.offerSurfaceDrawable(drawable, zOrder = 0.0)
+        if (isSurfaceShape) rc.offerSurfaceDrawable(drawable, zOrder)
         else rc.offerShapeDrawable(drawable, cameraDistance)
 
         // Configure the drawable to display the shape's extruded interior.

worldwind/src/commonMain/kotlin/earth/worldwind/shape/Polygon.kt

@@ -275,8 +275,8 @@ open class Polygon @JvmOverloads constructor(
 
         // Enqueue the drawable for processing on the OpenGL thread.
         if (isSurfaceShape|| activeAttributes.interiorColor.alpha >= 1.0) {
-            rc.offerSurfaceDrawable(drawable, zOrder = 0.0)
-            rc.offerSurfaceDrawable(drawableLines, zOrder = 0.0)
+            rc.offerSurfaceDrawable(drawable, zOrder)
+            rc.offerSurfaceDrawable(drawableLines, zOrder)
         } else {
             rc.offerShapeDrawable(drawableLines, cameraDistance)
             rc.offerShapeDrawable(drawable, cameraDistance)