[#33] Fix limitation of 3D path length

worldwind/src/androidMain/kotlin/earth/worldwind/util/kgl/AndroidKgl.kt

@@ -3,6 +3,7 @@ package earth.worldwind.util.kgl
 import android.opengl.GLES20
 import java.nio.ByteBuffer
 import java.nio.FloatBuffer
+import java.nio.IntBuffer
 import java.nio.ShortBuffer
 
 class AndroidKgl : Kgl {
@@ -80,7 +81,8 @@ class AndroidKgl : Kgl {
 
     override fun bufferData(target: Int, size: Int, sourceData: ShortArray, usage: Int, offset: Int) =
         GLES20.glBufferData(target, size, ShortBuffer.wrap(sourceData, offset, size / 2), usage)
-
+    override fun bufferData(target: Int, size: Int, sourceData: IntArray, usage: Int, offset: Int) =
+        GLES20.glBufferData(target, size, IntBuffer.wrap(sourceData, offset, size / 4), usage)
     override fun bufferData(target: Int, size: Int, sourceData: FloatArray, usage: Int, offset: Int) =
         GLES20.glBufferData(target, size, FloatBuffer.wrap(sourceData, offset, size / 4), usage)
 

worldwind/src/commonMain/kotlin/earth/worldwind/draw/DrawShapeState.kt

@@ -4,8 +4,8 @@ import earth.worldwind.geom.Matrix3
 import earth.worldwind.geom.Vec3
 import earth.worldwind.render.Color
 import earth.worldwind.render.Texture
+import earth.worldwind.render.buffer.AbstractBufferObject
 import earth.worldwind.render.buffer.FloatBufferObject
-import earth.worldwind.render.buffer.ShortBufferObject
 import earth.worldwind.render.program.BasicShaderProgram
 
 open class DrawShapeState internal constructor() {
@@ -15,7 +15,7 @@ open class DrawShapeState internal constructor() {
 
     var program: BasicShaderProgram? = null
     var vertexBuffer: FloatBufferObject? = null
-    var elementBuffer: ShortBufferObject? = null
+    var elementBuffer: AbstractBufferObject? = null
     val vertexOrigin = Vec3()
     var vertexStride = 0
     var enableCullFace = true

worldwind/src/commonMain/kotlin/earth/worldwind/render/buffer/IntBufferObject.kt

@@ -0,0 +1,22 @@
+package earth.worldwind.render.buffer
+
+import earth.worldwind.draw.DrawContext
+import earth.worldwind.util.kgl.GL_STATIC_DRAW
+
+open class IntBufferObject(target: Int, array: IntArray, size: Int = array.size) : AbstractBufferObject(target, size * 4) {
+    protected var array: IntArray? = array
+
+    override fun release(dc: DrawContext) {
+        super.release(dc)
+        array = null // array can be non-null if the object has not been bound
+    }
+
+    override fun bindBuffer(dc: DrawContext): Boolean {
+        array?.let{ loadBuffer(dc) }.also { array = null }
+        return super.bindBuffer(dc)
+    }
+
+    override fun loadBufferObjectData(dc: DrawContext) {
+        array?.let { dc.gl.bufferData(target, byteCount, it, GL_STATIC_DRAW) }
+    }
+}

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

@@ -7,7 +7,7 @@ import earth.worldwind.draw.DrawableSurfaceShape
 import earth.worldwind.geom.*
 import earth.worldwind.render.*
 import earth.worldwind.render.buffer.FloatBufferObject
-import earth.worldwind.render.buffer.ShortBufferObject
+import earth.worldwind.render.buffer.IntBufferObject
 import earth.worldwind.render.image.ImageOptions
 import earth.worldwind.render.image.ResamplingMode
 import earth.worldwind.render.image.WrapMode
@@ -27,9 +27,9 @@ open class Path @JvmOverloads constructor(
     protected var vertexArray = FloatArray(0)
     protected var vertexIndex = 0
     // TODO Use ShortArray instead of mutableListOf<Short> to avoid unnecessary memory re-allocations
-    protected val interiorElements = mutableListOf<Short>()
-    protected val outlineElements = mutableListOf<Short>()
-    protected val verticalElements = mutableListOf<Short>()
+    protected val interiorElements = mutableListOf<Int>()
+    protected val outlineElements = mutableListOf<Int>()
+    protected val verticalElements = mutableListOf<Int>()
     protected lateinit var vertexBufferKey: Any
     protected lateinit var elementBufferKey: Any
     protected val vertexOrigin = Vec3()
@@ -93,7 +93,7 @@ open class Path @JvmOverloads constructor(
 
         // Assemble the drawable's OpenGL element buffer object.
         drawState.elementBuffer = rc.getBufferObject(elementBufferKey) {
-            ShortBufferObject(GL_ELEMENT_ARRAY_BUFFER, (interiorElements + outlineElements + verticalElements).toShortArray())
+            IntBufferObject(GL_ELEMENT_ARRAY_BUFFER, (interiorElements + outlineElements + verticalElements).toIntArray())
         }
 
         // Configure the drawable's vertex texture coordinate attribute.
@@ -118,7 +118,7 @@ open class Path @JvmOverloads constructor(
             drawState.lineWidth(activeAttributes.outlineWidth + if (isSurfaceShape) 0.5f else 0f)
             drawState.drawElements(
                 GL_LINE_STRIP, outlineElements.size,
-                GL_UNSIGNED_SHORT, interiorElements.size * 2
+                GL_UNSIGNED_INT, interiorElements.size * Int.SIZE_BYTES
             )
         }
 
@@ -131,7 +131,7 @@ open class Path @JvmOverloads constructor(
             drawState.lineWidth(activeAttributes.outlineWidth)
             drawState.drawElements(
                 GL_LINES, verticalElements.size,
-                GL_UNSIGNED_SHORT, interiorElements.size * 2 + outlineElements.size * 2
+                GL_UNSIGNED_INT, (interiorElements.size + outlineElements.size) * Int.SIZE_BYTES
             )
         }
 
@@ -140,7 +140,7 @@ open class Path @JvmOverloads constructor(
             drawState.color(if (rc.isPickMode) pickColor else activeAttributes.interiorColor)
             drawState.drawElements(
                 GL_TRIANGLE_STRIP, interiorElements.size,
-                GL_UNSIGNED_SHORT, 0
+                GL_UNSIGNED_INT, 0
             )
         }
 
@@ -252,25 +252,25 @@ open class Path @JvmOverloads constructor(
             vertexArray[vertexIndex++] = (latitude.inDegrees - vertexOrigin.y).toFloat()
             vertexArray[vertexIndex++] = (altitude - vertexOrigin.z).toFloat()
             vertexArray[vertexIndex++] = texCoord1d.toFloat()
-            outlineElements.add(vertex.toShort())
+            outlineElements.add(vertex)
         } else {
             vertexArray[vertexIndex++] = (point.x - vertexOrigin.x).toFloat()
             vertexArray[vertexIndex++] = (point.y - vertexOrigin.y).toFloat()
             vertexArray[vertexIndex++] = (point.z - vertexOrigin.z).toFloat()
             vertexArray[vertexIndex++] = texCoord1d.toFloat()
-            outlineElements.add(vertex.toShort())
+            outlineElements.add(vertex)
             if (isExtrude) {
                 point = rc.geographicToCartesian(latitude, longitude, 0.0, altitudeMode, this.point)
                 vertexArray[vertexIndex++] = (point.x - vertexOrigin.x).toFloat()
                 vertexArray[vertexIndex++] = (point.y - vertexOrigin.y).toFloat()
                 vertexArray[vertexIndex++] = (point.z - vertexOrigin.z).toFloat()
                 vertexArray[vertexIndex++] = 0f /*unused*/
-                interiorElements.add(vertex.toShort())
-                interiorElements.add(vertex.inc().toShort())
+                interiorElements.add(vertex)
+                interiorElements.add(vertex.inc())
             }
             if (isExtrude && !intermediate) {
-                verticalElements.add(vertex.toShort())
-                verticalElements.add(vertex.inc().toShort())
+                verticalElements.add(vertex)
+                verticalElements.add(vertex.inc())
             }
         }
         return vertex

worldwind/src/commonMain/kotlin/earth/worldwind/util/kgl/Kgl.kt

@@ -412,6 +412,7 @@ interface Kgl {
     fun createBuffer(): KglBuffer
     fun bindBuffer(target: Int, buffer: KglBuffer)
     fun bufferData(target: Int, size: Int, sourceData: ShortArray, usage: Int, offset: Int = 0)
+    fun bufferData(target: Int, size: Int, sourceData: IntArray, usage: Int, offset: Int = 0)
     fun bufferData(target: Int, size: Int, sourceData: FloatArray, usage: Int, offset: Int = 0)
     fun deleteBuffer(buffer: KglBuffer)