diff --git a/vtm/src/org/oscim/renderer/BufferObject.java b/vtm/src/org/oscim/renderer/BufferObject.java
index e84d7201..c85b75b4 100644
--- a/vtm/src/org/oscim/renderer/BufferObject.java
+++ b/vtm/src/org/oscim/renderer/BufferObject.java
@@ -96,6 +96,10 @@ public final class BufferObject extends Inlist<BufferObject> {
 	private final static BufferObject pool[] = new BufferObject[2];
 	private final static int counter[] = new int[2];
 
+	/**
+	 * @param target can be GL20.GL_ARRAY_BUFFER or GL20.GL_ELEMENT_ARRAY_BUFFER
+	 * @param size requested size in bytes. optional - can be 0.
+	 */
 	public static synchronized BufferObject get(int target, int size) {
 
 		int t = (target == GL20.GL_ARRAY_BUFFER) ? 0 : 1;
diff --git a/vtm/src/org/oscim/renderer/ElementRenderer.java b/vtm/src/org/oscim/renderer/ElementRenderer.java
index 12d0351b..e4e55cdb 100644
--- a/vtm/src/org/oscim/renderer/ElementRenderer.java
+++ b/vtm/src/org/oscim/renderer/ElementRenderer.java
@@ -120,7 +120,7 @@ public abstract class ElementRenderer extends LayerRenderer {
 				continue;
 			}
 
-			log.debug("invalid layer {}", l.type);
+			log.error("invalid layer {}", l.type);
 			break;
 		}
 
@@ -136,7 +136,7 @@ public abstract class ElementRenderer extends LayerRenderer {
 				l = TextureLayer.Renderer.draw(layers, l, v, div);
 				continue;
 			}
-			log.debug("invalid layer {}", l.type);
+			log.error("invalid layer {}", l.type);
 			break;
 		}
 	}
diff --git a/vtm/src/org/oscim/renderer/GLShader.java b/vtm/src/org/oscim/renderer/GLShader.java
index 6ef2eb62..89357a1d 100644
--- a/vtm/src/org/oscim/renderer/GLShader.java
+++ b/vtm/src/org/oscim/renderer/GLShader.java
@@ -11,7 +11,7 @@ import org.slf4j.LoggerFactory;
 public abstract class GLShader {
 	final static Logger log = LoggerFactory.getLogger(GLShader.class);
 
-	private static GL20 GL;
+	protected static GL20 GL;
 
 	public int program;
 
diff --git a/vtm/src/org/oscim/renderer/MapRenderer.java b/vtm/src/org/oscim/renderer/MapRenderer.java
index 202ae68c..7723a15f 100644
--- a/vtm/src/org/oscim/renderer/MapRenderer.java
+++ b/vtm/src/org/oscim/renderer/MapRenderer.java
@@ -28,6 +28,7 @@ import org.oscim.backend.canvas.Color;
 import org.oscim.map.Map;
 import org.oscim.renderer.elements.ElementLayers;
 import org.oscim.renderer.elements.TextureItem;
+import org.oscim.renderer.elements.TextureLayer;
 import org.oscim.utils.pool.Inlist;
 import org.oscim.utils.pool.Pool;
 import org.slf4j.Logger;
@@ -234,8 +235,7 @@ public class MapRenderer {
 	}
 
 	public void onSurfaceChanged(int width, int height) {
-		log.debug("onSurfaceChanged: new={}, {}x{}",
-		          mNewSurface, width, height);
+		//log.debug("onSurfaceChanged: new={}, {}x{}", mNewSurface, width, height);
 
 		if (width <= 0 || height <= 0)
 			return;
@@ -266,7 +266,7 @@ public class MapRenderer {
 		int[] vboIds = GLUtils.glGenBuffers(2);
 
 		mQuadIndicesID = vboIds[0];
-		int maxIndices = maxQuads * 6;
+		int maxIndices = maxQuads * TextureLayer.INDICES_PER_SPRITE;
 		short[] indices = new short[maxIndices];
 		for (int i = 0, j = 0; i < maxIndices; i += 6, j += 4) {
 			indices[i + 0] = (short) (j + 0);
diff --git a/vtm/src/org/oscim/renderer/elements/ExtrusionLayers.java b/vtm/src/org/oscim/renderer/elements/ExtrusionLayers.java
index 74399baa..c59993e1 100644
--- a/vtm/src/org/oscim/renderer/elements/ExtrusionLayers.java
+++ b/vtm/src/org/oscim/renderer/elements/ExtrusionLayers.java
@@ -42,7 +42,7 @@ public class ExtrusionLayers extends TileData {
 	}
 
 	public ExtrusionLayer getLayers() {
-		return (ExtrusionLayer) layers;
+		return layers;
 	}
 
 	@Override