diff --git a/src/org/oscim/view/MapViewPosition.java b/src/org/oscim/view/MapViewPosition.java
index 619cdaa7..e4b2bd9d 100644
--- a/src/org/oscim/view/MapViewPosition.java
+++ b/src/org/oscim/view/MapViewPosition.java
@@ -66,12 +66,17 @@ public class MapViewPosition {
 	private float[] mTmpMatrix = new float[16];
 
 	private int mHeight, mWidth;
+	public final static float VIEW_SCALE = 1f / 2;
+	public final static float VIEW_DISTANCE = 1;
 
 	void setViewport(int width, int height) {
-		Matrix.frustumM(mProjMatrix, 0, -0.5f * width, 0.5f * width,
-				0.5f * height, -0.5f * height, 1, 2);
+		float sw = VIEW_SCALE;
+		float sh = VIEW_SCALE;
 
-		Matrix.translateM(mProjMatrix, 0, 0, 0, -1);
+		Matrix.frustumM(mProjMatrix, 0, -sw * width, sw * width,
+				sh * height, -sh * height, 1, 2);
+
+		Matrix.translateM(mProjMatrix, 0, 0, 0, -VIEW_DISTANCE);
 
 		Matrix.invertM(mProjMatrixI, 0, mProjMatrix, 0);
 		Matrix.invertM(mUnprojMatrix, 0, mProjMatrix, 0);
@@ -132,7 +137,7 @@ public class MapViewPosition {
 	private void unproject(float x, float y, float z, float[] coords, int position) {
 		mv[0] = x;
 		mv[1] = y;
-		mv[2] = z - 1;
+		mv[2] = z - VIEW_DISTANCE;
 		mv[3] = 1;
 
 		Matrix.multiplyMV(mv, 0, mUnprojMatrix, 0, mv, 0);
@@ -160,6 +165,8 @@ public class MapViewPosition {
 		// get unproject matrix:
 		// (transpose of rotation is its inverse)
 		Matrix.transposeM(mTmpMatrix, 0, mRotateMatrix, 0);
+		// Matrix.invertM(mTmpMatrix, 0, mRotateMatrix, 0);
+
 		// (AB)^-1 = B^-1*A^-1
 		Matrix.multiplyMM(mUnprojMatrix, 0, mTmpMatrix, 0, mProjMatrixI, 0);
 
diff --git a/src/org/oscim/view/renderer/GLRenderer.java b/src/org/oscim/view/renderer/GLRenderer.java
index 00802c26..66fbee4b 100644
--- a/src/org/oscim/view/renderer/GLRenderer.java
+++ b/src/org/oscim/view/renderer/GLRenderer.java
@@ -453,6 +453,7 @@ public class GLRenderer implements GLSurfaceView.Renderer {
 
 		if (project)
 			Matrix.multiplyMM(matrix, 0, mProjMatrix, 0, matrix, 0);
+
 	}
 
 	private static float scaleDiv(MapTile t) {
@@ -528,17 +529,33 @@ public class GLRenderer implements GLSurfaceView.Renderer {
 
 			float s = Tile.TILE_SIZE;
 			float scale = mapPosition.scale / div;
-			double px = mapPosition.x * div;
-			double py = mapPosition.y * div;
+			float px = (float) mapPosition.x * div;
+			float py = (float) mapPosition.y * div;
 
 			for (int i = 0; i < 8; i += 2) {
-				coords[i + 0] = (float) ((px + coords[i + 0] / scale) / s);
-				coords[i + 1] = (float) ((py + coords[i + 1] / scale) / s);
+				coords[i + 0] = (px + coords[i + 0] / scale) / s;
+				coords[i + 1] = (py + coords[i + 1] / scale) / s;
 			}
 
 			mHolderCount = 0;
 			mScanBox.scan(coords, tiles[0].zoomLevel);
 			tileCnt += mHolderCount;
+
+			// // TODO get the right function: trying to accomodate for the
+			// y-stretching introduced by the perspective transformation...
+			// float sw, sh;
+			// sw = MapViewPosition.VIEW_SCALE;
+			// sh = MapViewPosition.VIEW_SCALE;
+			// sh += (mMapViewPosition.mTilt / 150);
+			//
+			// Matrix.frustumM(mProjMatrix, 0, -sw * mWidth, sw * mWidth,
+			// sh * mHeight, -sh * mHeight, 1, 2);
+			//
+			// Matrix.translateM(mProjMatrix, 0, 0, 0,
+			// -MapViewPosition.VIEW_DISTANCE);
+			//
+			// mProjMatrix[10] = 0;
+			// mProjMatrix[14] = 0;
 		}
 
 		uploadCnt = 0;
@@ -795,13 +812,13 @@ public class GLRenderer implements GLSurfaceView.Renderer {
 		mWidth = width;
 		mHeight = height;
 
-		float s = 0.5f;
 		// use this to scale only the view to see better which tiles are
 		// rendered
-		// s = 1.0f;
+		float s = MapViewPosition.VIEW_SCALE;
 		Matrix.frustumM(mProjMatrix, 0, -s * width, s * width,
 				s * height, -s * height, 1, 2);
-		Matrix.translateM(mProjMatrix, 0, 0, 0, -1);
+
+		Matrix.translateM(mProjMatrix, 0, 0, 0, -MapViewPosition.VIEW_DISTANCE);
 
 		// set to zero: we modify the z value with polygon-offset for clipping
 		mProjMatrix[10] = 0;
diff --git a/src/org/oscim/view/renderer/MapRenderer.java b/src/org/oscim/view/renderer/MapRenderer.java
index d34bd040..5c50ccb7 100644
--- a/src/org/oscim/view/renderer/MapRenderer.java
+++ b/src/org/oscim/view/renderer/MapRenderer.java
@@ -208,14 +208,14 @@ public class MapRenderer extends GLSurfaceView {
 		float s = Tile.TILE_SIZE;
 		// load some additional tiles more than currently visible
 		float scale = mapPosition.scale * 0.75f;
-		double px = mapPosition.x;
-		double py = mapPosition.y;
+		float px = (float) mapPosition.x;
+		float py = (float) mapPosition.y;
 		float[] coords = mTileCoords;
 		int zdir = 0;
 
 		for (int i = 0; i < 8; i += 2) {
-			coords[i + 0] = (float) ((px + coords[i + 0] / scale) / s);
-			coords[i + 1] = (float) ((py + coords[i + 1] / scale) / s);
+			coords[i + 0] = (px + coords[i + 0] / scale) / s;
+			coords[i + 1] = (py + coords[i + 1] / scale) / s;
 		}
 
 		for (int i = 0; i < 8; i++)