OsmBitmapShader.java

package org.mozilla.osmdroid.views.drawing;

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Matrix;
import android.graphics.Point;

import org.mozilla.osmdroid.views.Projection;

public class OsmBitmapShader extends BitmapShader {
    private static final Point sPoint = new Point();

    private final Matrix mMatrix = new Matrix();
    private int mBitmapWidth;
    private int mBitmapHeight;

    public OsmBitmapShader(Bitmap bitmap, TileMode tileX, TileMode tileY) {
        super(bitmap, tileX, tileY);
        mBitmapWidth = bitmap.getWidth();
        mBitmapHeight = bitmap.getHeight();
    }

    public void onDrawCycle(Projection projection) {
        projection.toMercatorPixels(0, 0, sPoint);
        mMatrix.setTranslate(-sPoint.x % mBitmapWidth, -sPoint.y % mBitmapHeight);
        setLocalMatrix(mMatrix);
    }
}