All TMXTiles in a TMXLayer need to be in the same TMXTileSet.

[albundyszabolcs]

Hi,

I am writing a game that uses TMX maps and tilesets. There is a tileset for the land (desert, water, hill, etc) and there is another tileset for the environment(trees, bushes, buildings, etc). The map has two layers. When I implemented this part and tried out, I got this exception:
10-07 23:00:55.598: E/AndroidRuntime(26679): java.lang.NullPointerException
10-07 23:00:55.598: E/AndroidRuntime(26679): at org.andengine.extension.tmx.TMXLayer.addTileByGlobalTileID(TMXLayer.java:277)
10-07 23:00:55.598: E/AndroidRuntime(26679): at org.andengine.extension.tmx.TMXLayer.initializeTMXTilesFromDataString(TMXLayer.java:247)
10-07 23:00:55.598: E/AndroidRuntime(26679): at org.andengine.extension.tmx.TMXParser.endElement(TMXParser.java:197)
10-07 23:00:55.598: E/AndroidRuntime(26679): at org.apache.harmony.xml.ExpatParser.endElement(ExpatParser.java:156)

if the pGlobalTileID is 0 this exception is always thrown.
With a small reordering this exception can be avoided:

private void addTileByGlobalTileID(final int pGlobalTileID,
            final ITMXTilePropertiesListener pTMXTilePropertyListener) {
        final TMXTiledMap tmxTiledMap = mTMXTiledMap;

        final int tilesHorizontal = mTileColumns;

        final int column = mTilesAdded % tilesHorizontal;
        final int row = mTilesAdded / tilesHorizontal;

        final TMXTile[][] tmxTiles = mTMXTiles;

        final ITextureRegion tmxTileTextureRegion;
        if (pGlobalTileID != 0) {
            tmxTileTextureRegion = tmxTiledMap
                    .getTextureRegionFromGlobalTileID(pGlobalTileID);

            final int tileHeight = mTMXTiledMap.getTileHeight();
            final int tileWidth = mTMXTiledMap.getTileWidth();

            if (mTexture == null) {
                mTexture = tmxTileTextureRegion.getTexture();
                super.initBlendFunction(mTexture);
            } else {
                if (mTexture != tmxTileTextureRegion.getTexture()) {
                    throw new AndEngineRuntimeException(
                            "All TMXTiles in a TMXLayer need to be in the same TMXTileSet.");
                }
            }
            final TMXTile tmxTile = new TMXTile(pGlobalTileID, column, row,
                    tileWidth, tileHeight, tmxTileTextureRegion);
            tmxTiles[row][column] = tmxTile;

            setIndex(getSpriteBatchIndex(column, row));
            this.drawWithoutChecks(tmxTileTextureRegion, tmxTile.getTileX(),
                    tmxTile.getTileY(), tileWidth, tileHeight,
                    Color.WHITE_ABGR_PACKED_FLOAT);
            submit(); // TODO Doesn't need to be called here, but should rather
                        // be called in a "init" step, when parsing the XML is
                        // complete.

            /* Notify the ITMXTilePropertiesListener if it exists. */
            if (pTMXTilePropertyListener != null) {
                final TMXProperties<TMXTileProperty> tmxTileProperties = tmxTiledMap
                        .getTMXTileProperties(pGlobalTileID);
                if (tmxTileProperties != null) {
                    pTMXTilePropertyListener.onTMXTileWithPropertiesCreated(
                            tmxTiledMap, this, tmxTile, tmxTileProperties);
                }
            }
        } else {
            tmxTileTextureRegion = null;
        }

        mTilesAdded++;
    }

what is your opinion?
Br

Szabolcs