[1.7.10][solved] Tessellator brightness issue

Hey there,

I just tried to use the Tessellator in a TileEntitySpecialRenderer and everytime I try to render something the texture is just too dark.

Here is my small testing TESR (This just draws the top side of a block):

    @Override
    public void renderTileEntityAt(TileEntity tile, double x, double y, double z, float p_147500_8_) {
        GL11.glPushMatrix();

        GL11.glTranslated(x, y, z);

        bindTexture(TextureMap.locationBlocksTexture);

        RenderBlocks render = new RenderBlocks(tile.getWorldObj());

        Tessellator t = Tessellator.instance;
        t.startDrawingQuads();

        //makes no difference
        //GL11.glEnable(GL11.GL_BLEND);
        //GL11.glEnable(GL11.GL_LIGHTING);
        //t.setBrightness(tile.getBlockType().getMixedBrightnessForBlock(tile.getWorldObj(), tile.xCoord, tile.yCoord, tile.zCoord));
        //t.setColorOpaque_F(1.0F, 1.0F, 1.0F);

        //Just for testing purpose
        IIcon icon = Blocks.glass.getBlockTextureFromSide(0);

        float u = icon.getMinU();
        float v = icon.getMinV();
        float U = icon.getMaxU();
        float V = icon.getMaxV();

        t.addVertexWithUV(0, 1, 1, u, v);
        t.addVertexWithUV(1, 1, 1, u, V);
        t.addVertexWithUV(1, 1, 0, U, V);
        t.addVertexWithUV(0, 1, 0, U, v);

        t.draw();


        GL11.glPopMatrix();
    }

And my block:

public class BlockTest extends Block {
    public BlockTest() {
        super(Material.glass);

        setCreativeTab(CreativeTabs.tabFood);
    }

    @Override
    public TileEntity createTileEntity(World world, int metadata) {
        return new TileTest();
    }

    @Override
    public boolean renderAsNormalBlock() {
        return false;
    }

    @Override
    public boolean isOpaqueCube() {
        return false;
    }

    @Override
    public int getRenderType() {
        return -1;
    }

    @Override
    public boolean hasTileEntity(int metadata) {
        return true;
    }
}

and the ingame result (my BlockTest and a vanilla glass block for comparison):

Thanks for helping me 

Edit: I found the solution myslef. I had to use t.setNormal(0, 1, 0) to enable light