private void drawRectangle(int[] textures, FloatBuffer vertices)
{
for (int i = 0; i < 3; ++i)
{
GLES20.GlActiveTexture(GLES20.GlTexture0 + i);
GLES20.GlBindTexture(GLES20.GlTexture2d, textures[i]);
}
GLES20.GlVertexAttribPointer(posLocation, 2, GLES20.GlFloat, false, 0, vertices);
GLES20.GlEnableVertexAttribArray(posLocation);
GLES20.GlDrawArrays(GLES20.GlTriangleStrip, 0, 4);
checkNoGLES2Error();
}