public function test_400x400_crop() {
    // Landscape: crop 640x480 to fit 400x400: 400x400 taken from a 480x480 crop at (80. 0).
    $out = image_resize_dimensions( 640, 480, 400, 400, true );
    // dst_x, dst_y, src_x, src_y, dst_w, dst_h, src_w, src_h.
    $this->assertSame( array( 0, 0, 80, 0, 400, 400, 480, 480 ), $out );

    // Portrait: resize 480x640 to fit 400x400: 400x400 taken from a 480x480 crop at (0. 80).
    $out = image_resize_dimensions( 480, 640, 400, 400, true );
    // dst_x, dst_y, src_x, src_y, dst_w, dst_h, src_w, src_h.
    $this->assertSame( array( 0, 0, 0, 80, 400, 400, 480, 480 ), $out );
  }