Solved LibGDX: gaps between tiles when rotating them

Engines, Libraries and Tools
#1

Hi folks,

I have run into an issue with a tile grid I cannot seem to solve: gaps / lines appear between tiles when I rotate the grid. I think it has something to do with texture filtering, but cannot figure out how to solve it. The grid is a spaceship built out of tiles (hence why the grid has to rotate).

Here’s how the tile grid looks without rotating:

And here’s how it looks while rotating:

I’m using LibGDX and the textures are on a texture atlas with the following pack settings:

{
		wrapX: Repeat,
		wrapY: Repeat,
		filterMin: Linear,
        filterMag: Linear
}

This is the code I use to render the ship / grid:

Matrix4 m4 = new Matrix4();

   void drawShip(Ship ship, SpriteBatch batch) {
      float shipX = ship.body.getPosition().x * Constants.BOX2D_TO_SCREEN;
      float shipY = ship.body.getPosition().y * Constants.BOX2D_TO_SCREEN;
      float angle = ship.body.getAngle();
      m4.setToTranslation(shipX, shipY, 0);
      m4.rotateRad(0, 0, 1, angle);
      batch.setTransformMatrix(m4);
      int designWidthPx = ship.design.width * Constants.CELL_SIZE_PX;
      int designHeightPx = ship.design.height * Constants.CELL_SIZE_PX;
      for (int x = 0; x < ship.design.width; x++) {
         for (int y = 0; y < ship.design.height; y++) {
            Module module = ship.cells[x][y].module;
            if (module != null && ship.design.cells[x][y].topLeft) {
               TextureRegion tex = module.texture;
               batch.draw(tex, x * Constants.CELL_SIZE_PX - designWidthPx / 2 - Constants.CELL_SIZE_PX / 2, y
                     * Constants.CELL_SIZE_PX - designHeightPx / 2 - Constants.CELL_SIZE_PX / 2,
                     Constants.CELL_SIZE_PX / 2, Constants.CELL_SIZE_PX / 2, Constants.CELL_SIZE_PX,
                     Constants.CELL_SIZE_PX, 1f, 1f, directionToDegrees(ship.design.cells[x][y].direction));
            }
         }
      }
      m4.idt();
      batch.setTransformMatrix(m4);
   }

   public float directionToDegrees(int direction) {
      return -90f * direction;
   }

Does anyone have an idea on how I could resolve this?