Attach (recommended) or Link to PDF file here:
[PATTYP2.pdf](https://github.com/mozilla/pdf.js/files/6471935/PATTYP2.pdf)

Configuration:
- Web browser and its version: FF 88.0.1
- Operating system and its version: W10.0.19042.985
- PDF.js version: https://mozilla.github.io/pdf.js/web/viewer.html

Steps to reproduce the problem:
1. open file to display

What is the expected behavior? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114800-5e407800-b3e8-11eb-860f-019f48a8eabf.png)

What went wrong? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114841-6c8e9400-b3e8-11eb-8252-1517e5d76475.png)

(memo for me: when fixed, check the files in https://issues.apache.org/jira/browse/PDFBOX-1958 )

const transform = this.ctx.mozCurrentTransform;
      return [
        transform[0] * x + transform[2] * y + transform[4],
        transform[1] * x + transform[3] * y + transform[5],
      ];
    }
    isContentVisible() {
      for (let i = this.markedContentStack.length - 1; i >= 0; i--) {
        if (!this.markedContentStack[i].visible) {
          return false;
        }
      }
      return true;
    }
  }
  for (const op in OPS) {
    CanvasGraphics.prototype[OPS[op]] = CanvasGraphics.prototype[op];
  }
  return CanvasGraphics;
})();
export { CanvasGraphics };