code: private void initBaseCoordsProjection() {
          baseScreenCoords = new int[canvas.base.baseCoords.length][2];
          for (int i = 0; i < canvas.base.dimension + 1; i++) {
              double[] ratio = baseCoordsScreenProjectionRatio(canvas.base.baseCoords[i]);
              baseScreenCoords[i][0] = (int) (canvas.getWidth() * (canvas.margin + (1 - 2 * canvas.margin) * ratio[0]));
              baseScreenCoords[i][1] = (int) (canvas.getHeight() - canvas.getHeight() * (canvas.margin + (1 - 2 * canvas.margin) * ratio[1]));
          }
      }
docs: Initialize base coordinates on Java2D screen.