private static int drawTail()

in packages/stunner-editors/lienzo-core/src/main/java/com/ait/lienzo/client/core/shape/OrthogonalPolyLine.java [450:630]
147 lines of code
66 McCabe index (conditional complexity)

    private static int drawTail(Point2DArray points, NFastDoubleArray buffer, Direction lastDirection, Direction tailDirection, double correction, final OrthogonalPolyLine pline, double p0x, double p0y, double p1x, double p1y, boolean write) {
        double tailOffset = pline.getTailOffset();

        double distance = 0;
        Point2D p1 = points.get(points.size() - 1);

        // correct for tailOffset
        if (tailOffset > 0) {
            if (!write) {
                p1 = p1.copy();
            }
            correctEndWithOffset(tailOffset, tailDirection, p1);
            p1x = p1.getX();
            p1y = p1.getY();
        }

        // correct for correction
        if (correction > 0) {
            // must do this off a cloned Point2D, as we still need the p1, for the last part of the line at the end.
            Point2D p1Copy = p1.copy();
            correctEndWithOffset(correction, tailDirection, p1Copy);
            p1x = p1Copy.getX();
            p1y = p1Copy.getY();
        }

        final double dx = (p1x - p0x);
        final double dy = (p1y - p0y);

        int corners = 0;

        boolean behind = false;

        switch (tailDirection) {
            case NORTH:
                behind = dy < 0;
                break;
            case SOUTH:
                behind = dy > 0;
                break;
            case WEST:
                behind = dx < 0;
                break;
            case EAST:
                behind = dx > 0;
                break;
            case NONE:
                // do nothing as NONE is explicitey handled at the end
                break;
            default:
                throw new IllegalStateException("Invalid Direction " + tailDirection);
        }
        double x = p0x;

        double y = p0y;

        if (behind) {
            // means p0 is behind.
            switch (tailDirection) {
                case NORTH:
                case SOUTH:
                    if ((lastDirection == NORTH && tailDirection == SOUTH) ||
                            (lastDirection == SOUTH && tailDirection == NORTH) ||
                            (dx > 0 && lastDirection == EAST) ||
                            (dx < 0 && lastDirection == WEST)) {
                        // A mid point is needed to ensure an attractive line is drawn.
                        x = p0x + (dx / 2);
                        addPoint(buffer, x, y, write);

                        if (lastDirection == NORTH || lastDirection == SOUTH) {
                            corners++;
                        }
                    }

                    y = p1y;
                    addPoint(buffer, x, y, write);
                    if (lastDirection != tailDirection) {
                        corners++;
                    }

                    x = p1x;
                    addPoint(buffer, x, y, write);
                    corners++;

                    y = p1.getY();
                    addPoint(buffer, x, y, write);
                    corners++;
                    break;
                case WEST:
                case EAST:
                    if ((lastDirection == WEST && tailDirection == EAST) ||
                            (lastDirection == EAST && tailDirection == WEST) ||
                            (dy > 0 && lastDirection == SOUTH) ||
                            (dy < 0 && lastDirection == NORTH)) {
                        // A mid point is needed to ensure an attrictive line is drawn.
                        y = p0y + (dy / 2);
                        addPoint(buffer, x, y, write);

                        if (lastDirection == EAST || lastDirection == WEST) {
                            corners++;
                        }
                    }

                    x = p1x;
                    addPoint(buffer, x, y, write);
                    if (lastDirection != tailDirection) {
                        corners++;
                    }

                    y = p1y;
                    addPoint(buffer, x, y, write);
                    corners++;

                    x = p1.getX();
                    addPoint(buffer, x, y, write);
                    corners++;
                    break;
                default:
                    throw new IllegalStateException("Invalid Direction " + tailDirection);
            }
        } else {
            // means p0 is in front
            switch (tailDirection) {
                case NORTH:
                case SOUTH:
                    if ((lastDirection == NORTH && tailDirection == SOUTH) ||
                            (lastDirection == SOUTH && tailDirection == NORTH) ||
                            (dx > 0 && lastDirection == WEST) ||
                            (dx < 0 && lastDirection == EAST)) {
                        // A mid point is needed to ensure an attrictive line is drawn.
                        y = p0y + (dy / 2);
                        addPoint(buffer, x, y, write);

                        if (lastDirection == EAST || lastDirection == WEST) {
                            lastDirection = (dy < 0) ? NORTH : SOUTH;
                            corners++;
                        }
                    }

                    x = p1x;
                    addPoint(buffer, x, y, write);
                    if (lastDirection == NORTH || lastDirection == SOUTH) {
                        corners++;
                    }

                    y = p1.getY();
                    addPoint(buffer, x, y, write);
                    corners++;
                    break;
                case WEST:
                case EAST:
                    if ((lastDirection == WEST && tailDirection == EAST) ||
                            (lastDirection == EAST && tailDirection == WEST) ||
                            (dy > 0 && lastDirection == NORTH) ||
                            (dy < 0 && lastDirection == SOUTH)) {
                        // A mid point is needed to ensure an attrictive line is drawn.
                        x = p0x + (dx / 2);
                        addPoint(buffer, x, y, write);

                        if (lastDirection == NORTH || lastDirection == SOUTH) {
                            lastDirection = (dx < 0) ? WEST : EAST;
                            corners++;
                        }
                    }

                    y = p1y;
                    addPoint(buffer, x, y, write);
                    if (lastDirection == EAST || lastDirection == WEST) {
                        corners++;
                    }

                    x = p1.getX();
                    addPoint(buffer, x, y, write);
                    corners++;
                    break;
                default:
                    throw new IllegalStateException("Invalid Direction " + tailDirection);
            }
        }

        return corners;
    }