Package eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic.line

Class Line

java.lang.Object
eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractShape
eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape
eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic.line.Line
public class Line extends AbstractCoordinateShape
A 3D line segment with perspective-correct width and alpha blending.

This class represents a line between two 3D points, rendered with a specified width that adjusts based on perspective (distance from the viewer). The line is drawn using interpolators to handle edge cases and alpha blending for transparency effects.

The rendering algorithm: 1. For thin lines (below a threshold), draws single-pixel lines with alpha adjustment based on perspective. 2. For thicker lines, creates four interpolators to define the line's rectangular area and fills it scanline by scanline.

Note: The width is scaled by the LINE_WIDTH_MULTIPLIER and adjusted based on the distance from the viewer (z-coordinate) to maintain a consistent visual size.

  • Field Details

    • width

      public final double width
      width of the line.

    • color

      public Color color
      Color of the line.

  • Constructor Details

    • Line

      public Line(Line parentLine)
      Creates a copy of an existing line with cloned coordinates and color.
      Parameters:
      parentLine - the line to copy

    • Line

      public Line(Point3D point1, Point3D point2, Color color, double width)
      Creates a line between two points with the specified color and width.
      Parameters:
      point1 - the starting point of the line
      point2 - the ending point of the line
      color - the color of the line
      width - the width of the line in world units

  • Method Details

    • paint

      public void paint(RenderingContext buffer)
      Renders this line to the screen using perspective-correct width and alpha blending.

      This method handles two rendering modes:

      • Thin lines: When the projected width is below threshold, draws single-pixel lines with alpha adjusted for sub-pixel appearance.
      • Thick lines: Creates four edge interpolators and fills the rectangular area scanline by scanline with perspective-correct alpha fading at edges.
      Specified by:
      paint in class AbstractCoordinateShape
      Parameters:
      buffer - the rendering context containing the pixel buffer