All programs come with sources and executables: (Comments are in German, though)

Pascal and C programs for DOS:

  • Intersection of two lines:
    Intlines.ZIP
  • Intersection line circle: intersection of line and circle
    Lincirc.ZIP
  • Intersection of two circles:
    Intcirc.ZIP
  • Folium: Function discovered by German astronom Kepler
    Folium.ZIP
  • Rhodonea: Leaves of roses
    Rhodonea.ZIP
  • Parabola: drawn as envelope of tangents
    Parabola.ZIP
  • Lemniscate of Bernoulli: drawn as an envelope. Start with rectangular hyperbola and draw circles
    whose centres lie on the hyperbola and at the same time pass through the centre of the hyperbola.
    Lemniska.ZIP
  • Cardioid:Cardioid drawn as an envelope.
    Cardiod.ZIP
  • Cartesian ovals: Function that looks like an egg.
    Egg.ZIP
  • Area of quadrilateral: area of quadrilateral, need not be convex, according to Brahmagupta
    Brahma.ZIP
  • Plotting of implicit functions: Three programs in Pascal plotting only dots and no contours.
    Implicit.ZIP
  • Contour drawing: The Cartesian leaf drawn as a contour map r = a.(c + b.sin(t/2)); x = r.cos(t); y = r.sin(t)
    This code is based on a basic program in an old BYTE magazine article by Paul D. Bourke
    Included is a universal pascal unit for HPGL output on a HP Laserjet III printer.
    Contour1.ZIP
  • The devil's curve: parametric drawing of -x4 + y4 + 50.x2 - 48.y2 = 0
    Devil.ZIP
  • Morley's theorem:
    Morley1.ZIP
  • Polygon: Take any convex polygon.with an even number of sides. Find the mid-points of the sides
    and join them, thus inscribing a new polygon. Repeat that and you end up with opposite sides being
    parallel and equal in length.
    Polygon.ZIP
  • Polygons turned:Turning of polygon families
    Polyturn.ZIP
  • The quadratic equation: Ax2 + Bx + C = 0
    Two different algorithms show limitations of floating point library precision in Pascal and C.
    Coefficients A,B,C are real and x is complex.
    Equ2.ZIP
  • The exact solution of equations up to the 4th power: Ax4 + Bx3 + Cx2 + Dx + E = 0
    Coefficients A,B,C,D,E are real and x is complex.
    There are two versions in Pascal and C.
    If you know any source on the exact solution of the equation to the 5th power, please let me know via e-mail!
    Equ1to4.ZIP

    • GNU C programs for Linux using the X Library:

  • Raysphere: simple raytracing on a sphere and floor with triangls:
    Raysphere.ZIP
  • Equation to the 4th power: linux port of above DOS program
    Equation4.ZIP
  • Klothoid: Function used for road planning
    Klothoid.ZIP