2D Graphic Seed-head Patterns
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Seed Head
Up Fern Mandelbrot Parity SeedHead
To draw a seed-head on the PixelBlock, mix in the CSeedHeadStencil class below and define the Disc abstract method to use CCircleStencil::Disc:
This class uses the 'Golden Ratio' to create a picture of a Seed-head. The algorithm can be altered to draw other natural objects: Sunflower Seeds, Dandelion, Fir Cone, Pineapple etc.
#include <math.h>

class CSeedHeadStencil {
  virtual void Disc(WORD xCenter, WORD yCenter, WORD Radius, DWORD Colour) =0; // Antialiased, Filled apart from centre pixel:
public:
  CSeedHeadStencil() {}
  void Seeds(WORD x0, WORD y0, DWORD Colour, short SeedRadius=6, int Seeds=987) { // Seeds should be a number from the Fibonacci series
    const double  PI=3.1415926535897932384626433832795;
    const double Phi=1.6180339887498948482045868343656; // The Golden Ratio
    const double  dA=Phi/PI;
    double Angle= dA;
    for(int Seed=Seeds; Seed--; Angle+=(Phi-1)*2*PI) { // Move 0.618 of a circle round each time
      double r=sqrt(Seed)*SeedRadius*dA; // Position Radius is sqrt of the seed number scaled to suit SeedRadius
      Disc(x0+(WORD)(0.5+r*cos(Angle)), y0+(WORD)(0.5+r*sin(Angle)), SeedRadius-SeedRadius*Seed/Seeds, Colour);
    }
  }
};

The following image is drawn live according the these settings:
Seeds
0 Red Spirals
0 Blue Spirals
If you're using a PC, click the drop-list once to see the list, then again to close it - then use your keyboard up and down arrows to scan through the values. This browser doesn't support the canvas element :-(
It's like the top of a fir cone!

Here's a 3D version:
Dome
Then to create full spheres:
Golf Ball

You can mix in as many 'Stencils' as you like to provide all the primitives you need.

The Colours, Drawing and Effects sections have further extensions.

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 (3405) Last modified: Thu, 16 Jun 2016 17:16:08 +0100