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A Gentle Introduction to
Perl Programming

Tutorial: Drawing flags with lines

 
Interactive Programming Tutorials - Drawing flags using lines. You may want to look at: How to draw thick lines.

1. Scotland


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The cross of St. Andrew shows diagonal lines on a blue background.
  • Complete the flag by drawing the other diagonal line.
  • The white lines should be slightly thicker - try 60.

2. England


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The English flag is the cross of St. George. This is a red cross on a white background.
  • The line thickness should be 1/5 of the height of the flag.

3. Greece


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  • The flag of Greece has 5 blue stripes and 4 white stripes.
  • Each stripe has width 40.
  • Note that we let the computer do the arithmetic. Each stripe should be 80 pixels below the previous one.
  • The expression 20+i*80 - where i is 0, 1, 2, 3, 4 gives the height of the middle of each blue stripe.
  • The expression 60+i*80 - where i is 0, 1, 2, 3 gives the height of the middle of each white stripe.
  • You must include another two blue stripes and four white stripes.
Flag of Greece
for loops

4. Trinidad and Tobago


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There is a problem with this example

Seemingly the GD library being used here does not support drawing thick lines outside the drawing area as expected. If anyone can suggest how I might fix this problem (without resorting to polygons) I would appreciate it. ajcumming@gmail.com

We can start and end lines outside the confines of the surface.

Flag of Trinidad and Tobago