Difference between revisions of "Ruby:Programming Tutorial"

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(New page: An introduction to computer programming using Java. Comprising * Tutorials which present problems and their solutions. * How to... guides to completing common task...)
 
m (Andr3w moved page Ruby:ProgZoo to Ruby:Programming Tutorial)
 
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An introduction to computer programming using Java. Comprising
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{{topTenTips}}
*[[Tutorials| Tutorials]] which present problems and their solutions.
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An introduction to computer programming using Ruby. Comprising
*[[Guides| How to...]] guides to completing common tasks.
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*[[ruby:Tutorials| Tutorials]] which present problems and their solutions.
*[[Assessments| Assessments]] graded problems with solutions.
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*[[ruby:Guides| How to...]] guides to completing common tasks.
==Drawing the French tricolour with Java==  
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*[[ruby:Assessments| Assessments]] graded problems with solutions.
You can create images using Java. The first tutorial [[Flags]] looks at drawing flags of the world, from simple flags such as Libya to more complicated flags such as the Stars and Stripes of the USA. In Java you can use [[methods]] such as  <code>[[setColor]]</code> and <code>[[fillRect]]</code> to create simple images.        
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==An Example: drawing the French tricolour ==
<question height="100" width="150" imgOut="flag.png" className="Raster" title="France" rows="9" cols='28'>  
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You can create images using the GD2 library. The first tutorial [[{{NAMESPACE}}:Flags Tutorial|Flags]] looks at drawing flags of the world, from simple flags such as Libya to more complicated flags such as the Stars and Stripes of the USA.
[[Image:Flag_guide_france.png|border|right]]
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Notice that the blue rectangle is at (0,0), it is 50 wide and 100 deep so the commands to draw the blue rectangle are:    
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With GD2 you can set the canvas color and draw a rectangle to create simple images.      
  g.setColor(Color.blue);
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<question height="100" width="150" imgOut="flag.png" className="Raster" title="France" rows="9" cols="40" lang='rb'>  
  g.fillRect(0,0,50,100);
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[[Image:Flag_guide_france.png|border|right]]  
<shell lang="java" className="Flag" import="shells.xml#raster"/>
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Notice that the blue rectangle has corners at (0,0) and (50,100) and has color [1,0,0]
<prog lang="java">static void drawFlag(Graphics2D g){
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<div style='clear:right'>
   g.setColor(Color.blue);
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  g.color = image.palette.resolve Color[1.0, 0, 0]
   g.fillRect(0,0,50,100);
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  g.rectangle(0,0,50,100,filled=true)
   g.setColor(Color.white);
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</div>
   g.fillRect(50,0,50,100);
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<shell lang="rb" className="Flag" import="shells.xml#rasterrb"/>
   g.setColor(Color.red);
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<prog>
   g.fillRect(100,0,50,100);
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image.draw do |g|
}
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   g.color = image.palette.resolve Color[0,0,1.0]
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   g.rectangle(0,0,50,100,filled=true)
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   g.color = image.palette.resolve Color[1.0,1.0,1.0]
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   g.rectangle(50,0,100,100,filled=true)
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   g.color = image.palette.resolve Color[1.0,0,0]
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   g.rectangle(100,0,150,100,filled=true)
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end
 
</prog>
 
</prog>
<answer lang="java">static void drawFlag(Graphics2D g){
 
  g.setColor(Color.blue);
 
  g.fillRect(0,0,50,100);
 
  g.setColor(Color.white);
 
  g.fillRect(50,0,50,100);
 
  g.setColor(Color.red);
 
  g.fillRect(100,0,50,100);
 
}
 
</answer>
 
 
</question>
 
</question>
  

Latest revision as of 15:44, 21 March 2015

An introduction to computer programming using Ruby. Comprising

An Example: drawing the French tricolour

You can create images using the GD2 library. The first tutorial Flags looks at drawing flags of the world, from simple flags such as Libya to more complicated flags such as the Stars and Stripes of the USA.

With GD2 you can set the canvas color and draw a rectangle to create simple images.

Flag guide france.png

Notice that the blue rectangle has corners at (0,0) and (50,100) and has color [1,0,0]

g.color = image.palette.resolve Color[1.0, 0, 0]
g.rectangle(0,0,50,100,filled=true)


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