polargraph_processing/libraries/geomerative/README

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COPYRIGHT
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Copyright 2006-2008 Ricard Marxer <email@ricardmarxer.com>
This product includes software developed by the Solution Engineering, Inc. (http://www.seisw.com/).
This product includes software developed by the The Apache Software Foundation (http://www.apache.org/).
INSTALL
---------------
Unzip the geomerative-XX.zip in the Processing libraries directory.
The result shoul look like this:
/path/to/processing/libraries/geomerative/library/geomerative.jar
USAGE
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In the Processing IDE Sketch > Import Library > geomerative
DOCUMENTATION
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The documentation is in the documentation folder. Just open the index.html with any web browser.
MINI-TUTORIAL
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This geometry library consists of three main classes:
RShape - Contains subshapes formed of commands (move,lines,beziers,...)
RPolygon - Contains contours formed of points
RMesh - Contains strips formed of vertices
There are several uses of the library:
+ Draw shapes with holes, in order to do so, we create a new shape and add commands to it. Once the shape is created we can:
- draw it using draw(g) (note the use of g in order to draw the shape to the main PGraphics object)
- convert it to a polygon using toPolygon()
- acces its subshapes' commands or the points of these commands, accesing its attribute subshapes and the RSubshape methods
+ Draw polygons with holes, in order to do so, we create a new polygon and add points (addPoint(x,y)) or contours (addContour()) to it. Once the polygon is created we can:
- draw it using draw(g)
- convert it to a mesh using toMesh()
- acces its contours' points, accesing its attribute contours and the RContour methods
- do binary operations over two polygons, using the methods diff(), union(), xor() and intersection()
EXAMPLE
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/// Example to draw a simple shape with a hole
/// Converting the shape to a mesh in the setup() avoids having to tesselate it for each frame, therefore the use of RMesh
import geomerative.*;
RPolygon p;
RShape s;
RMesh m;
int t = 0;
void setup(){
size(100,100,P3D);
framerate(34);
background(255);
fill(0);
//noFill();
stroke(255,0,0);
s = new RShape();
s.addMoveTo(-30,250);
s.addLineTo(30,150);
s.addArcTo(50,75,100,30);
s.addBezierTo(130,90,75,100,90,150);
s.addLineTo(130,250);
s.addBezierTo(80,200,70,200,-30,250);
s.addMoveTo(60,120);
s.addBezierTo(75,110,85,130,75,140);
s.addBezierTo(70,150,65,140,60,120);
p = s.toPolygon(100);
m = p.toMesh();
}
void draw(){
scale(0.25);
translate(200,50);
background(255);
rotateY(PI/65*t);
fill(0);
m.draw(g);
rotateY(PI/64*t);
noFill();
p.draw(g);
t++;
}
/// End of example
/// Example calculating the difference of two polygons
/// Note the use of predefined polygons (createStar(), createCircle(), createRing(),...)
import geomerative.*;
RMesh m;
RPolygon p = RPolygon.createStar(120,70,6);
RPolygon p2 = RPolygon.createStar(60,50,30);
float t=0;
void setup(){
size(400,400,P3D);
framerate(24);
//smooth();
noStroke();
fill(0);
p=p.diff(p2);
m = p.toMesh();
}
void draw(){
background(255);
translate(width/2,height/2);
rotateX(t/39);
m.draw(g);
rotateY(-t/5);
scale(0.3);
m.draw(g);
t++;
}
/// End of example
KNOWN ISSUES
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- Under certain renderers there's a big loss of precision, resulting in really ugly renderings of fonts and polygons in general.
- When we decrease the font size we get bad results, bad shapes. This must have to do with the font fixed point arithmetics, haven't studied any of that yet.