Learning Processing: A Beginner's Guide to Programming Images ...

234 Learning Processing
We also have the option of creating more than one shape, for example, in a loop, as shown in Figure 14.7 .
stroke(0);
for (int i = 0; i < 10; i + + ) {
beginShape();
fill(175);
vertex(i*20,10-i);
vertex(i*20 + 15,10 + i);
vertex(i*20 + 15,180 + i);
vertex(i*20,180-i);
endShape(CLOSE);
}
You can also add an argument to beginShape( ) specifying exactly what type of shape you want to
make. Th is is particularly useful if you want to make more than one polygon. For example, if you
create six vertex points, there is no way for Processing to know that you really want to draw two
triangles (as opposed to one hexagon) unless you say beginShape(TRIANGLES) . If you do not want
to make a polygon at all, but want to draw points or lines, you can by saying beginShape(POINTS) or
beginShape(LINES) . See Figure 14.8 .
stroke(0);
beginShape(LINES);
for (int i = 10; i < width; i + = 20) {
vertex(i,10);
vertex(i,height–10);
}
endShape();
Note that LINES is meant for drawing a series of individual lines, not a continous loop. For a continuous
loop, do not use any argument. Instead, simply specify all the vertex points you need and include noFill( ) .
See Figure 14.9 .
noFill();
stroke(0);
beginShape();
for (int i = 10; i < width; i + = 20) {
vertex(i,10);
vertex(i,height–10);
}
endShape();
fi g. 14.7
fi g. 14.8
fi g. 14.9
Th e full list of possible arguments for beginShape( ) is available in the Processing reference
http://processing.org/reference/beginShape_.html
POINTS, LINES, TRIANGLES, TRIANGLE_FAN, TRIANGLE_STRIP, QUADS,
QUAD_STRIP