topical media & game development
graphic-processing-site-examples-3D-Form-Icosahedra-Icosahedron.pde / pde
class Icosahedron extends Shape3D{
// icosahedron
PVector topPoint;
PVector[] topPent = new PVector[5];
PVector bottomPoint;
PVector[] bottomPent = new PVector[5];
float angle = 0, radius = 150;
float triDist;
float triHt;
float a, b, c;
// constructor
Icosahedron(float radius){
this.radius = radius;
init();
}
Icosahedron(PVector v, float radius){
super(v);
this.radius = radius;
init();
}
// calculate geometry
void init(){
c = dist(cos(0)*radius, sin(0)*radius, cos(radians(72))*radius, sin(radians(72))*radius);
b = radius;
a = (float)(Math.sqrt(((c*c)-(b*b))));
triHt = (float)(Math.sqrt((c*c)-((c/2)*(c/2))));
for (int i=0; i<topPent.length; i++){
topPent[i] = new PVector(cos(angle)*radius, sin(angle)*radius, triHt/2.0f);
angle+=radians(72);
}
topPoint = new PVector(0, 0, triHt/2.0f+a);
angle = 72.0f/2.0f;
for (int i=0; i<topPent.length; i++){
bottomPent[i] = new PVector(cos(angle)*radius, sin(angle)*radius, -triHt/2.0f);
angle+=radians(72);
}
bottomPoint = new PVector(0, 0, -(triHt/2.0f+a));
}
// draws icosahedron
void create(){
for (int i=0; i<topPent.length; i++){
// icosahedron top
beginShape();
if (i<topPent.length-1){
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+topPoint.x, y+topPoint.y, z+topPoint.z);
vertex(x+topPent[i+1].x, y+topPent[i+1].y, z+topPent[i+1].z);
}
else {
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+topPoint.x, y+topPoint.y, z+topPoint.z);
vertex(x+topPent[0].x, y+topPent[0].y, z+topPent[0].z);
}
endShape(CLOSE);
// icosahedron bottom
beginShape();
if (i<bottomPent.length-1){
vertex(x+bottomPent[i].x, y+bottomPent[i].y, z+bottomPent[i].z);
vertex(x+bottomPoint.x, y+bottomPoint.y, z+bottomPoint.z);
vertex(x+bottomPent[i+1].x, y+bottomPent[i+1].y, z+bottomPent[i+1].z);
}
else {
vertex(x+bottomPent[i].x, y+bottomPent[i].y, z+bottomPent[i].z);
vertex(x+bottomPoint.x, y+bottomPoint.y, z+bottomPoint.z);
vertex(x+bottomPent[0].x, y+bottomPent[0].y, z+bottomPent[0].z);
}
endShape(CLOSE);
}
// icosahedron body
for (int i=0; i<topPent.length; i++){
if (i<topPent.length-2){
beginShape();
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+bottomPent[i+1].x, y+bottomPent[i+1].y, z+bottomPent[i+1].z);
vertex(x+bottomPent[i+2].x, y+bottomPent[i+2].y, z+bottomPent[i+2].z);
endShape(CLOSE);
beginShape();
vertex(x+bottomPent[i+2].x, y+bottomPent[i+2].y, z+bottomPent[i+2].z);
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+topPent[i+1].x, y+topPent[i+1].y, z+topPent[i+1].z);
endShape(CLOSE);
}
else if (i==topPent.length-2){
beginShape();
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+bottomPent[i+1].x, y+bottomPent[i+1].y, z+bottomPent[i+1].z);
vertex(x+bottomPent[0].x, y+bottomPent[0].y, z+bottomPent[0].z);
endShape(CLOSE);
beginShape();
vertex(x+bottomPent[0].x, y+bottomPent[0].y, z+bottomPent[0].z);
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+topPent[i+1].x, y+topPent[i+1].y, z+topPent[i+1].z);
endShape(CLOSE);
}
else if (i==topPent.length-1){
beginShape();
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+bottomPent[0].x, y+bottomPent[0].y, z+bottomPent[0].z);
vertex(x+bottomPent[1].x, y+bottomPent[1].y, z+bottomPent[1].z);
endShape(CLOSE);
beginShape();
vertex(x+bottomPent[1].x, y+bottomPent[1].y, z+bottomPent[1].z);
vertex(x+topPent[i].x, y+topPent[i].y, z+topPent[i].z);
vertex(x+topPent[0].x, y+topPent[0].y, z+topPent[0].z);
endShape(CLOSE);
}
}
}
// overrided methods fom Shape3D
void rotZ(float theta){
float tx=0, ty=0, tz=0;
// top point
tx = cos(theta)*topPoint.x+sin(theta)*topPoint.y;
ty = sin(theta)*topPoint.x-cos(theta)*topPoint.y;
topPoint.x = tx;
topPoint.y = ty;
// bottom point
tx = cos(theta)*bottomPoint.x+sin(theta)*bottomPoint.y;
ty = sin(theta)*bottomPoint.x-cos(theta)*bottomPoint.y;
bottomPoint.x = tx;
bottomPoint.y = ty;
// top and bottom pentagons
for (int i=0; i<topPent.length; i++){
tx = cos(theta)*topPent[i].x+sin(theta)*topPent[i].y;
ty = sin(theta)*topPent[i].x-cos(theta)*topPent[i].y;
topPent[i].x = tx;
topPent[i].y = ty;
tx = cos(theta)*bottomPent[i].x+sin(theta)*bottomPent[i].y;
ty = sin(theta)*bottomPent[i].x-cos(theta)*bottomPent[i].y;
bottomPent[i].x = tx;
bottomPent[i].y = ty;
}
}
void rotX(float theta){
}
void rotY(float theta){
}
}
(C) Æliens
20/2/2008
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