Java tetrahedro

README.md

@@ -4,7 +4,9 @@
 
 Hi! I'm [Alexandre Villares](https://abav.lugaralgum.com), let's see if I can make one small program (*sketch*) a day.
 
-![GIF](https://github.com/villares/sketch-a-day/blob/master/s180103/s180103.gif?raw=true)
+![GIF](https://github.com/villares/sketch-a-day/blob/master/s180104/s180104.gif?raw=true)
+
+003: [s180103](https://github.com/villares/sketch-a-day/tree/master/s180103) [[Processing Java](https://www.processing.org)] Tetrahedrons - [GIF](https://github.com/villares/sketch-a-day/tree/master/s180104/s180104.gif)
 
 003: [s180103](https://github.com/villares/sketch-a-day/tree/master/s180103) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)] Tetrahedrons - [GIF](https://github.com/villares/sketch-a-day/tree/master/s180103/s180103.gif)
 

s180104/s180104.pde

@@ -0,0 +1,67 @@
+Tetrahedron[] thList;
+float rot_x = 0;
+float rot_y = 0;
+
+void setup() {
+  int numTh = 400;
+  thList = new Tetrahedron[numTh];
+  size(500, 500, P3D);
+  noStroke();
+  for (int i = 0; i < numTh; i++) {
+    float x = random(0, width);
+    float y = random(0, height);
+    float z = random(-500, 0);
+    Tetrahedron t = new Tetrahedron(x, y, z, 40); // instancia um tetrah
+    thList[i] = t ; // acrescenta na lista
+  }
+}
+
+void draw() {
+  background(128);
+  for (int i = 0; i < thList.length; i++) { 
+    thList[i].plot();
+  }
+  // if (frameCount < 100){ saveFrame("##.png"); }
+}
+
+class Tetrahedron {
+  float x, y, z, radius, rot_x, rot_y;
+  boolean showFaces;
+  PVector[] vert = new PVector[5];
+  Tetrahedron(float x_, float y_, float z_, float radius_) {
+    x = x_;
+    y = y_;
+    z = z_;
+    radius = radius_;
+    rot_x = random(-0.03,0.03);
+    rot_y = random(-0.03,0.03);
+    float a = radius*2/3;
+    vert[0] = new PVector( a, a, a ); // vertex 1
+    vert[1] = new PVector(-a, -a, a ); // vertex 2
+    vert[2] = new PVector(-a, a, -a ); // vertex 3
+    vert[3] = new PVector( a, -a, -a ); // vertex 4
+  }
+ // draws tetrahedron 
+  void plot() {
+    color c = color(map(x, 0, width, 0, 255), 
+                    map(y, 0, height, 0, 255), 
+                    map(z, -500, 500, 255, 0), 100);
+    fill(c);
+    pushMatrix();
+    translate(x, y, z);
+    rotateX(rot_y * frameCount);
+    rotateY(rot_x * frameCount);
+    beginShape(TRIANGLE_STRIP);
+    vertex(vert[0].x, vert[0].y, vert[0].z); // vertex 1
+    vertex(vert[1].x, vert[1].y, vert[1].z); // vertex 2
+    vertex(vert[2].x, vert[2].y, vert[2].z); // vertex 3
+    vertex(vert[3].x, vert[3].y, vert[3].z); // vertex 4
+    vertex(vert[0].x, vert[0].y, vert[0].z); // vertex 1
+    vertex(vert[1].x, vert[1].y, vert[1].z); // vertex 2
+    vertex(vert[3].x, vert[3].y, vert[3].z); // vertex 4
+    vertex(vert[2].x, vert[2].y, vert[2].z); // vertex 3
+    vertex(vert[1].x, vert[1].y, vert[1].z); // vertex 2
+    endShape(CLOSE); 
+    popMatrix();
+  }
+}