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examples.py/3D/Form/Toroid/Toroid.py

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+"""
+ * Interactive Toroid
+ * PDE by Ira Greenberg, adapted to Python by Jonathan Feinberg 
+ * 
+ * Illustrates the geometric relationship between Toroid, Sphere, and Helix
+ * 3D primitives, as well as lathing principal.
+ * 
+ * Instructions: 
+ * UP arrow key pts++ 
+ * DOWN arrow key pts-- 
+ * LEFT arrow key segments-- 
+ * RIGHT arrow key segments++ 
+ * 'a' key toroid radius-- 
+ * 's' key toroid radius++ 
+ * 'z' key initial polygon radius-- 
+ * 'x' key initial polygon radius++ 
+ * 'w' key toggle wireframe/solid shading 
+ * 'h' key toggle sphere/helix 
+ """
+
+from processing.core import PVector
+
+pts = 40 
+radius = 60.0
+
+# lathe segments
+segments = 60
+latheAngle = 0
+latheRadius = 100.0
+
+# for shaded or wireframe rendering 
+isWireFrame = False
+
+# for optional helix
+isHelix = False
+helixOffset = 5.0
+
+def setup():
+    size(640, 360, OPENGL)
+
+def draw():
+    background(50, 64, 42)
+    # basic lighting setup
+    lights()
+    # 2 rendering styles
+    # wireframe or solid
+    if isWireFrame:
+        stroke(255, 255, 150)
+        noFill()
+    else:
+        noStroke()
+        fill(150, 195, 125)
+
+    #center and spin toroid
+    translate(width / 2, height / 2, -100)
+    rotateX(frameCount * PI / 150)
+    rotateY(frameCount * PI / 170)
+    rotateZ(frameCount * PI / 90)
+    # initialize point arrays
+    vertices = [PVector() for x in range(pts + 1)]
+    vertices2 = [PVector() for x in range(pts + 1)]
+    # fill arrays
+    angle = 0
+    for v in vertices:
+        v.x = latheRadius + sin(radians(angle)) * radius
+        if isHelix:
+            v.z = cos(radians(angle)) * radius - (helixOffset * segments) / 2
+        else:
+            v.z = cos(radians(angle)) * radius
+        angle += 360.0 / pts
+
+    # draw toroid
+    latheAngle = 0
+    for i in range(segments + 1):
+        beginShape(QUAD_STRIP)
+        for j in range(pts + 1):
+            v2 = vertices2[j]
+            if i > 0:
+                vertex(v2.x, v2.y, v2.z)
+
+            v2.x = cos(radians(latheAngle)) * vertices[j].x
+            v2.y = sin(radians(latheAngle)) * vertices[j].x
+            v2.z = vertices[j].z
+            # optional helix offset
+            if isHelix:
+                vertices[j].z += helixOffset
+
+            vertex(v2.x, v2.y, v2.z)
+        # create extra rotation for helix
+        if isHelix:
+            latheAngle += 720.0 / segments
+        else:
+            latheAngle += 360.0 / segments
+
+        endShape()
+
+"""
+ left/right arrow keys control ellipse detail
+ up/down arrow keys control segment detail.
+ 'a','s' keys control lathe radius
+ 'z','x' keys control ellipse radius
+ 'w' key toggles between wireframe and solid
+ 'h' key toggles between toroid and helix
+ """
+def keyPressed():
+    global pts, segments, isHelix, isWireFrame, latheRadius, radius
+    if key == CODED:
+        # pts
+        if keyCode == UP:
+            if pts < 40:
+                pts += 1
+        elif keyCode == DOWN:
+            if pts > 3:
+                pts -= 1
+        # extrusion length
+        if keyCode == LEFT:
+            if segments > 3:
+                segments -= 1
+        elif keyCode == RIGHT:
+            if segments < 80:
+                segments += 1
+    # lathe radius
+    if key == ord('a'):
+        if latheRadius > 0:
+            latheRadius -= 1
+    elif key == ord('s'):
+        latheRadius += 1
+    # ellipse radius
+    if key == ord('z'):
+        if radius > 10:
+            radius -= 1
+    elif key == ord('x'):
+        radius += 1
+    # wireframe
+    if key == ord('w'):
+        isWireFrame = not isWireFrame
+    # helix
+    if key == ord('h'):
+        isHelix = not isHelix