Extract indicators, drawing of geometric primitives

1 files changed, 36 insertions, 0 deletions

diff --git a/geometry/sphere.py b/geometry/sphere.py
new file mode 100644
index 0000000..9bc245c
--- /dev/null
+++ b/geometry/sphere.py
@@ -0,0 +1,36 @@
+import numpy
+
+from OpenGL.GL import *
+
+class Sphere:
+    def __init__(self, x, y, z, r):
+        self.x = x
+        self.y = y
+        self.z = z
+        self.r = r
+
+    def indicator(self):
+        return lambda x, y, z: (x - self.x)**2 + (y - self.y)**2 + (z - self.z)**2 < self.r*self.r
+
+    def draw(self, resolution = 32):
+        for i in range(0,resolution+1):
+            lat0 = numpy.pi * (-0.5 + (i - 1) / resolution)
+            z0   = numpy.sin(lat0)
+            zr0  = numpy.cos(lat0)
+
+            lat1 = numpy.pi * (-0.5 + i / resolution)
+            z1   = numpy.sin(lat1)
+            zr1  = numpy.cos(lat1)
+
+            glBegin(GL_QUAD_STRIP)
+            for j in range(0,resolution+1):
+                lng = 2 * numpy.pi * (j - 1) / resolution
+                x = numpy.cos(lng)
+                y = numpy.sin(lng)
+
+                glNormal(x * zr0, y * zr0, z0)
+                glVertex(self.x + self.r * x * zr0, self.y + self.r * y * zr0, self.z + self.r * z0)
+                glNormal(x * zr1, y * zr1, z1)
+                glVertex(self.x + self.r * x * zr1, self.y + self.r * y * zr1, self.z + self.r * z1)
+
+            glEnd()