From 1eedef65eef18b328a625b3b0dacc35d2863a835 Mon Sep 17 00:00:00 2001
From: Thomas FORGIONE <thomas.forgione@gmail.com>
Date: Tue, 22 Nov 2016 17:17:37 +0100
Subject: [PATCH] Added track ball controls

---
 conv3d/model.py |  9 ++++++++
 modelviewer.py  | 55 ++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/conv3d/model.py b/conv3d/model.py
index 968fc36..95b8681 100644
--- a/conv3d/model.py
+++ b/conv3d/model.py
@@ -17,6 +17,12 @@ class Vertex:
     def __add__(self, other):
         return Vertex(self.x + other.x, self.y + other.y, self.z + other.z)
 
+    def __mul__(self, other):
+        return Vertex(self.x * other, self.y * other, self.z * other)
+
+    def __rmul__(self, other):
+        return self.__mul__(other)
+
     def norm2(self):
         return self.x * self.x + self.y * self.y + self.z * self.z
 
@@ -45,6 +51,9 @@ class Vertex:
     def __str__(self):
         return '(' + ", ".join([str(self.x), str(self.y), str(self.z)]) + ")"
 
+    def dot(self, other):
+        return self.x * other.x + self.y * other.y + self.z * other.z
+
 Normal = Vertex
 TexCoord = Vertex
 
diff --git a/modelviewer.py b/modelviewer.py
index 1179239..0706680 100755
--- a/modelviewer.py
+++ b/modelviewer.py
@@ -5,6 +5,7 @@ import ctypes
 import pygame
 import argparse
 import os
+import math
 
 from pygame.locals import *
 from OpenGL.GL import *
@@ -12,6 +13,7 @@ from OpenGL.GLU import *
 from OpenGL.GLUT import *
 
 from conv3d.loadmodel import load_model
+from conv3d.model import Vertex
 
 
 WINDOW_WIDTH = 1024
@@ -22,15 +24,55 @@ y = 0.5
 width = 1
 height = 1
 
+class TrackBallControls:
+    def __init__(self):
+        self.vertex = Vertex()
+        self.theta = 0
+
+    def apply(self):
+        glRotatef(self.theta * 180 / math.pi, self.vertex.x, self.vertex.y, self.vertex.z)
+
+    def update(self, time = 10):
+
+        if not pygame.mouse.get_pressed()[0]:
+            return
+
+        coeff = 0.001
+        move = pygame.mouse.get_rel()
+
+        dV = Vertex(move[1] * time * coeff, move[0] * time * coeff, 0)
+        dTheta = dV.norm2()
+
+        if abs(dTheta) < 0.01:
+            return
+
+        dV.normalize()
+
+        cosT2 = math.cos(self.theta / 2)
+        sinT2 = math.sin(self.theta / 2)
+        cosDT2 = math.cos(dTheta / 2)
+        sinDT2 = math.sin(dTheta / 2)
+
+        A = cosT2 * sinDT2 * dV + cosDT2 * sinT2 * self.vertex + sinDT2 * sinT2 * Vertex.cross_product(dV, self.vertex)
+
+        self.theta = 2 * math.acos(cosT2 * cosDT2 - sinT2 * sinDT2 * Vertex.dot(dV, self.vertex))
+
+        self.vertex = A
+        self.vertex.normalize()
+
+
+
 def init_frame():
 
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
     glMatrixMode(GL_MODELVIEW)
     glLoadIdentity()
-    gluLookAt(5,5,5,0,0,0,0,1,0)
+    gluLookAt(0,0,5,0,0,0,0,1,0)
 
 def main(args):
 
+    controls = TrackBallControls()
+
     pygame.init()
     display = (WINDOW_WIDTH, WINDOW_HEIGHT)
     pygame.display.set_mode(display, DOUBLEBUF|OPENGL)
@@ -63,11 +105,22 @@ def main(args):
                 if event.key == pygame.K_ESCAPE:
                     pygame.quit()
                     quit()
+            elif event.type == pygame.MOUSEBUTTONDOWN:
+                pygame.mouse.get_rel()
 
         init_frame()
+
+        glPushMatrix()
+        controls.apply()
         model.gl_draw()
+        glPopMatrix()
+
         glFlush()
         pygame.display.flip()
+
+        # Update physics
+        controls.update()
+
         pygame.time.wait(10)