Separate classes into modules

12 files changed, 372 insertions, 332 deletions

diff --git a/boltzgas/__init__.py b/boltzgas/__init__.py
new file mode 100644
index 0000000..3b623dd
--- /dev/null
+++ b/boltzgas/__init__.py
@@ -0,0 +1,4 @@
+import boltzgas.initial_condition
+import boltzgas.visual
+
+from boltzgas.simulation import HardSphereSetup, HardSphereSimulation
diff --git a/boltzgas/initial_condition.py b/boltzgas/initial_condition.py
new file mode 100644
index 0000000..4d66263
--- /dev/null
+++ b/boltzgas/initial_condition.py
@@ -0,0 +1,15 @@
+import numpy as np
+
+def grid_of_random_velocity_particles(width, radius, u_scale):
+    np_position = np.ndarray((width**2, 2))
+    np_velocity = np.ndarray((width**2, 2))
+
+    grid = np.meshgrid(np.linspace(2*radius, 1-2*radius, width),
+                       np.linspace(2*radius, 1-2*radius, width))
+    np_position[:,0] = grid[0].flatten()
+    np_position[:,1] = grid[1].flatten()
+
+    np_velocity[:,0] = u_scale*(-0.5 + np.random.random_sample((width**2,)))
+    np_velocity[:,1] = u_scale*(-0.5 + np.random.random_sample((width**2,)))
+
+    return (np_position, np_velocity)
diff --git a/kernel.cl b/boltzgas/kernel.cl
index ad984bb..ad984bb 100644
--- a/kernel.cl
+++ b/boltzgas/kernel.cl
diff --git a/particles.py b/boltzgas/simulation.py
index 048e52c..a4ae4da 100644
--- a/particles.py
+++ b/boltzgas/simulation.py
@@ -18,27 +18,13 @@ class HardSphereSetup:
         self.n_particles = len(position[:,0])
 
 def build_kernel(delta_t, n_particles, radius):
-    with open('kernel.cl', 'r') as kernel_src:
+    with open('boltzgas/kernel.cl', 'r') as kernel_src:
         return Template(kernel_src.read()).substitute(
             delta_t     = delta_t,
             n_particles = n_particles,
             radius      = radius)
 
-def grid_of_random_velocity_particles(width, radius, u_scale):
-    np_position = np.ndarray((width**2, 2))
-    np_velocity = np.ndarray((width**2, 2))
-
-    grid = np.meshgrid(np.linspace(2*radius, 1-2*radius, width),
-                       np.linspace(2*radius, 1-2*radius, width))
-    np_position[:,0] = grid[0].flatten()
-    np_position[:,1] = grid[1].flatten()
-
-    np_velocity[:,0] = u_scale*(-0.5 + np.random.random_sample((width**2,)))
-    np_velocity[:,1] = u_scale*(-0.5 + np.random.random_sample((width**2,)))
-
-    return (np_position, np_velocity)
-
-class GasFlow:
+class HardSphereSimulation:
     def setup_cl(self):
         self.platform = cl.get_platforms()[0]
         if self.opengl:
@@ -75,6 +61,9 @@ class GasFlow:
         self.np_particle_velocity = setup.velocity.astype(np.float32)
 
         self.n_particles = setup.n_particles
+        self.radius      = setup.radius
+        self.char_u      = setup.char_u
+
         self.opengl = opengl
         self.t_scale = t_scale
 
@@ -83,7 +72,7 @@ class GasFlow:
 
         self.np_particle_velocity_norms = np.ndarray((self.n_particles, 1), dtype=np.float32)
 
-        self.kernel_src = build_kernel(self.t_scale*setup.radius/setup.char_u, self.n_particles, setup.radius)
+        self.kernel_src = build_kernel(self.t_scale*self.radius/self.char_u, self.n_particles, self.radius)
 
         self.setup_cl()
 
diff --git a/boltzgas/visual/__init__.py b/boltzgas/visual/__init__.py
new file mode 100644
index 0000000..3462d96
--- /dev/null
+++ b/boltzgas/visual/__init__.py
@@ -0,0 +1,4 @@
+from .box import ColoredBox
+from .histogram import VelocityHistogram
+from .tracer import Tracer
+from .view import View
diff --git a/boltzgas/visual/box.py b/boltzgas/visual/box.py
new file mode 100644
index 0000000..0a6ab5a
--- /dev/null
+++ b/boltzgas/visual/box.py
@@ -0,0 +1,16 @@
+from OpenGL.GL import *
+
+class ColoredBox:
+    def __init__(self, origin, extend, color):
+        self.origin = origin
+        self.extend = extend
+        self.color = color
+
+    def display(self, uniform):
+        glUniform3f(uniform['face_color'], *self.color)
+        glBegin(GL_TRIANGLE_STRIP)
+        glVertex(self.origin[0],                  self.origin[1]                 , 0.)
+        glVertex(self.origin[0] + self.extend[0], self.origin[1]                 , 0.)
+        glVertex(self.origin[0]                 , self.origin[1] + self.extend[1], 0.)
+        glVertex(self.origin[0] + self.extend[1], self.origin[1] + self.extend[1], 0.)
+        glEnd()
diff --git a/boltzgas/visual/histogram.py b/boltzgas/visual/histogram.py
new file mode 100644
index 0000000..2f90b8b
--- /dev/null
+++ b/boltzgas/visual/histogram.py
@@ -0,0 +1,125 @@
+from OpenGL.GL import *
+
+import numpy as np
+
+import scipy.stats as stats
+import scipy.constants as const
+from scipy.optimize import minimize
+
+import matplotlib
+import matplotlib.pyplot as plt
+
+from concurrent.futures import Future, ProcessPoolExecutor
+
+def get_histogram(velocities, char_u):
+    maxwellian = stats.maxwell.fit(velocities)
+
+    plt.style.use('dark_background')
+
+    fig = plt.figure(figsize=(8,8))
+    ax = fig.add_axes([0.1, 0.06, 0.88, 0.92])
+
+    plt.ylim(0, 0.003)
+    plt.ylabel('Probability')
+
+    plt.xlim(0, 1.2*char_u)
+    plt.xlabel('Velocity magnitude [m/s]')
+
+    plt.hist(velocities, bins=50, density=True, alpha=0.5, label='Simulated velocities')
+
+    xs = np.linspace(0, 1.2*char_u, 100)
+    plt.plot(xs, stats.maxwell.pdf(xs, *maxwellian), label='Maxwell-Boltzmann distribution')
+
+    plt.legend(loc='upper right')
+
+    fig.canvas.draw()
+    buf = fig.canvas.tostring_rgb()
+    width, height = fig.canvas.get_width_height()
+    texture = np.frombuffer(buf, dtype=np.uint8).reshape(width, height, 3)
+
+    plt.close(fig)
+
+    return (texture, height, width)
+
+
+class VelocityHistogram:
+    def __init__(self, gas, origin, extend):
+        self.gas = gas
+        self.origin = origin
+        self.extend = extend
+        self.steps = -1
+
+        self.pool = ProcessPoolExecutor(max_workers=1)
+        self.plotter = None
+
+        self.tick = False
+        self.mixing = 0.0
+
+    def setup(self):
+        self.vertices = np.array([
+            self.origin[0]                 , self.origin[1]                 , 0., 1.,
+            self.origin[0] + self.extend[0], self.origin[1]                 , 1., 1.,
+            self.origin[0]                 , self.origin[1] + self.extend[1], 0., 0.,
+            self.origin[0] + self.extend[0], self.origin[1] + self.extend[1], 1., 0.
+        ], dtype=np.float32)
+
+        self.vao = glGenVertexArrays(1)
+        self.vbo = glGenBuffers(1)
+
+        glBindVertexArray(self.vao)
+        glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
+        glBufferData(GL_ARRAY_BUFFER, self.vertices.tostring(), GL_STATIC_DRAW)
+
+        glEnableVertexAttribArray(0)
+        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*np.dtype(np.float32).itemsize, ctypes.c_void_p(0))
+        glEnableVertexAttribArray(1)
+        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4*np.dtype(np.float32).itemsize, ctypes.c_void_p(2*np.dtype(np.float32).itemsize))
+
+        self.texture_id = glGenTextures(2)
+
+        glBindTexture(GL_TEXTURE_2D, self.texture_id[0])
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        glBindTexture(GL_TEXTURE_2D, self.texture_id[1])
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    def update(self):
+        self.steps = self.steps + 1
+
+        if self.steps % 50 == 0 and self.plotter == None:
+            self.plotter = self.pool.submit(get_histogram, self.gas.get_velocity_norms(), self.gas.char_u)
+
+        else:
+            if self.plotter != None and self.plotter.done():
+                texture, width, height = self.plotter.result()
+                if self.tick:
+                    glBindTexture(GL_TEXTURE_2D, self.texture_id[0])
+                    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture)
+                    self.tick = False
+                    self.mixing = 1.0
+
+                else:
+                    glBindTexture(GL_TEXTURE_2D, self.texture_id[1])
+                    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture)
+                    self.tick = True
+                    self.mixing = 0.0
+
+                self.plotter = None
+
+
+    def display(self, uniform):
+        if self.tick:
+            self.mixing = min(self.mixing+0.1, 1.0);
+        else:
+            self.mixing = max(self.mixing-0.1, 0.0);
+
+        glBindTextures(self.texture_id[0], 2, self.texture_id)
+        glUniform1iv(uniform['picture'], len(self.texture_id), self.texture_id)
+        glUniform1f(uniform['mixing'], self.mixing)
+
+        glBindVertexArray(self.vao);
+        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4)
+        glBindVertexArray(0)
+
diff --git a/boltzgas/visual/shader.py b/boltzgas/visual/shader.py
new file mode 100644
index 0000000..b4295a8
--- /dev/null
+++ b/boltzgas/visual/shader.py
@@ -0,0 +1,15 @@
+from OpenGL.GL import GL_VERTEX_SHADER, GL_FRAGMENT_SHADER
+from OpenGL.GL import shaders
+
+class Shader:
+    def __init__(self, fragment_src, vertex_src, uniform):
+        self.program = shaders.compileProgram(
+            shaders.compileShader(vertex_src, GL_VERTEX_SHADER),
+            shaders.compileShader(fragment_src, GL_FRAGMENT_SHADER))
+        self.uniform = { }
+        for name in uniform:
+            self.uniform[name] = shaders.glGetUniformLocation(self.program, name)
+
+    def use(self):
+        shaders.glUseProgram(self.program)
+
diff --git a/boltzgas/visual/tracer.py b/boltzgas/visual/tracer.py
new file mode 100644
index 0000000..a5b2203
--- /dev/null
+++ b/boltzgas/visual/tracer.py
@@ -0,0 +1,20 @@
+from OpenGL.GL import *
+
+class Tracer:
+    def __init__(self, gas, iParticle):
+        self.gas = gas
+        self.iParticle = iParticle
+        self.trace = [ ]
+
+    def update(self):
+        position = self.gas.get_positions()[self.iParticle]
+        self.trace.append((position[0], position[1]))
+
+    def display(self, uniform):
+        glUniform3f(uniform['face_color'], 1., 0., 0.)
+        glLineWidth(2)
+        glBegin(GL_LINE_STRIP)
+        for v in self.trace:
+            glVertex(*v, 0.)
+        glEnd()
+
diff --git a/boltzgas/visual/view.py b/boltzgas/visual/view.py
new file mode 100644
index 0000000..d6e188b
--- /dev/null
+++ b/boltzgas/visual/view.py
@@ -0,0 +1,154 @@
+from OpenGL.GL   import *
+from OpenGL.GLUT import *
+
+from pyrr import matrix44
+
+import numpy as np
+
+from .shader import Shader
+
+particle_shader = (
+    """
+        #version 430
+
+        in vec3 color;
+
+        void main(){
+            if (length(gl_PointCoord - vec2(0.5)) > 0.5) {
+                discard;
+            }
+
+            gl_FragColor = vec4(color.xyz, 0.0);
+        }
+    """,
+    """
+        #version 430
+
+        layout (location=0) in vec2 particles;
+
+        out vec3 color;
+
+        uniform mat4 projection;
+        uniform vec3 face_color;
+        uniform vec3 trace_color;
+        uniform uint trace_id;
+
+        void main() {
+            gl_Position = projection * vec4(particles, 0., 1.);
+
+            if (gl_VertexID == trace_id) {
+                color = trace_color;
+            } else {
+                color = face_color;
+            }
+        }
+    """,
+    ['projection', 'face_color', 'trace_color', 'trace_id']
+)
+
+decoration_shader = (
+    """
+        #version 430
+
+        in vec3 color;
+
+        void main(){
+            gl_FragColor = vec4(color.xyz, 0.0);
+        }
+    """,
+    """
+        #version 430
+
+        in vec3 vertex;
+
+        out vec3 color;
+
+        uniform mat4 projection;
+        uniform vec3 face_color;
+
+        void main() {
+            gl_Position = projection * vec4(vertex, 1.);
+            color = face_color;
+        }
+    """,
+    ['projection', 'face_color']
+)
+
+texture_shader = (
+    """
+        #version 430
+
+        in vec2 tex_coord;
+
+        uniform sampler2D picture[2];
+
+        uniform float mixing;
+
+        void main() {
+            gl_FragColor = mix(texture(picture[0], tex_coord), texture(picture[1], tex_coord), mixing);
+        }
+    """,
+    """
+        #version 430
+
+        layout (location=0) in vec2 screen_vertex;
+        layout (location=1) in vec2 texture_vertex;
+
+        out vec2 tex_coord;
+
+        uniform mat4 projection;
+
+        void main() {
+            gl_Position = projection * vec4(screen_vertex, 0.0, 1.0);
+            tex_coord = texture_vertex;
+        }
+    """,
+    ['picture','projection','mixing']
+)
+
+class View:
+    def __init__(self, gas, decorations, windows):
+        self.gas = gas
+        self.decorations = decorations
+        self.windows = windows
+
+        self.texture_shader    = Shader(*texture_shader)
+        self.particle_shader   = Shader(*particle_shader)
+        self.decoration_shader = Shader(*decoration_shader)
+
+    def reshape(self, width, height):
+        glViewport(0,0,width,height)
+
+        world_height = 1.4
+        world_width = world_height / height * width
+
+        projection  = matrix44.create_orthogonal_projection(-world_width/2, world_width/2, -world_height/2, world_height/2, -1, 1)
+        translation = matrix44.create_from_translation([-1.05, -1.0/2, 0])
+
+        self.pixels_per_unit = height / world_height
+        self.projection = np.matmul(translation, projection)
+
+    def display(self):
+        glClearColor(0.,0.,0.,1.)
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
+
+        self.decoration_shader.use()
+        glUniformMatrix4fv(self.decoration_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
+        for decoration in self.decorations:
+            decoration.display(self.decoration_shader.uniform)
+
+        self.texture_shader.use()
+        glUniformMatrix4fv(self.texture_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
+        for window in self.windows:
+            window.display(self.texture_shader.uniform)
+
+        self.particle_shader.use()
+        glUniformMatrix4fv(self.particle_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
+        glUniform3f(self.particle_shader.uniform['face_color'],  1., 1., 1.)
+        glUniform3f(self.particle_shader.uniform['trace_color'], 1., 0., 0.)
+        glUniform1ui(self.particle_shader.uniform['trace_id'], 4)
+        glEnable(GL_POINT_SPRITE)
+        glPointSize(2*self.gas.radius*self.pixels_per_unit)
+        self.gas.gl_draw_particles()
+
+        glutSwapBuffers()
diff --git a/gas.py b/gas.py
index c1ccbce..9261d87 100644
--- a/gas.py
+++ b/gas.py
@@ -1,319 +1,16 @@
 from OpenGL.GL import *
 from OpenGL.GLUT import *
-from OpenGL.GL import shaders
-
-from pyrr import matrix44
 
 import numpy as np
 
-import scipy.stats as stats
-import scipy.constants as const
-from scipy.optimize import minimize
-
-import matplotlib
-import matplotlib.pyplot as plt
-
-from particles import GasFlow, HardSphereSetup, grid_of_random_velocity_particles
-
-from concurrent.futures import Future, ProcessPoolExecutor
+from boltzgas import HardSphereSetup, HardSphereSimulation
+from boltzgas.initial_condition import grid_of_random_velocity_particles
+from boltzgas.visual import View, VelocityHistogram, Tracer, ColoredBox
 
 glutInit()
 glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
 glutInitWindowPosition(0, 0)
-window = glutCreateWindow("gas")
-
-class Shader:
-    def __init__(self, vertex_src, fragment_src, uniform):
-        self.program = shaders.compileProgram(
-            shaders.compileShader(vertex_src, GL_VERTEX_SHADER),
-            shaders.compileShader(fragment_src, GL_FRAGMENT_SHADER))
-        self.uniform = { }
-        for name in uniform:
-            self.uniform[name] = shaders.glGetUniformLocation(self.program, name)
-
-    def use(self):
-        shaders.glUseProgram(self.program)
-
-particle_shader = Shader(
-    fragment_src = """
-        #version 430
-
-        in vec3 color;
-
-        void main(){
-            if (length(gl_PointCoord - vec2(0.5)) > 0.5) {
-                discard;
-            }
-
-            gl_FragColor = vec4(color.xyz, 0.0);
-        }""",
-    vertex_src = """
-        #version 430
-
-        layout (location=0) in vec2 particles;
-
-        out vec3 color;
-
-        uniform mat4 projection;
-        uniform vec3 face_color;
-        uniform vec3 trace_color;
-        uniform uint trace_id;
-
-        void main() {
-            gl_Position = projection * vec4(particles, 0., 1.);
-
-            if (gl_VertexID == trace_id) {
-                color = trace_color;
-            } else {
-                color = face_color;
-            }
-        }""",
-    uniform = ['projection', 'face_color', 'trace_color', 'trace_id']
-)
-
-decoration_shader = Shader(
-    fragment_src = """
-        #version 430
-
-        in vec3 color;
-
-        void main(){
-            gl_FragColor = vec4(color.xyz, 0.0);
-        }""",
-    vertex_src = """
-        #version 430
-
-        in vec3 vertex;
-
-        out vec3 color;
-
-        uniform mat4 projection;
-        uniform vec3 face_color;
-
-        void main() {
-            gl_Position = projection * vec4(vertex, 1.);
-            color = face_color;
-        }""",
-    uniform = ['projection', 'face_color']
-)
-
-texture_shader = Shader(
-    fragment_src = """
-        #version 430
-
-        in vec2 tex_coord;
-
-        uniform sampler2D picture[2];
-
-        uniform float mixing;
-
-        void main() {
-            gl_FragColor = mix(texture(picture[0], tex_coord), texture(picture[1], tex_coord), mixing);
-        }""",
-    vertex_src = """
-        #version 430
-
-        layout (location=0) in vec2 screen_vertex;
-        layout (location=1) in vec2 texture_vertex;
-
-        out vec2 tex_coord;
-
-        uniform mat4 projection;
-
-        void main() {
-            gl_Position = projection * vec4(screen_vertex, 0.0, 1.0);
-            tex_coord = texture_vertex;
-        }""",
-    uniform = ['picture','projection','mixing']
-)
-
-class View:
-    def __init__(self, gas, decorations, windows):
-        self.gas = gas
-        self.decorations = decorations
-        self.windows = windows
-
-    def reshape(self, width, height):
-        glViewport(0,0,width,height)
-
-        world_height = 1.4
-        world_width = world_height / height * width
-
-        projection  = matrix44.create_orthogonal_projection(-world_width/2, world_width/2, -world_height/2, world_height/2, -1, 1)
-        translation = matrix44.create_from_translation([-1.05, -1.0/2, 0])
-
-        self.pixels_per_unit = height / world_height
-        self.projection = np.matmul(translation, projection)
-
-    def display(self):
-        glClearColor(0.,0.,0.,1.)
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
-
-        decoration_shader.use()
-        glUniformMatrix4fv(decoration_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
-        for decoration in self.decorations:
-            decoration.display(decoration_shader.uniform)
-
-        texture_shader.use()
-        glUniformMatrix4fv(texture_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
-        for window in self.windows:
-            window.display(texture_shader.uniform)
-
-        particle_shader.use()
-        glUniformMatrix4fv(particle_shader.uniform['projection'], 1, False, np.asfortranarray(self.projection))
-        glUniform3f(particle_shader.uniform['face_color'],  1., 1., 1.)
-        glUniform3f(particle_shader.uniform['trace_color'], 1., 0., 0.)
-        glUniform1ui(particle_shader.uniform['trace_id'], 4)
-        glEnable(GL_POINT_SPRITE)
-        glPointSize(2*radius*self.pixels_per_unit)
-        self.gas.gl_draw_particles()
-
-        glutSwapBuffers()
-
-class Tracer:
-    def __init__(self, gas, iParticle):
-        self.gas = gas
-        self.iParticle = iParticle
-        self.trace = [ ]
-
-    def update(self):
-        position = self.gas.get_positions()[self.iParticle]
-        self.trace.append((position[0], position[1]))
-
-    def display(self, uniform):
-        glUniform3f(uniform['face_color'], 1., 0., 0.)
-        glLineWidth(2)
-        glBegin(GL_LINE_STRIP)
-        for v in self.trace:
-            glVertex(*v, 0.)
-        glEnd()
-
-class ColoredBox:
-    def __init__(self, origin, extend, color):
-        self.origin = origin
-        self.extend = extend
-        self.color = color
-
-    def display(self, uniform):
-        glUniform3f(uniform['face_color'], *self.color)
-        glBegin(GL_TRIANGLE_STRIP)
-        glVertex(self.origin[0],                  self.origin[1]                 , 0.)
-        glVertex(self.origin[0] + self.extend[0], self.origin[1]                 , 0.)
-        glVertex(self.origin[0]                 , self.origin[1] + self.extend[1], 0.)
-        glVertex(self.origin[0] + self.extend[1], self.origin[1] + self.extend[1], 0.)
-        glEnd()
-
-def get_histogram(velocities):
-    maxwellian = stats.maxwell.fit(velocities)
-
-    plt.style.use('dark_background')
-
-    fig = plt.figure(figsize=(10,10))
-    ax = fig.add_axes([0.1, 0.05, 0.88, 0.93])
-
-    plt.ylim(0, 0.003)
-    plt.ylabel('Probability')
-
-    plt.xlim(0, 1.2*char_u)
-    plt.xlabel('Velocity magnitude [m/s]')
-
-    plt.hist(velocities, bins=50, density=True, alpha=0.5, label='Simulated velocities')
-
-    xs = np.linspace(0, 1.2*char_u, 100)
-    plt.plot(xs, stats.maxwell.pdf(xs, *maxwellian), label='Maxwell-Boltzmann distribution')
-
-    plt.legend(loc='upper right')
-
-    fig.canvas.draw()
-    buf = fig.canvas.tostring_rgb()
-    width, height = fig.canvas.get_width_height()
-    texture = np.frombuffer(buf, dtype=np.uint8).reshape(width, height, 3)
-
-    plt.close(fig)
-
-    return (texture, height, width)
-
-
-class VelocityHistogram:
-    def __init__(self, gas, origin, extend):
-        self.gas = gas
-        self.origin = origin
-        self.extend = extend
-        self.steps = -1
-
-        self.pool = ProcessPoolExecutor(max_workers=1)
-        self.plotter = None
-
-        self.tick = False
-        self.mixing = 0.0
-
-    def setup(self):
-        self.vertices = np.array([
-            self.origin[0]                 , self.origin[1]                 , 0., 1.,
-            self.origin[0] + self.extend[0], self.origin[1]                 , 1., 1.,
-            self.origin[0]                 , self.origin[1] + self.extend[1], 0., 0.,
-            self.origin[0] + self.extend[0], self.origin[1] + self.extend[1], 1., 0.
-        ], dtype=np.float32)
-
-        self.vao = glGenVertexArrays(1)
-        self.vbo = glGenBuffers(1)
-
-        glBindVertexArray(self.vao)
-        glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
-        glBufferData(GL_ARRAY_BUFFER, self.vertices.tostring(), GL_STATIC_DRAW)
-
-        glEnableVertexAttribArray(0)
-        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*np.dtype(np.float32).itemsize, ctypes.c_void_p(0))
-        glEnableVertexAttribArray(1)
-        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4*np.dtype(np.float32).itemsize, ctypes.c_void_p(2*np.dtype(np.float32).itemsize))
-
-        self.texture_id = glGenTextures(2)
-
-        glBindTexture(GL_TEXTURE_2D, self.texture_id[0])
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-        glBindTexture(GL_TEXTURE_2D, self.texture_id[1])
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-    def update(self):
-        self.steps = self.steps + 1
-
-        if self.steps % 50 == 0 and self.plotter == None:
-            self.plotter = self.pool.submit(get_histogram, self.gas.get_velocity_norms())
-
-        else:
-            if self.plotter != None and self.plotter.done():
-                texture, width, height = self.plotter.result()
-                if self.tick:
-                    glBindTexture(GL_TEXTURE_2D, self.texture_id[0])
-                    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture)
-                    self.tick = False
-                    self.mixing = 1.0
-
-                else:
-                    glBindTexture(GL_TEXTURE_2D, self.texture_id[1])
-                    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture)
-                    self.tick = True
-                    self.mixing = 0.0
-
-                self.plotter = None
-
-
-    def display(self, uniform):
-        if self.tick:
-            self.mixing = min(self.mixing+0.1, 1.0);
-        else:
-            self.mixing = max(self.mixing-0.1, 0.0);
-
-        glBindTextures(self.texture_id[0], 2, self.texture_id)
-        glUniform1iv(uniform['picture'], len(self.texture_id), self.texture_id)
-        glUniform1f(uniform['mixing'], self.mixing)
-
-        glBindVertexArray(self.vao);
-        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4)
-        glBindVertexArray(0)
+glutCreateWindow("BoltzGas")
 
 grid_width = 32
 radius = 0.004
@@ -325,7 +22,7 @@ velocity[0,0] = 10*char_u
 velocity[0,1] = 4*char_u
 
 config = HardSphereSetup(radius, char_u, position, velocity)
-gas = GasFlow(config, opengl = True, t_scale = 1.0)
+gas = HardSphereSimulation(config, opengl = True, t_scale = 0.1)
 
 tracer = Tracer(gas, 4)
 histogram = VelocityHistogram(gas, [1.1,0], [1,1])
@@ -358,11 +55,11 @@ def on_keyboard(key, x, y):
 def on_close():
     histogram.pool.shutdown()
 
-if __name__ == "__main__":
-    glutDisplayFunc(on_display)
-    glutReshapeFunc(on_reshape)
-    glutTimerFunc(10, on_timer, 10)
-    glutKeyboardFunc(on_keyboard)
-    glutCloseFunc(on_close)
+glutDisplayFunc(on_display)
+glutReshapeFunc(on_reshape)
+glutTimerFunc(10, on_timer, 10)
+glutKeyboardFunc(on_keyboard)
+glutCloseFunc(on_close)
 
+if __name__ == "__main__":
     glutMainLoop()
diff --git a/shell.nix b/shell.nix
index d82cbe3..d2ea65e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -37,7 +37,8 @@ pkgs.stdenvNoCC.mkDerivation rec {
 
   shellHook = ''
     export NIX_SHELL_NAME="${name}"
+    export PYTHONPATH="$PWD/boltzgas:$PYTHONPATH"
     export PYOPENCL_COMPILER_OUTPUT=1
-    export PYTHONPATH="$PWD:$PYTHONPATH"
+    export PYTHONDONTWRITEBYTECODE=1
   '';
 }