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from __future__ import absolute_import
import pyopencl as cl
mf = cl.mem_flags
from pyopencl.tools import get_gl_sharing_context_properties
from OpenGL.GL import * # OpenGL - GPU rendering interface
from OpenGL.GLU import * # OpenGL tools (mipmaps, NURBS, perspective projection, shapes)
from OpenGL.GLUT import * # OpenGL tool to make a visualization window
from OpenGL.arrays import vbo
import numpy
import sys
width = 800
height = 600
num_particles = 100000
time_step = .005
mouse_old = {'x': 0., 'y': 0.}
rotate = {'x': 0., 'y': 0., 'z': 0.}
translate = {'x': 0., 'y': 0., 'z': 0.}
initial_translate = {'x': 0., 'y': 0., 'z': -10}
def glut_window():
glutInit(sys.argv)
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(width, height)
glutInitWindowPosition(0, 0)
window = glutCreateWindow("fieldicle")
glutDisplayFunc(on_display)
glutMouseFunc(on_click)
glutMotionFunc(on_mouse_move)
glutTimerFunc(10, on_timer, 10)
glViewport(0, 0, width, height)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(60., width / float(height), .1, 1000.)
return(window)
def initial_buffers(num_particles):
np_position = numpy.ndarray((num_particles, 4), dtype=numpy.float32)
np_color = numpy.ndarray((num_particles, 4), dtype=numpy.float32)
np_position[:,0] = 10*numpy.random.random_sample((num_particles,)) - 5
np_position[:,1] = 10*numpy.random.random_sample((num_particles,)) - 5
np_position[:,2] = 0.
np_position[:,3] = 1.
np_color[:,:] = [1.,1.,1.,1.]
np_color[:,3] = numpy.random.random_sample((num_particles,))
gl_position = vbo.VBO(data=np_position, usage=GL_DYNAMIC_DRAW, target=GL_ARRAY_BUFFER)
gl_position.bind()
gl_color = vbo.VBO(data=np_color, usage=GL_DYNAMIC_DRAW, target=GL_ARRAY_BUFFER)
gl_color.bind()
return (np_position, gl_position, gl_color)
def on_timer(t):
glutTimerFunc(t, on_timer, t)
glutPostRedisplay()
def on_click(button, state, x, y):
mouse_old['x'] = x
mouse_old['y'] = y
def on_mouse_move(x, y):
rotate['x'] += (y - mouse_old['y']) * .2
rotate['y'] += (x - mouse_old['x']) * .2
mouse_old['x'] = x
mouse_old['y'] = y
def on_display():
# Update or particle positions by calling the OpenCL kernel
cl.enqueue_acquire_gl_objects(queue, [cl_gl_position, cl_gl_color])
kernelargs = (cl_gl_position, cl_gl_color, cl_start_position, numpy.float32(time_step))
program.particle_fountain(queue, (num_particles,), None, *(kernelargs))
cl.enqueue_release_gl_objects(queue, [cl_gl_position, cl_gl_color])
queue.finish()
glFlush()
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
# Handle mouse transformations
glTranslatef(initial_translate['x'], initial_translate['y'], initial_translate['z'])
glRotatef(rotate['x'], 1, 0, 0)
glRotatef(rotate['y'], 0, 1, 0)
glTranslatef(translate['x'], translate['y'], translate['z'])
# Render the particles
glEnable(GL_POINT_SMOOTH)
glPointSize(1)
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
# Set up the VBOs
gl_color.bind()
glColorPointer(4, GL_FLOAT, 0, gl_color)
gl_position.bind()
glVertexPointer(4, GL_FLOAT, 0, gl_position)
glEnableClientState(GL_VERTEX_ARRAY)
glEnableClientState(GL_COLOR_ARRAY)
# Draw the VBOs
glDrawArrays(GL_POINTS, 0, num_particles)
glDisableClientState(GL_COLOR_ARRAY)
glDisableClientState(GL_VERTEX_ARRAY)
glDisable(GL_BLEND)
glutSwapBuffers()
window = glut_window()
(np_position, gl_position, gl_color) = initial_buffers(num_particles)
platform = cl.get_platforms()[0]
context = cl.Context(properties=[(cl.context_properties.PLATFORM, platform)] + get_gl_sharing_context_properties())
queue = cl.CommandQueue(context)
cl_start_position = cl.Buffer(context, mf.READ_ONLY | mf.COPY_HOST_PTR, hostbuf=np_position)
cl_gl_position = cl.GLBuffer(context, mf.READ_WRITE, int(gl_position))
cl_gl_color = cl.GLBuffer(context, mf.READ_WRITE, int(gl_color))
kernel = """__kernel void particle_fountain(__global float4* position,
__global float4* color,
__global float4* start_position,
float time_step)
{
unsigned int i = get_global_id(0);
float4 p = position[i];
float life = color[i].w;
life -= time_step;
if (life <= 0.f) {
p = start_position[i];
life = 1.0f;
}
p.x += cos(p.x) * time_step;
p.y += sin(2*p.x-2*p.y) * time_step;
p.z += 2*cos(p.x*p.y) * time_step;
position[i] = p;
color[i].w = life;
}"""
program = cl.Program(context, kernel).build()
glutMainLoop()
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