import time
from stl import *
import numpy as np
from pycuda import autoinit
from pycuda.compiler import SourceModule
import pycuda.driver as cuda
from pycuda import gpuarray

def array2float3(arr):
    if len(arr.shape) != 2 or arr.shape[-1] != 3:
        raise Exception('shape mismatch')

    x = np.empty(arr.shape[0], dtype=gpuarray.vec.float3)
    x['x'] = arr[:,0]
    x['y'] = arr[:,1]
    x['z'] = arr[:,2]

    return x

print 'device %s' % autoinit.device.name()

source = open('src/linalg.h').read() + open('src/matrix.h').read() + \
    open('src/rotate.h').read() + open('src/intersect.cu').read()

mod = SourceModule(source, no_extern_c=True, arch='sm_13')
intersect = mod.get_function('intersect_triangle_mesh')
rotate = mod.get_function('rotate')
translate = mod.get_function('translate')

mesh = array2float3(pull_vertices_binary('models/tie_interceptor6.stl'))

import pygame
size = width, height = 800, 600
screen = pygame.display.set_mode(size)

film_size = (0.035, 0.024)
focal_length = 0.05

grid = []
for x in np.linspace(-film_size[0]/2, film_size[0]/2, width):
    for z in np.linspace(-film_size[1]/2, film_size[1]/2, height):
        grid.append((x,0,z))
grid = np.array(grid)
grid += (0,focal_length,0)
grid += (0,300,0)

x = array2float3(grid)
p = array2float3(((0,300,0)-grid))

x_gpu = cuda.mem_alloc(x.nbytes)
cuda.memcpy_htod(x_gpu,x)

p_gpu = cuda.mem_alloc(p.nbytes)
cuda.memcpy_htod(p_gpu,p)

mesh_gpu = cuda.mem_alloc(mesh.nbytes)
cuda.memcpy_htod(mesh_gpu,mesh)

pixel = np.empty(size, dtype=np.int32).flatten()
pixel_gpu = cuda.mem_alloc(pixel.nbytes)
cuda.memcpy_htod(pixel_gpu,pixel)

rotate(np.int32(mesh.size), mesh_gpu, np.float32(-np.pi/2), gpuarray.vec.make_float3(1,0,0), block=(256,1,1), grid=(mesh.size//256+1,1))

translate(np.int32(mesh.size), mesh_gpu, gpuarray.vec.make_float3(0,30,0), block=(256,1,1), grid=(mesh.size//256+1,1))


for i in range(100):
    rotate(np.int32(x.size), x_gpu, np.float32(np.pi/100), gpuarray.vec.make_float3(0,0,1), block=(256,1,1), grid=(width*height//256+1,1))

    rotate(np.int32(p.size), p_gpu, np.float32(np.pi/100), gpuarray.vec.make_float3(0,0,1), block=(256,1,1), grid=(width*height//256+1,1))

    t0 = time.time()
    intersect(np.int32(x.size), x_gpu, p_gpu, np.int32(mesh.size//3), mesh_gpu, pixel_gpu, block=(256,1,1), grid=(width*height//256+1,1))
    cuda.Context.synchronize()

    elapsed = time.time() - t0

    print '%i triangles, %i photons, %f sec; (%f photons/s)' % \
        (mesh.size//3, pixel.size, elapsed, pixel.size/elapsed)

    cuda.memcpy_dtoh(pixel, pixel_gpu)
    pygame.surfarray.blit_array(screen, pixel.reshape(size))
    pygame.display.flip()

raw_input('press enter to exit')