simple.glsl

class MeshData( object):
def __init__ ( self , ** kwargs):
self . name = kwargs. get( "name" )
self . vertex_format = [
( b'v_pos' , 3 , 'float' ),
( b'v_normal' , 3 , 'float' ),
( b'v_tc0' , 2 , 'float' )]
self . vertices = []
self . indices = []
def calculate_normals ( self ):
for i in range ( len( self . indices ) / ( 3 )):
fi = i * 3
v1i = self . indices [ fi ]
v2i = self . indices [ fi + 1 ]
v3i = self . indices [ fi + 2 ]
vs = self . vertices
p1 = [ vs [ v1i + c ] for c in range ( 3 )]
p2 = [ vs [ v2i + c ] for c in range ( 3 )]
p3 = [ vs [ v3i + c ] for c in range ( 3 )]
u , v = [ 0 , 0 , 0 ], [ 0 , 0 , 0 ]
for j in range( 3 ):
v [ j ] = p2 [ j ] - p1 [ j ]
u [ j ] = p3 [ j ] - p1 [ j ]
n = [ 0 , 0 , 0 ]
n [ 0 ] = u [ 1 ] * v [ 2 ] - u [ 2 ] * v [ 1 ]
n [ 1 ] = u [ 2 ] * v [ 0 ] - u [ 0 ] * v [ 2 ]
n [ 2 ] = u [ 0 ] * v [ 1 ] - u [ 1 ] * v [ 0 ]
for k in range( 3 ):
self . vertices [ v1i + 3 + k ] = n [ k ]
self . vertices [ v2i + 3 + k ] = n [ k ]
self . vertices [ v3i + 3 + k ] = n [ k ]
class ObjFile :
def finish_object ( self ):
if self . _current_object is None:
return
mesh = MeshData()
idx = 0
for f in self . faces :
verts = f [ 0 ]
norms = f [ 1 ]
tcs = f [ 2 ]
for i in range( 3 ):
# get normal components
n = ( 0.0 , 0.0 , 0.0 )
if norms[ i ] != - 1 :
n = self . normals [ norms[ i ] - 1 ]
# get texture coordinate components
t = ( 0.0 , 0.0 )
if tcs[ i ] != - 1 :
t = self . texcoords[ tcs[ i ] - 1 ]
# get vertex components
v = self . vertices [ verts[ i ] - 1 ]
data = [ v [ 0 ], v [ 1 ], v [ 2 ], n [ 0 ], n [ 1 ], n [ 2 ], t [ 0 ], t [ 1 ]]
mesh . vertices . extend( data )
tri = [ idx, idx + 1 , idx + 2 ]
mesh . indices . extend( tri)
idx += 3
self . objects [ self . _current_object ] = mesh
# mesh.calculate_normals()
self . faces = []
def __init__ ( self , filename , swapyz= False):
"""Loads a Wavefront OBJ file. """
self . objects = {}
self . vertices = []
self . normals = []
self . texcoords = []
self . faces = []
self . _current_object = None
material = None
for line in open ( filename , "r" ):
if line . startswith ( '#' ):
continue
if line . startswith ( 's' ):
continue
values = line . split ()
if not values:
continue
if values[ 0 ] == 'o' :
self . finish_object ()
self . _current_object = values[ 1 ]
# elif values[0] == 'mtllib':
#    self.mtl = MTL(values[1])
# elif values[0] in ('usemtl', 'usemat'):
#    material = values[1]
if values[ 0 ] == 'v' :
v = list ( map( float , values[ 1 : 4 ]))
if swapyz:
v = v [ 0 ], v [ 2 ], v [ 1 ]
self . vertices . append( v )
elif values[ 0 ] == 'vn' :
v = list ( map( float , values[ 1 : 4 ]))
if swapyz:
v = v [ 0 ], v [ 2 ], v [ 1 ]
self . normals . append( v )
elif values[ 0 ] == 'vt' :
self . texcoords. append( map( float , values[ 1 : 3 ]))
elif values[ 0 ] == 'f' :
face = []
texcoords = []
norms = []
for v in values[ 1 :]:
w = v . split( '/' )
face . append( int( w [ 0 ]))
if len( w ) >= 2 and len( w [ 1 ]) > 0 :
texcoords. append( int( w [ 1 ]))
else:
texcoords. append( - 1 )
if len( w ) >= 3 and len( w [ 2 ]) > 0 :
norms . append( int( w [ 2 ]))
else:
norms . append( - 1 )
self . faces . append((face , norms , texcoords, material))
self . finish_object ()
def MTL( filename ):
contents = {}
mtl = None
return
for line in open ( filename, "r" ):
if line . startswith ( '#' ):
continue
values = line . split()
if not values:
continue
if values[ 0 ] == 'newmtl' :
mtl = contents [ values[ 1 ]] = {}
elif mtl is None:
raise ValueError ( "mtl file doesn't start with newmtl stmt" )
mtl[ values[ 0 ]] = values[ 1 :]
return contents