Difficult-Rocket/libs/pyglet/graphics/vertexattribute.py
2022-03-05 23:10:18 +08:00

149 lines
5.2 KiB
Python

# ----------------------------------------------------------------------------
# pyglet
# Copyright (c) 2006-2008 Alex Holkner
# Copyright (c) 2008-2021 pyglet contributors
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
# * Neither the name of pyglet nor the names of its
# contributors may be used to endorse or promote products
# derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# ----------------------------------------------------------------------------
import ctypes
from pyglet.gl import *
_c_types = {
GL_BYTE: ctypes.c_byte,
GL_UNSIGNED_BYTE: ctypes.c_ubyte,
GL_SHORT: ctypes.c_short,
GL_UNSIGNED_SHORT: ctypes.c_ushort,
GL_INT: ctypes.c_int,
GL_UNSIGNED_INT: ctypes.c_uint,
GL_FLOAT: ctypes.c_float,
GL_DOUBLE: ctypes.c_double,
}
class VertexAttribute:
"""Abstract accessor for an attribute in a mapped buffer."""
def __init__(self, name, location, count, gl_type, normalize):
"""Create the attribute accessor.
:Parameters:
`name` : str
Name of the vertex attribute.
`location` : int
Location (index) of the vertex attribute.
`count` : int
Number of components in the attribute.
`gl_type` : int
OpenGL type enumerant; for example, ``GL_FLOAT``
`normalize`: bool
True if OpenGL should normalize the values
"""
self.name = name
self.location = location
self.count = count
self.gl_type = gl_type
self.c_type = _c_types[gl_type]
self.normalize = normalize
self.align = ctypes.sizeof(self.c_type)
self.size = count * self.align
self.stride = self.size
def enable(self):
"""Enable the attribute."""
glEnableVertexAttribArray(self.location)
def set_pointer(self, pointer):
"""Setup this attribute to point to the currently bound buffer at
the given offset.
``offset`` should be based on the currently bound buffer's ``ptr``
member.
:Parameters:
`offset` : int
Pointer offset to the currently bound buffer for this
attribute.
"""
glVertexAttribPointer(self.location, self.count, self.gl_type, self.normalize, self.stride, pointer)
def get_region(self, buffer, start, count):
"""Map a buffer region using this attribute as an accessor.
The returned region consists of a contiguous array of component
data elements. For example, if this attribute uses 3 floats per
vertex, and the `count` parameter is 4, the number of floats mapped
will be ``3 * 4 = 12``.
:Parameters:
`buffer` : `AbstractMappable`
The buffer to map.
`start` : int
Offset of the first vertex to map.
`count` : int
Number of vertices to map
:rtype: `AbstractBufferRegion`
"""
byte_start = self.stride * start
byte_size = self.stride * count
array_count = self.count * count
ptr_type = ctypes.POINTER(self.c_type * array_count)
return buffer.get_region(byte_start, byte_size, ptr_type)
def set_region(self, buffer, start, count, data):
"""Set the data over a region of the buffer.
:Parameters:
`buffer` : AbstractMappable`
The buffer to modify.
`start` : int
Offset of the first vertex to set.
`count` : int
Number of vertices to set.
`data` : sequence
Sequence of data components.
"""
byte_start = self.stride * start
byte_size = self.stride * count
array_count = self.count * count
data = (self.c_type * array_count)(*data)
buffer.set_data_region(data, byte_start, byte_size)
def __repr__(self):
return f"VertexAttribute(name='{self.name}', location={self.location}, count={self.count})"