"""Textures, conforming to the glTF 2.0 standards as specified in
https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#reference-texture
Author: Matthew Matl
"""
import numpy as np
from OpenGL.GL import *
from .utils import format_texture_source
from .sampler import Sampler
[docs]class Texture(object):
"""A texture and its sampler.
Parameters
----------
name : str, optional
The user-defined name of this object.
sampler : :class:`Sampler`
The sampler used by this texture.
source : (h,w,c) uint8 or (h,w,c) float or :class:`PIL.Image.Image`
The image used by this texture. If None, the texture is created
empty and width and height must be specified.
source_channels : str
Either `D`, `R`, `RG`, `GB`, `RGB`, or `RGBA`. Indicates the
channels to extract from `source`. Any missing channels will be filled
with `1.0`.
width : int, optional
For empty textures, the width of the texture buffer.
height : int, optional
For empty textures, the height of the texture buffer.
tex_type : int
Either GL_TEXTURE_2D or GL_TEXTURE_CUBE.
data_format : int
For now, just GL_FLOAT.
"""
def __init__(self,
name=None,
sampler=None,
source=None,
source_channels=None,
width=None,
height=None,
tex_type=GL_TEXTURE_2D,
data_format=GL_UNSIGNED_BYTE):
self.source_channels = source_channels
self.name = name
self.sampler = sampler
self.source = source
self.width = width
self.height = height
self.tex_type = tex_type
self.data_format = data_format
self._texid = None
self._is_transparent = False
@property
def name(self):
"""str : The user-defined name of this object.
"""
return self._name
@name.setter
def name(self, value):
if value is not None:
value = str(value)
self._name = value
@property
def sampler(self):
""":class:`Sampler` : The sampler used by this texture.
"""
return self._sampler
@sampler.setter
def sampler(self, value):
if value is None:
value = Sampler()
self._sampler = value
@property
def source(self):
"""(h,w,c) uint8 or float or :class:`PIL.Image.Image` : The image
used in this texture.
"""
return self._source
@source.setter
def source(self, value):
if value is None:
self._source = None
else:
self._source = format_texture_source(value, self.source_channels)
self._is_transparent = False
@property
def source_channels(self):
"""str : The channels that were extracted from the original source.
"""
return self._source_channels
@source_channels.setter
def source_channels(self, value):
self._source_channels = value
@property
def width(self):
"""int : The width of the texture buffer.
"""
return self._width
@width.setter
def width(self, value):
self._width = value
@property
def height(self):
"""int : The height of the texture buffer.
"""
return self._height
@height.setter
def height(self, value):
self._height = value
@property
def tex_type(self):
"""int : The type of the texture.
"""
return self._tex_type
@tex_type.setter
def tex_type(self, value):
self._tex_type = value
@property
def data_format(self):
"""int : The format of the texture data.
"""
return self._data_format
@data_format.setter
def data_format(self, value):
self._data_format = value
[docs] def is_transparent(self, cutoff=1.0):
"""bool : If True, the texture is partially transparent.
"""
if self._is_transparent is None:
self._is_transparent = False
if self.source_channels == 'RGBA' and self.source is not None:
if np.any(self.source[:,:,3] < cutoff):
self._is_transparent = True
return self._is_transparent
[docs] def delete(self):
"""Remove this texture from the OpenGL context.
"""
self._unbind()
self._remove_from_context()
##################
# OpenGL code
##################
def _add_to_context(self):
if self._texid is not None:
raise ValueError('Texture already loaded into OpenGL context')
fmt = GL_DEPTH_COMPONENT
if self.source_channels == 'R':
fmt = GL_RED
elif self.source_channels == 'RG' or self.source_channels == 'GB':
fmt = GL_RG
elif self.source_channels == 'RGB':
fmt = GL_RGB
elif self.source_channels == 'RGBA':
fmt = GL_RGBA
# Generate the OpenGL texture
self._texid = glGenTextures(1)
glBindTexture(self.tex_type, self._texid)
# Flip data for OpenGL buffer
data = None
width = self.width
height = self.height
if self.source is not None:
data = np.ascontiguousarray(np.flip(self.source, axis=0).flatten())
width = self.source.shape[1]
height = self.source.shape[0]
# Bind texture and generate mipmaps
glTexImage2D(
self.tex_type, 0, fmt, width, height, 0, fmt,
self.data_format, data
)
if self.source is not None:
glGenerateMipmap(self.tex_type)
if self.sampler.magFilter is not None:
glTexParameteri(
self.tex_type, GL_TEXTURE_MAG_FILTER, self.sampler.magFilter
)
else:
if self.source is not None:
glTexParameteri(self.tex_type, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
else:
glTexParameteri(self.tex_type, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
if self.sampler.minFilter is not None:
glTexParameteri(
self.tex_type, GL_TEXTURE_MIN_FILTER, self.sampler.minFilter
)
else:
if self.source is not None:
glTexParameteri(self.tex_type, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR)
else:
glTexParameteri(self.tex_type, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
glTexParameteri(self.tex_type, GL_TEXTURE_WRAP_S, self.sampler.wrapS)
glTexParameteri(self.tex_type, GL_TEXTURE_WRAP_T, self.sampler.wrapT)
border_color = 255 * np.ones(4).astype(np.uint8)
if self.data_format == GL_FLOAT:
border_color = np.ones(4).astype(np.float32)
glTexParameterfv(
self.tex_type, GL_TEXTURE_BORDER_COLOR,
border_color
)
# Unbind texture
glBindTexture(self.tex_type, 0)
def _remove_from_context(self):
if self._texid is not None:
# TODO OPENGL BUG?
# glDeleteTextures(1, [self._texid])
glDeleteTextures([self._texid])
self._texid = None
def _in_context(self):
return self._texid is not None
def _bind(self):
# TODO HANDLE INDEXING INTO OTHER UV's
glBindTexture(self.tex_type, self._texid)
def _unbind(self):
glBindTexture(self.tex_type, 0)
def _bind_as_depth_attachment(self):
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
self.tex_type, self._texid, 0)
def _bind_as_color_attachment(self):
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
self.tex_type, self._texid, 0)