import enum
import importlib
from OpenGL import GL
import numpy as np
from ...Qt import QtGui, QT_LIB
from .. import shaders
from ..GLGraphicsItem import GLGraphicsItem
from ..MeshData import MeshData
if QT_LIB in ["PyQt5", "PySide2"]:
QtOpenGL = QtGui
else:
QtOpenGL = importlib.import_module(f"{QT_LIB}.QtOpenGL")
__all__ = ['GLMeshItem']
class DirtyFlag(enum.Flag):
POSITION = enum.auto()
NORMAL = enum.auto()
COLOR = enum.auto()
FACES = enum.auto()
EDGE_VERTS = enum.auto()
EDGES = enum.auto()
[docs]
class GLMeshItem(GLGraphicsItem):
"""
**Bases:** :class:`GLGraphicsItem <pyqtgraph.opengl.GLGraphicsItem.GLGraphicsItem>`
Displays a 3D triangle mesh.
"""
[docs]
def __init__(self, parentItem=None, **kwds):
"""
============== =====================================================
**Arguments:**
meshdata MeshData object from which to determine geometry for
this item.
color Default face color used if no vertex or face colors
are specified.
edgeColor Default edge color to use if no edge colors are
specified in the mesh data.
drawEdges If True, a wireframe mesh will be drawn.
(default=False)
drawFaces If True, mesh faces are drawn. (default=True)
shader Name of shader program to use when drawing faces.
(None for no shader)
smooth If True, normal vectors are computed for each vertex
and interpolated within each face.
computeNormals If False, then computation of normal vectors is
disabled. This can provide a performance boost for
meshes that do not make use of normals.
============== =====================================================
"""
self.opts = {
'meshdata': None,
'color': (1., 1., 1., 1.),
'drawEdges': False,
'drawFaces': True,
'edgeColor': (0.5, 0.5, 0.5, 1.0),
'shader': None,
'smooth': True,
'computeNormals': True,
}
super().__init__(parentItem=parentItem)
glopts = kwds.pop('glOptions', 'opaque')
self.setGLOptions(glopts)
shader = kwds.pop('shader', None)
self.setShader(shader)
self.setMeshData(**kwds)
## storage for data compiled from MeshData object
self.vertexes = None
self.normals = None
self.colors = None
self.faces = None
self.m_vbo_position = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.VertexBuffer)
self.m_vbo_normal = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.VertexBuffer)
self.m_vbo_color = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.VertexBuffer)
self.m_ibo_faces = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.IndexBuffer)
self.m_vbo_edgeVerts = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.VertexBuffer)
self.m_ibo_edges = QtOpenGL.QOpenGLBuffer(QtOpenGL.QOpenGLBuffer.Type.IndexBuffer)
[docs]
def setShader(self, shader):
"""Set the shader used when rendering faces in the mesh. (see the GL shaders example)"""
self.opts['shader'] = shader
self.update()
def shader(self):
shader = self.opts['shader']
if isinstance(shader, shaders.ShaderProgram):
return shader
else:
return shaders.getShaderProgram(shader)
[docs]
def setColor(self, c):
"""Set the default color to use when no vertex or face colors are specified."""
self.opts['color'] = c
self.update()
[docs]
def setMeshData(self, **kwds):
"""
Set mesh data for this item. This can be invoked two ways:
1. Specify *meshdata* argument with a new MeshData object
2. Specify keyword arguments to be passed to MeshData(..) to create a new instance.
"""
md = kwds.get('meshdata', None)
if md is None:
opts = {}
for k in ['vertexes', 'faces', 'edges', 'vertexColors', 'faceColors']:
try:
opts[k] = kwds.pop(k)
except KeyError:
pass
md = MeshData(**opts)
self.opts['meshdata'] = md
self.opts.update(kwds)
self.meshDataChanged()
self.update()
[docs]
def meshDataChanged(self):
"""
This method must be called to inform the item that the MeshData object
has been altered.
"""
self.vertexes = None
self.faces = None
self.normals = None
self.colors = None
self.edges = None
self.edgeVerts = None
self.edgeColors = None
self.update()
def upload_vertex_buffers(self, dirty_bits):
def upload_vbo(vbo, arr):
if arr is None:
vbo.destroy()
return
if not vbo.isCreated():
vbo.create()
vbo.bind()
if vbo.size() != arr.nbytes:
vbo.allocate(arr, arr.nbytes)
else:
vbo.write(0, arr, arr.nbytes)
vbo.release()
if DirtyFlag.POSITION in dirty_bits:
upload_vbo(self.m_vbo_position, self.vertexes)
if DirtyFlag.NORMAL in dirty_bits:
upload_vbo(self.m_vbo_normal, self.normals)
if DirtyFlag.COLOR in dirty_bits:
upload_vbo(self.m_vbo_color, self.colors)
if DirtyFlag.FACES in dirty_bits:
upload_vbo(self.m_ibo_faces, self.faces)
if DirtyFlag.EDGE_VERTS in dirty_bits:
upload_vbo(self.m_vbo_edgeVerts, self.edgeVerts)
if DirtyFlag.EDGES in dirty_bits:
upload_vbo(self.m_ibo_edges, self.edges)
def parseMeshData(self) -> DirtyFlag:
## interpret vertex / normal data before drawing
dirty_bits = DirtyFlag(0)
# self.vertexes acts as a flag to determine whether mesh data
# has been parsed
if self.vertexes is not None:
return dirty_bits
if self.opts['meshdata'] is not None:
md = self.opts['meshdata']
if self.opts['smooth'] and not md.hasFaceIndexedData():
self.vertexes = md.vertexes()
dirty_bits |= DirtyFlag.POSITION
if self.opts['computeNormals']:
self.normals = md.vertexNormals()
dirty_bits |= DirtyFlag.NORMAL
self.faces = md.faces().astype(np.uint32)
dirty_bits |= DirtyFlag.FACES
if md.hasVertexColor():
self.colors = md.vertexColors()
dirty_bits |= DirtyFlag.COLOR
elif md.hasFaceColor():
self.colors = md.faceColors()
dirty_bits |= DirtyFlag.COLOR
else:
self.vertexes = md.vertexes(indexed='faces')
dirty_bits |= DirtyFlag.POSITION
if self.opts['computeNormals']:
if self.opts['smooth']:
self.normals = md.vertexNormals(indexed='faces')
else:
self.normals = md.faceNormals(indexed='faces')
dirty_bits |= DirtyFlag.NORMAL
self.faces = None
if md.hasVertexColor():
self.colors = md.vertexColors(indexed='faces')
dirty_bits |= DirtyFlag.COLOR
elif md.hasFaceColor():
self.colors = md.faceColors(indexed='faces')
dirty_bits |= DirtyFlag.COLOR
if self.opts['drawEdges']:
if not md.hasFaceIndexedData():
self.edges = md.edges().astype(np.uint32)
self.edgeVerts = md.vertexes()
else:
self.edges = md.edges().astype(np.uint32)
self.edgeVerts = md.vertexes(indexed='faces')
dirty_bits |= DirtyFlag.EDGE_VERTS
dirty_bits |= DirtyFlag.EDGES
# NOTE: it is possible for self.vertexes to be None at this point.
# this situation is encountered with the bundled animated
# GLSurfacePlot example. This occurs because it only sets the
# z component within update().
return dirty_bits
def paint(self):
self.setupGLState()
if (dirty_bits := self.parseMeshData()):
self.upload_vertex_buffers(dirty_bits)
mat_mvp = self.mvpMatrix()
mat_mvp = np.array(mat_mvp.data(), dtype=np.float32)
mat_normal = self.modelViewMatrix().normalMatrix()
mat_normal = np.array(mat_normal.data(), dtype=np.float32)
context = QtGui.QOpenGLContext.currentContext()
es2_compat = context.hasExtension(b'GL_ARB_ES2_compatibility')
if self.opts['drawFaces'] and self.vertexes is not None:
shader = self.shader()
program = shader.program(es2_compat=es2_compat)
enabled_locs = []
if (loc := GL.glGetAttribLocation(program, "a_position")) != -1:
self.m_vbo_position.bind()
GL.glVertexAttribPointer(loc, 3, GL.GL_FLOAT, False, 0, None)
self.m_vbo_position.release()
enabled_locs.append(loc)
if (loc := GL.glGetAttribLocation(program, "a_normal")) != -1:
if self.normals is None:
# the shader needs a normal but the user set computeNormals=False...
GL.glVertexAttrib3f(loc, 0, 0, 1)
else:
self.m_vbo_normal.bind()
GL.glVertexAttribPointer(loc, 3, GL.GL_FLOAT, False, 0, None)
self.m_vbo_normal.release()
enabled_locs.append(loc)
if (loc := GL.glGetAttribLocation(program, "a_color")) != -1:
if self.colors is None:
color = self.opts['color']
if isinstance(color, QtGui.QColor):
color = color.getRgbF()
GL.glVertexAttrib4f(loc, *color)
else:
self.m_vbo_color.bind()
if self.colors.dtype == np.uint8:
GL.glVertexAttribPointer(loc, 4, GL.GL_UNSIGNED_BYTE, True, 0, None)
else:
GL.glVertexAttribPointer(loc, 4, GL.GL_FLOAT, False, 0, None)
self.m_vbo_color.release()
enabled_locs.append(loc)
for loc in enabled_locs:
GL.glEnableVertexAttribArray(loc)
with shader: # "with shader" will load extra uniforms
loc = GL.glGetUniformLocation(program, "u_mvp")
GL.glUniformMatrix4fv(loc, 1, False, mat_mvp)
if (uloc_normal := GL.glGetUniformLocation(program, "u_normal")) != -1:
GL.glUniformMatrix3fv(uloc_normal, 1, False, mat_normal)
if (faces := self.faces) is None:
GL.glDrawArrays(GL.GL_TRIANGLES, 0, np.prod(self.vertexes.shape[:-1]))
else:
self.m_ibo_faces.bind()
GL.glDrawElements(GL.GL_TRIANGLES, faces.size, GL.GL_UNSIGNED_INT, None)
self.m_ibo_faces.release()
for loc in enabled_locs:
GL.glDisableVertexAttribArray(loc)
if self.opts['drawEdges']:
shader = shaders.getShaderProgram(None)
program = shader.program(es2_compat=es2_compat)
enabled_locs = []
if (loc := GL.glGetAttribLocation(program, "a_position")) != -1:
self.m_vbo_edgeVerts.bind()
GL.glVertexAttribPointer(loc, 3, GL.GL_FLOAT, False, 0, None)
self.m_vbo_edgeVerts.release()
enabled_locs.append(loc)
# edge colors are always just one single color
if (loc := GL.glGetAttribLocation(program, "a_color")) != -1:
color = self.opts['edgeColor']
if isinstance(color, QtGui.QColor):
color = color.getRgbF()
GL.glVertexAttrib4f(loc, *color)
for loc in enabled_locs:
GL.glEnableVertexAttribArray(loc)
with program:
loc = GL.glGetUniformLocation(program, "u_mvp")
GL.glUniformMatrix4fv(loc, 1, False, mat_mvp)
self.m_ibo_edges.bind()
GL.glDrawElements(GL.GL_LINES, self.edges.size, GL.GL_UNSIGNED_INT, None)
self.m_ibo_edges.release()
for loc in enabled_locs:
GL.glDisableVertexAttribArray(loc)
