def link_shader_program(vertex_shader, fragment_shader):
program = gl.glCreateProgram()
gl.glAttachShader(program, vertex_shader)
gl.glAttachShader(program, fragment_shader)
gl.glLinkProgram(program)
result = gl.glGetProgramiv(program, gl.GL_LINK_STATUS)
if not (result):
raise RuntimeError(gl.glGetProgramInfoLog(program))
return program
def _update(self):
""" Called when the object is activated and the _need_update
flag is set
"""
# Check if we have something to link
if not self._verts:
raise ProgramError("No vertex shader has been given")
if not self._frags:
raise ProgramError("No fragment shader has been given")
# Detach any attached shaders
attached = gl.glGetAttachedShaders(self._handle)
for handle in attached:
gl.glDetachShader(self._handle, handle)
# Attach and activate vertex and fragment shaders
for shader in self.shaders:
shader.activate()
gl.glAttachShader(self._handle, shader.handle)
# Only proceed if all shaders compiled ok
oks = [shader._valid for shader in self.shaders]
if not (oks and all(oks)):
raise ProgramErrorr('Shaders did not compile.')
# Link the program
# todo: should there be a try-except around this?
gl.glLinkProgram(self._handle)
if not gl.glGetProgramiv(self._handle, gl.GL_LINK_STATUS):
errors = gl.glGetProgramInfoLog(self._handle)
print(errors)
#parse_shader_errors(errors)
raise ProgramError('Linking error')
# Mark all active attributes and uniforms
self._mark_active_attributes()
self._mark_active_uniforms()