Snippet¶

class glumpy.gloo.Snippet(code=None, default=None, *args, **kwargs)¶

Bases: object

A snippet is a piece of GLSL code that can be injected into an another GLSL code. It provides the necessary machinery to take care of name collisions, external variables and snippet composition (call, +, -, /, *).

Parameters:	code (string) – Shader code default (string) – Default function to be called if none is specified. args (list) – Arguments kwargs (dict) – Keyword arguments

A snippet can declare uniforms, const, attributes and varying using random names. However, these names will be later mangled such as to avoid name collisions with other snippets and/or main code. This means that any snippet variable must be accessed through the snippet (snippet[“variable”]) to be able to change its value within the main program.

Snippet can be composed together through call:

A = Snippet(code="...")
B = Snippet(code="...")
C = A(B("P"))

Warning

Calling a snippet does not create a new snippet but instead links it the called snippet to the calling one. In the example above, the A._call is now B.

and arithmetic composition:

A = Snippet(code="...")
B = Snippet(code="...")
C = A("P") + B("P")

args¶: Call arguments

attach(program)¶: Attach this snippet to a program

Note

Attachment is recursive and will attach all the snippets composing self.

call¶: Computes and returns the GLSL code that correspond to the call

code¶: Mangled code

copy(deep=False)¶: Shallow or deep copy of the snippet

dependencies¶

Compute all snippet dependencies.

Example:

A,B,C,D = Snippet(...), Snippet(...), Snippet(...), Snippet(...)
AB = A(B)
CD = C(D)
S = AB+CD
S.dependencies # [A,B,C,D]

detach(program)¶

Detach this snippet from a program

Parameters:	program (Program) – Program to detach this snippet from

Note

Detachment is recursive and will detach all the snippets composing self.

globals¶: Global string symbols generated from all the codes composing this snippet, taking into account symbols from arguments (call) and next (operators).

is_attached¶: Whether snippet is attached to one or several programs.

last¶

Get last snippet in the arithmetic chain

Example:

A,B,C = Snippet(...), Snippet(...), Snippet(...)
D = A(B) + C
D.last # C

locals¶: Local table of symbols defined from the code of this snippet only, not taking into account symbols from arguments (call) or next (operators).

lookup(name, deepsearch=True)¶

Search for a specific symbol.

Parameters:	name (str) – Name to be search in symbols deepsearch (bool) – Whether to restrict search to self (False) or to search into all snippets (True)

mangled_call(function=None, arguments=None, override=False)¶

Compute tGLSL code that corresponds to the actual call of the snippet

Parameters:	function (string) – Snippet’s function to be called arguments (list) – Arguments to give to the function call override (bool) – Whether to override python arguments with shader arguments

mangled_code()¶: Generate mangled code

name¶: Name of the snippet

next¶: Next snippet in the arihmetic chain.

objects¶

Objects composing this snippet only.

Object are uniforms, attributes, consts, varying and functions.

process_kwargs(**kwargs)¶: Process kwargs as given in __init__() or __call__()

programs¶: Currently attached programs

snippets¶

Get all snippets composing this snippet (including self).

Example:

A,B,C = Snippet(...), Snippet(...), Snippet(...)
D = A(B) + C
D.snippets # [A,B,C]

symbols¶: Symbol table defined as a list of (name, mangled_name).

Snippet¶

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