Class: SFML::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/sfml/window/context.rb

Overview

Headless OpenGL context — for compiling shaders, generating textures, or doing GL work without a window. SFML attaches the context to whichever thread constructed it.

ctx = SFML::Context.new
ctx.active = true
# … raw GL work / shader compile …
ctx.active = false

CSFML always returns a non-NULL context on creation (it falls back to a pbuffer / EGL surface if no display is available), so the constructor doesn’t raise.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Context

Returns a new instance of Context.

Raises:



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# File 'lib/sfml/window/context.rb', line 15

def initialize
  ptr = C::Window.sfContext_create
  raise Error, "sfContext_create returned NULL" if ptr.null?
  @handle = FFI::AutoPointer.new(ptr, C::Window.method(:sfContext_destroy))
end

Instance Attribute Details

#handle ⇒ Object (readonly)

:nodoc:



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# File 'lib/sfml/window/context.rb', line 54

def handle
  @handle
end

Class Method Details

.active_context_id ⇒ Object

ID of the context currently active on this thread, or 0 if none. Useful for “am I in the GL context I expect?” assertions.



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# File 'lib/sfml/window/context.rb', line 37

def self.active_context_id
  C::Window.sfContext_getActiveContextId
end

.extension_available?(extension_name) ⇒ Boolean

Is ‘extension_name` (e.g. “GL_ARB_compute_shader”) supported by the active context?

Returns:

  • (Boolean) 


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# File 'lib/sfml/window/context.rb', line 43

def self.extension_available?(extension_name)
  C::Window.sfContext_isExtensionAvailable(extension_name.to_s)
end

.gl_function(name) ⇒ Object

Look up a raw GL function pointer by name. Useful when interoping with a GL extension that SFML doesn’t wrap. Returns an FFI::Pointer (nil pointer if the function isn’t loaded).



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# File 'lib/sfml/window/context.rb', line 50

def self.gl_function(name)
  C::Window.sfContext_getFunction(name.to_s)
end

Instance Method Details

#active=(value) ⇒ Object

Activate / deactivate this context on the current thread. Only one context can be current per thread; setting another active implicitly deactivates this one.



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# File 'lib/sfml/window/context.rb', line 24

def active=(value)
  C::Window.sfContext_setActive(@handle, !!value)
end

#settings ⇒ Object

The settings the GL driver actually granted (might differ from what you asked for if the driver couldn’t meet every constraint).



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# File 'lib/sfml/window/context.rb', line 31

def settings
  ContextSettings.from_native(C::Window.sfContext_getSettings(@handle))
end