FBO

demosys.opengl.FBO

A framebuffer object is a collection of buffers that can be used as the destination for rendering. The buffers for framebuffer objects reference images from either textures.

A typical FBO has one or multiple color layers and a depth. Shaders can write to these buffers when activated.

Create

static FBO.create(size, components=4, depth=False, dtype='f1', layers=1) → FBO

Create a single or multi layer FBO

Parameters:
  • size – (tuple) with and height
  • components – (tuple) number of components. 1, 2, 3, 4
  • depth – (bool) Create a depth attachment
  • dtype – (string) data type per r, g, b, a …
  • layers – (int) number of color attachments
Returns:

A new FBO
static FBO.create_from_textures(color_buffers:List[Texture2D], depth_buffer:DepthTexture=None) → FBO

Create FBO from existing textures

Parameters:
  • color_buffers – List of textures
  • depth_buffer – Depth texture
Returns:

A new FBO

Methods

FBO.use(stack=True)

Bind FBO adding it to the stack. Optionally a context manager can be used:

optonally a context manager can be used:

with fbo:
    # draw stuff
Parameters:stack – (bool) If the bind should push the current FBO on the stack.
FBO.release(stack=True)

Bind FBO popping it from the stack

Parameters:stack – (bool) If the bind should be popped form the FBO stack.
FBO.clear(red=0.0, green=0.0, blue=0.0, alpha=0.0, depth=1.0)

Clears all FBO layers including depth

FBO.draw_color_layer(layer=0, pos=(0.0, 0.0), scale=(1.0, 1.0))

Draw a color layer in the FBO.

Parameters:
  • layer – Layer ID
  • pos – (tuple) offset x, y
  • scale – (tuple) scale x, y
FBO.draw_depth(near, far, pos=(0.0, 0.0), scale=(1.0, 1.0))

Draw a depth buffer in the FBO.

Parameters:
  • near – projection near.
  • far – projection far.
  • pos – (tuple) offset x, y
  • scale – (tuple) scale x, y
FBO.read(viewport=None, components=3, attachment=0, alignment=1, dtype='f1') → bytes

Read the content of the framebuffer.

Parameters:
  • viewport – (tuple) The viewport
  • components – The number of components to read.
  • attachment – The color attachment
  • alignment – The byte alignment of the pixels
  • dtype – (str) dtype
FBO.read_into(buffer, viewport=None, components=3, attachment=0, alignment=1, dtype='f1', write_offset=0)

Read the content of the framebuffer into a buffer.

Parameters:
  • buffer – (bytearray) The buffer that will receive the pixels.
  • viewport – (tuple) The viewport.
  • components – (int) The number of components to read.
  • attachment – (int) The color attachment.
  • alignment – (int) The byte alignment of the pixels.
  • dtype – (str) Data type.
  • write_offset – (int) The write offset.

Attributes

FBO.size

(w, h) tuple representing the size in pixels

FBO.samples

int: The samples of the framebuffer.

FBO.viewport

tuple: The viewport of the framebuffer.

FBO.color_mask

tuple[bool, bool, bool, bool]: The color mask of the framebuffer.

FBO.depth_mask

bool: The depth mask of the framebuffer.

FBO.mglo

Internal ModernGL fbo