Framebuffer#

class Framebuffer#

Returned by Context.framebuffer()

A Framebuffer is a collection of buffers that can be used as the destination for rendering.

The buffers for Framebuffer objects reference images from either Textures or Renderbuffers.

Methods#

Framebuffer.clear(red: float = 0.0, green: float = 0.0, blue: float = 0.0, alpha: float = 0.0, depth: float = 1.0, viewport=..., color=...) None#

Clear the framebuffer.

If a viewport passed in, a scissor test will be used to clear the given viewport. This viewport take presence over the framebuffers scissor. Clearing can still be done with scissor if no viewport is passed in.

This method also respects the color_mask and depth_mask. It can for example be used to only clear the depth or color buffer or specific components in the color buffer.

If the viewport is a 2-tuple it will clear the (0, 0, width, height) where (width, height) is the 2-tuple.

If the viewport is a 4-tuple it will clear the given viewport.

Parameters:
  • red (float) – color component.

  • green (float) – color component.

  • blue (float) – color component.

  • alpha (float) – alpha component.

  • depth (float) – depth value.

  • viewport (tuple) – The viewport.

  • color (tuple) – Optional tuple replacing the red, green, blue and alpha arguments

Framebuffer.read(viewport=..., components: int = 3, attachment: int = 0, alignment: int = 1, dtype: str = 'f1', clamp: bool = False) bytes#

Read the content of the framebuffer.

Parameters:
  • viewport (tuple) – The viewport.

  • components (int) – The number of components to read.

  • attachment (int) – The color attachment number. -1 for the depth attachment

  • alignment (int) – The byte alignment of the pixels.

  • dtype (str) – Data type.

  • clamp (bool) – Clamps floating point values to [0.0, 1.0]

# Read the first color attachment's RGBA data
data = fbo.read(components=4)
# Read the second color attachment's RGB data
data = fbo.read(attachment=1)
# Read the depth attachment
data = fbo.read(attachment=-1)
# Read the lower left 10 x 10 pixels from the first color attachment
data = fbo.read(viewport=(0, 0, 10, 10))
Framebuffer.read_into(buffer, viewport, components: int = 3, attachment: int = 0, alignment: int = 1, dtype: str = 'f1', write_offset: int = 0) None#

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.

Framebuffer.use()#

Bind the framebuffer.

Framebuffer.release()#

Attributes#

Framebuffer.viewport: tuple#

Get or set the viewport of the framebuffer.

Framebuffer.scissor: tuple#

Get or set the scissor box of the framebuffer.

When scissor testing is enabled fragments outside the defined scissor box will be discarded. This applies to rendered geometry or Framebuffer.clear().

Setting is value enables scissor testing in the framebuffer. Setting the scissor to None disables scissor testing and reverts the scissor box to match the framebuffer size.

Example:

# Enable scissor testing
>>> ctx.scissor = 100, 100, 200, 100
# Disable scissor testing
>>> ctx.scissor = None
Framebuffer.color_mask: tuple#

The color mask of the framebuffer.

Color masking controls what components in color attachments will be affected by fragment write operations. This includes rendering geometry and clearing the framebuffer.

Default value: (True, True, True, True).

Examples:

# Block writing to all color components (rgba) in color attachments
fbo.color_mask = False, False, False, False

# Re-enable writing to color attachments
fbo.color_mask = True, True, True, True

# Block fragment writes to alpha channel
fbo.color_mask = True, True, True, False
Framebuffer.depth_mask: bool#

The depth mask of the framebuffer.

Depth mask enables or disables write operations to the depth buffer. This also applies when clearing the framebuffer. If depth testing is enabled fragments will still be culled, but the depth buffer will not be updated with new values. This is a very useful tool in many rendering techniques.

Default value: True

Framebuffer.width: int#

The width of the framebuffer.

Framebuffers created by a window will only report its initial size. It’s better get size information from the window itself.

Framebuffer.height: int#

The height of the framebuffer.

Framebuffers created by a window will only report its initial size. It’s better get size information from the window itself.

Framebuffer.size: Tuple[int, int]#

The size of the framebuffer.

Framebuffers created by a window will only report its initial size. It’s better get size information from the window itself.

Framebuffer.samples: int#

The samples of the framebuffer.

Framebuffer.bits: int#

The bits of the framebuffer.

Framebuffer.color_attachments: tuple#
Framebuffer.depth_attachment: tuple#
Framebuffer.ctx: Context#

The context this object belongs to

Framebuffer.glo: int#

The internal OpenGL object. This values is provided for interoperability and debug purposes only.

Framebuffer.extra: Any#

User defined data.