Class reference

RDPipelineColorBlendStateAttachment

Inherits RefCounted

Pipeline color blend state attachment (used by RenderingDevice).

Description

Controls how blending between source and destination fragments is performed when using RenderingDevice. For reference, this is how common user-facing blend modes are implemented in Redot's 2D renderer: Mix:

		var attachment = RDPipelineColorBlendStateAttachment.new()
		attachment.enable_blend = true
		attachment.color_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.src_color_blend_factor = RenderingDevice.BLEND_FACTOR_SRC_ALPHA
		attachment.dst_color_blend_factor = RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA
		attachment.alpha_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.src_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE
		attachment.dst_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA

Add:

		var attachment = RDPipelineColorBlendStateAttachment.new()
		attachment.enable_blend = true
		attachment.alpha_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.color_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.src_color_blend_factor = RenderingDevice.BLEND_FACTOR_SRC_ALPHA
		attachment.dst_color_blend_factor = RenderingDevice.BLEND_FACTOR_ONE
		attachment.src_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_SRC_ALPHA
		attachment.dst_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE

Subtract:

		var attachment = RDPipelineColorBlendStateAttachment.new()
		attachment.enable_blend = true
		attachment.alpha_blend_op = RenderingDevice.BLEND_OP_REVERSE_SUBTRACT
		attachment.color_blend_op = RenderingDevice.BLEND_OP_REVERSE_SUBTRACT
		attachment.src_color_blend_factor = RenderingDevice.BLEND_FACTOR_SRC_ALPHA
		attachment.dst_color_blend_factor = RenderingDevice.BLEND_FACTOR_ONE
		attachment.src_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_SRC_ALPHA
		attachment.dst_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE

Multiply:

		var attachment = RDPipelineColorBlendStateAttachment.new()
		attachment.enable_blend = true
		attachment.alpha_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.color_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.src_color_blend_factor = RenderingDevice.BLEND_FACTOR_DST_COLOR
		attachment.dst_color_blend_factor = RenderingDevice.BLEND_FACTOR_ZERO
		attachment.src_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_DST_ALPHA
		attachment.dst_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ZERO

Pre-multiplied alpha:

		var attachment = RDPipelineColorBlendStateAttachment.new()
		attachment.enable_blend = true
		attachment.alpha_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.color_blend_op = RenderingDevice.BLEND_OP_ADD
		attachment.src_color_blend_factor = RenderingDevice.BLEND_FACTOR_ONE
		attachment.dst_color_blend_factor = RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA
		attachment.src_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE
		attachment.dst_alpha_blend_factor = RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA

Properties

`int alpha_blend_op = 0`

The blend mode to use for the alpha channel.

`int color_blend_op = 0`

The blend mode to use for the red/green/blue color channels.

`int dst_alpha_blend_factor = 0`

Controls how the blend factor for the alpha channel is determined based on the destination's fragments.

`int dst_color_blend_factor = 0`

Controls how the blend factor for the color channels is determined based on the destination's fragments.

`bool enable_blend = false`

If true, performs blending between the source and destination according to the factors defined in src_color_blend_factor, dst_color_blend_factor, src_alpha_blend_factor and dst_alpha_blend_factor. The blend modes color_blend_op and alpha_blend_op are also taken into account, with write_r, write_g, write_b and write_a controlling the output.

`int src_alpha_blend_factor = 0`

Controls how the blend factor for the alpha channel is determined based on the source's fragments.

`int src_color_blend_factor = 0`

Controls how the blend factor for the color channels is determined based on the source's fragments.

`bool write_a = true`

If true, writes the new alpha channel to the final result.

`bool write_b = true`

If true, writes the new blue color channel to the final result.

`bool write_g = true`

If true, writes the new green color channel to the final result.

`bool write_r = true`

If true, writes the new red color channel to the final result.

Methods

`void set_as_mix()`

Convenience method to perform standard mix blending with straight (non-premultiplied) alpha. This sets enable_blend to true, src_color_blend_factor to RenderingDevice.BLEND_FACTOR_SRC_ALPHA, dst_color_blend_factor to RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA, src_alpha_blend_factor to RenderingDevice.BLEND_FACTOR_SRC_ALPHA and dst_alpha_blend_factor to RenderingDevice.BLEND_FACTOR_ONE_MINUS_SRC_ALPHA.

Source revision 4f5b14abade2