RDPipelineColorBlendStateAttachment

Inherits: RefCounted < Object

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

BlendOperation	alpha_blend_op	0
BlendOperation	color_blend_op	0
BlendFactor	dst_alpha_blend_factor	0
BlendFactor	dst_color_blend_factor	0
bool	enable_blend	false
BlendFactor	src_alpha_blend_factor	0
BlendFactor	src_color_blend_factor	0
bool	write_a	true
bool	write_b	true
bool	write_g	true
bool	write_r	true

Methods

void	set_as_mix\ (\ )

---

Property Descriptions

BlendOperation alpha_blend_op = 0 🔗

• void set_alpha_blend_op\ (\ value: BlendOperation\ )
• BlendOperation get_alpha_blend_op\ (\ )

The blend mode to use for the alpha channel.

---

BlendOperation color_blend_op = 0 🔗

• void set_color_blend_op\ (\ value: BlendOperation\ )
• BlendOperation get_color_blend_op\ (\ )

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

---

BlendFactor dst_alpha_blend_factor = 0 🔗

• void set_dst_alpha_blend_factor\ (\ value: BlendFactor\ )
• BlendFactor get_dst_alpha_blend_factor\ (\ )

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

---

BlendFactor dst_color_blend_factor = 0 🔗

• void set_dst_color_blend_factor\ (\ value: BlendFactor\ )
• BlendFactor get_dst_color_blend_factor\ (\ )

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

---

bool enable_blend = false 🔗

• void set_enable_blend\ (\ value: bool\ )
• bool get_enable_blend\ (\ )

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.

---

BlendFactor src_alpha_blend_factor = 0 🔗

• void set_src_alpha_blend_factor\ (\ value: BlendFactor\ )
• BlendFactor get_src_alpha_blend_factor\ (\ )

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

---

BlendFactor src_color_blend_factor = 0 🔗

• void set_src_color_blend_factor\ (\ value: BlendFactor\ )
• BlendFactor get_src_color_blend_factor\ (\ )

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

---

bool write_a = true 🔗

• void set_write_a\ (\ value: bool\ )
• bool get_write_a\ (\ )

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

---

bool write_b = true 🔗

• void set_write_b\ (\ value: bool\ )
• bool get_write_b\ (\ )

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

---

bool write_g = true 🔗

• void set_write_g\ (\ value: bool\ )
• bool get_write_g\ (\ )

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

---

bool write_r = true 🔗

• void set_write_r\ (\ value: bool\ )
• bool get_write_r\ (\ )

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

---

Method Descriptions

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.