impeller::ColorAttachmentDescriptor Struct Reference

Describe the color attachment that will be used with this pipeline. More...

#include <formats.h>

Public Member Functions
constexpr bool	operator== (const ColorAttachmentDescriptor &o) const
constexpr size_t	Hash () const

Public Attributes
PixelFormat	format = PixelFormat::kUnknown
bool	blending_enabled = false
BlendFactor	src_color_blend_factor = BlendFactor::kSourceAlpha
BlendOperation	color_blend_op = BlendOperation::kAdd
BlendFactor	dst_color_blend_factor = BlendFactor::kOneMinusSourceAlpha
BlendFactor	src_alpha_blend_factor = BlendFactor::kSourceAlpha
BlendOperation	alpha_blend_op = BlendOperation::kAdd
BlendFactor	dst_alpha_blend_factor = BlendFactor::kOneMinusSourceAlpha
ColorWriteMask	write_mask = ColorWriteMaskBits::kAll

Detailed Description

Describe the color attachment that will be used with this pipeline.

Blending at specific color attachments follows the pseudo-code:

if (blending_enabled) {
  final_color.rgb = (src_color_blend_factor * new_color.rgb)
                            <color_blend_op>
                    (dst_color_blend_factor * old_color.rgb);
  final_color.a = (src_alpha_blend_factor * new_color.a)
                            <alpha_blend_op>
                    (dst_alpha_blend_factor * old_color.a);
} else {
  final_color = new_color;
}
// IMPORTANT: The write mask is applied irrespective of whether
//            blending_enabled is set.
final_color = final_color & write_mask;

The default blend mode is 1 - source alpha.

Definition at line 512 of file formats.h.

Member Function Documentation

Hash()

constexpr size_t impeller::ColorAttachmentDescriptor::Hash ( ) const

inlineconstexpr

Definition at line 538 of file formats.h.

                                {
    return fml::HashCombine(
        format, blending_enabled, src_color_blend_factor, color_blend_op,
        dst_color_blend_factor, src_alpha_blend_factor, alpha_blend_op,
        dst_alpha_blend_factor, static_cast<uint64_t>(write_mask));
  }

operator==()

constexpr bool impeller::ColorAttachmentDescriptor::operator== ( const ColorAttachmentDescriptor &  o ) const

inlineconstexpr

Definition at line 526 of file formats.h.

                                                                      {
    return format == o.format &&                                  //
           blending_enabled == o.blending_enabled &&              //
           src_color_blend_factor == o.src_color_blend_factor &&  //
           color_blend_op == o.color_blend_op &&                  //
           dst_color_blend_factor == o.dst_color_blend_factor &&  //
           src_alpha_blend_factor == o.src_alpha_blend_factor &&  //
           alpha_blend_op == o.alpha_blend_op &&                  //
           dst_alpha_blend_factor == o.dst_alpha_blend_factor &&  //
           write_mask == o.write_mask;
  }

Member Data Documentation

alpha_blend_op

BlendOperation impeller::ColorAttachmentDescriptor::alpha_blend_op = BlendOperation::kAdd

Definition at line 521 of file formats.h.

blending_enabled

bool impeller::ColorAttachmentDescriptor::blending_enabled = false

Definition at line 514 of file formats.h.

color_blend_op

BlendOperation impeller::ColorAttachmentDescriptor::color_blend_op = BlendOperation::kAdd

Definition at line 517 of file formats.h.

dst_alpha_blend_factor

BlendFactor impeller::ColorAttachmentDescriptor::dst_alpha_blend_factor = BlendFactor::kOneMinusSourceAlpha

Definition at line 522 of file formats.h.

dst_color_blend_factor

BlendFactor impeller::ColorAttachmentDescriptor::dst_color_blend_factor = BlendFactor::kOneMinusSourceAlpha

Definition at line 518 of file formats.h.

format

PixelFormat impeller::ColorAttachmentDescriptor::format = PixelFormat::kUnknown

Definition at line 513 of file formats.h.

src_alpha_blend_factor

BlendFactor impeller::ColorAttachmentDescriptor::src_alpha_blend_factor = BlendFactor::kSourceAlpha

Definition at line 520 of file formats.h.

src_color_blend_factor

BlendFactor impeller::ColorAttachmentDescriptor::src_color_blend_factor = BlendFactor::kSourceAlpha

Definition at line 516 of file formats.h.

write_mask

ColorWriteMask impeller::ColorAttachmentDescriptor::write_mask = ColorWriteMaskBits::kAll

Definition at line 524 of file formats.h.

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The documentation for this struct was generated from the following file:

• impeller/core/formats.h