#include <eevee_gbuffer.hh>

Public Member Functions
void	acquire (int2 extent, int data_count, int normal_count)
void	bind (Framebuffer &gbuffer_fb)
void	release ()
template<typename PassType>
void	bind_resources (PassType &pass)

Public Attributes
Texture	header_tx = {"GBufferHeader"}
Texture	closure_tx = {"GBufferClosure"}
Texture	normal_tx = {"GBufferNormal"}
GPUTexture *	closure_img_tx = nullptr
GPUTexture *	normal_img_tx = nullptr

Detailed Description

Full-screen textures containing geometric and surface data. Used by deferred shading passes. Only one g-buffer is allocated per view and is reused for each deferred layer. This is why there can only be temporary texture inside it.

Everything is stored inside two array texture, one for each format. This is to fit the limitation of the number of images we can bind on a single shader.

The content of the g-buffer is polymorphic. A 8bit header specify the layout of the data. The first layer is always written to while others are written only if needed using imageStore operations reducing the bandwidth needed. Except for some special configurations, the g-buffer holds up to 3 closures.

For each output closure, we also output the color to apply after the lighting computation. The color is stored with a 2 exponent that allows input color with component higher than 1. Color degradation is expected to happen in this case.

Here are special configurations:

Opaque Dielectric:
- 1 Diffuse lobe and 1 Reflection lobe without anisotropy.
- Share a single normal.
- Reflection is not colored.
- Layout:
  - Color 1 : Diffuse color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Roughness (isotropic)
  - Closure 1 A : Reflection intensity
Simple Car-paint: (TODO)
- 2 Reflection lobe without anisotropy.
- Share a single normal.
- Coat layer is not colored.
- Layout:
  - Color 1 : Bottom layer color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Roughness (isotropic)
  - Closure 1 A : Coat layer intensity
Simple Glass: (TODO)
- 1 Refraction lobe and 1 Reflection lobe without anisotropy.
- Share a single normal.
- Reflection intensity is derived from IOR.
- Layout:
  - Color 1 : Refraction color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Roughness (isotropic)
  - Closure 1 A : IOR

Here are Closure configurations:

Reflection (Isotropic):
- Layout:
  - Color : Reflection color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Roughness
  - Closure 1 A : Unused
Reflection (Anisotropic): (TODO)
- Layout:
  - Color : Reflection color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Tangent packed X
  - Closure 1 A : Tangent packed Y
  - Closure 2 R : Roughness X
  - Closure 2 G : Roughness Y
  - Closure 2 B : Unused
  - Closure 2 A : Unused
Refraction (Isotropic):
- Layout:
  - Color : Refraction color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Roughness
  - Closure 1 A : IOR
Diffuse:
- Layout:
  - Color : Diffuse color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Unused
  - Closure 1 A : Unused (Could be used for diffuse roughness)
Sub-Surface Scattering:
- Layout:
  - Color : Diffuse color
  - Closure 1 R : Normal packed X
  - Closure 1 G : Normal packed Y
  - Closure 1 B : Thickness
  - Closure 1 A : Unused (Could be used for diffuse roughness)
  - Closure 2 R : Scattering radius R
  - Closure 2 G : Scattering radius G
  - Closure 2 B : Scattering radius B
  - Closure 2 A : Object ID
contains persistent data.