Shader Storage Buffer (SSBO): Declares a structured storage buffer for compute and storage.

Transpiled to Vulkan GLSL layout(std430, set = X, binding = Y) buffer ....

Options:

• set: Vulkan descriptor set index (default: 0).
• binding: Vulkan descriptor binding slot index (default: 0).
• std: Memory layout standard ("std430" or "std140", default: "std430").
• restrict: Informs compiler that memory does not alias other pointers.
• readonly: Marks the buffer as read-only for hardware caching optimizations.

Example:

buffer ParticleBuffer, set: 0, binding: 0, std: "std430" do
  particles : ParticleData[]
end

Compile-Time Constant: Declares a static compile-time constant.

Evaluated and emitted as a const expression in the target shader.

Example:

const PI = 3.14159265359_f32
const MAX_LIGHTS = 8

Alias for const.

Global Uniform: Declares a project-wide global uniform registered in Project Settings.

Global uniforms (Godot 4.x) are shared across all materials in the game simultaneously with zero CPU overhead. Useful for wind direction, player position, or time of day.

Transpiled to Godot's global uniform ....

Example:

global_uniform global_wind_dir : Vec3
global_uniform global_water_level : Float32

Image Uniform: Declares a direct read/write texture image binding for compute shaders.

Enables direct pixel access via imageLoad and imageStore.

Options:

• format: Vulkan pixel format (:rgba32f, :rgba16f, :r32f, :r32ui, default: :rgba32f).
• set: Vulkan descriptor set index (default: 0).
• binding: Vulkan descriptor binding index (default: 0).

Example:

image2d input_tex, format: :rgba32f, set: 0, binding: 0
image2d output_tex, format: :rgba32f, set: 0, binding: 1

Alias for require.

Instance Uniform: Declares a per-instance uniform stored in InstanceData.

Instance uniforms allow multiple nodes sharing the same material (e.g. MultiMeshInstance3D or multiple MeshInstance3D nodes) to have unique values without duplicating the material.

Transpiled to Godot's instance uniform ....

Example:

instance_uniform custom_tint : Color = Color.new(1.0, 1.0, 1.0, 1.0), hint: :source_color
instance_uniform instance_offset : Vec3 = vec3(0.0, 0.0, 0.0)

Push Constant Block: Declares a low-latency Vulkan push constant block.

Push constants are stored directly in GPU command registers for maximum transmission speed.

Example:

push_constant FrameUniforms do
  delta_time : Float32
  screen_size : Vec2
end

Module Inclusion: Imports standard library routines or local shader definitions.

Available Standard Library Modules:

Example:

require "std/noise"
require "std/lighting"

Workgroup Shared Memory: Declares memory shared among compute threads in a workgroup.

Accessible to all invocations in the current local workgroup. Much faster than VRAM.

Example:

shared tile_cache : UInt32[256]

Material Uniform: Declares a variable exposed to the Godot Inspector and script API.

Uniforms allow runtime scripts and material properties in the editor to pass values into the shader.

Inspector Hints & Options:

Examples:

uniform albedo : Color = Color.new(1.0, 0.5, 0.2, 1.0), hint: :source_color
uniform wave_speed : Float32 = 2.5, hint: hint_range(0.0, 10.0, 0.1)
uniform roughness : Float32 = 0.5, hint: hint_range(0.0, 1.0)
uniform base_texture : Sampler2D, filter: :linear_mipmap, repeat: :enable
uniform bone_matrices : Mat4[64] # Array uniform

Varying Variable: Declares an interpolated variable passed between shader stages.

Varying variables are calculated in the vertex processor and smoothly interpolated across polygon faces before arriving at the fragment or light processors.

Interpolation Qualifiers:

• :smooth: Standard perspective-correct interpolation (default).
• :flat: No interpolation; uses the value from the primitive's first vertex.

Example:

varying v_world_pos : Vec3
varying v_normal : Vec3, qualifier: :smooth
varying v_tile_id : Int32, qualifier: :flat

def vertex
  v_world_pos = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz
  v_normal = (MODEL_MATRIX * vec4(NORMAL, 0.0)).xyz
end

def fragment
  dist = length(v_world_pos)
end

Inspector Group: Groups subsequent uniforms under a categorized accordion section.

Example:

group "Water Dynamics"
uniform wave_height : Float32 = 0.5
uniform wave_speed : Float32 = 1.0

Workgroup Layout: Specifies compute shader local invocation workgroup size.

Transpiled to GLSL layout(local_size_x = X, local_size_y = Y, local_size_z = Z) in;.

Parameters:

• x: Number of invocations in the X dimension (default: 8).
• y: Number of invocations in the Y dimension (default: 8).
• z: Number of invocations in the Z dimension (default: 1).

Example:

shader_type :compute
local_size 16, 16, 1

Render Modes: Specifies engine pipeline flags and rendering optimizations.

Render modes tell Godot how to configure the hardware rasterizer, blend states, face culling, and depth testing before executing shader stages.

Spatial Render Modes (:spatial):

CanvasItem Render Modes (:canvas_item):

Example:

render_mode :unshaded, :cull_disabled, :depth_draw_always

Compatibility Setup: Enables standard Godot GDShader macros and compatibility helpers.

Synthesizes helper definitions allowing smooth interoperation with legacy Godot shaders.

Shader Target: Specifies the operating mode of the shader pipeline.

Godot divides shaders into distinct operational categories. Setting #shader_type selects which built-in variables are accessible and which renderer pipeline executes the code.

Supported Shader Modes:

Example:

shader_type :spatial

Inspector Subgroup: Groups subsequent uniforms under an inspector subsection.

Example:

subgroup "Foam Parameters"
uniform foam_color : Color = Color.new(1.0, 1.0, 1.0, 1.0)
uniform foam_threshold : Float32 = 0.8