From 784576c3fc974e33fa5625858343652af66c9e80 Mon Sep 17 00:00:00 2001
From: Rob Kelly <contact@robkel.ly>
Date: Fri, 29 Aug 2025 16:04:56 -0600
Subject: [PATCH] Compute shader experiments

---
 .../compute_shader_sandbox.gd                 | 74 +++++++++++++++++++
 .../compute_shader_sandbox.gd.uid             |  1 +
 .../compute_shader_sandbox.tscn               |  8 ++
 .../compute_shader_sandbox/compute_sum.glsl   | 19 +++++
 .../compute_sum.glsl.import                   | 14 ++++
 5 files changed, 116 insertions(+)
 create mode 100644 utilities/compute_shader_sandbox/compute_shader_sandbox.gd
 create mode 100644 utilities/compute_shader_sandbox/compute_shader_sandbox.gd.uid
 create mode 100644 utilities/compute_shader_sandbox/compute_shader_sandbox.tscn
 create mode 100644 utilities/compute_shader_sandbox/compute_sum.glsl
 create mode 100644 utilities/compute_shader_sandbox/compute_sum.glsl.import

diff --git a/utilities/compute_shader_sandbox/compute_shader_sandbox.gd b/utilities/compute_shader_sandbox/compute_shader_sandbox.gd
new file mode 100644
index 0000000..36c6f5e
--- /dev/null
+++ b/utilities/compute_shader_sandbox/compute_shader_sandbox.gd
@@ -0,0 +1,74 @@
+extends Node
+
+@export var mask_texture: Texture2D
+
+var shader: RID
+var pipeline: RID
+var output_buffer: PackedByteArray
+
+var output_uniform: RDUniform
+var texture_uniform: RDUniform
+
+
+func _ready() -> void:
+	RenderingServer.call_on_render_thread(init_compute_shader)
+
+
+func init_compute_shader() -> void:
+	# Rendering device handle
+	var rd := RenderingServer.get_rendering_device()
+	# Load shader
+	var shader_file: RDShaderFile = load("res://utilities/compute_shader_sandbox/compute_sum.glsl")
+	# Compile shader
+	shader = rd.shader_create_from_spirv(shader_file.get_spirv())
+	# Create pipeline
+	pipeline = rd.compute_pipeline_create(shader)
+
+	# Build output buffer uniform
+	output_buffer = PackedInt32Array([0]).to_byte_array()
+	var storage_buffer := rd.storage_buffer_create(output_buffer.size(), output_buffer)
+	output_uniform = RDUniform.new()
+	output_uniform.uniform_type = RenderingDevice.UNIFORM_TYPE_STORAGE_BUFFER
+	output_uniform.binding = 0
+	output_uniform.add_id(storage_buffer)
+
+	# Build texture uniform
+	texture_uniform = RDUniform.new()
+	texture_uniform.uniform_type = RenderingDevice.UNIFORM_TYPE_IMAGE
+	texture_uniform.binding = 1
+
+	var tex_view := RDTextureView.new()
+	var tex_fmt := RDTextureFormat.new()
+	tex_fmt.width = 64
+	tex_fmt.height = 64
+	tex_fmt.format = RenderingDevice.DATA_FORMAT_R8_UINT
+	tex_fmt.usage_bits = (
+		RenderingDevice.TEXTURE_USAGE_STORAGE_BIT + RenderingDevice.TEXTURE_USAGE_SAMPLING_BIT
+	)
+	var image := mask_texture.get_image()
+	image.convert(Image.FORMAT_R8)
+	var texture := rd.texture_create(tex_fmt, tex_view, [image.get_data()])
+	texture_uniform.add_id(texture)
+
+
+func _process(_delta: float) -> void:
+	RenderingServer.call_on_render_thread(dispatch_compute)
+
+	# Get result
+	var out_data := output_buffer.to_int32_array()
+	print(out_data)
+
+
+func dispatch_compute() -> void:
+	# Rendering device handle
+	var rd := RenderingServer.get_rendering_device()
+
+	# Prepare shader context
+	var uniform_set := rd.uniform_set_create([output_uniform, texture_uniform], shader, 0)
+
+	# Bind context
+	var compute_list := rd.compute_list_begin()
+	rd.compute_list_bind_compute_pipeline(compute_list, pipeline)
+	rd.compute_list_bind_uniform_set(compute_list, uniform_set, 0)
+	rd.compute_list_dispatch(compute_list, 32, 32, 1)
+	rd.compute_list_end()
diff --git a/utilities/compute_shader_sandbox/compute_shader_sandbox.gd.uid b/utilities/compute_shader_sandbox/compute_shader_sandbox.gd.uid
new file mode 100644
index 0000000..46ab463
--- /dev/null
+++ b/utilities/compute_shader_sandbox/compute_shader_sandbox.gd.uid
@@ -0,0 +1 @@
+uid://bpkwaloqvlvod
diff --git a/utilities/compute_shader_sandbox/compute_shader_sandbox.tscn b/utilities/compute_shader_sandbox/compute_shader_sandbox.tscn
new file mode 100644
index 0000000..382f1cc
--- /dev/null
+++ b/utilities/compute_shader_sandbox/compute_shader_sandbox.tscn
@@ -0,0 +1,8 @@
+[gd_scene load_steps=3 format=3 uid="uid://ywmbsmw2em5n"]
+
+[ext_resource type="Script" uid="uid://bpkwaloqvlvod" path="res://utilities/compute_shader_sandbox/compute_shader_sandbox.gd" id="1_0g1hn"]
+[ext_resource type="Texture2D" uid="uid://wqqwtmtmp147" path="res://levels/ghost_ship/level/mess_hall/overhead_light_mask_C.png" id="2_ckeim"]
+
+[node name="ComputeShaderSandbox" type="Node"]
+script = ExtResource("1_0g1hn")
+mask_texture = ExtResource("2_ckeim")
diff --git a/utilities/compute_shader_sandbox/compute_sum.glsl b/utilities/compute_shader_sandbox/compute_sum.glsl
new file mode 100644
index 0000000..217855d
--- /dev/null
+++ b/utilities/compute_shader_sandbox/compute_sum.glsl
@@ -0,0 +1,19 @@
+#[compute]
+#version 450
+
+layout(local_size_x = 32, local_size_y = 32, local_size_z = 1) in;
+
+layout(set = 0, binding = 0, std430) restrict buffer outputBuffer {
+    uint sum_value;
+} out_data;
+
+
+layout(set = 0, binding = 1, r8ui) uniform readonly uimage2D inputTexture;
+
+
+void main() {
+    ivec2 uv = ivec2(gl_GlobalInvocationID.xy);
+    uint value = imageLoad(inputTexture, uv).r + 1;
+    out_data.sum_value = atomicAdd(out_data.sum_value, value);
+    //out_data.sum_value += value;
+}
diff --git a/utilities/compute_shader_sandbox/compute_sum.glsl.import b/utilities/compute_shader_sandbox/compute_sum.glsl.import
new file mode 100644
index 0000000..0f1ebe6
--- /dev/null
+++ b/utilities/compute_shader_sandbox/compute_sum.glsl.import
@@ -0,0 +1,14 @@
+[remap]
+
+importer="glsl"
+type="RDShaderFile"
+uid="uid://bc34sy37cdf6k"
+path="res://.godot/imported/compute_sum.glsl-65c025c095b2ca4b78b25d3c010d401d.res"
+
+[deps]
+
+source_file="res://utilities/compute_shader_sandbox/compute_sum.glsl"
+dest_files=["res://.godot/imported/compute_sum.glsl-65c025c095b2ca4b78b25d3c010d401d.res"]
+
+[params]
+