Initial commit

.gitignore

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+# Godot-specific ignores
+.import/
+export.cfg
+export_presets.cfg
+
+# Imported translations (automatically generated from CSV files)
+*.translation
+
+# Mono-specific ignores
+.mono/
+data_*/

CellularAutomata.tscn

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+[gd_scene load_steps=7 format=2]
+
+[ext_resource path="res://render.shader" type="Shader" id=1]
+[ext_resource path="res://cellular_automata.gd" type="Script" id=2]
+[ext_resource path="res://world.png" type="Texture" id=3]
+[ext_resource path="res://simulation.shader" type="Shader" id=4]
+
+[sub_resource type="ShaderMaterial" id=1]
+shader = ExtResource( 4 )
+
+[sub_resource type="ShaderMaterial" id=2]
+shader = ExtResource( 1 )
+
+[node name="CellularAutomata" type="Node"]
+script = ExtResource( 2 )
+
+[node name="CanvasLayer" type="CanvasLayer" parent="."]
+
+[node name="GUI" type="MarginContainer" parent="CanvasLayer"]
+anchor_right = 1.0
+anchor_bottom = 1.0
+custom_constants/margin_right = 20
+custom_constants/margin_top = 20
+custom_constants/margin_left = 20
+custom_constants/margin_bottom = 20
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="Selection" type="PanelContainer" parent="CanvasLayer/GUI"]
+margin_left = 478.0
+margin_top = 20.0
+margin_right = 546.0
+margin_bottom = 50.0
+size_flags_horizontal = 4
+size_flags_vertical = 0
+
+[node name="Material" type="HBoxContainer" parent="CanvasLayer/GUI/Selection"]
+margin_left = 7.0
+margin_top = 7.0
+margin_right = 61.0
+margin_bottom = 23.0
+alignment = 1
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="Color" type="ColorRect" parent="CanvasLayer/GUI/Selection/Material"]
+margin_right = 16.0
+margin_bottom = 16.0
+rect_min_size = Vector2( 16, 16 )
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="Label" type="Label" parent="CanvasLayer/GUI/Selection/Material"]
+margin_left = 20.0
+margin_top = 1.0
+margin_right = 54.0
+margin_bottom = 15.0
+text = "Label"
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="Simulation" type="ViewportContainer" parent="."]
+modulate = Color( 0, 0, 0, 0 )
+anchor_right = 1.0
+anchor_bottom = 1.0
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="Viewport" type="Viewport" parent="Simulation"]
+size = Vector2( 1024, 600 )
+transparent_bg = true
+handle_input_locally = false
+disable_3d = true
+keep_3d_linear = true
+usage = 0
+render_target_v_flip = true
+render_target_clear_mode = 1
+render_target_update_mode = 3
+gui_disable_input = true
+
+[node name="World" type="Sprite" parent="Simulation/Viewport"]
+material = SubResource( 1 )
+texture = ExtResource( 3 )
+centered = false
+
+[node name="Brush" type="Polygon2D" parent="Simulation/Viewport"]
+visible = false
+polygon = PoolVector2Array( -5, -5, 5, -5, 5, 5, -5, 5 )
+
+[node name="Render" type="Node2D" parent="."]
+material = SubResource( 2 )
+
+[node name="World" type="Sprite" parent="Render"]
+use_parent_material = true
+z_index = 1
+centered = false

LICENSE

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+MIT License
+
+Copyright (c) 2021 Fabio Iotti
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

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+GPU Cellular Automata Template
+==============================
+
+GPU-accelerated cellular automata template in Godot.
+
+Uses GLSL3, but it should be possible to run it on GLSL2 with minor tweaks.
+
+![](screen/screen1.jpg)
+
+## Controls
+
+Scroll wheel = select material
+
+Click = place material
+
+Enter = pause/play
+
+Space = step once
+
+## How it works
+
+The current state of the simulation is stored in a texture, rendered in a special
+viewport named `Simulation/Viewport`.
+
+A [simulation.shader](simulation.shader) reads the viewport to compute the next
+frame and writes the result back to the same viewport.
+
+Finally, the result is shaded through the [render.shader](render.shader) and
+presented on the screen.
+
+Setup and input are handled from [cellular_automata.gd](cellular_automata.gd).
+
+## License
+
+Copyright (c) 2021 Fabio Iotti. Released under the [MIT License](LICENSE).

cellular_automata.gd

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+extends Node
+
+const materials = [
+	{ "color": Color8(  0,   0,   0, 255), "name": "Wall"  },
+	{ "color": Color8(156,  68,   0, 255), "name": "Dirt"  },
+	{ "color": Color8(134, 134, 134, 255), "name": "Stone" },
+	{ "color": Color8( 32, 125, 253, 255), "name": "Water" },
+	{ "color": Color8(207, 156, 110, 255), "name": "Sand"  },
+	{ "color": Color8( 95,  20,   0, 255), "name": "Wood"  },
+	{ "color": Color8(  0,  95,   0, 255), "name": "Grass" },
+	{ "color": Color8(255,  78,   0, 255), "name": "Lava"  },
+	{ "color": Color8(255,   0,   0, 255), "name": "Fire"  },
+	{ "color": Color8(136, 164, 201, 255), "name": "Steam" },
+];
+
+var _first_frame_rendered = false
+var _material_opacity = 0
+
+func _ready():
+	# The simulation computes the cellular automata, but doesn't draw anything
+	# on the screen. The "Render" sprite renders a copy of the simulation.
+	$Render/World.texture = $Simulation/Viewport.get_texture()
+
+	# Initially hide material selection label.
+	$CanvasLayer/GUI/Selection.modulate.a8 = 0
+
+func _process(delta):
+	if !_first_frame_rendered:
+		_first_frame_rendered = true
+	else:
+		# After the first frame is rendered, assign viewport back to itself,
+		# so that next frame can be computed from the previous.
+		$Simulation/Viewport/World.texture = $Simulation/Viewport.get_texture()
+
+	# Fade out material selection panel.
+	if _material_opacity > 0:
+		_material_opacity = _material_opacity - 3
+		$CanvasLayer/GUI/Selection.modulate.a8 = clamp(_material_opacity, 0, 255)
+
+func _input(event):
+	# Brush follows mouse movements.
+	if event is InputEventMouseMotion:
+		$Simulation/Viewport/Brush.position = get_viewport().get_mouse_position()
+
+	elif event is InputEventKey:
+		if event.pressed:
+			if event.scancode == KEY_SPACE:
+				$Simulation/Viewport.render_target_update_mode = Viewport.UPDATE_ONCE
+			elif event.scancode == KEY_ENTER:
+				var is_paused = $Simulation/Viewport.render_target_update_mode != Viewport.UPDATE_ALWAYS
+				var new_mode = Viewport.UPDATE_ALWAYS if is_paused else Viewport.UPDATE_DISABLED
+				$Simulation/Viewport.render_target_update_mode = new_mode
+
+	elif event is InputEventMouseButton:
+		# Mouse wheel to change material.
+		if event.button_index == BUTTON_WHEEL_UP || event.button_index == BUTTON_WHEEL_DOWN:
+			if event.pressed:
+				var current_material = 0
+				for i in range(materials.size()):
+					if materials[i].color == $Simulation/Viewport/Brush.color:
+						current_material = i
+						break
+
+				var offset = -1 if event.button_index == BUTTON_WHEEL_UP else +1
+				var set_material = (current_material + offset) % materials.size()
+
+				$Simulation/Viewport/Brush.color = materials[set_material].color
+				$CanvasLayer/GUI/Selection/Material/Color.color = materials[set_material].color
+				$CanvasLayer/GUI/Selection/Material/Label.text = materials[set_material].name
+
+				_material_opacity = 400
+
+		# Click to paint.
+		elif event.button_index == BUTTON_LEFT:
+			$Simulation/Viewport/Brush.visible = event.pressed

icon.png.import

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+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://icon.png"
+dest_files=[ "res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=true
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=true
+svg/scale=1.0

project.godot

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+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=4
+
+_global_script_classes=[  ]
+_global_script_class_icons={
+
+}
+
+[application]
+
+config/name="GPU Cellular Automata"
+run/main_scene="res://CellularAutomata.tscn"
+config/icon="res://icon.png"
+
+[display]
+
+window/stretch/mode="2d"
+window/stretch/aspect="keep"
+
+[rendering]
+
+vram_compression/import_etc=true
+vram_compression/import_etc2=false
+environment/default_clear_color=Color( 0.709804, 0.94902, 1, 1 )

render.shader

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+shader_type canvas_item;
+
+const vec4 black = vec4(0, 0, 0, 1);
+const vec4 white = vec4(1, 1, 1, 1);
+
+// Random number generator.
+float rand(vec2 coords) {
+	return fract(sin(dot(coords, vec2(12.9898,78.233))) * 43758.5453);
+}
+
+void fragment() {
+	// Get the color of this pixel and its neighbours.
+	vec4 here = texture(TEXTURE, UV);
+	vec4 up = texture(TEXTURE, UV + vec2(0, -1) * TEXTURE_PIXEL_SIZE);
+	vec4 down = texture(TEXTURE, UV + vec2(0, +1) * TEXTURE_PIXEL_SIZE);
+
+	// Use the color of this pixel.
+	COLOR = here;
+
+	// Randomize the color a bit, to make it more interesting.
+	vec2 coords = UV - mod(UV, TEXTURE_PIXEL_SIZE);
+	COLOR = mix(COLOR, black, rand(coords) * 0.1);
+
+	// If the materia below is different, make it a little darker.
+	if (here != down)
+		COLOR = mix(COLOR, black, 0.2);
+
+	// Or else, if the material above is different, make it a litte lighter.
+	else if (here != up)
+		COLOR = mix(COLOR, white, 0.2);
+}