Add freshwater habitats and saltwater tide ribbons

world/README-WORLD-AUTHORING.md

@@ -34,6 +34,12 @@ children. Child transforms are local offsets owned by that feature.
 
 ## Water bodies
 
+Every fishable region must author its `water_type` explicitly. The starter pond
+is `FRESH_WATER`; the starter coast is `SALT_WATER`. Fish species use the same
+central type definition through an allowed-water-type bitmask, so pool contents
+and authoritative selection are both validated against the region. Do not infer
+habitat from node names, pool filenames, coordinates, or water height.
+
 Select `WaterBodies/Pond` to move or resize the pond. Its transform is the
 authoritative surface position. The `surface_size`, fishing padding, recovery
 padding, and recovery depth properties update the visible water and gameplay
@@ -86,3 +92,36 @@ for provisional props when visual and collision scale together. Avoid
 non-uniform root scaling because it can deform collision and imported geometry
 unpredictably. Make mutable per-instance shapes, meshes, and materials local to
 the scene so editing one prop does not change unrelated instances.
+
+## Shoreline tide ribbons
+
+Each map that uses generated tide ribbons owns a `ShorelineRibbonBaker` node and
+one `ShorelineRibbonConfig` resource per water body. Each fishable water body
+declares the shared `WaterType` value used by fishing, Logbook classification,
+and shoreline presentation. A configuration designates
+only the static terrain `CollisionShape3D` or `MeshInstance3D` to intersect, the
+water height, explicit generation bounds, water-facing reference, optional
+smoothing overrides, and the generated `.tres` output path. Props, docks,
+players, bobbers, and gameplay areas are not scanned unless a map author
+explicitly selects one as the terrain source. The baker reports every configured
+body but intentionally generates ribbons only for `SALT_WATER`; freshwater uses
+the shared depth-tinted shader without tide marks or an advancing wash.
+
+To rebuild in the editor, select the map's `ShorelineRibbonBaker` node and press
+**Rebuild Shoreline Ribbons** in the Inspector. The equivalent validation/CI
+command for the starter map is:
+
+```sh
+godot --headless --path . --script scripts/bake_shoreline_ribbons.gd
+```
+
+Set the baker's `debug_path_stage` to Raw, Simplified, or Smoothed before an
+editor rebuild to compare the extraction stages. Keep it Off in the finished
+scene; the temporary editor-only line preview is never saved as gameplay data.
+
+Rebuild a saltwater ribbon only when its terrain at the waterline, configured
+water height, or generation bounds change. Freshwater terrain changes do not
+require a ribbon rebuild because freshwater bodies have no ribbon. Adding or
+moving unrelated props, fishing areas, recovery volumes, or other gameplay
+nodes does not require a rebuild. Normal gameplay loads the committed generated
+saltwater meshes and never runs the extraction step.

world/fishable_water_region.gd

@@ -10,6 +10,7 @@ enum SurfaceHeightMode {
 }
 
 @export var location_tags: Array[StringName] = []
+@export var water_type: WaterType.Type = WaterType.Type.FRESH_WATER
 @export var fish_pool: FishPoolType
 @export var selection_priority: int = 0
 @export_group("Surface")

world/materials/shoreline_tide.gdshader

@@ -0,0 +1,71 @@
+shader_type spatial;
+render_mode blend_mix, depth_draw_never, cull_disabled, unshaded;
+
+uniform vec4 lead_color : source_color = vec4(0.620, 0.875, 0.855, 1.0);
+uniform vec4 trail_color : source_color = vec4(0.430, 0.780, 0.770, 1.0);
+uniform float ribbon_width : hint_range(0.2, 2.0, 0.01) = 0.85;
+uniform float land_inset : hint_range(0.0, 0.4, 0.01) = 0.10;
+uniform float tide_speed : hint_range(0.1, 3.0, 0.01) = 1.42;
+uniform float tide_distance : hint_range(0.0, 0.6, 0.01) = 0.30;
+uniform float lead_width : hint_range(0.01, 0.2, 0.005) = 0.065;
+uniform float trail_width : hint_range(0.02, 0.4, 0.005) = 0.18;
+uniform float lead_strength : hint_range(0.0, 1.0, 0.01) = 0.48;
+uniform float trail_strength : hint_range(0.0, 1.0, 0.01) = 0.25;
+uniform float phase_scale : hint_range(0.001, 0.2, 0.001) = 0.035;
+uniform float phase_strength : hint_range(0.0, 2.0, 0.01) = 0.55;
+
+varying vec3 world_position;
+
+
+float hash_21(vec2 point) {
+	return fract(sin(dot(point, vec2(127.1, 311.7))) * 43758.5453);
+}
+
+
+float value_noise(vec2 point) {
+	vec2 cell = floor(point);
+	vec2 local = fract(point);
+	vec2 blend = local * local * (3.0 - 2.0 * local);
+	float bottom = mix(hash_21(cell), hash_21(cell + vec2(1.0, 0.0)), blend.x);
+	float top = mix(
+		hash_21(cell + vec2(0.0, 1.0)),
+		hash_21(cell + vec2(1.0, 1.0)),
+		blend.x
+	);
+	return mix(bottom, top, blend.y);
+}
+
+
+float soft_line(float coordinate, float center, float width) {
+	float normalized_width = max(width / ribbon_width, 0.001);
+	float derivative_width = min(fwidth(coordinate) * 1.25, normalized_width * 0.65);
+	return 1.0 - smoothstep(
+		max(normalized_width * 0.25 - derivative_width, 0.0),
+		normalized_width + derivative_width,
+		abs(coordinate - center)
+	);
+}
+
+
+void vertex() {
+	world_position = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
+}
+
+
+void fragment() {
+	float phase = (
+		value_noise(world_position.xz * phase_scale) * 2.0 - 1.0
+	) * phase_strength;
+	float ebb = sin(TIME * tide_speed + phase) * 0.5 + 0.5;
+	float shoreline = land_inset / ribbon_width;
+	float lead_position = shoreline + ebb * tide_distance / ribbon_width;
+	float trail_position = lead_position + max(tide_distance * 0.72, 0.10) / ribbon_width;
+	float lead = soft_line(UV.y, lead_position, lead_width);
+	float trail = soft_line(UV.y, trail_position, trail_width);
+	float edge_fade = smoothstep(0.0, 0.055, UV.y) * (1.0 - smoothstep(0.90, 1.0, UV.y));
+	float lead_alpha = lead * lead_strength;
+	float trail_alpha = trail * trail_strength;
+	float combined_alpha = max(lead_alpha, trail_alpha) * edge_fade;
+	ALBEDO = mix(trail_color.rgb, lead_color.rgb, lead_alpha);
+	ALPHA = combined_alpha;
+}

world/materials/shoreline_tide.gdshader.uid

@@ -0,0 +1 @@
+uid://5dauni8hb2lv

world/materials/shoreline_tide.tres

@@ -0,0 +1,19 @@
+[gd_resource type="ShaderMaterial" load_steps=2 format=3]
+
+[ext_resource type="Shader" path="res://world/materials/shoreline_tide.gdshader" id="1_shader"]
+
+[resource]
+render_priority = 1
+shader = ExtResource("1_shader")
+shader_parameter/lead_color = Color(0.619608, 0.87451, 0.854902, 1)
+shader_parameter/trail_color = Color(0.431373, 0.780392, 0.768627, 1)
+shader_parameter/ribbon_width = 0.85
+shader_parameter/land_inset = 0.1
+shader_parameter/tide_speed = 1.42
+shader_parameter/tide_distance = 0.3
+shader_parameter/lead_width = 0.065
+shader_parameter/trail_width = 0.18
+shader_parameter/lead_strength = 0.48
+shader_parameter/trail_strength = 0.25
+shader_parameter/phase_scale = 0.035
+shader_parameter/phase_strength = 0.55

world/materials/stylized_water.gdshader

@@ -1,93 +1,241 @@
 shader_type spatial;
-render_mode cull_back, diffuse_burley, specular_schlick_ggx;
+render_mode blend_mix, depth_draw_never, cull_back, unshaded;
 
-uniform vec4 deep_color : source_color = vec4(0.055, 0.31, 0.50, 1.0);
-uniform vec4 wave_color : source_color = vec4(0.18, 0.59, 0.74, 1.0);
-uniform vec4 highlight_color : source_color = vec4(0.64, 0.88, 0.93, 1.0);
+uniform sampler2D depth_texture : hint_depth_texture, repeat_disable, filter_nearest;
 
-uniform float primary_wave_scale : hint_range(0.01, 2.0, 0.01) = 0.52;
-uniform float secondary_wave_scale : hint_range(0.01, 2.0, 0.01) = 0.29;
-uniform vec2 primary_speed = vec2(0.16, 0.07);
-uniform vec2 secondary_speed = vec2(-0.08, 0.12);
-uniform float wave_strength : hint_range(0.0, 1.0, 0.01) = 0.42;
+uniform vec4 shore_color : source_color = vec4(0.475, 0.788, 0.796, 1.0);
+uniform vec4 shallow_color : source_color = vec4(0.227, 0.604, 0.663, 1.0);
+uniform vec4 deep_color : source_color = vec4(0.110, 0.345, 0.435, 1.0);
+uniform vec4 tide_wash_color : source_color = vec4(0.360, 0.720, 0.735, 1.0);
 
-uniform float highlight_fresnel_strength : hint_range(0.0, 1.0, 0.01) = 0.22;
-uniform float fresnel_power : hint_range(0.5, 12.0, 0.1) = 4.0;
-uniform float roughness : hint_range(0.0, 1.0, 0.01) = 0.32;
-uniform float specular_strength : hint_range(0.0, 1.0, 0.01) = 0.28;
+uniform float shallow_depth : hint_range(0.1, 3.0, 0.01) = 0.70;
+uniform float deep_depth : hint_range(0.5, 12.0, 0.05) = 3.60;
+uniform float shore_depth_width : hint_range(0.02, 1.0, 0.01) = 0.16;
+
+uniform float shore_alpha : hint_range(0.1, 1.0, 0.01) = 0.44;
+uniform float shallow_alpha : hint_range(0.1, 1.0, 0.01) = 0.60;
+uniform float deep_alpha : hint_range(0.1, 1.0, 0.01) = 0.82;
+
+uniform bool tide_effect_enabled = true;
+uniform float tide_speed : hint_range(0.1, 3.0, 0.01) = 1.42;
+uniform float tide_distance : hint_range(0.0, 0.6, 0.01) = 0.30;
+uniform float tide_wash_width : hint_range(0.05, 1.0, 0.01) = 0.38;
+uniform float tide_wash_strength : hint_range(0.0, 0.3, 0.01) = 0.11;
+uniform float tide_wash_alpha_shift : hint_range(0.0, 0.15, 0.005) = 0.045;
+
+uniform float phase_noise_scale : hint_range(0.001, 0.5, 0.001) = 0.055;
+uniform float phase_noise_strength : hint_range(0.0, 2.0, 0.01) = 0.68;
+uniform float contour_corner_variation : hint_range(0.0, 0.15, 0.005) = 0.045;
+uniform float contour_smoothing_pixels : hint_range(0.0, 2.5, 0.05) = 1.0;
+uniform float contour_smoothing_strength : hint_range(0.0, 1.0, 0.01) = 0.72;
+uniform float contour_depth_reject : hint_range(0.05, 2.0, 0.01) = 0.60;
+uniform float open_water_drift_scale : hint_range(0.001, 0.3, 0.001) = 0.018;
+uniform vec2 open_water_drift_speed = vec2(0.010, -0.007);
+uniform float open_water_drift_strength : hint_range(0.0, 0.08, 0.001) = 0.045;
+
+uniform float distant_alpha_start : hint_range(10.0, 2000.0, 1.0) = 260.0;
+uniform float distant_alpha_end : hint_range(20.0, 5000.0, 1.0) = 1400.0;
 
 varying vec3 world_position;
+varying float surface_view_depth;
+
+
+float hash_21(vec2 point) {
+	return fract(sin(dot(point, vec2(127.1, 311.7))) * 43758.5453);
+}
+
+
+float value_noise(vec2 point) {
+	vec2 cell = floor(point);
+	vec2 local = fract(point);
+	vec2 blend = local * local * (3.0 - 2.0 * local);
+	float bottom = mix(hash_21(cell), hash_21(cell + vec2(1.0, 0.0)), blend.x);
+	float top = mix(
+		hash_21(cell + vec2(0.0, 1.0)),
+		hash_21(cell + vec2(1.0, 1.0)),
+		blend.x
+	);
+	return mix(bottom, top, blend.y);
+}
+
+
+float reconstruct_view_depth(
+	vec2 screen_uv,
+	float raw_depth,
+	mat4 inverse_projection
+) {
+	#if CURRENT_RENDERER == RENDERER_COMPATIBILITY
+	vec3 ndc = vec3(screen_uv, raw_depth) * 2.0 - 1.0;
+	#else
+	vec3 ndc = vec3(screen_uv * 2.0 - 1.0, raw_depth);
+	#endif
+	vec4 view_position = inverse_projection * vec4(ndc, 1.0);
+	return -view_position.z / max(abs(view_position.w), 0.00001);
+}
+
+
+float sample_water_depth(
+	vec2 screen_uv,
+	float water_surface_depth,
+	mat4 inverse_projection
+) {
+	float raw_depth = texture(depth_texture, screen_uv).r;
+	float scene_depth = reconstruct_view_depth(
+		screen_uv,
+		raw_depth,
+		inverse_projection
+	);
+	return scene_depth - water_surface_depth;
+}
+
+
+float contour_neighbor_weight(
+	float center_depth,
+	float neighbor_depth,
+	float rejection_distance
+) {
+	if (neighbor_depth <= 0.0) {
+		return 0.0;
+	}
+	float safe_rejection = max(rejection_distance, 0.001);
+	return 1.0 - smoothstep(
+		safe_rejection * 0.35,
+		safe_rejection,
+		abs(neighbor_depth - center_depth)
+	);
+}
 
 
 void vertex() {
-	world_position = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
+	vec4 world_vertex = MODEL_MATRIX * vec4(VERTEX, 1.0);
+	vec4 view_vertex = VIEW_MATRIX * world_vertex;
+	world_position = world_vertex.xyz;
+	surface_view_depth = -view_vertex.z;
 }
 
 
 void fragment() {
-	const vec2 primary_direction = vec2(0.835, 0.550);
-	const vec2 secondary_direction = vec2(-0.485, 0.875);
+	float raw_depth = texture(depth_texture, SCREEN_UV).r;
+	float scene_view_depth = reconstruct_view_depth(
+		SCREEN_UV,
+		raw_depth,
+		INV_PROJECTION_MATRIX
+	);
+	float water_depth = max(scene_view_depth - surface_view_depth, 0.0);
+	water_depth = min(water_depth, deep_depth * 4.0);
 
-	vec2 primary_coordinates = (
-		world_position.xz * primary_wave_scale
-		+ TIME * primary_speed
+	float contour_depth = water_depth;
+	float contour_feature_support = 1.0;
+	if (tide_effect_enabled) {
+	vec2 contour_texel = (
+		vec2(1.0) / vec2(textureSize(depth_texture, 0))
+		* contour_smoothing_pixels
 	);
-	vec2 secondary_coordinates = (
-		world_position.xz * secondary_wave_scale
-		+ TIME * secondary_speed
+	float contour_depth_sum = water_depth;
+	float contour_weight_sum = 1.0;
+	float left_depth = sample_water_depth(
+		SCREEN_UV - vec2(contour_texel.x, 0.0),
+		surface_view_depth,
+		INV_PROJECTION_MATRIX
 	);
-	float primary_phase = dot(primary_coordinates, primary_direction);
-	float secondary_phase = dot(
-		secondary_coordinates,
-		secondary_direction
+	float right_depth = sample_water_depth(
+		SCREEN_UV + vec2(contour_texel.x, 0.0),
+		surface_view_depth,
+		INV_PROJECTION_MATRIX
 	);
-	float primary_wave = sin(primary_phase);
-	float secondary_wave = sin(secondary_phase);
-	float combined_wave = (
-		primary_wave * 0.62
-		+ secondary_wave * 0.38
+	float upper_depth = sample_water_depth(
+		SCREEN_UV - vec2(0.0, contour_texel.y),
+		surface_view_depth,
+		INV_PROJECTION_MATRIX
 	);
-	float wave_band = smoothstep(
-		0.34,
-		0.66,
-		combined_wave * 0.5 + 0.5
+	float lower_depth = sample_water_depth(
+		SCREEN_UV + vec2(0.0, contour_texel.y),
+		surface_view_depth,
+		INV_PROJECTION_MATRIX
 	);
+	float left_weight = contour_neighbor_weight(
+		water_depth, left_depth, contour_depth_reject
+	);
+	float right_weight = contour_neighbor_weight(
+		water_depth, right_depth, contour_depth_reject
+	);
+	float upper_weight = contour_neighbor_weight(
+		water_depth, upper_depth, contour_depth_reject
+	);
+	float lower_weight = contour_neighbor_weight(
+		water_depth, lower_depth, contour_depth_reject
+	);
+	contour_depth_sum += left_depth * left_weight;
+	contour_depth_sum += right_depth * right_weight;
+	contour_depth_sum += upper_depth * upper_weight;
+	contour_depth_sum += lower_depth * lower_weight;
+	float neighbor_support = left_weight + right_weight + upper_weight + lower_weight;
+	contour_weight_sum += neighbor_support;
+	float smoothed_contour_depth = contour_depth_sum / contour_weight_sum;
+	contour_depth = mix(
+		water_depth,
+		smoothed_contour_depth,
+		contour_smoothing_strength
+	);
+	contour_feature_support = smoothstep(0.75, 1.75, neighbor_support);
+	}
 
-	vec2 wave_slope = (
-		cos(primary_phase)
-		* primary_direction
-		* primary_wave_scale
-		* 0.62
-		+ cos(secondary_phase)
-		* secondary_direction
-		* secondary_wave_scale
-		* 0.38
-	);
-	vec3 world_normal = normalize(
-		vec3(
-			-wave_slope.x * wave_strength * 0.34,
-			1.0,
-			-wave_slope.y * wave_strength * 0.34
-		)
-	);
-	NORMAL = normalize(
-		(VIEW_MATRIX * vec4(world_normal, 0.0)).xyz
-	);
+	float shallow_mix = smoothstep(0.0, shallow_depth, water_depth);
+	float deep_mix = smoothstep(shallow_depth, deep_depth, water_depth);
+	vec3 water_color = mix(shore_color.rgb, shallow_color.rgb, shallow_mix);
+	water_color = mix(water_color, deep_color.rgb, deep_mix);
+	float water_alpha = mix(shore_alpha, shallow_alpha, shallow_mix);
+	water_alpha = mix(water_alpha, deep_alpha, deep_mix);
 
-	float fresnel = pow(
-		1.0 - clamp(dot(NORMAL, VIEW), 0.0, 1.0),
-		fresnel_power
+	if (tide_effect_enabled) {
+	vec2 phase_coordinates = world_position.xz * phase_noise_scale;
+	float phase_variation = (
+		value_noise(phase_coordinates)
+		+ value_noise(phase_coordinates * 0.47 + vec2(9.7, 3.1)) * 0.5
+		- 0.75
+	) * phase_noise_strength;
+	float corner_variation = (
+		value_noise(phase_coordinates * 1.73 + vec2(4.2, 13.6)) * 2.0 - 1.0
+	) * contour_corner_variation;
+	float ebb = sin(TIME * tide_speed + phase_variation) * 0.5 + 0.5;
+	float lead_threshold = shore_depth_width + ebb * tide_distance + corner_variation;
+	float tide_wash = 1.0 - smoothstep(
+		lead_threshold,
+		lead_threshold + max(tide_wash_width, 0.001),
+		contour_depth
 	);
-	vec3 water_color = mix(
-		deep_color.rgb,
-		wave_color.rgb,
-		wave_band * wave_strength
-	);
-	ALBEDO = mix(
+	tide_wash *= contour_feature_support;
+	tide_wash *= 1.0 - smoothstep(shallow_depth, deep_depth, water_depth);
+	water_color = mix(
 		water_color,
-		highlight_color.rgb,
-		fresnel * highlight_fresnel_strength
+		tide_wash_color.rgb,
+		tide_wash * tide_wash_strength
 	);
-	ROUGHNESS = roughness;
-	SPECULAR = specular_strength;
+	water_alpha = min(
+		water_alpha
+		+ tide_wash * tide_wash_alpha_shift,
+		0.96
+	);
+	}
+
+	vec2 drift_coordinates = (
+		world_position.xz * open_water_drift_scale
+		+ TIME * open_water_drift_speed
+	);
+	float broad_drift = value_noise(drift_coordinates) * 2.0 - 1.0;
+	water_color *= 1.0 + broad_drift * open_water_drift_strength * deep_mix;
+
+	float distant_mix = smoothstep(
+		distant_alpha_start,
+		max(distant_alpha_end, distant_alpha_start + 1.0),
+		surface_view_depth
+	);
+	water_color = mix(water_color, deep_color.rgb, distant_mix * 0.72);
+	water_alpha = mix(water_alpha, 0.96, distant_mix);
+
+	ALBEDO = water_color;
+	ALPHA = clamp(water_alpha, 0.1, 0.96);
+	METALLIC = 0.0;
+	SPECULAR = 0.0;
+	ROUGHNESS = 1.0;
 }

world/materials/stylized_water.tres

@@ -5,3 +5,30 @@
 [resource]
 render_priority = 0
 shader = ExtResource("1_water_shader")
+shader_parameter/shore_color = Color(0.47451, 0.788235, 0.796078, 1)
+shader_parameter/shallow_color = Color(0.227451, 0.603922, 0.662745, 1)
+shader_parameter/deep_color = Color(0.109804, 0.345098, 0.435294, 1)
+shader_parameter/tide_wash_color = Color(0.360784, 0.721569, 0.733333, 1)
+shader_parameter/shallow_depth = 0.7
+shader_parameter/deep_depth = 3.6
+shader_parameter/shore_depth_width = 0.16
+shader_parameter/shore_alpha = 0.44
+shader_parameter/shallow_alpha = 0.6
+shader_parameter/deep_alpha = 0.82
+shader_parameter/tide_effect_enabled = true
+shader_parameter/tide_speed = 1.42
+shader_parameter/tide_distance = 0.3
+shader_parameter/tide_wash_width = 0.38
+shader_parameter/tide_wash_strength = 0.11
+shader_parameter/tide_wash_alpha_shift = 0.045
+shader_parameter/phase_noise_scale = 0.055
+shader_parameter/phase_noise_strength = 0.68
+shader_parameter/contour_corner_variation = 0.045
+shader_parameter/contour_smoothing_pixels = 1.0
+shader_parameter/contour_smoothing_strength = 0.72
+shader_parameter/contour_depth_reject = 0.6
+shader_parameter/open_water_drift_scale = 0.018
+shader_parameter/open_water_drift_speed = Vector2(0.01, -0.007)
+shader_parameter/open_water_drift_strength = 0.045
+shader_parameter/distant_alpha_start = 260.0
+shader_parameter/distant_alpha_end = 1400.0

world/materials/stylized_water_fresh.tres

@@ -0,0 +1,23 @@
+[gd_resource type="ShaderMaterial" load_steps=2 format=3]
+
+[ext_resource type="Shader" path="res://world/materials/stylized_water.gdshader" id="1_water_shader"]
+
+[resource]
+render_priority = 0
+shader = ExtResource("1_water_shader")
+shader_parameter/shore_color = Color(0.47451, 0.788235, 0.796078, 1)
+shader_parameter/shallow_color = Color(0.227451, 0.603922, 0.662745, 1)
+shader_parameter/deep_color = Color(0.109804, 0.345098, 0.435294, 1)
+shader_parameter/tide_wash_color = Color(0.360784, 0.721569, 0.733333, 1)
+shader_parameter/shallow_depth = 0.7
+shader_parameter/deep_depth = 3.6
+shader_parameter/shore_depth_width = 0.16
+shader_parameter/shore_alpha = 0.44
+shader_parameter/shallow_alpha = 0.6
+shader_parameter/deep_alpha = 0.82
+shader_parameter/tide_effect_enabled = false
+shader_parameter/open_water_drift_scale = 0.018
+shader_parameter/open_water_drift_speed = Vector2(0.01, -0.007)
+shader_parameter/open_water_drift_strength = 0.045
+shader_parameter/distant_alpha_start = 260.0
+shader_parameter/distant_alpha_end = 1400.0

world/water/shoreline_ribbon_baker.gd

@@ -0,0 +1,138 @@
+@tool
+class_name ShorelineRibbonBaker
+extends Node
+
+@export var water_bodies: Array[ShorelineRibbonConfig] = []
+@export_enum("Off", "Raw", "Simplified", "Smoothed") var debug_path_stage := 0
+@export_tool_button("Rebuild Shoreline Ribbons")
+var rebuild_shorelines: Callable = rebuild_all
+
+
+func rebuild_all() -> Array[Dictionary]:
+	var results: Array[Dictionary] = []
+	for configuration: ShorelineRibbonConfig in water_bodies:
+		var result := _rebuild(configuration)
+		if result.is_empty():
+			return []
+		results.append(result)
+	_update_debug_display(results)
+	return results
+
+
+func _rebuild(configuration: ShorelineRibbonConfig) -> Dictionary:
+	if configuration == null:
+		push_error("Shoreline ribbon configuration is missing.")
+		return {}
+	if configuration.water_type != WaterType.Type.SALT_WATER:
+		return {
+			"skipped": true,
+			"water_type": configuration.water_type,
+			"output_path": configuration.output_resource_path,
+		}
+	var source := get_node_or_null(configuration.terrain_source) as Node3D
+	if source == null:
+		push_error(
+			"Shoreline terrain source was not found: %s"
+			% configuration.terrain_source
+		)
+		return {}
+	if configuration.output_resource_path.is_empty():
+		push_error("Shoreline output resource path is empty.")
+		return {}
+	var faces := _terrain_faces(source)
+	if faces.is_empty():
+		push_error("Configured shoreline terrain source exposes no triangles.")
+		return {}
+	var result := ShorelineRibbonGenerator.generate(
+		faces,
+		configuration.water_height,
+		configuration.generation_bounds,
+		configuration.water_reference,
+		configuration.water_is_inside,
+		configuration.simplification_tolerance,
+		configuration.smoothing_iterations,
+		configuration.resample_spacing
+	)
+	var output_directory := configuration.output_resource_path.get_base_dir()
+	DirAccess.make_dir_recursive_absolute(ProjectSettings.globalize_path(output_directory))
+	var save_error := ResourceSaver.save(
+		result["mesh"], configuration.output_resource_path
+	)
+	if save_error != OK:
+		push_error(
+			"Failed to save %s: %s"
+			% [configuration.output_resource_path, error_string(save_error)]
+		)
+		return {}
+	result["output_path"] = configuration.output_resource_path
+	result["water_height"] = configuration.water_height
+	result["water_type"] = configuration.water_type
+	result["skipped"] = false
+	return result
+
+
+func _update_debug_display(results: Array[Dictionary]) -> void:
+	var previous := get_node_or_null("_ShorelinePathDebug")
+	if previous != null:
+		previous.queue_free()
+	if not Engine.is_editor_hint() or debug_path_stage == 0:
+		return
+	var debug_mesh := ImmediateMesh.new()
+	var debug_material := StandardMaterial3D.new()
+	debug_material.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	debug_material.albedo_color = Color(1.0, 0.35, 0.65, 1.0)
+	var stage_key: String = [
+		"", "debug_raw_paths", "debug_simplified_paths", "debug_smoothed_paths"
+	][debug_path_stage]
+	for result: Dictionary in results:
+		if result.get("skipped", false):
+			continue
+		var height := float(result["water_height"]) + 0.06
+		for path_data: Dictionary in result[stage_key]:
+			var points: PackedVector2Array = path_data["points"]
+			if points.size() < 2:
+				continue
+			debug_mesh.surface_begin(Mesh.PRIMITIVE_LINE_STRIP, debug_material)
+			for point: Vector2 in points:
+				debug_mesh.surface_add_vertex(Vector3(point.x, height, point.y))
+			if path_data["closed"]:
+				debug_mesh.surface_add_vertex(Vector3(points[0].x, height, points[0].y))
+			debug_mesh.surface_end()
+	var debug_instance := MeshInstance3D.new()
+	debug_instance.name = "_ShorelinePathDebug"
+	debug_instance.mesh = debug_mesh
+	add_child(debug_instance)
+
+
+func _terrain_faces(source: Node3D) -> PackedVector3Array:
+	var result := PackedVector3Array()
+	if source is CollisionShape3D:
+		var collision_shape := source as CollisionShape3D
+		var concave_shape := collision_shape.shape as ConcavePolygonShape3D
+		if concave_shape == null:
+			return result
+		for vertex: Vector3 in concave_shape.get_faces():
+			result.append(_to_map_space(source, vertex))
+		return result
+	if source is MeshInstance3D:
+		var mesh_instance := source as MeshInstance3D
+		if mesh_instance.mesh == null:
+			return result
+		for surface: int in mesh_instance.mesh.get_surface_count():
+			var arrays := mesh_instance.mesh.surface_get_arrays(surface)
+			var vertices := arrays[Mesh.ARRAY_VERTEX] as PackedVector3Array
+			var indices := arrays[Mesh.ARRAY_INDEX] as PackedInt32Array
+			if indices.is_empty():
+				for vertex: Vector3 in vertices:
+					result.append(_to_map_space(source, vertex))
+			else:
+				for index: int in indices:
+					result.append(_to_map_space(source, vertices[index]))
+	return result
+
+
+func _to_map_space(source: Node3D, vertex: Vector3) -> Vector3:
+	var map_root := get_parent() as Node3D
+	if map_root == null:
+		return source.to_global(vertex)
+	return map_root.to_local(source.to_global(vertex))

world/water/shoreline_ribbon_baker.gd.uid

@@ -0,0 +1 @@
+uid://bj704rvwwh77b

world/water/shoreline_ribbon_config.gd

@@ -0,0 +1,14 @@
+class_name ShorelineRibbonConfig
+extends Resource
+
+@export_node_path("CollisionShape3D", "MeshInstance3D") var terrain_source: NodePath
+@export var water_type: WaterType.Type = WaterType.Type.FRESH_WATER
+@export var water_height := 0.0
+@export var generation_bounds := Rect2()
+@export var water_reference := Vector2.ZERO
+@export var water_is_inside := true
+@export_file("*.tres") var output_resource_path := ""
+@export_group("Optional Smoothing Overrides")
+@export var simplification_tolerance := -1.0
+@export_range(-1, 4, 1) var smoothing_iterations := -1
+@export var resample_spacing := -1.0

world/water/shoreline_ribbon_config.gd.uid

@@ -0,0 +1 @@
+uid://c8hk3eojujyax

world/water/shoreline_ribbon_generator.gd

@@ -0,0 +1,443 @@
+class_name ShorelineRibbonGenerator
+extends RefCounted
+
+const WATER_PLANE_EPSILON := 0.001
+const ENDPOINT_MERGE_TOLERANCE := 0.03
+const LOOP_CLOSURE_TOLERANCE := 0.06
+const MINIMUM_FRAGMENT_LENGTH := 2.0
+const SIMPLIFICATION_TOLERANCE := 0.20
+const SMOOTHING_ITERATIONS := 2
+const RESAMPLE_SPACING := 0.22
+const RIBBON_WIDTH := 0.85
+const LAND_INSET := 0.10
+const SURFACE_OFFSET := 0.018
+
+
+static func generate(
+	faces: PackedVector3Array,
+	water_height: float,
+	bounds: Rect2,
+	water_reference: Vector2,
+	water_is_inside: bool,
+	simplification_override := -1.0,
+	smoothing_iterations_override := -1,
+	resample_spacing_override := -1.0
+) -> Dictionary:
+	var simplification := (
+		SIMPLIFICATION_TOLERANCE
+		if simplification_override < 0.0
+		else simplification_override
+	)
+	var smoothing_iterations := (
+		SMOOTHING_ITERATIONS
+		if smoothing_iterations_override < 0
+		else smoothing_iterations_override
+	)
+	var resample_spacing := (
+		RESAMPLE_SPACING
+		if resample_spacing_override < 0.0
+		else resample_spacing_override
+	)
+	var segments := _extract_segments(faces, water_height, bounds)
+	var raw_paths := _stitch_segments(segments)
+	var processed_paths: Array[Dictionary] = []
+	var simplified_paths: Array[Dictionary] = []
+	var raw_point_count := 0
+	var simplified_point_count := 0
+	var smoothed_point_count := 0
+	for path_data: Dictionary in raw_paths:
+		var raw_points: PackedVector2Array = path_data["points"]
+		var closed: bool = path_data["closed"]
+		if _path_length(raw_points, closed) < MINIMUM_FRAGMENT_LENGTH:
+			continue
+		var simplified := _simplify(raw_points, closed, simplification)
+		simplified_paths.append({"points": simplified, "closed": closed})
+		var smoothed := _chaikin(simplified, closed, smoothing_iterations)
+		var resampled := _resample(smoothed, closed, resample_spacing)
+		if resampled.size() < (3 if closed else 2):
+			continue
+		raw_point_count += raw_points.size()
+		simplified_point_count += simplified.size()
+		smoothed_point_count += resampled.size()
+		processed_paths.append({"points": resampled, "closed": closed})
+	var mesh := _build_mesh(
+		processed_paths,
+		water_height,
+		water_reference,
+		water_is_inside
+	)
+	return {
+		"mesh": mesh,
+		"segment_count": segments.size(),
+		"loop_count": processed_paths.size(),
+		"raw_point_count": raw_point_count,
+		"simplified_point_count": simplified_point_count,
+		"smoothed_point_count": smoothed_point_count,
+		"triangle_count": _mesh_triangle_count(mesh),
+		"debug_raw_paths": raw_paths,
+		"debug_simplified_paths": simplified_paths,
+		"debug_smoothed_paths": processed_paths,
+	}
+
+
+static func _extract_segments(
+	faces: PackedVector3Array,
+	water_height: float,
+	bounds: Rect2
+) -> Array[PackedVector2Array]:
+	var segments: Array[PackedVector2Array] = []
+	for index: int in range(0, faces.size(), 3):
+		var triangle: Array[Vector3] = [
+			faces[index], faces[index + 1], faces[index + 2]
+		]
+		var hits := PackedVector2Array()
+		for edge: int in 3:
+			var a := triangle[edge]
+			var b := triangle[(edge + 1) % 3]
+			var distance_a := a.y - water_height
+			var distance_b := b.y - water_height
+			if (
+				absf(distance_a) <= WATER_PLANE_EPSILON
+				and absf(distance_b) <= WATER_PLANE_EPSILON
+			):
+				continue
+			if not (
+				distance_a * distance_b < 0.0
+				or absf(distance_a) <= WATER_PLANE_EPSILON
+				or absf(distance_b) <= WATER_PLANE_EPSILON
+			):
+				continue
+			var denominator := distance_a - distance_b
+			var amount := (
+				0.0
+				if absf(denominator) <= WATER_PLANE_EPSILON
+				else distance_a / denominator
+			)
+			var hit3 := a.lerp(b, clampf(amount, 0.0, 1.0))
+			var hit := Vector2(hit3.x, hit3.z)
+			if bounds.has_point(hit) and not _contains_near(hits, hit):
+				hits.append(hit)
+		if (
+			hits.size() == 2
+			and hits[0].distance_to(hits[1]) > WATER_PLANE_EPSILON
+		):
+			segments.append(hits)
+	return segments
+
+
+static func _stitch_segments(
+	segments: Array[PackedVector2Array]
+) -> Array[Dictionary]:
+	var point_by_key: Dictionary = {}
+	var adjacency: Dictionary = {}
+	var unused_edges: Dictionary = {}
+	for segment: PackedVector2Array in segments:
+		var a_key := _point_key(segment[0])
+		var b_key := _point_key(segment[1])
+		if a_key == b_key:
+			continue
+		point_by_key[a_key] = segment[0]
+		point_by_key[b_key] = segment[1]
+		if not adjacency.has(a_key):
+			adjacency[a_key] = []
+		if not adjacency.has(b_key):
+			adjacency[b_key] = []
+		var edge_key := _edge_key(a_key, b_key)
+		if unused_edges.has(edge_key):
+			continue
+		(adjacency[a_key] as Array).append(b_key)
+		(adjacency[b_key] as Array).append(a_key)
+		unused_edges[edge_key] = true
+
+	var starts: Array = []
+	for key: Vector2i in adjacency:
+		if (adjacency[key] as Array).size() != 2:
+			starts.append(key)
+	for key: Vector2i in adjacency:
+		if not starts.has(key):
+			starts.append(key)
+
+	var paths: Array[Dictionary] = []
+	for start: Vector2i in starts:
+		while _has_unused_neighbor(start, adjacency, unused_edges):
+			var walked := _walk_path(start, point_by_key, adjacency, unused_edges)
+			if (walked["points"] as PackedVector2Array).size() >= 2:
+				paths.append(walked)
+	return paths
+
+
+static func _walk_path(
+	start: Vector2i,
+	point_by_key: Dictionary,
+	adjacency: Dictionary,
+	unused_edges: Dictionary
+) -> Dictionary:
+	var points := PackedVector2Array()
+	var previous := Vector2i(2147483647, 2147483647)
+	var current := start
+	var closed := false
+	var guard := unused_edges.size() + 2
+	while guard > 0:
+		guard -= 1
+		points.append(point_by_key[current])
+		var next_key := Vector2i(2147483647, 2147483647)
+		for candidate: Vector2i in adjacency[current]:
+			if candidate == previous and (adjacency[current] as Array).size() > 1:
+				continue
+			if unused_edges.get(_edge_key(current, candidate), false):
+				next_key = candidate
+				break
+		if next_key.x == 2147483647:
+			for candidate: Vector2i in adjacency[current]:
+				if unused_edges.get(_edge_key(current, candidate), false):
+					next_key = candidate
+					break
+		if next_key.x == 2147483647:
+			break
+		unused_edges[_edge_key(current, next_key)] = false
+		previous = current
+		current = next_key
+		if current == start:
+			closed = true
+			break
+	return {"points": points, "closed": closed}
+
+
+static func _simplify(
+	points: PackedVector2Array,
+	closed: bool,
+	tolerance: float
+) -> PackedVector2Array:
+	if points.size() <= (4 if closed else 2):
+		return points
+	if not closed:
+		return _rdp_open(points, tolerance)
+	var split_a := 0
+	var split_b := 1
+	var greatest_distance := 0.0
+	for a: int in points.size():
+		for b: int in range(a + 1, points.size()):
+			var distance := points[a].distance_squared_to(points[b])
+			if distance > greatest_distance:
+				greatest_distance = distance
+				split_a = a
+				split_b = b
+	var first_arc := _closed_arc(points, split_a, split_b)
+	var second_arc := _closed_arc(points, split_b, split_a)
+	var first_result := _rdp_open(first_arc, tolerance)
+	var second_result := _rdp_open(second_arc, tolerance)
+	var result := PackedVector2Array()
+	for index: int in first_result.size() - 1:
+		result.append(first_result[index])
+	for index: int in second_result.size() - 1:
+		result.append(second_result[index])
+	return result if result.size() >= 4 else points
+
+
+static func _rdp_open(
+	points: PackedVector2Array,
+	tolerance: float
+) -> PackedVector2Array:
+	if points.size() <= 2:
+		return points
+	var greatest_distance := 0.0
+	var split_index := 0
+	for index: int in range(1, points.size() - 1):
+		var distance := _point_segment_distance(
+			points[index], points[0], points[points.size() - 1]
+		)
+		if distance > greatest_distance:
+			greatest_distance = distance
+			split_index = index
+	if greatest_distance <= tolerance:
+		return PackedVector2Array([points[0], points[points.size() - 1]])
+	var left := _rdp_open(points.slice(0, split_index + 1), tolerance)
+	var right := _rdp_open(points.slice(split_index), tolerance)
+	var result := PackedVector2Array()
+	for index: int in left.size() - 1:
+		result.append(left[index])
+	result.append_array(right)
+	return result
+
+
+static func _closed_arc(
+	points: PackedVector2Array,
+	start: int,
+	finish: int
+) -> PackedVector2Array:
+	var result := PackedVector2Array()
+	var index := start
+	result.append(points[index])
+	while index != finish:
+		index = (index + 1) % points.size()
+		result.append(points[index])
+	return result
+
+
+static func _chaikin(
+	points: PackedVector2Array,
+	closed: bool,
+	iterations: int
+) -> PackedVector2Array:
+	var result := points
+	for _iteration: int in iterations:
+		var next := PackedVector2Array()
+		if not closed:
+			next.append(result[0])
+		var edge_count := result.size() if closed else result.size() - 1
+		for index: int in edge_count:
+			var a := result[index]
+			var b := result[(index + 1) % result.size()]
+			next.append(a.lerp(b, 0.25))
+			next.append(a.lerp(b, 0.75))
+		if not closed:
+			next.append(result[result.size() - 1])
+		result = next
+	return result
+
+
+static func _resample(
+	points: PackedVector2Array,
+	closed: bool,
+	spacing: float
+) -> PackedVector2Array:
+	var total_length := _path_length(points, closed)
+	if total_length <= spacing:
+		return points
+	var count := maxi(roundi(total_length / spacing), 3 if closed else 2)
+	var actual_spacing := total_length / float(count if closed else count - 1)
+	var result := PackedVector2Array()
+	var edge := 0
+	var edge_start_distance := 0.0
+	var edge_length := points[0].distance_to(points[1])
+	for sample: int in count:
+		var target := actual_spacing * sample
+		while target > edge_start_distance + edge_length and edge < points.size() - 1:
+			edge_start_distance += edge_length
+			edge += 1
+			if edge >= points.size() - 1:
+				edge_length = points[edge].distance_to(points[0]) if closed else 0.0
+			else:
+				edge_length = points[edge].distance_to(points[edge + 1])
+		var next_index := (edge + 1) % points.size()
+		var amount := (
+			0.0
+			if edge_length <= WATER_PLANE_EPSILON
+			else (target - edge_start_distance) / edge_length
+		)
+		result.append(points[edge].lerp(points[next_index], clampf(amount, 0.0, 1.0)))
+	return result
+
+
+static func _build_mesh(
+	paths: Array[Dictionary],
+	water_height: float,
+	water_reference: Vector2,
+	water_is_inside: bool
+) -> ArrayMesh:
+	var vertices := PackedVector3Array()
+	var normals := PackedVector3Array()
+	var uvs := PackedVector2Array()
+	var indices := PackedInt32Array()
+	for path_data: Dictionary in paths:
+		var points: PackedVector2Array = path_data["points"]
+		var closed: bool = path_data["closed"]
+		var base_index := vertices.size()
+		var path_distance := 0.0
+		for index: int in points.size():
+			if index > 0:
+				path_distance += points[index - 1].distance_to(points[index])
+			var previous := points[(index - 1 + points.size()) % points.size()]
+			var following := points[(index + 1) % points.size()]
+			if not closed:
+				previous = points[maxi(index - 1, 0)]
+				following = points[mini(index + 1, points.size() - 1)]
+			var tangent := previous.direction_to(following)
+			var water_normal := Vector2(-tangent.y, tangent.x)
+			var toward_reference := points[index].direction_to(water_reference)
+			if (
+				(water_is_inside and water_normal.dot(toward_reference) < 0.0)
+				or (not water_is_inside and water_normal.dot(toward_reference) > 0.0)
+			):
+				water_normal = -water_normal
+			var land_point := points[index] - water_normal * LAND_INSET
+			var water_point := points[index] + water_normal * (RIBBON_WIDTH - LAND_INSET)
+			vertices.append(Vector3(land_point.x, water_height + SURFACE_OFFSET, land_point.y))
+			vertices.append(Vector3(water_point.x, water_height + SURFACE_OFFSET, water_point.y))
+			normals.append(Vector3.UP)
+			normals.append(Vector3.UP)
+			uvs.append(Vector2(path_distance, 0.0))
+			uvs.append(Vector2(path_distance, 1.0))
+		var edge_count := points.size() if closed else points.size() - 1
+		for index: int in edge_count:
+			var next := (index + 1) % points.size()
+			var a := base_index + index * 2
+			var b := a + 1
+			var c := base_index + next * 2
+			var d := c + 1
+			indices.append_array(PackedInt32Array([a, c, b, b, c, d]))
+	var arrays := []
+	arrays.resize(Mesh.ARRAY_MAX)
+	arrays[Mesh.ARRAY_VERTEX] = vertices
+	arrays[Mesh.ARRAY_NORMAL] = normals
+	arrays[Mesh.ARRAY_TEX_UV] = uvs
+	arrays[Mesh.ARRAY_INDEX] = indices
+	var mesh := ArrayMesh.new()
+	if not vertices.is_empty():
+		mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays)
+	return mesh
+
+
+static func _point_key(point: Vector2) -> Vector2i:
+	return Vector2i(
+		roundi(point.x / ENDPOINT_MERGE_TOLERANCE),
+		roundi(point.y / ENDPOINT_MERGE_TOLERANCE)
+	)
+
+
+static func _edge_key(a: Vector2i, b: Vector2i) -> String:
+	if a.x < b.x or (a.x == b.x and a.y <= b.y):
+		return "%d:%d|%d:%d" % [a.x, a.y, b.x, b.y]
+	return "%d:%d|%d:%d" % [b.x, b.y, a.x, a.y]
+
+
+static func _has_unused_neighbor(
+	key: Vector2i,
+	adjacency: Dictionary,
+	unused_edges: Dictionary
+) -> bool:
+	for neighbor: Vector2i in adjacency[key]:
+		if unused_edges.get(_edge_key(key, neighbor), false):
+			return true
+	return false
+
+
+static func _contains_near(points: PackedVector2Array, point: Vector2) -> bool:
+	for existing: Vector2 in points:
+		if existing.distance_to(point) <= WATER_PLANE_EPSILON:
+			return true
+	return false
+
+
+static func _point_segment_distance(point: Vector2, a: Vector2, b: Vector2) -> float:
+	var segment := b - a
+	if segment.length_squared() <= WATER_PLANE_EPSILON:
+		return point.distance_to(a)
+	var amount := clampf((point - a).dot(segment) / segment.length_squared(), 0.0, 1.0)
+	return point.distance_to(a + segment * amount)
+
+
+static func _path_length(points: PackedVector2Array, closed: bool) -> float:
+	var result := 0.0
+	for index: int in points.size() - 1:
+		result += points[index].distance_to(points[index + 1])
+	if closed and points.size() > 2:
+		result += points[points.size() - 1].distance_to(points[0])
+	return result
+
+
+static func _mesh_triangle_count(mesh: ArrayMesh) -> int:
+	if mesh.get_surface_count() == 0:
+		return 0
+	var arrays := mesh.surface_get_arrays(0)
+	return (arrays[Mesh.ARRAY_INDEX] as PackedInt32Array).size() / 3

world/water/shoreline_ribbon_generator.gd.uid

@@ -0,0 +1 @@
+uid://dhp7ctspabll

world/water/water_type.gd

@@ -0,0 +1,26 @@
+class_name WaterType
+extends RefCounted
+
+enum Type {
+	FRESH_WATER,
+	SALT_WATER,
+	OTHER,
+}
+
+const FRESH_WATER_MASK := 1 << Type.FRESH_WATER
+const SALT_WATER_MASK := 1 << Type.SALT_WATER
+const ALL_FISHABLE_MASK := FRESH_WATER_MASK | SALT_WATER_MASK
+
+
+static func mask_for(type: Type) -> int:
+	return 1 << int(type) if type != Type.OTHER else 0
+
+
+static func label(type: Type) -> String:
+	match type:
+		Type.FRESH_WATER:
+			return "Fresh Water"
+		Type.SALT_WATER:
+			return "Salt Water"
+		_:
+			return "Other"

world/water/water_type.gd.uid

@@ -0,0 +1 @@
+uid://nao2xukkyoc8