Lighting element shader

shaders/CompoundCloudPlane.gdshader

@@ -27,7 +27,8 @@ const float CLOUD_MAX_INTENSITY_SHOWN = 1000.f;
 
 float getIntensity(float value)
 {
-    return min(DENSITY_MULTIPLIER * atan(0.006f * CLOUD_MAX_INTENSITY_SHOWN * value), 1.0f) * BrightnessMultiplier;
+    float baseIntensity = DENSITY_MULTIPLIER * atan(0.006f * CLOUD_MAX_INTENSITY_SHOWN * value);
+    return min(baseIntensity * BrightnessMultiplier, 1.0f);
 }
 
 void fragment() {
@@ -60,7 +61,7 @@ void fragment() {
                   colour4 * cloud4;
 
     float adjustedAlpha = min(cloud1 + cloud2 + cloud3 + cloud4, 1.0) *
-        clamp(min(cloud1 + cloud2 + cloud3 + cloud4, 1.0) * 0.5, 0.5, 0.9);
+       clamp(min(cloud1 + cloud2 + cloud3 + cloud4, 1.0) * 0.5, 0.5, 0.9);
 
     ALPHA = adjustedAlpha;
     ALBEDO = colour.rgb;

shaders/MicrobeBackground.gdshader

@@ -2,7 +2,7 @@ shader_type spatial;
 render_mode unshaded;
 
 // this is 1 by default to keep the dark BGs looking nice
-uniform float lightLevel = 1.0f;
+uniform vec3 lightColor = vec3(1.0f, 1.0f, 1.0f);
 
 uniform vec2 repeats = vec2(1.0f, 1.0f);
 uniform sampler2D layer0 : source_color;
@@ -32,25 +32,6 @@ const vec2 speed3 = vec2(1050.0f);
 varying vec2 UV3;
 varying vec2 UV4;
 
-vec3 LightInfluence(float amount)
-{
-    if (amount > 0.5f)
-    {
-        // Day
-        return mix(vec3(0.75f, 0.5f, 0.5f), vec3(1.0f, 1.0f, 1.0f), 2.0f * amount - 1.0f);
-    }
-    else if (amount > 0.25f)
-    {
-        // Dawn and Dusk
-        return mix(vec3(0.25f, 0.25f, 0.25f), vec3(0.75f, 0.5f, 0.5f), 4.0f * amount - 1.0f);
-    }
-    else
-    {
-        // Night
-        return mix(vec3(0.052f, 0.05f, 0.17f), vec3(0.25f, 0.25f, 0.25f), 4.0f * amount);
-    }
-}
-
 void vertex(){
     vec2 offset = (repeats - 1.0f) / 2.0f;
 
@@ -95,8 +76,8 @@ void fragment(){
     vec3 mixture1 = mix(colour2.rgb, colour3.rgb * colour3.a, 1.0f);
     vec3 mixture2 = mix(mixture0.rgb, mixture1.rgb, 0.5f);
     vec3 composition = mix(colour0.rgb, mixture2.rgb, 0.5f);
-
-    ALBEDO.rgb = composition.rgb * LightInfluence(lightLevel);
+	
+	ALBEDO.rgb = composition.rgb * lightColor;
 
     ALPHA = 1.0f;
 }

src/microbe_stage/BackgroundPlane.cs

@@ -9,8 +9,8 @@ public partial class BackgroundPlane : Node3D
     private readonly StringName blurAmountParameter = new("blurAmount");
     private readonly StringName textureAlbedoParameter = new("textureAlbedo");
     private readonly StringName worldPositionParameter = new("worldPos");
-    private readonly StringName lightLevelParameter = new("lightLevel");
     private readonly StringName distortionStrengthParameter = new("distortionFactor");
+    private readonly StringName lightColorParameter = new("lightColor");
 
 #pragma warning disable CA2213
 
@@ -47,6 +47,8 @@ public partial class BackgroundPlane : Node3D
 
     private Vector2 previousWindowSize = new(1280, 720);
 
+    private Color previousColor;
+
     public float PlaneOffset
     {
         get => backgroundPlane.Position.Z;
@@ -163,9 +165,16 @@ public void SetVisibility(bool visible)
             OnDisplayBackgroundParticlesChanged(Settings.Instance.DisplayBackgroundParticles);
     }
 
-    public void UpdateLightLevel(float lightLevel)
+    public void SetCompoundColoring(Color color)
     {
-        currentBackgroundMaterial.SetShaderParameter(lightLevelParameter, lightLevel);
+        // Don't do the calculation and sending to gpu again if not needed.
+        if (previousColor == color)
+            return;
+
+        previousColor = color;
+
+        currentBackgroundMaterial.SetShaderParameter(lightColorParameter,
+            new Vector3(color.R, color.G, color.B));
     }
 
     protected override void Dispose(bool disposing)
@@ -174,9 +183,9 @@ protected override void Dispose(bool disposing)
         {
             textureAlbedoParameter.Dispose();
             blurAmountParameter.Dispose();
-            lightLevelParameter.Dispose();
             distortionStrengthParameter.Dispose();
             worldPositionParameter.Dispose();
+            lightColorParameter.Dispose();
         }
 
         base.Dispose(disposing);

src/microbe_stage/BackgroundPlane.tscn

@@ -13,22 +13,22 @@
 frequency = 0.0035
 
 [sub_resource type="NoiseTexture2D" id="NoiseTexture2D_f6pop"]
-seamless = true
 noise = SubResource("FastNoiseLite_dor76")
+seamless = true
 
 [sub_resource type="FastNoiseLite" id="FastNoiseLite_ve355"]
 seed = 2
 frequency = 0.0017
 
 [sub_resource type="NoiseTexture2D" id="NoiseTexture2D_tsmw6"]
-seamless = true
 noise = SubResource("FastNoiseLite_ve355")
+seamless = true
 
 [sub_resource type="ShaderMaterial" id="2"]
 resource_local_to_scene = true
 render_priority = -100
 shader = ExtResource("4_5y6kw")
-shader_parameter/lightLevel = 1.0
+shader_parameter/lightColor = Vector3(1, 1, 1)
 shader_parameter/repeats = Vector2(2, 1)
 shader_parameter/layer0 = ExtResource("5_waqnb")
 shader_parameter/layer1 = ExtResource("6_qx2cp")

src/microbe_stage/MicrobeCamera.cs

@@ -72,11 +72,6 @@ public partial class MicrobeCamera : Camera3D, ISaveLoadedTracked, IGameCamera,
     private BackgroundPlane backgroundPlane = null!;
 #pragma warning restore CA2213
 
-    /// <summary>
-    ///   Used to manually tween the light level to the target value
-    /// </summary>
-    private float lastSetLightLevel = 1;
-
     private Vector3 cursorWorldPos = new(0, 0, 0);
     private bool cursorDirty = true;
 
@@ -179,13 +174,6 @@ public override void _Process(double delta)
     {
         base._Process(delta);
 
-        // Once target is reached the value is set exactly the same
-        // ReSharper disable once CompareOfFloatsByEqualityOperator
-        if (lastSetLightLevel != lightLevel)
-        {
-            UpdateLightLevel((float)delta);
-        }
-
         if (AutoProcessWhilePaused && PauseManager.Instance.Paused)
         {
             UpdateCameraPosition(delta, null);
@@ -299,6 +287,11 @@ public void SetBackground(Background background)
         backgroundPlane.SetBackground(background);
     }
 
+    public void SetWaterColorFromCompounds(Color color)
+    {
+        backgroundPlane.SetCompoundColoring(color);
+    }
+
     public void WritePropertiesToArchive(ISArchiveWriter writer)
     {
         writer.Write(ZoomSpeed);
@@ -405,28 +398,4 @@ private void UpdateBackgroundVisibility()
     {
         backgroundPlane.SetVisibility(Current);
     }
-
-    private void UpdateLightLevel(float delta)
-    {
-        if (lastSetLightLevel < lightLevel)
-        {
-            lastSetLightLevel += LightLevelInterpolateSpeed * delta;
-
-            if (lastSetLightLevel > lightLevel)
-                lastSetLightLevel = lightLevel;
-        }
-        else if (lastSetLightLevel > lightLevel)
-        {
-            lastSetLightLevel -= LightLevelInterpolateSpeed * delta;
-
-            if (lastSetLightLevel < lightLevel)
-                lastSetLightLevel = lightLevel;
-        }
-        else
-        {
-            lastSetLightLevel = lightLevel;
-        }
-
-        backgroundPlane.UpdateLightLevel(lastSetLightLevel);
-    }
 }

src/microbe_stage/MicrobeStage.cs

@@ -90,6 +90,12 @@ public sealed partial class MicrobeStage : CreatureStageBase<Entity, MicrobeWorl
 
     private float templateMaxLightLevel;
 
+    private Color environmentColor;
+
+    private Color compoundColor;
+
+    private float previousLightLevel;
+
     private bool appliedPlayerGodMode;
 
     private bool appliedUnlimitGrowthSpeed;
@@ -1460,6 +1466,8 @@ protected override void UpdatePatchSettings(bool promptPatchNameChange = true)
 
         HUD.UpdateEnvironmentalBars(currentPatch.Biome);
 
+        CalculateEnvironmentalLight();
+
         UpdateBackground();
 
         UpdatePatchLightLevelSettings();
@@ -1500,20 +1508,29 @@ protected override void OnLightLevelUpdate()
             var lightLevel =
                 currentPatch.Biome.GetCompound(Compound.Sunlight, CompoundAmountType.Current).Ambient;
 
+            // Don't update the entire lighting pipeline if no need
+            if (lightLevel == previousLightLevel)
+                return;
+
+            previousLightLevel = lightLevel;
+
             float lightModifier = lightLevel / maxLightLevel;
 
             // Normalise by maximum light level in the patch
             Camera.LightLevel = lightModifier;
 
-            microbeWorldEnvironment.UpdateAmbientReflection(
-                currentPatch.BiomeTemplate.EnvironmentColour * lightModifier);
+            var environmentLightColor = environmentColor * lightModifier;
+            environmentLightColor = environmentLightColor.Lerp(new Color(0.65f, 0.65f, 0.65f), 0.3f);
+
+            microbeWorldEnvironment.UpdateAmbientReflection(environmentLightColor);
+            Camera.SetWaterColorFromCompounds(compoundColor);
         }
         else
         {
             // Don't change lighting for patches without day/night effects
             Camera.LightLevel = 1.0f;
-
-            microbeWorldEnvironment.UpdateAmbientReflection(currentPatch.BiomeTemplate.EnvironmentColour);
+            microbeWorldEnvironment.UpdateAmbientReflection(environmentColor);
+            Camera.SetWaterColorFromCompounds(compoundColor);
         }
     }
 
@@ -1572,6 +1589,51 @@ private void UpdatePatchLightLevelSettings()
             .Ambient;
         templateMaxLightLevel = GameWorld.Map.CurrentPatch.BiomeTemplate.Conditions
             .GetCompound(Compound.Sunlight, CompoundAmountType.Biome).Ambient;
+
+        Camera.SetWaterColorFromCompounds(compoundColor);
+    }
+
+    private Color UpdateEnvironmentalCompoundAwareness()
+    {
+        GameWorld.Map.CurrentPatch!.Biome.TryGetCompound(Compound.Oxygen, CompoundAmountType.Current, out var oxygen);
+        var ironAmount = GameWorld.Map.CurrentPatch.GetCompoundAmountInSnapshotForDisplay(
+            GameWorld.Map.CurrentPatch.CurrentSnapshot, Compound.Iron);
+
+        // A lot of magic numbers here, just parameters to tune this.
+        // When settled on good values I'll formalise it.
+        var ironNormalized = ironAmount / 4.0f;
+        var oxygenPercent = oxygen.Ambient;
+        var oxygenNormalize = MathF.Min(oxygenPercent / 0.4f, 1.0f);
+        float greenIron = ironNormalized * (1.0f - 0.8f * oxygenNormalize);
+        float redRust = 0.9f * ironNormalized * oxygenNormalize;
+
+        var baseGreen = 0.15f;
+        var baseRed = 0.1f;
+        var baseBlue = 0.2f;
+
+        var g = Math.Clamp(baseGreen + 0.6f * greenIron, 0.0f, 1.0f);
+        var r = Math.Clamp(baseRed + 0.8f * redRust, 0.0f, 1.0f);
+        var b = Math.Clamp(baseBlue - 0.25f * ironNormalized, 0.0f, 1.0f);
+
+        return new Color(r, g, b);
+    }
+
+    private void CalculateEnvironmentalLight()
+    {
+        compoundColor = UpdateEnvironmentalCompoundAwareness();
+        var envColor = GameWorld.Map.CurrentPatch!.BiomeTemplate.EnvironmentColour;
+
+        var tintStrength = 0.35f;
+        var envColorTinted = envColor * (1.0f - tintStrength) + compoundColor * tintStrength;
+        environmentColor = DesaturateColor(envColorTinted, 0.15f);
+    }
+
+    private Color DesaturateColor(Color c, float amount)
+    {
+        float grayValue = 0.2126f * c.R + 0.7152f * c.G + 0.0722f * c.B;
+        var gray = new Color(grayValue, grayValue, grayValue);
+
+        return c.Lerp(gray, amount);
     }
 
     private void OnFinishLoading()