Make the "softness" of soft shadows adjustible per-light. (#1454)

Note: Thanks to the nature of YAML properties in RobustToolbox, this commit is only an API blocker if the Softness property is directly manipulated from code, which is unlikely.

Resources/Shaders/Internal/light-soft.swsl

@@ -13,7 +13,7 @@ highp float createOcclusion(highp vec2 diff)
     // Change soft shadow size based on distance from primary occluder.
     highp float distRatio = (ourDist - occlDist.x) / occlDist.x / 2.0;
 
-    perpendicular *= distRatio;
+    perpendicular *= distRatio * lightSoftness;
 
     // Totally not hacky PCF on top of VSM.
     highp float occlusion = smoothstep(0.1, 1.0, ChebyshevUpperBound(occlDist, ourDist));

Resources/Shaders/Internal/light_shared.swsl

@@ -13,6 +13,7 @@ uniform highp vec4 lightColor;
 uniform highp vec2 lightCenter;
 uniform highp float lightRange;
 uniform highp float lightPower;
+uniform highp float lightSoftness;
 uniform highp float lightIndex;
 uniform sampler2D shadowMap;
 

Robust.Client/GameObjects/Components/Light/PointLightComponent.cs

@@ -83,6 +83,18 @@ namespace Robust.Client.GameObjects
             set => _energy = value;
         }
 
+        /// <summary>
+        ///     Soft shadow strength multiplier.
+        ///     Has no effect if soft shadows are not enabled.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        [Animatable]
+        public float Softness
+        {
+            get => _softness;
+            set => _softness = value;
+        }
+
         [ViewVariables(VVAccess.ReadWrite)]
         public bool VisibleNested
         {
@@ -115,6 +127,7 @@ namespace Robust.Client.GameObjects
         private bool _maskAutoRotate;
         private Angle _rotation;
         private float _energy;
+        private float _softness;
 
         /// <summary>
         ///     Radius, in meters.
@@ -167,6 +180,7 @@ namespace Robust.Client.GameObjects
             serializer.DataFieldCached(ref _color, "color", Color.White);
             serializer.DataFieldCached(ref _enabled, "enabled", true);
             serializer.DataFieldCached(ref _energy, "energy", 1f);
+            serializer.DataFieldCached(ref _softness, "softness", 1f);
             serializer.DataFieldCached(ref _maskAutoRotate, "autoRot", false);
             serializer.DataFieldCached(ref _visibleNested, "nestedvisible", true);
 

Robust.Client/Graphics/Clyde/Clyde.LightRendering.cs

@@ -377,6 +377,7 @@ namespace Robust.Client.Graphics.Clyde
             var lastRange = float.NaN;
             var lastPower = float.NaN;
             var lastColor = new Color(float.NaN, float.NaN, float.NaN, float.NaN);
+            var lastSoftness = float.NaN;
             Texture? lastMask = null;
 
             for (var i = 0; i < count; i++)
@@ -424,6 +425,12 @@ namespace Robust.Client.Graphics.Clyde
                     lightShader.SetUniformMaybe("lightColor", lastColor);
                 }
 
+                if (_enableSoftShadows && !MathHelper.CloseTo(lastSoftness, component.Softness))
+                {
+                    lastSoftness = component.Softness;
+                    lightShader.SetUniformMaybe("lightSoftness", lastSoftness);
+                }
+
                 lightShader.SetUniformMaybe("lightCenter", lightPos);
                 lightShader.SetUniformMaybe("lightIndex", (i + 0.5f) / ShadowTexture.Height);