Add fade exponent

osu.Game.Resources/Shaders/sh_CursorTrail.vs

@@ -15,6 +15,7 @@ uniform mat3 g_ToMaskingSpace;
 uniform mat3 g_ToDrawingSpace;
 
 uniform float g_FadeClock;
+uniform float g_FadeExponent;
 
 void main(void)
 {
@@ -26,7 +27,7 @@ void main(void)
     vec3 drawingPos = g_ToDrawingSpace * vec3(m_Position, 1.0);
     v_DrawingPosition = drawingPos.xy / drawingPos.z;
 
-    v_Colour = vec4(m_Colour.rgb, m_Colour.a * pow(clamp(m_Time - g_FadeClock, 0.0, 1.0), 1.7));
+    v_Colour = vec4(m_Colour.rgb, m_Colour.a * pow(clamp(m_Time - g_FadeClock, 0.0, 1.0), g_FadeExponent));
      
     v_TexCoord = m_TexCoord;
     v_TexRect = m_TexRect;

osu.Game.Resources/Shaders/sh_LegacyCursorTrail.vs

@@ -1,35 +0,0 @@
-attribute vec2 m_Position;
-attribute vec4 m_Colour;
-attribute vec2 m_TexCoord;
-attribute vec4 m_TexRect;
-attribute float m_Time;
-
-varying vec2 v_DrawingPosition;
-varying vec2 v_MaskingPosition;
-varying vec4 v_Colour;
-varying vec2 v_TexCoord;
-varying vec4 v_TexRect;
-
-uniform mat4 g_ProjMatrix;
-uniform mat3 g_ToMaskingSpace;
-uniform mat3 g_ToDrawingSpace;
-
-uniform float g_FadeClock;
-
-void main(void)
-{
-    // Transform to position to masking space.
-    vec3 maskingPos = g_ToMaskingSpace * vec3(m_Position, 1.0);
-    v_MaskingPosition = maskingPos.xy / maskingPos.z;
-
-    // Transform to position to masking space.
-    vec3 drawingPos = g_ToDrawingSpace * vec3(m_Position, 1.0);
-    v_DrawingPosition = drawingPos.xy / drawingPos.z;
-
-    v_Colour = vec4(m_Colour.rgb, m_Colour.a * clamp(m_Time - g_FadeClock, 0.0, 1.0));
-     
-    v_TexCoord = m_TexCoord;
-    v_TexRect = m_TexRect;
-    
-    gl_Position = g_ProjMatrix * vec4(m_Position, 1.0, 1.0);
-}