Adjust cursor trail easing

osu.Game.Resources/Shaders/sh_CursorTrail.vs

@@ -24,7 +24,8 @@ 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 * clamp(m_Time - g_FadeClock, 0.0, 1.0));
+    v_Colour = vec4(m_Colour.rgb, m_Colour.a * pow(clamp(m_Time - g_FadeClock, 0.0, 1.0), 1.7));
+     
 	v_TexCoord = m_TexCoord;
 	gl_Position = g_ProjMatrix * vec4(m_Position, 1.0, 1.0);
 }