Masking shader with alpha Color

Hi !

I'm working on a basic masking shader (texture image + texture mask) that allow one to have any images masked by a texture where all white part are shown and all transparent part are transparent. This works really great but does not support alpha. Indeed I would like to add fadeIn and FadeOut operation to my object with the masking shader. Thus I end up with this :

 Shader "Custom/Masking" {
     Properties
     {
       _Color ("Main Color", Color) = (1, 1, 1, 1)
       _MainTex ("Base (RGBA)", 2D) = "white" {}
       _Mask ("Culling Mask", 2D) = "white" {}
       _Cutoff ("Alpha cutoff", Range (0,1)) = 0.1
      }
      
     SubShader {
         Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
         LOD 200
         
         Lighting Off
         ZWrite Off
         Blend SrcAlpha OneMinusSrcAlpha
         AlphaTest GEqual [_Cutoff]
         
         
         Pass {
           SetTexture [_Mask] {combine texture}
           SetTexture [_MainTex] {
               combine texture, previous * constant ConstantColor[_Color]
           }
           
         }
     } 
 }
 

It is borrowed from the wiki + constantColor is aded to handle alpha ! I works, but, all the texture under this one does not show up. For instance, I have a glow quad behind my masking shader plan. This glow plan appear fine until I add the alpha to the shader plan.

Any help would be appreciate.

Thanks !

P.S : here is the second glow shader :

 Shader "Glow" {
 Properties {
     _TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
     _MainTex ("Particle Texture", 2D) = "white" {}
     _InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
     _GlowTex ("Glow", 2D) = "" {}
     _GlowColor ("Glow Color", Color)  = (1,1,1,1)
     _GlowStrength ("Glow Strength", Float) = 1.0
 }
 
 Category {
     Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderEffect"="Glow11Transparent" "RenderType"="Glow11Transparent"  }
     Blend SrcAlpha OneMinusSrcAlpha
     AlphaTest Greater .01
     ColorMask RGB
     Cull Off Lighting Off ZWrite Off
     BindChannels {
         Bind "Color", color
         Bind "Vertex", vertex
         Bind "TexCoord", texcoord
     }
     
     // ---- Fragment program cards
     SubShader {
         Pass {
         
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma fragmentoption ARB_precision_hint_fastest
             #pragma multi_compile_particles
             
             #include "UnityCG.cginc"
 
             sampler2D _MainTex;
             fixed4 _TintColor;
             
             struct appdata_t {
                 float4 vertex : POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
             };
 
             struct v2f {
                 float4 vertex : POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
                 #ifdef SOFTPARTICLES_ON
                 float4 projPos : TEXCOORD1;
                 #endif
             };
             
             float4 _MainTex_ST;
 
             v2f vert (appdata_t v)
             {
                 v2f o;
                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                 #ifdef SOFTPARTICLES_ON
                 o.projPos = ComputeScreenPos (o.vertex);
                 COMPUTE_EYEDEPTH(o.projPos.z);
                 #endif
                 o.color = v.color;
                 o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
                 return o;
             }
 
             sampler2D _CameraDepthTexture;
             float _InvFade;
             
             fixed4 frag (v2f i) : COLOR
             {
                 #ifdef SOFTPARTICLES_ON
                 float sceneZ = LinearEyeDepth (UNITY_SAMPLE_DEPTH(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos))));
                 float partZ = i.projPos.z;
                 float fade = saturate (_InvFade * (sceneZ-partZ));
                 i.color.a *= fade;
                 #endif
                 
                 return 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
             }
             ENDCG 
         }
     }     
     
     // ---- Dual texture cards
     SubShader {
         Pass {
             SetTexture [_MainTex] {
                 constantColor [_TintColor]
                 combine constant * primary
             }
             SetTexture [_MainTex] {
                 combine texture * previous DOUBLE
             }
         }
     }
     
     // ---- Single texture cards (does not do color tint)
     SubShader {
         Pass {
             SetTexture [_MainTex] {
                 combine texture * primary
             }
         }
     }
 }
 CustomEditor "GlowMatInspector"
 }