GHZMRClassXR/Assets/Mirza Beig/Shaders/Particles/Mask/Mask-Alpha.shader

Shader "Mirza Beig/Particles/Mask/Alpha Blended"
{
	Properties
	{
		_TintColor("Tint Color", Color) = (0.5, 0.5, 0.5, 0.5)

		_MainTex("Particle Texture", 2D) = "white" {}
		_MaskTex	("Mask Texture", 2D) = "white" {}

		_InvFade("Soft Particles Factor", Range(0.01, 8.0)) = 1.0
	}

	Category
	{
		Tags { "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }

		Blend SrcAlpha OneMinusSrcAlpha
		AlphaTest Greater .01
		ColorMask RGB
		Cull Off Lighting Off ZWrite Off

		SubShader {
			Pass {

				CGPROGRAM

				#pragma vertex vert
				#pragma fragment frag
				#pragma multi_compile_particles
				#pragma multi_compile_fog

				#include "UnityCG.cginc"

				sampler2D _MainTex;
				sampler2D _MaskTex;

				fixed4 _TintColor;

				struct appdata_t 
				{
					float4 vertex : POSITION;
					fixed4 color : COLOR;

					float2 texcoord : TEXCOORD0;
					float2 texcoord2 : TEXCOORD1;
				};

				struct v2f 
				{
					float4 vertex : SV_POSITION;
					fixed4 color : COLOR;

					float2 texcoord : TEXCOORD0;
					float2 texcoord2 : TEXCOORD1;

	#ifdef SOFTPARTICLES_ON
						float4 projPos : TEXCOORD2;
	#endif

					UNITY_FOG_COORDS(3)
				};

				float4 _MainTex_ST;
				float4 _MaskTex_ST;

				v2f vert(appdata_t v)
				{
					v2f o;
					o.vertex = UnityObjectToClipPos(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);
					o.texcoord2 = TRANSFORM_TEX(v.texcoord2, _MaskTex);

					UNITY_TRANSFER_FOG(o, o.vertex);

					return o;
				}

				sampler2D_float _CameraDepthTexture;
				float _InvFade;

				uniform float _alphaCutoffThreshold;
				uniform float _textureBased;

				fixed4 frag(v2f i) : SV_Target
				{
					// Get texture colour.

					float4 texColour = tex2D(_MainTex, i.texcoord);
					float4 maskColour = tex2D(_MaskTex, i.texcoord2);

					//texColour = maskColour;
					texColour.a *= maskColour.a;

					// Tint.

					fixed4 colour = _TintColor * texColour;

					#ifdef SOFTPARTICLES_ON

					// Scene depth.

					//float sceneZ = LinearEyeDepth(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)).r);
					float sceneZ = LinearEyeDepth(SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));

					// Distance to the camera.

					float partZ = i.projPos.z;

					// Soft particles (soft factor).
					// "Comparing depth values of the particle with depth values of world geometry (in view space)." - Special Effects with Depth (Siggraph, 2011).

					// float softFactor = saturate((depthEye - zEye) * fade)

					// Inverse fade: 0.0f = off.

					float fade = saturate(_InvFade * (sceneZ - partZ));
					colour.a *= fade;

				#endif

					// Input colour.

					colour *= i.color * 2.0f;

					// Alpha test. Automatic cutoff inversion detection.
					// Could use an if-statement, but I think that's slower?

					float alphaCutoffSign = sign(_alphaCutoffThreshold);
					clip(alphaCutoffSign * ((!_textureBased ? colour.a : texColour.a) - _alphaCutoffThreshold * alphaCutoffSign));

					// Fog towards nothing.

					UNITY_APPLY_FOG(i.fogCoord, colour);

					return colour;
				}
				ENDCG
			}
		}
	}
}