// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Unlit/AlphaTexture"
{
	Properties{
		_MainTex("Base (RGB)", 2D) = "white" {}
		_Color("Color",Color) = (1,1,1,1)
	}
	
	SubShader{
		Tags{ "RenderType" = "Queue" "Queue" = "Transparent" } // "Queue"="Transparent"将其设置为透明，不然无法看见后面的东西（即使透明）  
		Blend SrcAlpha OneMinusSrcAlpha //实现Alpha的核心，使用语句进行Alpha混合  
		
		Pass{
			CGPROGRAM
			#pragma vertex vert    
			#pragma fragment frag    

			#include "UnityCG.cginc"    

			sampler2D _MainTex;
			float4 _Color;

			struct v2f {
				float4 pos : POSITION;
				float2 uv : TEXCOORD0;
				//float3 color : TEXCOORD1;
			};

			v2f vert(appdata_base v) {
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				//TRANSFORM_TEX是在_MainTex_ST中的宏  
				//原始方法o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);  
				//将uv贴图的坐标取出来  
				o.uv = v.texcoord;
				//o.color = ShadeVertexLights(v.vertex, v.normal);取得法线贴图的光照    
				return o;
			}

			float4 frag(v2f i) : COLOR{
				half4 c = tex2D(_MainTex, i.uv);
				//在这个位置接收i.color的话可以接收光照    
				c.rgb = c.rgb * _Color;
				return c*_Color;
			}
			ENDCG
		}
	}
}