此shader需和EmojiText配合使用
主要设计原理是重写 protected override void OnPopulateMesh(VertexHelper vertex)函数
改变里面的UV坐标，文字的坐标设计为小于等于0.5，表情符则大于0.5。在shader中则小等0.5时取_MainTex纹理的像素，大于则取_emoji纹理中的像素，实际效果请看我Unity3D多线程UI
Shader "Custom/UIEmoji"
{
Properties
{
_emoji("Sprite Texture", 2D) = "white" {}
[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
_Color("Tint", Color) = (1,1,1,1)
_StencilComp("Stencil Comparison", Float) = 8
_Stencil("Stencil ID", Float) = 0
_StencilOp("Stencil Operation", Float) = 0
_StencilWriteMask("Stencil Write Mask", Float) = 255
_StencilReadMask("Stencil Read Mask", Float) = 255
_ColorMask("Color Mask", Float) = 15
[Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip", Float) = 0
}
SubShader
{
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"PreviewType" = "Plane"
"CanUseSpriteAtlas" = "True"
}
Stencil
{
Ref[_Stencil]
Comp[_StencilComp]
Pass[_StencilOp]
ReadMask[_StencilReadMask]
WriteMask[_StencilWriteMask]
}
Cull Off
Lighting Off
ZWrite Off
ZTest[unity_GUIZTestMode]
Blend SrcAlpha OneMinusSrcAlpha
ColorMask[_ColorMask]
Pass
{
Name "Default"
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
#include "UnityCG.cginc"
#include "UnityUI.cginc"
#pragma multi_compile __ UNITY_UI_ALPHACLIP
struct appdata_t
{
float4 vertex : POSITION;
float4 color : COLOR;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
float4 color : COLOR;
float2 texcoord : TEXCOORD0;
float4 worldPosition : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
fixed4 _Color;
fixed4 _TextureSampleAdd;
float4 _ClipRect;
v2f vert(appdata_t IN)
{
v2f OUT;
UNITY_SETUP_INSTANCE_ID(IN);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);
OUT.worldPosition = IN.vertex;
OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);
OUT.texcoord = IN.texcoord;
OUT.color = IN.color * _Color;
return OUT;
}
sampler2D _MainTex;
sampler2D _emoji;
fixed4 frag(v2f IN) : SV_Target
{
half4 color;
if (IN.texcoord.x > 0.5)
{
IN.texcoord.x -= 0.5;
IN.texcoord.x *= 2;
color = tex2D(_emoji, IN.texcoord);
color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);
}
else {
IN.texcoord.x *= 2;
color = (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd);
color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);
color.xyz = IN.color.xyz;
#ifdef UNITY_UI_ALPHACLIP
clip(color.a - 0.001);
#endif
}
return color;
}
ENDCG
}
}
}
