Unity3d《Shader篇》绘制圆角图片

Pass
        {
            CGPROGRAM
// Upgrade NOTE: excluded shader from OpenGL ES 2.0 because it does not contain a surface program or both vertex and fragment programs.
#pragma exclude_renderers gles
 
            #pragma fragment frag
            #include "UnityCG.cginc"
 
            sampler2D _MainTex;
            float4 _MainColor;
            float _RoundRadius;
 
            struct texCoord
            {
                float2 inputTexCoord : TEXCOORD0;
            };
 
            float4 frag(texCoord input) : COLOR
            {
                float x = input.inputTexCoord.x;
                float y = input.inputTexCoord.y;
                float4 col = tex2D(_MainTex,input.inputTexCoord)*_MainColor;
 
                float radius = _RoundRadius;
 
                if(x<radius && y<radius)
                {
                    if(pow(x-radius,)+pow(y-radius,)>radius*radius)
                    {
                        discard;
                    }
                }
                else if(x>-radius && y>-radius)
                {
                    if(pow(x-(-radius),)+pow(y-(-radius),)>radius*radius)
                    {
                        discard;
                    }
                }
                else if(x<radius && y>-radius)
                {
                    if(pow(x-radius,)+pow(y-(-radius),)>radius*radius)
                    {
                        discard;
                    }
                }
 
                else if(x>-radius && y<radius)
                {
                    if(pow(x-(-radius),)+pow(y-radius,)>radius*radius)
                    {
                        discard;
                    }
                }
 
                return col;
            }
 
            ENDCG
        }

效果图