Vertex shader examples not compiling

Unity Engine
1

I’m not having much luck getting the documentation’s vertex shader examples to compile:

For example, the UV 1 shader produced the following errors:

  • GLSL vertex shader: ERROR: 0:33: " : boolean expression expected at line 5
  • Shader program had errors at line 6
  • Program ‘frag’, scalar Boolean expression expected at line 28
  • Parse error: syntax error at line 58

Do the shaders perhaps need to be rewritten for Unity 3?

2

the 1st shader on that page compiles OK.

can you post the code which produces errors?

3

Actually, the issue seems only to occur with UV1 and UV2 shaders (the other errors were my fault):

Shader "!Debug/UV 1" {
SubShader {
    Pass {
        Fog { Mode Off }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag

// vertex input: position, UV
struct appdata {
    float4 vertex;
    float4 texcoord;
};

struct v2f {
    float4 pos : POSITION;
    float4 uv : TEXCOORD0;
};
v2f vert (appdata v) {
    v2f o;
    o.pos = mul( UNITY_MATRIX_MVP, v.vertex );
    o.uv = float4( v.texcoord.xy, 0, 0 );
    return o;
}
half4 frag( v2f i ) : COLOR {
    half4 c = frac( i.uv );
    if( saturate(i.uv) != i.uv )
        c.b = 0.5;
    return c;
}
ENDCG
    }
}
}
4

ok, now I am also interested in knowing why this doesn’t compile

5

Strange… I’m very new to Cg - is vector comparison an uncommon thing to do in a shader, or have I just hit a weird edge case?

I’ve stripped the shader down to the simplest test case:

Shader "!Debug/VectorComparison" {
SubShader {
Pass {
CGPROGRAM
#pragma exclude_renderers gles
#pragma fragment frag

half4 frag() : COLOR {
	if( half4(1,0,0,0) == half4(1,0,0,0) )
		return 1;
	return 0;
}

ENDCG
}
}
}
6

Maybe a bit late, but CG won’t do vector comparison.
You can work around by just do:

float3 myFloat1 = float3(1.0f, 0.0f, 0.0f);
flaot3 myFloat2 = float3(1.0f, 0.0f, 0.0f);

if (myFloat1.r == myFloat2.r && myFloat1.g == myFloat2.g && myFloat1.b == myFloat2.b) {
    // This should work
}
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