Shader 2

float4x4 wvp : register( c0 );
float4x4 world : register( c5 );

#ifdef USE_LIGHTING

#define MAX_LIGHTS 16

    float3 lightPosition[ MAX_LIGHTS ] : register( c[10] );
    float3 lightColor[ MAX_LIGHTS ] : register( c[27] );
    float lightRange[ MAX_LIGHTS ] : register( c[44] );
    float3 ambientColor : register( c[61] );
    float lightCount : register( c[62] );
#endif

struct VS_INPUT {
    float4 position : POSITION;
    float2 texcoord : TEXCOORD0;
    float4 color : COLOR0;
};

struct VS_OUTPUT {
    float4 position : POSITION;
    float2 texcoord : TEXCOORD0;
    float4 color : TEXCOORD1;
};

VS_OUTPUT main( VS_INPUT input ) {
    VS_OUTPUT output;

    output.position = mul( wvp, input.position );
    output.texcoord = input.texcoord;

#ifdef USE_LIGHTING
    float4 worldPos = mul( world, input.position );
    output.color = float4( ambientColor.xyz * input.color.xyz, 1.0f );
    for( int i = 0; i < (int)lightCount; i++ ) {
        float distance = length( worldPos - lightPosition[i] );
        float attenuation = saturate( lightRange[i].x * 1.25f / ( 1 + distance * distance ));
        output.color.xyz += lightColor[i].xyz * attenuation;
    }
    output.color = saturate( output.color );
#else
    output.color = input.color;
#endif

    return output;
};