47 lines
1.1 KiB
HLSL
47 lines
1.1 KiB
HLSL
#ifndef __SHADER_HELPERS__
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#define __SHADER_HELPERS__
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// gets view vector, needed once per shader
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float3 getView(float3 cameraPosition, float3 pixelWorldPosition)
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{
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return normalize(cameraPosition - pixelWorldPosition);
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}
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// gets reflection vector, needed per light
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float3 getReflection(float3 direction, float3 normal)
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{
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return reflect(direction, normal);
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}
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// gets specular exponent: (1-roughness) * max
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float getSpecularExponent(float roughness, float max)
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{
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return (1.0f - roughness) * max;
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}
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// gets specular value: clamp(dot(r,v))^e
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float getSpecular(float3 view, float3 reflection, float exponent)
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{
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float specular = 0;
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if (exponent > 0.05f)
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{
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specular = pow(saturate(dot(reflection, view)), exponent);
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}
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return specular;
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}
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// gets diffuse value: clamp(dot(n,d))
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float getDiffuse(float3 normal, float3 direction)
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{
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return saturate(dot(normal, direction));
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}
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// gets attenuation: clamp(1 - (distance^2 / range^2))^2
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float getAttenuation(float3 pointPosition, float3 worldPosition, float3 range)
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{
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float dist = distance(pointPosition, worldPosition);
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float attn = saturate(1.0f - (dist * dist / (range * range)));
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return attn * attn;
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}
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#endif
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