ambient & diffuse colours

This commit is contained in:
2024-08-19 00:24:01 +10:00
parent 5a7b53833d
commit 83972502bb
3 changed files with 16 additions and 6 deletions

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@ -37,18 +37,26 @@ fragment half4 fragmentMain(
constexpr metal::sampler sampler(metal::address::repeat, metal::filter::nearest);
auto normal = metal::normalize(in.normal);
// Components for blinn-phong & fresnel
auto lightVec = -u.directionalLight;
float lambert = metal::dot(normal, lightVec);
float diffuse = metal::max(0.0, lambert);
auto eyeVector = metal::normalize(u.cameraPosition - in.world);
auto halfDir = metal::normalize(lightVec + eyeVector);
// Compute diffuse component
float lambert = metal::dot(normal, lightVec);
float diffuseAmount = metal::max(0.0, lambert);
half4 diffuse = half4(u.diffuseColor) * diffuseAmount;
// Compute specular component (blinn-phong)
float specularAngle = metal::max(0.0, metal::dot(halfDir, normal));
float specularTerm = metal::pow(specularAngle, u.specularIntensity);
half4 specularAmount = specularTerm * metal::smoothstep(0, 2, lambert * u.specularIntensity);
// smoothstep hack to ensure highlight tapers gracefully at grazing angles
float specularAmount = specularTerm * metal::smoothstep(0, 2, lambert * u.specularIntensity);
half4 specular = half4(u.specularColor) * specularAmount;
// Sample texture & vertex color to get albedo
half4 albedo = texture.sample(sampler, in.texCoord);
albedo *= in.color;
return albedo * diffuse + half4(u.specularColor) * specularAmount;
return albedo * (half4(u.ambientColor) + diffuse) + specular;
}