#include "shadertypes.h" #include struct FragmentInput { float4 position [[position]]; float3 world; float3 normal; float2 texCoord; half4 color; }; vertex FragmentInput vertexMain( uint vertexID [[vertex_id]], uint instanceID [[instance_id]], device const ShaderVertex* vtx [[buffer(VertexShaderInputIdxVertices)]], device const VertexShaderInstance* i [[buffer(VertexShaderInputIdxInstance)]], constant VertexShaderUniforms& u [[buffer(VertexShaderInputIdxUniforms)]] ) { auto position = vtx[vertexID].position; auto world = i[instanceID].model * float4(position, 1); FragmentInput out; out.position = u.projView * world; out.world = world.xyz; out.color = half4(vtx[vertexID].color) * half4(i[instanceID].color); out.normal = (i[instanceID].normalModel * float4(vtx[vertexID].normal, 0)).xyz; out.texCoord = vtx[vertexID].texCoord; return out; } fragment half4 fragmentMain( FragmentInput in [[stage_in]], metal::texture2d texture [[texture(0)]], constant FragmentShaderUniforms& u [[buffer(FragmentShaderInputIdxUniforms)]] ) { 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; 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); // 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 *= half4(in.color); return albedo * (half4(u.ambientColor) + diffuse) + specular; }