Cleanup: remove redundant lerp function, mix already does the same

intern/cycles/blender/curves.cpp

@@ -389,7 +389,7 @@ static float4 LerpCurveSegmentMotionCV(ParticleCurveData *CData, int sys, int cu
   }
   const float4 mP = CurveSegmentMotionCV(CData, sys, curve, first_curve_key + curvekey);
   const float4 mP2 = CurveSegmentMotionCV(CData, sys, curve, first_curve_key + curvekey2);
-  return lerp(mP, mP2, remainder);
+  return mix(mP, mP2, remainder);
 }
 
 static void export_hair_motion_validate_attribute(Hair *hair,
@@ -899,9 +899,9 @@ static float4 interpolate_curve_points(const float (*b_attr_position)[3],
   const int point_a = clamp((int)curve_t, 0, num_points - 1);
   const int point_b = min(point_a + 1, num_points - 1);
   const float t = curve_t - (float)point_a;
-  return lerp(curve_point_as_float4(b_attr_position, b_attr_radius, first_point_index + point_a),
-              curve_point_as_float4(b_attr_position, b_attr_radius, first_point_index + point_b),
-              t);
+  return mix(curve_point_as_float4(b_attr_position, b_attr_radius, first_point_index + point_a),
+             curve_point_as_float4(b_attr_position, b_attr_radius, first_point_index + point_b),
+             t);
 }
 
 static void export_hair_curves(Scene *scene,

intern/cycles/bvh/split.cpp

@@ -360,7 +360,7 @@ void BVHSpatialSplit::split_triangle_primitive(const Mesh *mesh,
 
     /* edge intersects the plane => insert intersection to both boxes. */
     if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) {
-      float3 t = lerp(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
+      float3 t = mix(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
       left_bounds.grow(t);
       right_bounds.grow(t);
     }
@@ -408,7 +408,7 @@ void BVHSpatialSplit::split_curve_primitive(const Hair *hair,
 
   /* edge intersects the plane => insert intersection to both boxes. */
   if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) {
-    float3 t = lerp(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
+    float3 t = mix(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f));
     left_bounds.grow(t);
     right_bounds.grow(t);
   }

intern/cycles/integrator/work_balancer.cpp

@@ -62,7 +62,7 @@ bool work_balance_do_rebalance(vector<WorkBalanceInfo> &work_balance_infos)
   bool has_big_difference = false;
 
   for (const WorkBalanceInfo &info : work_balance_infos) {
-    const double time_target = lerp(info.time_spent, time_average, lerp_weight);
+    const double time_target = mix(info.time_spent, time_average, lerp_weight);
     const double new_weight = info.weight * time_target / info.time_spent;
     new_weights.push_back(new_weight);
     total_weight += new_weight;

intern/cycles/kernel/closure/bsdf_util.h

@@ -96,7 +96,7 @@ ccl_device_forceinline Spectrum interpolate_fresnel_color(float3 L,
 {
   /* Compute the real Fresnel term and remap it from real_F0..1 to F0..1.
    * The reason why we use this remapping instead of directly doing the
-   * Schlick approximation lerp(F0, 1.0, (1.0-cosLH)^5) is that for cases
+   * Schlick approximation mix(F0, 1.0, (1.0-cosLH)^5) is that for cases
    * with similar IORs (e.g. ice in water), the relative IOR can be close
    * enough to 1.0 that the Schlick approximation becomes inaccurate. */
   float real_F = fresnel_dielectric_cos(dot(L, H), ior);

intern/cycles/scene/camera.cpp

@@ -36,7 +36,7 @@ static float shutter_curve_eval(float x, array<float> &shutter_curve)
   int index = (int)x;
   float frac = x - index;
   if (index < shutter_curve.size() - 1) {
-    return lerp(shutter_curve[index], shutter_curve[index + 1], frac);
+    return mix(shutter_curve[index], shutter_curve[index + 1], frac);
   }
   else {
     return shutter_curve[shutter_curve.size() - 1];

intern/cycles/test/render_graph_finalize_test.cpp

@@ -1291,7 +1291,7 @@ template<class T> void init_test_curve(array<T> &buffer, T start, T end, int ste
   buffer.resize(steps);
 
   for (int i = 0; i < steps; i++) {
-    buffer[i] = lerp(start, end, float(i) / (steps - 1));
+    buffer[i] = mix(start, end, float(i) / (steps - 1));
   }
 }
 

intern/cycles/util/math.h

@@ -555,16 +555,6 @@ CCL_NAMESPACE_END
 
 CCL_NAMESPACE_BEGIN
 
-#if !defined(__KERNEL_METAL__)
-/* Interpolation */
-
-template<class A, class B> A lerp(const A &a, const A &b, const B &t)
-{
-  return (A)(a * ((B)1 - t) + b * t);
-}
-
-#endif /* __KERNEL_METAL__ */
-
 /* Triangle */
 
 ccl_device_inline float triangle_area(ccl_private const float3 &v1,

intern/cycles/util/transform.h

@@ -379,7 +379,7 @@ ccl_device_inline Transform transform_empty()
 
 ccl_device_inline float4 quat_interpolate(float4 q1, float4 q2, float t)
 {
-  /* Optix and MetalRT are using lerp to interpolate motion transformations. */
+  /* Optix and MetalRT are using linear interpolation to interpolate motion transformations. */
 #if defined(__KERNEL_GPU_RAYTRACING__)
   return normalize((1.0f - t) * q1 + t * q2);
 #else  /* defined(__KERNEL_GPU_RAYTRACING__) */