rewrite dogshit ai code, make less ass

2 files changed, 21 insertions, 24 deletions

diff --git a/3ner.shader b/3ner.shader
index bb14f24..0819f3d 100644
--- a/3ner.shader
+++ b/3ner.shader
@@ -210,7 +210,7 @@ Shader "yum_food/3ner"
               _Vertex_Deformation_XZ_Tube_p("p", Vector) = (0, 0, 1)
               _Vertex_Deformation_XZ_Tube_r("r", Vector) = (0, 0, -1)
               _Vertex_Deformation_XZ_Tube_s("s", Vector) = (0, 0, -1)
-              _Vertex_Deformation_XZ_Tube_t("t", Range(-1,1)) = 0
+              _Vertex_Deformation_XZ_Tube_t("t", Range(-1,4)) = 0
             [HideInInspector] m_end_Vertex_Deformation_XZ_Tube("XZ Tube", Float) = 0
             //endex
 
@@ -220,7 +220,7 @@ Shader "yum_food/3ner"
               _Vertex_Deformation_YZ_Tube_p("p", Vector) = (0, 0, 1)
               _Vertex_Deformation_YZ_Tube_r("r", Vector) = (0, 0, -1)
               _Vertex_Deformation_YZ_Tube_s("s", Vector) = (0, 0, -1)
-              _Vertex_Deformation_YZ_Tube_t("t", Range(-1,1)) = 0
+              _Vertex_Deformation_YZ_Tube_t("t", Range(-1,4)) = 0
             [HideInInspector] m_end_Vertex_Deformation_YZ_Tube("YZ Tube", Float) = 0
             //endex
 
@@ -230,7 +230,7 @@ Shader "yum_food/3ner"
               _Vertex_Deformation_XY_Tube_p("p", Vector) = (0, 0, 1)
               _Vertex_Deformation_XY_Tube_r("r", Vector) = (0, 0, -1)
               _Vertex_Deformation_XY_Tube_s("s", Vector) = (0, 0, -1)
-              _Vertex_Deformation_XY_Tube_t("t", Range(-1,1)) = 0
+              _Vertex_Deformation_XY_Tube_t("t", Range(-1,4)) = 0
             [HideInInspector] m_end_Vertex_Deformation_XY_Tube("XY Tube", Float) = 0
             //endex
           [HideInInspector] m_end_Vertex_Deformation_Tubes("Tubes", Float) = 0
diff --git a/vertex_deformation.slang b/vertex_deformation.slang
index dc77516..c193889 100644
--- a/vertex_deformation.slang
+++ b/vertex_deformation.slang
@@ -110,29 +110,26 @@ public float3 plane_to_tube(float3 xyz,
 
   // Components in pivot basis: n (neutral axis), b (tangential), h (axial s).
   float epsilon = 1e-4f;
-  float r = xyz.x;     // neutral-axis coordinate
-  float s = xyz.y;     // axial coordinate along s_cart
-  float rxs = xyz.z;   // tangential coordinate along rxs_cart
-
-  float r0 = length(float2(r, rxs));     // |(r, rxs)| at identity
-  float r1 = max(abs(r), epsilon);       // target radius |r|
-
-  // Directions for identity and wrapped states in the (n, b) plane.
-  float2 dir0 = float2(r, rxs) / max(r0, epsilon);
-  float theta_wrap = rxs / r1;           // theta = w / r per derivation
-  float signish = r / r1;                // preserves sign of r without branch
-  float2 dir1 = float2(signish * cos(theta_wrap), sin(theta_wrap));
-
-  // Shortest-arc angular blend (delta = atan2(cross, dot)) without branchy conditionals.
-  float dot01 = clamp(dot(dir0, dir1), -1.0f, 1.0f);
-  float cross01 = dir0.x * dir1.y - dir0.y * dir1.x;
-  float delta = atan2(cross01, dot01);
-  float theta0 = atan2(dir0.y, dir0.x);
-  float theta_p = theta0 + t * delta;
+  float r = xyz.x;     // Lr
+  float s = xyz.y;     // Lv0 x Lr
+  float rxs = xyz.z;   // Lv0
+
+  // Blend between two vectors:
+  //  v0: vector of length ||Lr + Lv0|| at angle atan2(Lv0, Lr)
+  //  v1: vector of length ||Lr|| at angle ||Lv0|| / ||Lr||
+  // Interpolate in polar coordinates to make it wrap nicely.
+  float radius_src = length(float2(r, rxs));
+  float radius_dst = max(abs(r), epsilon);
+
+  float angle_src = atan2(rxs, r);
+  float angle_dst = rxs / radius_dst;
+
+  float delta = angle_dst - angle_src;
+  float angle = angle_src + t * delta;
 
   // Radial interpolation per derivation.
-  float radius = dlerp(r0, r1, t);
-  float2 nb_t = float2(cos(theta_p), sin(theta_p)) * radius;
+  float radius = dlerp(radius_src, radius_dst, t);
+  float2 nb_t = float2(cos(angle), sin(angle)) * radius;
 
   // Reconstruct with preserved axial component.
   xyz = float3(nb_t.x, s, nb_t.y);