From 12c223b5b8bf1860d77f41551cf9e5374196aed7 Mon Sep 17 00:00:00 2001
From: yum <yum.food.vr@gmail.com>
Date: Sat, 1 Nov 2025 11:45:25 -0700
Subject: meow

---
 vertex.cginc | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 123 insertions(+), 1 deletion(-)

(limited to 'vertex.cginc')

diff --git a/vertex.cginc b/vertex.cginc
index 303fc00..cd3382c 100644
--- a/vertex.cginc
+++ b/vertex.cginc
@@ -178,7 +178,129 @@ void deform_normal(inout float3 objPos, inout float3 objNorm, inout float3 objTa
 //  3. Repeat step 2 until we're back in the un-deforme coordinate system. At
 //     each step, we use the cached objPos from the forward pass (step 1), so
 //     that we evaluate the normal deformation at the correct point in space.
-void undeform_normal(float3 objPos, inout float3 objNorm, inout float3 objTan) {
+void undeform_normal(inout float3 objPos, inout float3 objNorm, inout float3 objTan) {
+  const float t = getTime();
+  const int kMaxDeformations = 8;
+  // Cache each intermediate position so we can undo stages in reverse order.
+  float3 posHistory[kMaxDeformations + 1];
+  int posCount = 0;
+  posHistory[posCount++] = objPos;
+
+#if defined(_VERTEX_DEFORMATION_XZ_TUBE)
+  {
+    VERTEX_DEFORM_XZ_TUBE_PREAMBLE;
+    VERTEX_DEFORM_XZ_TUBE_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_YZ_TUBE)
+  {
+    VERTEX_DEFORM_YZ_TUBE_PREAMBLE;
+    VERTEX_DEFORM_YZ_TUBE_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_XY_TUBE)
+  {
+    VERTEX_DEFORM_XY_TUBE_PREAMBLE;
+    VERTEX_DEFORM_XY_TUBE_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_SEAL)
+  {
+    VERTEX_DEFORM_SEAL_PREAMBLE;
+    VERTEX_DEFORM_SEAL_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_SINE_WAVES)
+  {
+    VERTEX_DEFORM_SINE_WAVES_PREAMBLE;
+    VERTEX_DEFORM_SINE_WAVES_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_FBM)
+  {
+    VERTEX_DEFORM_FBM_PREAMBLE;
+    VERTEX_DEFORM_FBM_POS;
+    posHistory[posCount++] = objPos;
+  }
+#endif
+  float3 objPos_deformed = objPos;
+
+  int cursor = posCount - 1;
+  objPos = posHistory[cursor];
+
+#if defined(_VERTEX_DEFORMATION_FBM)
+  if (cursor > 0) {
+    VERTEX_DEFORM_FBM_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    fbm_undeform_normal(stageInput, st, amplitude, gain, lacunarity, scale,
+        octaves, velocity, objNorm, objTan);
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_SINE_WAVES)
+  if (cursor > 0) {
+    VERTEX_DEFORM_SINE_WAVES_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    sine_wave_undeform_normal(stageInput, objNorm, objTan, amplitude, direction,
+        k, omega, st);
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_SEAL)
+  if (cursor > 0) {
+    VERTEX_DEFORM_SEAL_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    seal_undeform_normal(stageInput, objNorm, objTan, A, k, st);
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_XY_TUBE)
+  if (cursor > 0) {
+    VERTEX_DEFORM_XY_TUBE_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    float3 xyPos = stageInput.xzy;
+    float3 xyNorm = objNorm.xzy;
+    float3 xyTan = objTan.xzy;
+    plane_to_tube_undeform_normal(xyPos, xyNorm, xyTan, t);
+    objNorm = xyNorm.xzy;
+    objTan = xyTan.xzy;
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_YZ_TUBE)
+  if (cursor > 0) {
+    VERTEX_DEFORM_YZ_TUBE_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    float3 yzPos = stageInput.yxz;
+    float3 yzNorm = objNorm.yxz;
+    float3 yzTan = objTan.yxz;
+    plane_to_tube_undeform_normal(yzPos, yzNorm, yzTan, t);
+    objNorm = yzNorm.yxz;
+    objTan = yzTan.yxz;
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+#if defined(_VERTEX_DEFORMATION_XZ_TUBE)
+  if (cursor > 0) {
+    VERTEX_DEFORM_XZ_TUBE_PREAMBLE;
+    float3 stageInput = posHistory[cursor - 1];
+    plane_to_tube_undeform_normal(stageInput, objNorm, objTan, t);
+    objPos = stageInput;
+    cursor -= 1;
+  }
+#endif
+
+  objPos = objPos_deformed;
 }
 
 void propagateObjPos(inout v2f i) {
-- 
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