sdf interpreter

scripts/format.sh

@@ -14,7 +14,7 @@ $CLANG_FORMAT -i bindings/wasm/*.{js,ts} &
 $CLANG_FORMAT -i bindings/wasm/examples/*.{js,ts,html} &
 $CLANG_FORMAT -i bindings/wasm/examples/public/*.{js,ts} &
 $CLANG_FORMAT -i src/*.{h,cpp} &
-$CLANG_FORMAT -i src/*/*.cpp &
+$CLANG_FORMAT -i src/*/*.{h,cpp} &
 $CLANG_FORMAT -i include/manifold/*.h &
 
 black --quiet bindings/python/examples/*.py &

src/CMakeLists.txt

@@ -29,6 +29,8 @@ set(
   smoothing.cpp
   sort.cpp
   subdivision.cpp
+  sdf/value.cpp
+  sdf/context.cpp
   # optional source files
   $<$<BOOL:${MANIFOLD_CROSS_SECTION}>:cross_section/cross_section.cpp>
   $<$<BOOL:${MANIFOLD_EXPORT}>:meshIO/meshIO.cpp>
@@ -51,6 +53,10 @@ set(
   tri_dist.h
   utils.h
   vec.h
+  sdf/interval.h
+  sdf/tape.h
+  sdf/value.h
+  sdf/context.h
 )
 
 # Include directories

src/sdf.cpp

@@ -477,6 +477,7 @@ Manifold Manifold::LevelSet(std::function<double(vec3)> sdf, Box bounds,
 
   const vec3 origin = bounds.min;
   Vec<double> voxels(maxIndex);
+
   for_each_n(
       pol, countAt(0_uz), maxIndex,
       [&voxels, sdf, level, origin, spacing, gridSize, gridPow](Uint64 idx) {

src/sdf/affine_value.h

@@ -0,0 +1,42 @@
+// Copyright 2024 The Manifold Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+
+#include "context.h"
+
+namespace manifold::sdf {
+struct AffineValue {
+  // value = var * a + b
+  Operand var;
+  double a;
+  double b;
+
+  AffineValue(Operand var, double a, double b) : var(var), a(a), b(b) {}
+  AffineValue(double constant) : var(Operand::none()), a(0.0), b(constant) {}
+  bool operator==(const AffineValue &other) const {
+    return var == other.var && a == other.a && b == other.b;
+  }
+  AffineValue operator+(double d) { return AffineValue(var, a, b + d); }
+  AffineValue operator*(double d) { return AffineValue(var, a * d, b * d); }
+};
+}  // namespace manifold::sdf
+
+template <>
+struct std::hash<AffineValue> {
+  size_t operator()(const AffineValue &value) const {
+    size_t h = std::hash<int>()(value.var.id);
+    hash_combine(h, value.a, value.b);
+    return h;
+  }
+};