fix cube performance

src/manifold/src/constructors.cpp

@@ -153,10 +153,9 @@ Manifold Manifold::Cube(glm::vec3 size, bool center) {
       glm::length(size) == 0.) {
     return Invalid();
   }
-  auto cube = Manifold(std::make_shared<Impl>(Impl::Shape::Cube));
-  cube = cube.Scale(size);
-  if (center) cube = cube.Translate(-size / 2.0f);
-  return cube.AsOriginal();
+  glm::mat4x3 m =
+      glm::translate(center ? (-size / 2.0f) : glm::vec3(0)) * glm::scale(size);
+  return Manifold(std::make_shared<Impl>(Manifold::Impl::Shape::Cube, m));
 }
 
 /**

src/manifold/src/impl.cpp

@@ -534,7 +534,7 @@ Manifold::Impl::Impl(const Mesh& mesh, const MeshRelationD& relation,
  * Create either a unit tetrahedron, cube or octahedron. The cube is in the
  * first octant, while the others are symmetric about the origin.
  */
-Manifold::Impl::Impl(Shape shape) {
+Manifold::Impl::Impl(Shape shape, const glm::mat4x3 m) {
   std::vector<glm::vec3> vertPos;
   std::vector<glm::ivec3> triVerts;
   switch (shape) {
@@ -547,19 +547,19 @@ Manifold::Impl::Impl(Shape shape) {
       break;
     case Shape::Cube:
       vertPos = {{0.0f, 0.0f, 0.0f},  //
-                 {1.0f, 0.0f, 0.0f},  //
-                 {1.0f, 1.0f, 0.0f},  //
-                 {0.0f, 1.0f, 0.0f},  //
                  {0.0f, 0.0f, 1.0f},  //
+                 {0.0f, 1.0f, 0.0f},  //
+                 {0.0f, 1.0f, 1.0f},  //
+                 {1.0f, 0.0f, 0.0f},  //
                  {1.0f, 0.0f, 1.0f},  //
-                 {1.0f, 1.0f, 1.0f},  //
-                 {0.0f, 1.0f, 1.0f}};
-      triVerts = {{0, 2, 1}, {0, 3, 2},  //
-                  {4, 5, 6}, {4, 6, 7},  //
-                  {0, 1, 5}, {0, 5, 4},  //
-                  {1, 2, 6}, {1, 6, 5},  //
-                  {2, 3, 7}, {2, 7, 6},  //
-                  {3, 0, 4}, {3, 4, 7}};
+                 {1.0f, 1.0f, 0.0f},  //
+                 {1.0f, 1.0f, 1.0f}};
+      triVerts = {{1, 0, 4}, {2, 4, 0},  //
+                  {1, 3, 0}, {3, 1, 5},  //
+                  {3, 2, 0}, {3, 7, 2},  //
+                  {5, 4, 6}, {5, 1, 4},  //
+                  {6, 4, 2}, {7, 6, 2},  //
+                  {7, 3, 5}, {7, 5, 6}};
       break;
     case Shape::Octahedron:
       vertPos = {{1.0f, 0.0f, 0.0f},   //
@@ -575,6 +575,7 @@ Manifold::Impl::Impl(Shape shape) {
       break;
   }
   vertPos_ = vertPos;
+  for (auto& v : vertPos_) v = m * glm::vec4(v, 1.0f);
   CreateHalfedges(triVerts);
   Finish();
   meshRelation_.originalID = ReserveIDs(1);

src/manifold/src/impl.h

@@ -59,7 +59,7 @@ struct Manifold::Impl {
 
   Impl() {}
   enum class Shape { Tetrahedron, Cube, Octahedron };
-  Impl(Shape);
+  Impl(Shape, const glm::mat4x3 = glm::mat4x3(1));
 
   Impl(const MeshGL&, std::vector<float> propertyTolerance = {});
   Impl(const Mesh&, const MeshRelationD& relation,

test/boolean_test.cpp

@@ -55,7 +55,7 @@ TEST(Boolean, MeshGLRoundTrip) {
   const Manifold result2(inGL);
 
   ASSERT_LT(result2.OriginalID(), 0);
-  ExpectMeshes(result2, {{18, 32}});
+  ExpectMeshes(result2, {{16, 28}});
   RelatedGL(result2, {original});
 
   const MeshGL outGL = result2.GetMeshGL();