toGeometry static method

BufferGeometry toGeometry(CSG csg, Matrix4 toMatrix)

Implementation

static BufferGeometry toGeometry(CSG csg, Matrix4 toMatrix){
  int triCount = 0;
  final ps = csg.polygons;
  for (final p in ps) {
    triCount += p.vertices.length - 2;
  }
  final geom = BufferGeometry();

  final vertices = NBuf3(triCount * 3 * 3);
  final normals = NBuf3(triCount * 3 * 3);
  final uvs = NBuf2(triCount * 2 * 3);
  NBuf3? colors;
  final Map<int,List<int>> grps = {};
  final List<int> dgrp = [];
  for (final p in ps) {
    final pvs = p.vertices;
    final pvlen = pvs.length;
    if (p.shared != null) {
      if (grps[p.shared!] == null) grps[p.shared!] = [];
    }
    if (pvlen > 0 && pvs[0].color != null) {
      colors ??= NBuf3(triCount * 3 * 3);
    }
    for (int j = 3; j <= pvlen; j++) {
      final grp = p.shared == null ? dgrp : grps[p.shared!];
      grp!.addAll([vertices.top ~/ 3, vertices.top ~/ 3 + 1, vertices.top ~/ 3 + 2]);
      vertices.write(pvs[0].position);
      vertices.write(pvs[j - 2].position);
      vertices.write(pvs[j - 1].position);
      normals.write(pvs[0].normal);
      normals.write(pvs[j - 2].normal);
      normals.write(pvs[j - 1].normal);
      //if (uvs != null) {
        uvs.write(pvs[0].uv);
        uvs.write(pvs[j - 2].uv);
        uvs.write(pvs[j - 1].uv);
      //}

      if (colors != null) {
        colors.write(pvs[0].color!);
        colors.write(pvs[j - 2].color!);
        colors.write(pvs[j - 1].color!);
      }
    }
  }
  geom.setAttributeFromString('position', Float32BufferAttribute.fromList(vertices.array, 3));
  geom.setAttributeFromString('normal', Float32BufferAttribute.fromList(normals.array, 3));
  //if(uvs != null)
  geom.setAttributeFromString('uv', Float32BufferAttribute.fromList(uvs.array, 2));
  if(colors != null) geom.setAttributeFromString('color', Float32BufferAttribute.fromList(colors.array, 3));
  for (int gi = 0; gi < grps.length; gi++) {
    if (grps[gi] == null) {
      grps[gi] = [];
    }
  }
  if (grps.isNotEmpty) {
    List<int> index = [];
    int gbase = 0;
    for (int gi = 0; gi < grps.length; gi++) {
      geom.addGroup(gbase, grps[gi]!.length, gi);
      gbase += grps[gi]!.length;
      index = List.from(index)..addAll(grps[gi]!);
    }
    geom.addGroup(gbase, dgrp.length, grps.length);
    index = List.from(index)..addAll(dgrp);
    geom.setIndex(index);
  }
  final inv = Matrix4().setFrom(toMatrix).invert();
  geom.applyMatrix4(inv);
  geom.computeBoundingSphere();
  geom.computeBoundingBox();

  return geom;
}