R/00_triangle.R

In mdsumner/sc: Common Forms for Complex Hierarchical and Relational Data Structures

## this all stuff belongs in silicate (rgl)
## pondering sc_quad (or just sc_primitive, because quads can be triangles)



sc_triangle <- function(x, ...) {
  UseMethod("sc_triangle")
}

sc_triangle.default <- function(x, ...) {
  sc_triangle(silicate::TRI0(x), ...)
}

sc_triangle.TRI0 <- function(x, ...) {
  obj <- sc_object(x)
  topol <- obj$topology_
  for (i in seq_along(topol)) {
    topol[[i]][["object_"]] <- as.character(i)
  }
  do.call(rbind, topol)
}

sc_triangle.TRI <- function(x, ...) {
  x[["triangle"]]
}

sc_triangle.mesh3d <- function(x, ...) {
  tri <- x[["it"]]
  if (is.null(tri)) stop("no triangles in this model")  ## could convert quads, though

  tibble::tibble(.vx0 = tri[1L, ],
                 .vx1 = tri[2L, ],
                 .vx2 = tri[3L, ])  ## visible = TRUE, object_ = 1 ??
}