1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
#' Low-level wk filters and handlers
#'
#' @inheritParams wk::wk_handle
#' @param projection,s2_projection One of [s2_projection_plate_carree()] or
#' [s2_projection_mercator()]
#' @param tessellate_tol,s2_tessellate_tol An angle in radians.
#' Points will not be added if a line segment is within this
#' distance of a point.
#' @param x_scale The maximum x value of the projection
#' @param centre The center point of the orthographic projection
#' @param epsilon_east_west,epsilon_north_south Use a positive number to
#' define the edges of a Cartesian world slightly inward from -180, -90,
#' 180, 90. This may be used to define a world outline for a projection where
#' projecting at the extreme edges of the earth results in a non-finite value.
#' @inheritParams as_s2_geography
#'
#' @return
#' - `s2_projection_plate_carree()`, `s2_projection_mercator()`: An external pointer
#' to an S2 projection.
#' @importFrom wk wk_handle
#' @export
#'
wk_handle.s2_geography <- function(handleable, handler, ...,
s2_projection = s2_projection_plate_carree(),
s2_tessellate_tol = Inf) {
stopifnot(is.null(s2_projection) || inherits(s2_projection, "s2_projection"))
attr(handleable, "s2_projection") <- s2_projection
if (identical(s2_tessellate_tol, Inf)) {
.Call(c_s2_handle_geography, handleable, wk::as_wk_handler(handler))
} else {
attr(handleable, "s2_tessellate_tol") <- as.double(s2_tessellate_tol)[1]
.Call(c_s2_handle_geography_tessellated, handleable, wk::as_wk_handler(handler))
}
}
#' @rdname wk_handle.s2_geography
#' @export
s2_geography_writer <- function(oriented = FALSE, check = TRUE,
projection = s2_projection_plate_carree(),
tessellate_tol = Inf) {
stopifnot(is.null(projection) || inherits(projection, "s2_projection"))
wk::new_wk_handler(
.Call(
c_s2_geography_writer_new,
as.logical(oriented)[1],
as.logical(check)[1],
projection,
as.double(tessellate_tol[1])
),
"s2_geography_writer"
)
}
#' @rdname wk_handle.s2_geography
#' @importFrom wk wk_writer
#' @method wk_writer s2_geography
#' @export
wk_writer.s2_geography <- function(handleable, ...) {
s2_geography_writer()
}
#' @rdname wk_handle.s2_geography
#' @export
s2_trans_point <- function() {
wk::new_wk_trans(.Call(c_s2_trans_s2_point_new))
}
#' @rdname wk_handle.s2_geography
#' @export
s2_trans_lnglat <- function() {
wk::new_wk_trans(.Call(c_s2_trans_s2_lnglat_new))
}
#' @rdname wk_handle.s2_geography
#' @export
s2_projection_plate_carree <- function(x_scale = 180) {
structure(
.Call(c_s2_projection_plate_carree, as.double(x_scale)[1]),
class = "s2_projection"
)
}
#' @rdname wk_handle.s2_geography
#' @export
s2_projection_mercator <- function(x_scale = 20037508.3427892) {
structure(
.Call(c_s2_projection_mercator, as.double(x_scale)[1]),
class = "s2_projection"
)
}
#' @rdname wk_handle.s2_geography
#' @export
s2_hemisphere <- function(centre) {
cap_to_polygon(centre, pi / 2)
}
#' @rdname wk_handle.s2_geography
#' @export
s2_world_plate_carree <- function(epsilon_east_west = 0, epsilon_north_south = 0) {
s2_make_polygon(
c(
-180 + epsilon_east_west, 0, 180 - epsilon_east_west,
180 - epsilon_east_west, 180 - epsilon_east_west, 0,
-180 + epsilon_east_west, -180 + epsilon_east_west
),
c(
-90 + epsilon_north_south, -90 + epsilon_north_south,
-90 + epsilon_north_south, 0, 90 - epsilon_north_south,
90 - epsilon_north_south, 90 - epsilon_north_south, 0
),
oriented = TRUE
)
}
#' @rdname wk_handle.s2_geography
#' @export
s2_projection_orthographic <- function(centre = s2_lnglat(0, 0)) {
centre <- as_s2_lnglat(centre)
centre <- as.matrix(centre)
structure(
.Call(c_s2_projection_orthographic, centre[1:2]),
class = "s2_projection"
)
}
|
