使用网格填充在R中绘制的贝塞尔曲线

我有一张图纸如下：

library(grid)

grid.newpage()

grid.rect(x = 0.1, y = 0.4, width = unit(0.18, "npc"), 
          height = unit(0.6, "npc"))
grid.rect(x = 0.65, y = 0.4, width = unit(0.6, "npc"), 
          height = unit(0.6, "npc"))

for (i in c(0.1, 0.17)) {
  x <- c(0.08, 0.05, i, 0.08)
  y <- c(0.15, 0.25, 0.25, 0.5)
  grid.bezier(x, y, gp = gpar(col = "green3"))
}

for (i in c(0.38, 0.8)) {
  x <- c(0.4, i, i, 0.9)
  y <- c(0.4, i, 0.15, 0.15)
  grid.bezier(x, y, gp = gpar(col = "blue3"))
}

库（网格）
grid.newpage（）
grid.rect（x=0.1，y=0.4，宽度=单位（0.18，“npc”），
高度=单位（0.6，“npc”））
grid.rect（x=0.65，y=0.4，宽度=单位（0.6，“npc”），
高度=单位（0.6，“npc”））
（c（0.1,0.17）中的i）{
x您是否考虑过使用
grid.xspline
？它可以采用闭合形状（
open=FALSE
），从而采用
填充
颜色。但是，形状会有所不同，如下所示

library(grid)
grid.newpage()
pushViewport(viewport(layout = grid.layout(2, 1)))

## Beziers
pushViewport(viewport(layout.pos.row = 1))
grid.text("Bezier", x = 0.05, y = 0.8, just = "left", gp=gpar(cex = 2))

grid.rect(x = 0.1, y = 0.4, width = unit(0.18, "npc"), 
          height = unit(0.6, "npc"))
grid.rect(x = 0.65, y = 0.4, width = unit(0.6, "npc"), 
          height = unit(0.6, "npc"))

x1 <- c(0.08, 0.05, 0.1, 0.08, 0.08, 0.17, 0.05, 0.08)
y1 <- c(0.15, 0.25, 0.25, 0.5, 0.5, 0.25, 0.25, 0.15)
id <- rep(1:2, each = 4)
grid.bezier(x1, y1, id = id, gp = gpar(col = "green3"))

x2 <- c(0.4, .38, .38, 0.9, .9, .8, .8, .4)
y2 <- c(0.4, .38, 0.15, 0.15, .15, .15, .8, .4)
grid.bezier(x2, y2, id = id, gp = gpar(col = "blue4"))

upViewport(1)

## X-splines
pushViewport(viewport(layout.pos.row = 2))
grid.text("X-spline", x = .05, y = 0.8, just = "left", gp=gpar(cex = 2))

grid.rect(x = 0.1, y = 0.4, width = unit(0.18, "npc"), 
          height = unit(0.6, "npc"))
grid.rect(x = 0.65, y = 0.4, width = unit(0.6, "npc"), 
          height = unit(0.6, "npc"))

s <- c(0, 1, 1, 0, 0, 1, 1, 0)
grid.xspline(x1, y1, shape = s, open = FALSE, gp = gpar(col = "green3", fill = "green3"))
grid.xspline(x2, y2, shape = s, open = FALSE, gp = gpar(col = "blue4", fill = "blue4"))

upViewport(0)

库（网格）
grid.newpage（）
推送视口（视口（布局=栅格布局（2，1）））
##贝齐尔
推送视口（视口（layout.pos.row=1））
text（“Bezier”，x=0.05，y=0.8，just=“left”，gp=gpar（cex=2））
grid.rect（x=0.1，y=0.4，宽度=单位（0.18，“npc”），
高度=单位（0.6，“npc”））
grid.rect（x=0.65，y=0.4，宽度=单位（0.6，“npc”），
高度=单位（0.6，“npc”））
x1