如何将grob裁剪为grobTree对象

Question

在R网格图形中，如何在grobTree中裁剪grob对象？以某种方式，我只需要调用grid.draw即可绘制裁剪的grob。

例如，当我直接绘制我的东西时：

# Direct plotting ----

library(grid)

grid.newpage()
vp <- viewport(x = 0.25, y = 0.25, width = 0.5,height = 0.5,
               just = c("left", "bottom"), name = "vp")
pushViewport(vp)

grid.rect()
grid.polygon(x = c(0.4,0.9, 1.4, 0.9), y = c(0.5, 0.75, 0.5, 0.25), 
             gp = gpar(lty = 3))

grid.clip()

grid.polygon(x = c(0.4,0.9, 1.4, 0.9), y = c(0.5, 0.75, 0.5, 0.25), 
             gp = gpar(fill = "grey"))

我获得了剪切的版本：

但是当我尝试将其放入grobTree对象（以供以后操作）时，它不起作用：

# Indirect plotting ----

library(grid)

aGrob <- grobTree()

vp <- viewport(x = 0.25, y = 0.25,,width = 0.5,,height = 0.5,
               just = c("left", "bottom"), name = "vp")

r1 <- rectGrob(vp = vp)
p1 <- grid.polygon(x = c(0.4,0.9, 1.4, 0.9), y = c(0.5, 0.75, 0.5, 0.25), 
                   gp = gpar(lty = 3), vp = vp)

c1 <- clipGrob(vp = vp)

p2 <- grid.polygon(x = c(0.4,0.9, 1.4, 0.9), y = c(0.5, 0.75, 0.5, 0.25), 
                   gp = gpar(fill = "grey"), vp = vp)

aGrob <- grobTree(aGrob, r1, p1, c1, p2)

grid.newpage()

grid.draw(aGrob)

我得到一个未压缩的版本：

如何在我的grobTree对象中拥有剪切的版本？

Answer 1

尝试在视口clip = TRUE中使用vp，>