generate_compass_overlay: Generate Compass Overlay

In tylermorganwall/rayshader: Create Maps and Visualize Data in 2D and 3D

Generate Compass Overlay

Description

This adds the compass

Based on code from "Auxiliary Cartographic Functions in R: North Arrow, Scale Bar, and Label with a Leader Arrow"

Usage

generate_compass_overlay(
  x = 0.85,
  y = 0.15,
  size = 0.075,
  text_size = 1,
  bearing = 0,
  heightmap = NULL,
  width = NA,
  height = NA,
  resolution_multiply = 1,
  color1 = "white",
  color2 = "black",
  text_color = "black",
  border_color = "black",
  border_width = 1,
  halo_color = NA,
  halo_expand = 1,
  halo_alpha = 1,
  halo_offset = c(0, 0),
  halo_blur = 1
)

Arguments

x	Default 'NULL'. The horizontal percentage across the map (measured from the bottom-left corner) where the compass is located.
y	Default 'NULL'. The vertical percentage across the map (measured from the bottom-left corner) where the compass is located.
size	Default '0.05'. Size of the compass, in percentage of the map size..
text_size	Default '1'. Text size.
bearing	Default '0'. Angle (in degrees) of north.
heightmap	Default 'NULL'. The original height map. Pass this in to extract the dimensions of the resulting RGB image array automatically.
width	Default 'NA'. Width of the resulting image array. Default the same dimensions as height map.
height	Default 'NA'. Width of the resulting image array. Default the same dimensions as height map.
resolution_multiply	Default '1'. If passing in 'heightmap' instead of width/height, amount to increase the resolution of the overlay, which should make lines/polygons finer. Should be combined with 'add_overlay(rescale_original = TRUE)' to ensure those added details are captured in the final map.
color1	Default 'white'. Primary color of the compass.
color2	Default 'black'. Secondary color of the symcompass.
text_color	Default 'black'. Text color.
border_color	Default 'black'. Border color of the scale bar.
border_width	Default '1'. Width of the scale bar border.
halo_color	Default 'NA', no halo. If a color is specified, the compass will be surrounded by a halo of this color.
halo_expand	Default '1'. Number of pixels to expand the halo.
halo_alpha	Default '1'. Transparency of the halo.
halo_offset	Default 'c(0,0)'. Horizontal and vertical offset to apply to the halo, in percentage of the image.
halo_blur	Default ‘1'. Amount of blur to apply to the halo. Values greater than '30' won’t result in further blurring.

Value

Semi-transparent overlay with a compass.

Examples

if(run_documentation()) {
#Create the water palette
water_palette = colorRampPalette(c("darkblue", "dodgerblue", "lightblue"))(200)
bathy_hs = height_shade(montereybay, texture = water_palette)

#Generate flat water heightmap
mbay = montereybay
mbay[mbay < 0] = 0

base_map = mbay %>% 
 height_shade() %>% 
 add_overlay(generate_altitude_overlay(bathy_hs, montereybay, 0, 0))  %>%
 add_shadow(lamb_shade(montereybay,zscale=50),0.3)
 
#Plot a compass
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay)) %>% 
 plot_map()
}

if(run_documentation()) {
#Change the position to be over the water
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15)) %>% 
 plot_map()
}
if(run_documentation()) {
#Change the text color for visibility
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, text_color="white")) %>% 
 plot_map()
} 
if(run_documentation()) {
#Alternatively, add a halo color to improve contrast
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             halo_color="white", halo_expand = 1)) %>% 
 plot_map()
}
if(run_documentation()) {
#Alternatively, add a halo color to improve contrast
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             halo_color="white", halo_expand = 1)) %>% 
 plot_map()
}
if(run_documentation()) {
#Change the color scheme
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             halo_color="white", halo_expand = 1, color1 = "purple", color2 = "red")) %>% 
 plot_map()
}
if(run_documentation()) {
#Remove the inner border
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             border_color=NA,
             halo_color="white", halo_expand = 1, 
             color1 = "darkolivegreen4", color2 = "burlywood3")) %>% 
 plot_map()
}
if(run_documentation()) {
#Change the size of the compass and text
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.75, y=0.75,
             halo_color="white", halo_expand = 1, 
             size=0.075*2, text_size = 1.25)) %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.45, y=0.45,
             halo_color="white", halo_expand = 1, 
             size=0.075)) %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             halo_color="white", halo_expand = 1, 
             size=0.075/2, text_size = 0.75)) %>% 
 plot_map()
}
if(run_documentation()) {
#Change the bearing of the compass
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.85, y=0.85,
             halo_color="white", halo_expand = 1, bearing=30,
             size=0.075)) %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.5, y=0.5,
             halo_color="white", halo_expand = 1, bearing=15,
             size=0.075)) %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             halo_color="white", halo_expand = 1, bearing=-45,
             size=0.075)) %>% 
 plot_map()
}
if(run_documentation()) {
#Create a drop shadow effect
base_map %>% 
 add_overlay(generate_compass_overlay(heightmap = montereybay, x = 0.15, y=0.15,
             text_color="white", halo_alpha=0.5, halo_blur=2,
             halo_color="black", halo_expand = 1, halo_offset = c(0.003,-0.003))) %>% 
 plot_map()
}

tylermorganwall/rayshader documentation built on Nov. 21, 2024, 8:11 a.m.