Draw lots of line segments

This is a custom function to draw lots of line segments within C with a single call from R. Use this function when you want to draw lots of segments and need to speed up the creation of the final image.

cairo_segment_vec(cr, x1, y1, x2, y2, r, g, b, a)

Arguments

cr	cairo_t *
x1, y1, x2, y2	coordinates of endpoints
r, g, b, a	colour values in range [0,1]

Details

Besides the cr context, all arguments should either be the same length as the initial argument (xc) or have a length of 1.

Vectors which have a length of 1 will be considered to have a constant value for all objects

See also

Other bespoke: cairo_arc_vec(), cairo_image_surface_create_from_array(), cairo_image_surface_get_array(), cairo_image_surface_get_raster(), cairo_image_surface_get_raw(), cairo_image_surface_write_array(), cairo_polygon_vec(), cairo_polygon(), cairo_rectangle_vec()

Other vectorised: cairo_arc_vec(), cairo_polygon_vec(), cairo_rectangle_vec()

Examples

if (FALSE) {
# Draw 10 lines - all black
N <- 10
x1 <- runif(N)
y1 <- runif(N)
x2 <- runif(N)
y2 <- runif(N)
cairo_segment_vec(cr, x1, y2, x2, y2,  0, 0, 0, 1)
}