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// radare - LGPL - Copyright 2013-2020 - pancake, xarkes
// ansi 256 color extension for r_cons
// https://en.wikipedia.org/wiki/ANSI_color
module ui
const (
value_range = [0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff]!
color_table = init_color_table()
)
[direct_array_access]
fn init_color_table() []int {
mut color_table_ := []int{len: 256}
// ansi colors
color_table_[0] = 0x000000
color_table_[1] = 0x800000
color_table_[2] = 0x008000
color_table_[3] = 0x808000
color_table_[4] = 0x000080
color_table_[5] = 0x800080
color_table_[6] = 0x008080
color_table_[7] = 0xc0c0c0
color_table_[8] = 0x808080
color_table_[9] = 0xff0000
color_table_[10] = 0x00ff00
color_table_[11] = 0xffff00
color_table_[12] = 0x0000ff
color_table_[13] = 0xff00ff
color_table_[14] = 0x00ffff
color_table_[15] = 0xffffff
// color palette
for i in 0 .. 216 {
r := ui.value_range[(i / 36) % 6]
g := ui.value_range[(i / 6) % 6]
b := ui.value_range[i % 6]
color_table_[i + 16] = ((r << 16) & 0xffffff) + ((g << 8) & 0xffff) + (b & 0xff)
}
// grayscale
for i in 0 .. 24 {
r := 8 + (i * 10)
color_table_[i + 232] = ((r << 16) & 0xffffff) + ((r << 8) & 0xffff) + (r & 0xff)
}
return color_table_
}
fn clamp(x int, y int, z int) int {
if x < y {
return y
}
if x > z {
return z
}
return x
}
fn approximate_rgb(r int, g int, b int) int {
grey := r > 0 && r < 255 && r == g && r == b
if grey {
return 232 + int(f64(r) / (255 / 24.1))
}
k := int(256.0 / 6)
r2 := clamp(r / k, 0, 5)
g2 := clamp(g / k, 0, 5)
b2 := clamp(b / k, 0, 5)
return 16 + (r2 * 36) + (g2 * 6) + b2
}
fn lookup_rgb(r int, g int, b int) int {
color := (r << 16) + (g << 8) + b
// lookup extended colors only, coz non-extended can be changed by users.
for i in 16 .. 256 {
if ui.color_table[i] == color {
return i
}
}
return -1
}
// converts an RGB color to an ANSI 256-color, approximating it to the nearest available color
// if an exact match is not found
fn rgb2ansi(r int, g int, b int) int {
c := lookup_rgb(r, g, b)
if c == -1 {
return approximate_rgb(r, g, b)
}
return c
}
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