bin/bright: Don't hardcode parameters

1 files changed, 14 insertions, 5 deletions

diff --git a/bin/bright b/bin/bright
index 87126e1..dd8f2df 100755
--- a/bin/bright
+++ b/bin/bright
@@ -2,14 +2,20 @@
 
 set -eu
 
+STEPS=8
+MIN=2
+max=
+
 get_b()
 {
 	local b=
 
 	b=$(brightnessctl --class=backlight get) || return 1
 	printf '%.0f\n' $(printf \
-		'scale = 4; (7 * sqrt((2 - %d) * (%d - 3102))) / 1550\n' \
-		${b} ${b} | bc)
+		'scale = 4;'$(: \
+		)'((%d - 1) * sqrt((%d - %d) * (%d - (2 * %d - %d)))) / '$(: \
+		)'(%d - %d)\n' \
+		${STEPS} ${MIN} ${b} ${b} ${max} ${MIN} ${max} ${MIN} | bc)
 
 	return 0
 }
@@ -19,9 +25,10 @@ set_b()
 	local b="${1}"
 	shift 1
 
-	brightnessctl --class=backlight set $(printf '%.0f\n' \
-		$(printf 'scale = 4; 2 + (1 - sqrt(1 - (%d / 7)^2)) * 1550\n' \
-		${b} | bc)) || return 1
+	brightnessctl --class=backlight set $(printf '%.0f\n' $(printf \
+		'scale = 4;'$(: \
+		)'%d + (1 - sqrt(1 - (%d / (%d - 1))^2)) * (%d - %d)\n' \
+		${MIN} ${b} ${STEPS} ${max} ${MIN} | bc)) || return 1
 
 	return 0
 }
@@ -53,6 +60,8 @@ main()
 			;;
 	esac
 
+	max=$(brightnessctl --class=backlight max)
+
 	b=$(get_b) || return 1
 	: $((b += 1))
 	: $((b ${dir}= 1))