From 2cc38ed13f1b0f9d80a2d0acc2916af94922f27e Mon Sep 17 00:00:00 2001 From: "Antonino A. Daplas" Date: Fri, 9 Sep 2005 13:04:38 -0700 Subject: [PATCH] [PATCH] fbcon: Saner 16-color to 4-color conversion Currently, the default linux 16-colors are converted to 4-colors by simply dividing the values by 4. However, this is not necessarily correct since the first 4 colors are converted to black, rendering them invisible. So, for black, no conversion; for light colors, convert to gray, for normal text color, no conversion, and for bright colors, convert to intense white. Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/console/fbcon.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 88bd8ef56fd..bb4ea50b54a 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -247,9 +247,26 @@ static inline int get_color(struct vc_data *vc, struct fb_info *info, case 2: /* * Scale down 16-colors to 4 colors. Default 4-color palette - * is grayscale. + * is grayscale. However, simply dividing the values by 4 + * will not work, as colors 1, 2 and 3 will be scaled-down + * to zero rendering them invisible. So empirically convert + * colors to a sane 4-level grayscale. */ - color /= 4; + switch (color) { + case 0: + color = 0; /* black */ + break; + case 1 ... 6: + color = 2; /* white */ + break; + case 7 ... 8: + color = 1; /* gray */ + break; + default: + color = 3; /* intense white */ + break; + } + break; case 3: /* * Last 8 entries of default 16-color palette is a more intense -- 2.41.0