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authorRose Hogenson <rosehogenson@posteo.net>2026-06-09 22:28:35 -0700
committerRose Hogenson <rosehogenson@posteo.net>2026-06-09 22:28:35 -0700
commitfc87933442e1f8fc1621c63f12d9f2ac4e693e3c (patch)
tree19ad2920d2f6ecb14f09c17f87d504ce81533aa8 /sixel.go
parent0757d8d7a2d74cbff143f6c02756964531fd0afe (diff)
downloadsixel-fc87933442e1f8fc1621c63f12d9f2ac4e693e3c.tar.zst
Revert "Round for greater color accuracy"
This reverts commit 0757d8d7a2d74cbff143f6c02756964531fd0afe.
Diffstat (limited to 'sixel.go')
-rw-r--r--sixel.go16
1 files changed, 6 insertions, 10 deletions
diff --git a/sixel.go b/sixel.go
index fee1ce6..180d28c 100644
--- a/sixel.go
+++ b/sixel.go
@@ -13,16 +13,12 @@ import (
"slices"
)
-func divRound(n, d uint32) uint32 {
- return (n + d/2) / d
-}
-
type sixelRGB struct {
r, g, b int8
}
func (c sixelRGB) RGBA() (r, g, b, a uint32) {
- return divRound(uint32(c.r)*0xffff, 100), divRound(uint32(c.g)*0xffff, 100), divRound(uint32(c.b)*0xffff, 100), 0xffff
+ return uint32(c.r) * 0xffff / 100, uint32(c.g) * 0xffff / 100, uint32(c.b) * 0xffff / 100, 0xffff
}
var defaultSixelPalette color.Palette
@@ -31,7 +27,7 @@ func init() {
defaultSixelPalette = slices.Grow(color.Palette{color.Transparent}, len(palette.WebSafe))
for _, c := range palette.WebSafe {
r, g, b, _ := c.RGBA()
- defaultSixelPalette = append(defaultSixelPalette, sixelRGB{int8(divRound(r*100, 0xffff)), int8(divRound(g*100, 0xffff)), int8(divRound(b*100, 0xffff))})
+ defaultSixelPalette = append(defaultSixelPalette, sixelRGB{int8(r * 100 / 0xffff), int8(g * 100 / 0xffff), int8(b * 100 / 0xffff)})
}
}
@@ -44,7 +40,7 @@ func sixelizePalette(p color.Palette) color.Palette {
includeTransparent = true
continue
}
- result = append(result, sixelRGB{r: int8(divRound(r*100, 0xffff)), g: int8(divRound(g*100, 0xffff)), b: int8(divRound(b*100, 0xffff))})
+ result = append(result, sixelRGB{r: int8(r * 100 / 0xffff), g: int8(g * 100 / 0xffff), b: int8(b * 100 / 0xffff)})
}
if includeTransparent {
result = append(color.Palette{color.Transparent}, result...)
@@ -186,14 +182,14 @@ func PrintBlock(w io.Writer, img image.Image) error {
}
} else {
r, g, b, _ := img.At(x, y+1).RGBA()
- if _, err := fmt.Fprintf(bw, "\033[38;2;%d;%d;%dm\033[49m▄", divRound(r, 1<<8), divRound(g, 1<<8), divRound(b, 1<<8)); err != nil {
+ if _, err := fmt.Fprintf(bw, "\033[38;2;%d;%d;%dm\033[49m▄", r>>8, g>>8, b>>8); err != nil {
return err
}
}
} else {
if y+1 < img.Bounds().Max.Y && !isFullyTransparent(img.At(x, y+1)) {
r, g, b, _ := img.At(x, y+1).RGBA()
- if _, err := fmt.Fprintf(bw, "\033[48;2;%d;%d;%dm", divRound(r, 1<<8), divRound(g, 1<<8), divRound(b, 1<<8)); err != nil {
+ if _, err := fmt.Fprintf(bw, "\033[48;2;%d;%d;%dm", r>>8, g>>8, b>>8); err != nil {
return err
}
} else {
@@ -202,7 +198,7 @@ func PrintBlock(w io.Writer, img image.Image) error {
}
}
r, g, b, _ := hi.RGBA()
- if _, err := fmt.Fprintf(bw, "\033[38;2;%d;%d;%dm▀", divRound(r, 1<<8), divRound(g, 1<<8), divRound(b, 1<<8)); err != nil {
+ if _, err := fmt.Fprintf(bw, "\033[38;2;%d;%d;%dm▀", r>>8, g>>8, b>>8); err != nil {
return err
}
}