From 6ba6eed90a247bc02d6c4b9667439fa1ea1e4217 Mon Sep 17 00:00:00 2001
From: Caleb Foust <cfoust@sqweebloid.com>
Date: Wed, 3 Jul 2024 06:33:47 +0800
Subject: [PATCH] fix: lots of runewidth bugs

---
 pkg/emu/module.go             |  9 +++++----
 pkg/emu/wrap.go               | 12 +++---------
 pkg/geom/tty/render.go        |  2 +-
 pkg/replay/motion/jump.go     |  8 ++------
 pkg/replay/motion/physical.go |  4 +---
 pkg/replay/motion/screen.go   |  6 +-----
 6 files changed, 13 insertions(+), 28 deletions(-)

diff --git a/pkg/emu/module.go b/pkg/emu/module.go
index be80fbe3..376ebe2e 100644
--- a/pkg/emu/module.go
+++ b/pkg/emu/module.go
@@ -83,7 +83,9 @@ func (g Glyph) IsDefault() bool {
 }
 
 func (g Glyph) Width() int {
-	return runewidth.RuneWidth(g.Char)
+	// runewidth can be 0, but we strictly want visible glyphs to be at
+	// least one cell wide.
+	return geom.Max(runewidth.RuneWidth(g.Char), 1)
 }
 
 func (g Glyph) Equal(other Glyph) bool {
@@ -103,7 +105,7 @@ type Line []Glyph
 func (l Line) String() (str string) {
 	for i := 0; i < len(l); i++ {
 		str += string(l[i].Char)
-		i += runewidth.RuneWidth(l[i].Char) - 1
+		i += l[i].Width() - 1
 	}
 
 	return str
@@ -138,8 +140,7 @@ func (l Line) Occupancy() []bool {
 		}
 
 		// handle wide runes
-		r := l[i].Char
-		w := runewidth.RuneWidth(r)
+		w := l[i].Width()
 		for j := 0; j < w; j++ {
 			occupancy[i+j] = true
 		}
diff --git a/pkg/emu/wrap.go b/pkg/emu/wrap.go
index 655e0106..d96d4226 100644
--- a/pkg/emu/wrap.go
+++ b/pkg/emu/wrap.go
@@ -2,8 +2,6 @@ package emu
 
 import (
 	"github.com/cfoust/cy/pkg/geom"
-
-	"github.com/mattn/go-runewidth"
 )
 
 type ScreenLine struct {
@@ -143,7 +141,7 @@ func getLineLength(line Line) int {
 			continue
 		}
 
-		length = i + runewidth.RuneWidth(glyph.Char)
+		length = i + glyph.Width()
 		break
 	}
 	return length
@@ -180,9 +178,7 @@ findOld:
 	for row, line := range oldLine {
 		numChars := line.C1 - line.C0
 		for col := 0; col < numChars; col++ {
-			width := runewidth.RuneWidth(
-				oldLines[line.R][line.C0+col].Char,
-			)
+			width := oldLines[line.R][line.C0+col].Width()
 
 			if oldCursor.R == row && oldCursor.C >= col && oldCursor.C < col+width {
 				didFind = true
@@ -230,9 +226,7 @@ findNew:
 				break findNew
 			}
 
-			width := runewidth.RuneWidth(
-				newLines[line.R][line.C0+col].Char,
-			)
+			width := newLines[line.R][line.C0+col].Width()
 			isLast = (col + width) == numCols
 			newOffset++
 			col += width - 1
diff --git a/pkg/geom/tty/render.go b/pkg/geom/tty/render.go
index 5b341951..636be3fb 100644
--- a/pkg/geom/tty/render.go
+++ b/pkg/geom/tty/render.go
@@ -102,7 +102,7 @@ func swapImage(
 			info.Fprintf(data, terminfo.ExitAttributeMode)
 
 			// CJK characters
-			col += geom.Max(srcCell.Width(), 1) - 1
+			col += srcCell.Width() - 1
 		}
 	}
 
diff --git a/pkg/replay/motion/jump.go b/pkg/replay/motion/jump.go
index 3301e32e..1c9cff1d 100644
--- a/pkg/replay/motion/jump.go
+++ b/pkg/replay/motion/jump.go
@@ -3,8 +3,6 @@ package motion
 import (
 	"github.com/cfoust/cy/pkg/emu"
 	"github.com/cfoust/cy/pkg/geom"
-
-	"github.com/mattn/go-runewidth"
 )
 
 func calculateJump(line emu.Line, needle string, isForward bool, isTo bool, oldPos int) int {
@@ -18,8 +16,7 @@ func calculateJump(line emu.Line, needle string, isForward bool, isTo bool, oldP
 				break
 			}
 
-			w := runewidth.RuneWidth(char)
-			for i := 1; i < w; i++ {
+			for i := 1; i < line[i].Width(); i++ {
 				i++
 			}
 		}
@@ -35,8 +32,7 @@ func calculateJump(line emu.Line, needle string, isForward bool, isTo bool, oldP
 				continue
 			}
 
-			w := runewidth.RuneWidth(char)
-			for i := 1; i < w; i++ {
+			for i := 1; i < line[i].Width(); i++ {
 				i++
 			}
 		}
diff --git a/pkg/replay/motion/physical.go b/pkg/replay/motion/physical.go
index 595c2ea9..1fb98213 100644
--- a/pkg/replay/motion/physical.go
+++ b/pkg/replay/motion/physical.go
@@ -3,8 +3,6 @@ package motion
 import (
 	"github.com/cfoust/cy/pkg/emu"
 	"github.com/cfoust/cy/pkg/geom"
-
-	"github.com/mattn/go-runewidth"
 )
 
 func lineMotion(getIndex func(line emu.Line) int) Motion {
@@ -22,7 +20,7 @@ func lineMotion(getIndex func(line emu.Line) int) Motion {
 		)
 
 		// Need to check for CJK
-		if index > 0 && runewidth.RuneWidth(line[index-1].Char) == 2 {
+		if index > 0 && line[index-1].Width() == 2 {
 			index--
 		}
 
diff --git a/pkg/replay/motion/screen.go b/pkg/replay/motion/screen.go
index 3543f3c9..a32df84a 100644
--- a/pkg/replay/motion/screen.go
+++ b/pkg/replay/motion/screen.go
@@ -3,8 +3,6 @@ package motion
 import (
 	"github.com/cfoust/cy/pkg/emu"
 	"github.com/cfoust/cy/pkg/geom"
-
-	"github.com/mattn/go-runewidth"
 )
 
 func getCurrentLine(m Movable) (line emu.ScreenLine, ok bool) {
@@ -36,9 +34,7 @@ func screenLineMotion(getIndex func(
 		)
 
 		// Need to check for CJK
-		if index > 0 && runewidth.RuneWidth(
-			line.Chars[index-1].Char,
-		) == 2 {
+		if index > 0 && line.Chars[index-1].Width() == 2 {
 			index--
 		}