Improve layout

1 files changed, 92 insertions, 38 deletions

diff --git a/ils.go b/ils.go
index 55a8eb2..05ece82 100644
--- a/ils.go
+++ b/ils.go
@@ -12,7 +12,6 @@ import (
 	"os"
 	"path/filepath"
 	"slices"
-	"strings"
 
 	runewidth "github.com/mattn/go-runewidth"
 	_ "golang.org/x/image/bmp"
@@ -95,7 +94,7 @@ func imageDimensions(filename string) (width, height int, err error) {
 	}
 	defer f.Close()
 	config, _, err := image.DecodeConfig(f)
-	return config.Width, config.Height, nil
+	return config.Width, config.Height, err
 }
 
 func load(filename string) (image.Image, error) {
@@ -130,17 +129,22 @@ type pixelAspectRatio struct {
 	x, y int
 }
 
-func compositeImageRow(imagePaths []string, width, padding int, aspectRatio pixelAspectRatio) (image.Image, error) {
-	resultWidth := width*len(imagePaths) + padding*(len(imagePaths)-1)
-	maxHeight := 0
-	for _, filename := range imagePaths {
+func compositeImageRow(imagePaths []string, width, rowWidth, cellX int, aspectRatio pixelAspectRatio) (image.Image, error) {
+	var logicalWidth, maxHeight int
+	for i, filename := range imagePaths {
+		if i > 0 {
+			logicalWidth += 2 * cellX
+		}
+		fileNameWidth := cellX * runewidth.StringWidth(filepath.Base(filename))
+		logicalWidth += max(width, fileNameWidth)
+
 		imageWidth, imageHeight, err := imageDimensions(filename)
 		if err != nil {
 			return nil, err
 		}
 		maxHeight = max(maxHeight, imageHeight*width/(imageWidth*aspectRatio.y/aspectRatio.x))
 	}
-	bounds := image.Rect(0, 0, resultWidth, maxHeight)
+	bounds := image.Rect(0, 0, rowWidth, maxHeight)
 	result := image.NewRGBA(bounds)
 	offset := 0
 	for _, filename := range imagePaths {
@@ -149,50 +153,101 @@ func compositeImageRow(imagePaths []string, width, padding int, aspectRatio pixe
 			return nil, err
 		}
 		height := img.Bounds().Dy() * width / (img.Bounds().Dx() * aspectRatio.y / aspectRatio.x)
-		dstBounds := image.Rect(offset, (maxHeight-height)/2, offset+width, (maxHeight-height)/2+height)
+		imageWidth := max(width, cellX*runewidth.StringWidth(filepath.Base(filename)))
+		start := (offset*rowWidth + logicalWidth - 1) / logicalWidth
+		end := ((offset+imageWidth)*rowWidth + logicalWidth - 1) / logicalWidth
+		offsetStart := start + (end-start-width)/2
+		dstBounds := image.Rect(offsetStart, (maxHeight-height)/2, offsetStart+width, (maxHeight-height)/2+height)
 		draw.BiLinear.Scale(result, dstBounds, img, img.Bounds(), draw.Src, nil)
-		offset += width + padding
+		offset += imageWidth + 2*cellX
 	}
 	return result, nil
 }
 
-func thumbnailFiles(w io.Writer, imagePaths []string, width, imagesPerRow, cellX, cellY int) error {
-	imageWidth := width
-	padding := 1
+func splitRows(imagePaths []string, width, rowWidth int) [][]string {
+	var rows [][]string
+	for len(imagePaths) > 0 {
+		row := imagePaths[:0]
+		thisRowWidth := 0
+		for ; len(row) < len(imagePaths); row = row[:len(row)+1] {
+			nextW := max(width, runewidth.StringWidth(filepath.Base(imagePaths[len(row)])))
+			if len(row) > 0 {
+				nextW += 2
+			}
+			if thisRowWidth > 0 && thisRowWidth+nextW > rowWidth {
+				break
+			}
+			thisRowWidth += nextW
+		}
+		imagePaths = imagePaths[len(row):]
+		rows = append(rows, row)
+	}
+	return rows
+}
+
+func thumbnailFiles(w io.Writer, imagePaths []string, width, rowWidth, cellX, cellY int) error {
+	padding := 2
 	aspectRatio := pixelAspectRatio{1, 1}
 	switch *m {
 	case modeBlock:
 		aspectRatio = pixelAspectRatio{cellX, cellY}
+		cellX = 1
 	case modeBlock24:
 		aspectRatio = pixelAspectRatio{2 * cellX, cellY}
+		cellX = 1
 	case modeSixel:
-		imageWidth = width * cellX
-		padding = cellX
+		padding *= cellX
 	}
-	for row := range slices.Chunk(imagePaths, imagesPerRow) {
-		rowImage, err := compositeImageRow(row, imageWidth, padding, aspectRatio)
-		if err != nil {
+	rows := splitRows(imagePaths, width, rowWidth)
+	rowImages := make([]chan image.Image, len(rows))
+	for i := range rowImages {
+		rowImages[i] = make(chan image.Image, 1)
+	}
+	errCh := make(chan error, 1)
+	for i, row := range rows {
+		go func() {
+			img, err := compositeImageRow(row, width*cellX, rowWidth*cellX, cellX, aspectRatio)
+			if err != nil {
+				select {
+				case errCh <- err:
+				default:
+				}
+				return
+			}
+			rowImages[i] <- img
+		}()
+	}
+	for i, row := range rows {
+		thisRowWidth := 0
+		for j, filename := range row {
+			if j > 0 {
+				thisRowWidth += 2
+			}
+			thisRowWidth += max(width, runewidth.StringWidth(filepath.Base(filename)))
+		}
+		var rowImage image.Image
+		select {
+		case err := <-errCh:
 			return err
+		case rowImage = <-rowImages[i]:
 		}
 		printImg(w, rowImage)
-		names := make([][]string, len(row))
-		maxLen := 0
+		fmt.Fprintln(w)
+		offset := 0
+		realOffset := 0
 		for i, filename := range row {
-			names[i] = strings.Split(runewidth.Wrap(filepath.Base(filename), width), "\n")
-			maxLen = max(maxLen, len(names[i]))
-		}
-		for i := 0; i < maxLen; i++ {
-			fmt.Fprintln(w)
-			for imgIdx, name := range names {
-				if imgIdx > 0 {
-					fmt.Fprint(w, " ")
-				}
-				if i < len(name) {
-					fmt.Fprintf(w, "%s", runewidth.FillRight(name[i], width))
-				} else {
-					fmt.Fprintf(w, "%*s", width, "")
-				}
+			if i > 0 {
+				offset += 2
 			}
+			start := (offset*rowWidth + thisRowWidth - 1) / thisRowWidth
+			fmt.Fprintf(w, "%*s", start-realOffset, "")
+			realOffset = start
+			fileNameWidth := runewidth.StringWidth(filepath.Base(filename))
+			offset += max(width, fileNameWidth)
+			end := (offset*rowWidth + thisRowWidth - 1) / thisRowWidth
+			padding := (end - start - fileNameWidth) / 2
+			fmt.Fprintf(w, "%*s%s", padding, "", filepath.Base(filename))
+			realOffset += padding + fileNameWidth
 		}
 		fmt.Fprintln(w)
 	}
@@ -211,13 +266,13 @@ func readDir(d string) ([]string, error) {
 	return filenames, nil
 }
 
-func thumbnailDir(w io.Writer, dir string, width, imagesPerRow, cellX, cellY int) error {
+func thumbnailDir(w io.Writer, dir string, width, rowWidth, cellX, cellY int) error {
 	files, err := readDir(dir)
 	if err != nil {
 		return err
 	}
 	files = slices.DeleteFunc(files, func(filename string) bool { return !isImage(filename) })
-	return thumbnailFiles(w, files, width, imagesPerRow, cellX, cellY)
+	return thumbnailFiles(w, files, width, rowWidth, cellX, cellY)
 }
 
 func thumbnailer(args []string) error {
@@ -233,7 +288,6 @@ func thumbnailer(args []string) error {
 	cellX, cellY := int(ws.Xpixel)/int(ws.Col), int(ws.Ypixel)/int(ws.Row)
 
 	cols = min(cols, termCols)
-	imagesPerRow := (termCols + 1) / (cols + 1)
 
 	var files, dirs []string
 	if len(args) == 0 {
@@ -249,7 +303,7 @@ func thumbnailer(args []string) error {
 	}
 	w := bufio.NewWriter(os.Stdout)
 	defer w.Flush()
-	if err := thumbnailFiles(w, files, cols, imagesPerRow, cellX, cellY); err != nil {
+	if err := thumbnailFiles(w, files, cols, termCols, cellX, cellY); err != nil {
 		return err
 	}
 	if len(files) > 0 && len(dirs) > 0 {
@@ -262,7 +316,7 @@ func thumbnailer(args []string) error {
 		if len(dirs) > 1 {
 			fmt.Fprintf(w, "%s:\n", d)
 		}
-		if err := thumbnailDir(w, d, cols, imagesPerRow, cellX, cellY); err != nil {
+		if err := thumbnailDir(w, d, cols, termCols, cellX, cellY); err != nil {
 			return err
 		}
 	}