Slight refactor to deduplicate some logic

1 files changed, 39 insertions, 20 deletions

diff --git a/ils.go b/ils.go
index c18e07d..fe6bc1a 100644
--- a/ils.go
+++ b/ils.go
@@ -25,6 +25,7 @@ import (
 
 var (
 	x = flag.Int("x", 15, "set image width in columns")
+	l = flag.Bool("l", false, "print image attributes")
 	m = flagPrintMode(flag.CommandLine, "m", modeSixel, "one of 'block', 'block24', or 'sixel'")
 )
 
@@ -143,15 +144,31 @@ type pixelAspectRatio struct {
 	x, y int
 }
 
-func compositeImageRow(imagePaths []string, width, rowWidth, cellX int, aspectRatio pixelAspectRatio) (image.Image, error) {
-	var logicalWidth, maxHeight int
-	for i, filename := range imagePaths {
+func layoutRow(imagePaths []string, width, rowWidth, cellX int) []int {
+	filenameWidths := make([]int, len(imagePaths))
+	for i, path := range imagePaths {
+		filenameWidths[i] = cellX * runewidth.StringWidth(escapeString(filepath.Base(path)))
+	}
+	var logicalWidth int
+	for i, filenameWidth := range filenameWidths {
 		if i > 0 {
 			logicalWidth += 2 * cellX
 		}
-		fileNameWidth := cellX * runewidth.StringWidth(escapeString(filepath.Base(filename)))
-		logicalWidth += max(width, fileNameWidth)
+		logicalWidth += max(width, filenameWidth)
+	}
+	layout := make([]int, len(imagePaths))
+	var offset int
+	for i, filenameWidth := range filenameWidths {
+		imageWidth := max(width, filenameWidth)
+		layout[i] = divRound(offset*rowWidth, logicalWidth)
+		offset += imageWidth + 2*cellX
+	}
+	return layout
+}
 
+func compositeImageRow(imagePaths []string, layout []int, width, rowWidth, cellX int, aspectRatio pixelAspectRatio) (image.Image, error) {
+	var maxHeight int
+	for _, filename := range imagePaths {
 		imageWidth, imageHeight, err := imageDimensions(filename)
 		if err != nil {
 			return nil, err
@@ -160,20 +177,20 @@ func compositeImageRow(imagePaths []string, width, rowWidth, cellX int, aspectRa
 	}
 	bounds := image.Rect(0, 0, rowWidth, maxHeight)
 	result := image.NewRGBA(bounds)
-	offset := 0
-	for _, filename := range imagePaths {
+	for i, filename := range imagePaths {
 		img, err := load(filename)
 		if err != nil {
 			return nil, err
 		}
+		start := layout[i]
+		end := rowWidth
+		if i+1 < len(imagePaths) {
+			end = layout[i+1]
+		}
 		height := divRound(img.Bounds().Dy()*width*aspectRatio.x, img.Bounds().Dx()*aspectRatio.y)
-		imageWidth := max(width, cellX*runewidth.StringWidth(escapeString(filepath.Base(filename))))
-		start := divRound(offset*rowWidth, logicalWidth)
-		end := divRound((offset+imageWidth)*rowWidth, 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 += imageWidth + 2*cellX
 	}
 	return result, nil
 }
@@ -213,6 +230,10 @@ func thumbnailFiles(w io.Writer, imagePaths []string, width, rowWidth, cellX, ce
 		padding *= cellX
 	}
 	rows := splitRows(imagePaths, width, rowWidth)
+	layouts := make([][]int, len(rows))
+	for i, row := range rows {
+		layouts[i] = layoutRow(row, width*cellX, rowWidth*cellX, cellX)
+	}
 	rowImages := make([]chan image.Image, len(rows))
 	for i := range rowImages {
 		rowImages[i] = make(chan image.Image, 1)
@@ -224,7 +245,7 @@ func thumbnailFiles(w io.Writer, imagePaths []string, width, rowWidth, cellX, ce
 			sem <- struct{}{}
 			go func() {
 				defer func() { <-sem }()
-				img, err := compositeImageRow(row, width*cellX, rowWidth*cellX, cellX, aspectRatio)
+				img, err := compositeImageRow(row, layouts[i], width*cellX, rowWidth*cellX, cellX, aspectRatio)
 				if err != nil {
 					select {
 					case errCh <- err:
@@ -252,19 +273,17 @@ func thumbnailFiles(w io.Writer, imagePaths []string, width, rowWidth, cellX, ce
 		}
 		printImg(w, rowImage)
 		fmt.Fprintln(w)
-		offset := 0
 		realOffset := 0
-		for i, filename := range row {
-			if i > 0 {
-				offset += 2
+		for j, filename := range row {
+			start := divRound(layouts[i][j], cellX)
+			end := rowWidth
+			if j+1 < len(row) {
+				end = divRound(layouts[i][j+1], cellX)
 			}
-			start := divRound(offset*rowWidth, thisRowWidth)
 			fmt.Fprintf(w, "%*s", start-realOffset, "")
 			realOffset = start
 			fileNameWidth := runewidth.StringWidth(escapeString(filepath.Base(filename)))
-			offset += max(width, fileNameWidth)
-			end := divRound(offset*rowWidth, thisRowWidth)
-			padding := (end - start - fileNameWidth) / 2
+			padding := max((end-start-fileNameWidth)/2, 0)
 			fmt.Fprintf(w, "%*s%s", padding, "", escapeString(filepath.Base(filename)))
 			realOffset += padding + fileNameWidth
 		}