From 3524ce6d043596c17d1b0c96d482315fc61ae76c Mon Sep 17 00:00:00 2001
From: celogeek <65178+celogeek@users.noreply.github.com>
Date: Tue, 3 Jan 2023 19:58:19 +0100
Subject: [PATCH] add workers and autorotate options

---
 internal/epub/core.go             |  2 ++
 internal/epub/image_filters.go    | 46 +++++++++++++++++++++++++++++++
 internal/epub/image_processing.go | 21 ++++++--------
 main.go                           | 11 ++++++++
 4 files changed, 68 insertions(+), 12 deletions(-)
 create mode 100644 internal/epub/image_filters.go

diff --git a/internal/epub/core.go b/internal/epub/core.go
index 1c6cef0..09602f5 100644
--- a/internal/epub/core.go
+++ b/internal/epub/core.go
@@ -20,6 +20,8 @@ type ImageOptions struct {
 	Palette    color.Palette
 	Brightness int
 	Contrast   int
+	AutoRotate bool
+	Workers    int
 }
 
 type EpubOptions struct {
diff --git a/internal/epub/image_filters.go b/internal/epub/image_filters.go
new file mode 100644
index 0000000..edfebe6
--- /dev/null
+++ b/internal/epub/image_filters.go
@@ -0,0 +1,46 @@
+package epub
+
+import (
+	"image"
+	"image/draw"
+
+	"github.com/disintegration/gift"
+)
+
+func NewGift(options *ImageOptions) *gift.GIFT {
+	g := gift.New()
+	g.SetParallelization(false)
+
+	if options.AutoRotate {
+		g.Add(&autoRotateFilter{})
+	}
+	if options.Contrast != 0 {
+		g.Add(gift.Contrast(float32(options.Contrast)))
+	}
+	if options.Brightness != 0 {
+		g.Add(gift.Brightness(float32(options.Brightness)))
+	}
+	g.Add(
+		gift.ResizeToFit(options.ViewWidth, options.ViewHeight, gift.LanczosResampling),
+	)
+	return g
+}
+
+type autoRotateFilter struct{}
+
+func (p *autoRotateFilter) Bounds(srcBounds image.Rectangle) (dstBounds image.Rectangle) {
+	if srcBounds.Dx() > srcBounds.Dy() {
+		dstBounds = gift.Rotate90().Bounds(srcBounds)
+	} else {
+		dstBounds = srcBounds
+	}
+	return
+}
+
+func (p *autoRotateFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
+	if src.Bounds().Dx() > src.Bounds().Dy() {
+		gift.Rotate90().Draw(dst, src, options)
+	} else {
+		draw.Draw(dst, dst.Bounds(), src, src.Bounds().Min, draw.Src)
+	}
+}
diff --git a/internal/epub/image_processing.go b/internal/epub/image_processing.go
index 01c36ae..3589542 100644
--- a/internal/epub/image_processing.go
+++ b/internal/epub/image_processing.go
@@ -11,13 +11,11 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
-	"runtime"
 	"sort"
 	"strings"
 	"sync"
 
 	"github.com/disintegration/gift"
-
 	"github.com/nwaples/rardecode"
 	pdfimage "github.com/raff/pdfreader/image"
 	"github.com/raff/pdfreader/pdfread"
@@ -122,9 +120,8 @@ func LoadImages(path string, options *ImageOptions) ([]*Image, error) {
 
 	// processing
 	wg := &sync.WaitGroup{}
-	bar := NewBar(imageCount, "Processing", 1, 2)
 
-	for i := 0; i < runtime.NumCPU(); i++ {
+	for i := 0; i < options.Workers; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
@@ -136,14 +133,14 @@ func LoadImages(path string, options *ImageOptions) ([]*Image, error) {
 					panic(err)
 				}
 
-				// prepare filter
-				g := gift.New(
-					gift.Crop(findMarging(src)),
-					gift.Contrast(float32(options.Contrast)),
-					gift.Brightness(float32(options.Brightness)),
-					gift.ResizeToFit(options.ViewWidth, options.ViewHeight, gift.LanczosResampling),
-				)
-				g.SetParallelization(false)
+				if options.AutoRotate {
+					g := gift.New(gift.Crop(findMarging(src)))
+					newSrc := image.NewNRGBA(g.Bounds(src.Bounds()))
+					g.Draw(newSrc, src)
+					src = newSrc
+				}
+
+				g := NewGift(options)
 
 				// Convert image
 				dst := image.NewPaletted(g.Bounds(src.Bounds()), options.Palette)
diff --git a/main.go b/main.go
index 315fd0b..0234099 100644
--- a/main.go
+++ b/main.go
@@ -6,6 +6,7 @@ import (
 	"image/color"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strings"
 
 	"github.com/celogeek/go-comic-converter/internal/epub"
@@ -65,6 +66,8 @@ type Option struct {
 	NoCrop     bool
 	Brightness int
 	Contrast   int
+	AutoRotate bool
+	Workers    int
 	LimitMb    int
 }
 
@@ -95,7 +98,9 @@ Options:
     Crop      : %v
     Brightness: %d
     Contrast  : %d
+    AutoRotate: %v
     LimitMb   : %s
+    Workers   : %d
 `,
 		o.Input,
 		o.Output,
@@ -106,7 +111,9 @@ Options:
 		!o.NoCrop,
 		o.Brightness,
 		o.Contrast,
+		o.AutoRotate,
 		limitmb,
+		o.Workers,
 	)
 }
 
@@ -132,7 +139,9 @@ func main() {
 	flag.BoolVar(&opt.NoCrop, "nocrop", false, "Disable cropping")
 	flag.IntVar(&opt.Brightness, "brightness", 0, "Brightness readjustement: between -100 and 100, > 0 lighter, < 0 darker")
 	flag.IntVar(&opt.Contrast, "contrast", 0, "Contrast readjustement: between -100 and 100, > 0 more contrast, < 0 less contrast")
+	flag.BoolVar(&opt.AutoRotate, "autorotate", false, "Auto Rotate page when width > height")
 	flag.IntVar(&opt.LimitMb, "limitmb", 0, "Limit size of the ePub: Default nolimit (0), Minimum 20")
+	flag.IntVar(&opt.Workers, "workers", runtime.NumCPU(), "Number of workers")
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "Usage of %s:\n", filepath.Base(os.Args[0]))
 		flag.PrintDefaults()
@@ -229,6 +238,8 @@ func main() {
 			Palette:    profile.Palette,
 			Brightness: opt.Brightness,
 			Contrast:   opt.Contrast,
+			AutoRotate: opt.AutoRotate,
+			Workers:    opt.Workers,
 		},
 	}).Write(); err != nil {
 		fmt.Fprintf(os.Stderr, "Error: %v\n", err)