From 13103b0eba44e259f9b982e5094731dc0973bcb1 Mon Sep 17 00:00:00 2001
From: celogeek <65178+celogeek@users.noreply.github.com>
Date: Mon, 1 May 2023 14:11:44 +0200
Subject: [PATCH] do not enlarge smaller images
all width/height are computed based on viewport dimension.
images will enlarge if smaller, and resize to fit if larger.
---
internal/epub/image/epub_image.go | 47 +++++++++++++-----
.../imagefilters/epub_image_filters_resize.go | 48 -------------------
.../imageprocessor/epub_image_processor.go | 4 +-
.../templates/epub_templates_text.xhtml.tmpl | 4 +-
4 files changed, 39 insertions(+), 64 deletions(-)
delete mode 100644 internal/epub/imagefilters/epub_image_filters_resize.go
diff --git a/internal/epub/image/epub_image.go b/internal/epub/image/epub_image.go
index e88a414..8f74281 100644
--- a/internal/epub/image/epub_image.go
+++ b/internal/epub/image/epub_image.go
@@ -6,6 +6,7 @@ package epubimage
import (
"fmt"
"image"
+ "strings"
)
type Image struct {
@@ -72,24 +73,48 @@ func (i *Image) EPUBImgPath() string {
// center by default.
// align to left or right if it's part of the splitted double page.
func (i *Image) ImgStyle(viewWidth, viewHeight int, align string) string {
- marginW, marginH := float64(viewWidth-i.Width)/2, float64(viewHeight-i.Height)/2
+ relWidth, relHeight := i.RelSize(viewWidth, viewHeight)
+ marginW, marginH := float64(viewWidth-relWidth)/2, float64(viewHeight-relHeight)/2
+ style := []string{}
+
+ style = append(style, fmt.Sprintf("width:%dpx", relWidth))
+ style = append(style, fmt.Sprintf("height:%dpx", relHeight))
+ style = append(style, fmt.Sprintf("top:%.2f%%", marginH*100/float64(viewHeight)))
if align == "" {
switch i.Position {
case "rendition:page-spread-left":
- align = "right:0"
+ style = append(style, "right:0")
case "rendition:page-spread-right":
- align = "left:0"
+ style = append(style, "left:0")
default:
- align = fmt.Sprintf("left:%.2f%%", marginW*100/float64(viewWidth))
+ style = append(style, fmt.Sprintf("left:%.2f%%", marginW*100/float64(viewWidth)))
}
+ } else {
+ style = append(style, align)
}
- return fmt.Sprintf(
- "width:%dpx; height:%dpx; top:%.2f%%; %s;",
- i.Width,
- i.Height,
- marginH*100/float64(viewHeight),
- align,
- )
+ return strings.Join(style, "; ")
+}
+
+func (i *Image) RelSize(viewWidth, viewHeight int) (relWidth, relHeight int) {
+ w, h := viewWidth, viewHeight
+ srcw, srch := i.Width, i.Height
+
+ if w <= 0 || h <= 0 || srcw <= 0 || srch <= 0 {
+ return
+ }
+
+ wratio := float64(srcw) / float64(w)
+ hratio := float64(srch) / float64(h)
+
+ if wratio > hratio {
+ relWidth = w
+ relHeight = int(float64(srch)/wratio + 0.5)
+ } else {
+ relHeight = h
+ relWidth = int(float64(srcw)/hratio + 0.5)
+ }
+
+ return
}
diff --git a/internal/epub/imagefilters/epub_image_filters_resize.go b/internal/epub/imagefilters/epub_image_filters_resize.go
deleted file mode 100644
index 3e910fb..0000000
--- a/internal/epub/imagefilters/epub_image_filters_resize.go
+++ /dev/null
@@ -1,48 +0,0 @@
-package epubimagefilters
-
-import (
- "image"
- "image/draw"
-
- "github.com/disintegration/gift"
-)
-
-// Resize image by keeping aspect ratio.
-// This will reduce or enlarge image to fit into the viewWidth and viewHeight.
-func Resize(viewWidth, viewHeight int, resampling gift.Resampling) gift.Filter {
- return &resizeFilter{
- viewWidth, viewHeight, resampling,
- }
-}
-
-type resizeFilter struct {
- viewWidth, viewHeight int
- resampling gift.Resampling
-}
-
-func (p *resizeFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
- w, h := p.viewWidth, p.viewHeight
- srcw, srch := srcBounds.Dx(), srcBounds.Dy()
-
- if w <= 0 || h <= 0 || srcw <= 0 || srch <= 0 {
- return image.Rect(0, 0, 0, 0)
- }
-
- wratio := float64(srcw) / float64(w)
- hratio := float64(srch) / float64(h)
-
- var dstw, dsth int
- if wratio > hratio {
- dstw = w
- dsth = int(float64(srch)/wratio + 0.5)
- } else {
- dsth = h
- dstw = int(float64(srcw)/hratio + 0.5)
- }
-
- return image.Rect(0, 0, dstw, dsth)
-}
-
-func (p *resizeFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
- gift.Resize(dst.Bounds().Dx(), dst.Bounds().Dy(), p.resampling).Draw(dst, src, options)
-}
diff --git a/internal/epub/imageprocessor/epub_image_processor.go b/internal/epub/imageprocessor/epub_image_processor.go
index 44a794e..948c757 100644
--- a/internal/epub/imageprocessor/epub_image_processor.go
+++ b/internal/epub/imageprocessor/epub_image_processor.go
@@ -202,7 +202,7 @@ func (e *EPUBImageProcessor) transformImage(src image.Image, srcId int) []image.
}
filters = append(filters,
- epubimagefilters.Resize(e.Image.View.Width, e.Image.View.Height, gift.LanczosResampling),
+ gift.ResizeToFit(e.Image.View.Width, e.Image.View.Height, gift.LanczosResampling),
epubimagefilters.Pixel(),
)
@@ -234,7 +234,7 @@ func (e *EPUBImageProcessor) transformImage(src image.Image, srcId int) []image.
g := gift.New(splitFilter...)
g.Add(
epubimagefilters.CropSplitDoublePage(b),
- epubimagefilters.Resize(e.Image.View.Width, e.Image.View.Height, gift.LanczosResampling),
+ gift.ResizeToFit(e.Image.View.Width, e.Image.View.Height, gift.LanczosResampling),
)
dst := e.createImage(src, g.Bounds(src.Bounds()))
g.Draw(dst, src)
diff --git a/internal/epub/templates/epub_templates_text.xhtml.tmpl b/internal/epub/templates/epub_templates_text.xhtml.tmpl
index a88b9e1..21cea8f 100644
--- a/internal/epub/templates/epub_templates_text.xhtml.tmpl
+++ b/internal/epub/templates/epub_templates_text.xhtml.tmpl
@@ -8,8 +8,6 @@
-
-
-