Added BG-to-FG image colorization mode

17 files changed, 30 insertions, 7 deletions

diff --git a/po/en.po b/po/en.po
index 46514e49..97bab2c4 100644
--- a/po/en.po
+++ b/po/en.po
@@ -1342,6 +1342,10 @@ msgstr "None"
 msgid "prefs.imagestyle.grayscale"
 msgstr "Grayscale"
 
+# Abbrevation: background-to-foreground
+msgid "prefs.imagestyle.bgfg"
+msgstr "BG-to-FG"
+
 msgid "prefs.imagestyle.text"
 msgstr "Text Color"
 
diff --git a/res/lang/de.bin b/res/lang/de.bin
index 5788ed84..8e09c601 100644
--- a/res/lang/de.bin
+++ b/res/lang/de.bin
diff --git a/res/lang/en.bin b/res/lang/en.bin
index 536ca6a2..859c6461 100644
--- a/res/lang/en.bin
+++ b/res/lang/en.bin
diff --git a/res/lang/es.bin b/res/lang/es.bin
index 14203f8e..a1e31cb4 100644
--- a/res/lang/es.bin
+++ b/res/lang/es.bin
diff --git a/res/lang/fi.bin b/res/lang/fi.bin
index 875413a5..19aa8c35 100644
--- a/res/lang/fi.bin
+++ b/res/lang/fi.bin
diff --git a/res/lang/fr.bin b/res/lang/fr.bin
index 6976a00f..7ad2f654 100644
--- a/res/lang/fr.bin
+++ b/res/lang/fr.bin
diff --git a/res/lang/ia.bin b/res/lang/ia.bin
index a77a1d61..6d69af59 100644
--- a/res/lang/ia.bin
+++ b/res/lang/ia.bin
diff --git a/res/lang/ie.bin b/res/lang/ie.bin
index 33850dc5..dc519da2 100644
--- a/res/lang/ie.bin
+++ b/res/lang/ie.bin
diff --git a/res/lang/pl.bin b/res/lang/pl.bin
index 0b4c3e10..93877061 100644
--- a/res/lang/pl.bin
+++ b/res/lang/pl.bin
diff --git a/res/lang/ru.bin b/res/lang/ru.bin
index fbafc283..0b97d0ec 100644
--- a/res/lang/ru.bin
+++ b/res/lang/ru.bin
diff --git a/res/lang/sr.bin b/res/lang/sr.bin
index b9ce2f5a..182a2dca 100644
--- a/res/lang/sr.bin
+++ b/res/lang/sr.bin
diff --git a/res/lang/tok.bin b/res/lang/tok.bin
index f1988dff..8fee6738 100644
--- a/res/lang/tok.bin
+++ b/res/lang/tok.bin
diff --git a/res/lang/zh_Hans.bin b/res/lang/zh_Hans.bin
index 0ef1a915..7c7d9487 100644
--- a/res/lang/zh_Hans.bin
+++ b/res/lang/zh_Hans.bin
diff --git a/res/lang/zh_Hant.bin b/res/lang/zh_Hant.bin
index f12f0ef2..5691aef9 100644
--- a/res/lang/zh_Hant.bin
+++ b/res/lang/zh_Hant.bin
diff --git a/src/defs.h b/src/defs.h
index 135cc053..6b12c86c 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -44,8 +44,9 @@ enum iFileVersion {
 enum iImageStyle {
     original_ImageStyle           = 0,
     grayscale_ImageStyle          = 1,
-    textColorized_ImageStyle      = 2,
-    preformatColorized_ImageStyle = 3,
+    bgFg_ImageStyle               = 2,
+    textColorized_ImageStyle      = 3,
+    preformatColorized_ImageStyle = 4,
 };
 
 enum iScrollType {
diff --git a/src/media.c b/src/media.c
index 94de0bc6..999368c5 100644
--- a/src/media.c
+++ b/src/media.c
@@ -91,8 +91,27 @@ static void applyImageStyle_(enum iImageStyle style, iInt2 size, uint8_t *imgDat
     if (style == original_ImageStyle) {
         return;
     }
-    iColor colorize = (iColor){ 255, 255, 255, 255};
-    float brighten = 0.0f;
+    uint8_t *pos       = imgData;
+    size_t   numPixels = size.x * size.y;
+    float    brighten  = 0.0f;
+    if (style == bgFg_ImageStyle) {
+        iColor dark  = get_Color(tmBackground_ColorId);
+        iColor light = get_Color(tmParagraph_ColorId);
+        if (hsl_Color(dark).lum > hsl_Color(light).lum) {
+            iSwap(iColor, dark, light);
+        }        
+        while (numPixels-- > 0) {
+            iHSLColor hsl = hsl_Color((iColor){ pos[0], pos[1], pos[2], 255 });
+            const float s = 1.0f - hsl.lum;
+            const float t = hsl.lum;
+            pos[0] = dark.r * s + light.r * t;
+            pos[1] = dark.g * s + light.g * t;
+            pos[2] = dark.b * s + light.b * t;
+            pos += 4;
+        }        
+        return;
+    }
+    iColor colorize = (iColor){ 255, 255, 255, 255 };
     if (style != grayscale_ImageStyle) {
         colorize = get_Color(style == textColorized_ImageStyle ? tmParagraph_ColorId
                                                                : tmPreformatted_ColorId);
@@ -100,9 +119,7 @@ static void applyImageStyle_(enum iImageStyle style, iInt2 size, uint8_t *imgDat
         const int colMax = iMax(iMax(colorize.r, colorize.g), colorize.b);
         brighten = iClamp(1.0f - (colorize.r + colorize.g + colorize.b) / (colMax * 3), 0.0f, 0.5f); /* compensate loss of light */
     }
-    uint8_t *pos = imgData;
-    size_t numPixels = size.x * size.y;
-    iHSLColor hslColorize = hsl_Color(colorize);                           
+    iHSLColor hslColorize = hsl_Color(colorize);
     while (numPixels-- > 0) {
         iHSLColor hsl = hsl_Color((iColor){ pos[0], pos[1], pos[2], 255 });
         iHSLColor out = { hslColorize.hue, hslColorize.sat, hsl.lum, 1.0f };
diff --git a/src/ui/util.c b/src/ui/util.c
index 8a42f75b..906d30ae 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -1836,6 +1836,7 @@ iWidget *makePreferences_Widget(void) {
             const iMenuItem imgStyles[] = {
                 { "${prefs.imagestyle.original}",  0, 0, format_CStr("imagestyle.set arg:%d", original_ImageStyle) },
                 { "${prefs.imagestyle.grayscale}", 0, 0, format_CStr("imagestyle.set arg:%d", grayscale_ImageStyle) },
+                { "${prefs.imagestyle.bgfg}",      0, 0, format_CStr("imagestyle.set arg:%d", bgFg_ImageStyle) },
                 { "${prefs.imagestyle.text}",      0, 0, format_CStr("imagestyle.set arg:%d", textColorized_ImageStyle) },
                 { "${prefs.imagestyle.preformat}", 0, 0, format_CStr("imagestyle.set arg:%d", preformatColorized_ImageStyle) },   
             };