21 files changed, 98 insertions, 4 deletions

diff --git a/po/en.po b/po/en.po
index 609a4bca..46514e49 100644
--- a/po/en.po
+++ b/po/en.po
@@ -1333,6 +1333,21 @@ msgstr "High Contrast"
 msgid "prefs.saturation"
 msgstr "Saturation:"
 
+msgid "prefs.imagestyle"
+msgstr "Colorize images:"
+
+msgid "prefs.imagestyle.original"
+msgstr "None"
+
+msgid "prefs.imagestyle.grayscale"
+msgstr "Grayscale"
+
+msgid "prefs.imagestyle.text"
+msgstr "Text Color"
+
+msgid "prefs.imagestyle.preformat"
+msgstr "Preformatted Color"
+
 msgid "prefs.headingfont"
 msgstr "Heading font:"
 
diff --git a/res/lang/de.bin b/res/lang/de.bin
index bac3d41b..5788ed84 100644
--- a/res/lang/de.bin
+++ b/res/lang/de.bin
diff --git a/res/lang/en.bin b/res/lang/en.bin
index d2f19cef..536ca6a2 100644
--- a/res/lang/en.bin
+++ b/res/lang/en.bin
diff --git a/res/lang/es.bin b/res/lang/es.bin
index 8462461d..14203f8e 100644
--- a/res/lang/es.bin
+++ b/res/lang/es.bin
diff --git a/res/lang/fi.bin b/res/lang/fi.bin
index 2f1bb18f..875413a5 100644
--- a/res/lang/fi.bin
+++ b/res/lang/fi.bin
diff --git a/res/lang/fr.bin b/res/lang/fr.bin
index 86282bc2..6976a00f 100644
--- a/res/lang/fr.bin
+++ b/res/lang/fr.bin
diff --git a/res/lang/ia.bin b/res/lang/ia.bin
index 4b82125e..a77a1d61 100644
--- a/res/lang/ia.bin
+++ b/res/lang/ia.bin
diff --git a/res/lang/ie.bin b/res/lang/ie.bin
index a8bce39d..33850dc5 100644
--- a/res/lang/ie.bin
+++ b/res/lang/ie.bin
diff --git a/res/lang/pl.bin b/res/lang/pl.bin
index f905414b..0b4c3e10 100644
--- a/res/lang/pl.bin
+++ b/res/lang/pl.bin
diff --git a/res/lang/ru.bin b/res/lang/ru.bin
index 687adc01..fbafc283 100644
--- a/res/lang/ru.bin
+++ b/res/lang/ru.bin
diff --git a/res/lang/sr.bin b/res/lang/sr.bin
index df8e532b..b9ce2f5a 100644
--- a/res/lang/sr.bin
+++ b/res/lang/sr.bin
diff --git a/res/lang/tok.bin b/res/lang/tok.bin
index f2b59891..f1988dff 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 49decd2d..0ef1a915 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 10a8e86c..f12f0ef2 100644
--- a/res/lang/zh_Hant.bin
+++ b/res/lang/zh_Hant.bin
diff --git a/src/app.c b/src/app.c
index be96bf6c..9ff8ebc8 100644
--- a/src/app.c
+++ b/src/app.c
@@ -242,6 +242,7 @@ static iString *serializePrefs_App_(const iApp *d) {
     appendFormat_String(str, "doctheme.dark.set arg:%d\n", d->prefs.docThemeDark);
     appendFormat_String(str, "doctheme.light.set arg:%d\n", d->prefs.docThemeLight);
     appendFormat_String(str, "saturation.set arg:%d\n", (int) ((d->prefs.saturation * 100) + 0.5f));
+    appendFormat_String(str, "imagestyle.set arg:%d\n", d->prefs.imageStyle);
     appendFormat_String(str, "ca.file noset:1 path:%s\n", cstr_String(&d->prefs.caFile));
     appendFormat_String(str, "ca.path path:%s\n", cstr_String(&d->prefs.caPath));
     appendFormat_String(str, "proxy.gemini address:%s\n", cstr_String(&d->prefs.geminiProxy));
@@ -1655,6 +1656,7 @@ static void updateDropdownSelection_(iLabelWidget *dropButton, const char *selec
 }
 
 static void updateColorThemeButton_(iLabelWidget *button, int theme) {
+    /* TODO: These three functions are all the same? Cleanup? */
     if (!button) return;
     updateDropdownSelection_(button, format_CStr(".set arg:%d", theme));
 }
@@ -1664,6 +1666,11 @@ static void updateFontButton_(iLabelWidget *button, int font) {
     updateDropdownSelection_(button, format_CStr(".set arg:%d", font));
 }
 
+static void updateImageStyleButton_(iLabelWidget *button, int style) {
+    if (!button) return;
+    updateDropdownSelection_(button, format_CStr(".set arg:%d", style));
+}
+
 static iBool handlePrefsCommands_(iWidget *d, const char *cmd) {
     if (equal_Command(cmd, "prefs.dismiss") || equal_Command(cmd, "preferences")) {
         setupSheetTransition_Mobile(d, iFalse);
@@ -1745,6 +1752,10 @@ static iBool handlePrefsCommands_(iWidget *d, const char *cmd) {
         updateColorThemeButton_(findChild_Widget(d, "prefs.doctheme.light"), arg_Command(cmd));
         return iFalse;
     }
+    else if (equal_Command(cmd, "imagestyle.set")) {
+        updateImageStyleButton_(findChild_Widget(d, "prefs.imagestyle"), arg_Command(cmd));
+        return iFalse;
+    }
     else if (equal_Command(cmd, "font.set")) {
         updateFontButton_(findChild_Widget(d, "prefs.font"), arg_Command(cmd));
         return iFalse;
@@ -2177,6 +2188,10 @@ iBool handleCommand_App(const char *cmd) {
         }
         return iTrue;
     }
+    else if (equal_Command(cmd, "imagestyle.set")) {
+        d->prefs.imageStyle = arg_Command(cmd);
+        return iTrue;
+    }
     else if (equal_Command(cmd, "linewidth.set")) {
         d->prefs.lineWidth = iMax(20, arg_Command(cmd));
         postCommand_App("document.layout.changed");
@@ -2611,6 +2626,7 @@ iBool handleCommand_App(const char *cmd) {
         setToggle_Widget(findChild_Widget(dlg, "prefs.collapsepreonload"), d->prefs.collapsePreOnLoad);
         updateColorThemeButton_(findChild_Widget(dlg, "prefs.doctheme.dark"), d->prefs.docThemeDark);
         updateColorThemeButton_(findChild_Widget(dlg, "prefs.doctheme.light"), d->prefs.docThemeLight);
+        updateImageStyleButton_(findChild_Widget(dlg, "prefs.imagestyle"), d->prefs.imageStyle);
         updateFontButton_(findChild_Widget(dlg, "prefs.font"), d->prefs.font);
         updateFontButton_(findChild_Widget(dlg, "prefs.headingfont"), d->prefs.headingFont);
         setFlags_Widget(
diff --git a/src/defs.h b/src/defs.h
index cf04514e..135cc053 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -41,6 +41,13 @@ enum iFileVersion {
     latest_FileVersion = 4,
 };
 
+enum iImageStyle {
+    original_ImageStyle           = 0,
+    grayscale_ImageStyle          = 1,
+    textColorized_ImageStyle      = 2,
+    preformatColorized_ImageStyle = 3,
+};
+
 enum iScrollType {
     keyboard_ScrollType,
     mouse_ScrollType,
diff --git a/src/gmdocument.c b/src/gmdocument.c
index 75f6f06b..4e92c89c 100644
--- a/src/gmdocument.c
+++ b/src/gmdocument.c
@@ -464,6 +464,7 @@ static void doLayout_GmDocument_(iGmDocument *d) {
     const iBool   isNarrow          = d->size.x < 90 * gap_Text;
     const iBool   isVeryNarrow      = d->size.x <= 70 * gap_Text;
     const iBool   isExtremelyNarrow = d->size.x <= 60 * gap_Text;
+    const iBool   isFullWidthImages = (d->outsideMargin < 5 * gap_UI);
     const iBool   isDarkBg          = isDark_GmDocumentTheme(
         isDark_ColorTheme(colorTheme_App()) ? prefs->docThemeDark : prefs->docThemeLight);
     /* TODO: Collect these parameters into a GmTheme. */
@@ -817,7 +818,7 @@ static void doLayout_GmDocument_(iGmDocument *d) {
             rts.layoutWidth   = d->size.x;
             rts.indent        = indent * gap_Text;
             /* The right margin is used for balancing lines horizontally. */
-            if (isVeryNarrow) {
+            if (isVeryNarrow || isFullWidthImages) {
                 rts.rightMargin = 0;
             }
             else {
@@ -900,14 +901,15 @@ static void doLayout_GmDocument_(iGmDocument *d) {
                 pos.y += margin;
                 run.bounds.pos = pos;
                 run.bounds.size.x = d->size.x;
+                const float aspect = (float) imgSize.y / (float) imgSize.x;
+                run.bounds.size.y = d->size.x * aspect;
                 /* Extend the image to full width, including outside margin, if the viewport
                    is narrow enough. */
-                if (d->outsideMargin < 5 * gap_UI) {
+                if (isFullWidthImages) {
                     run.bounds.size.x += d->outsideMargin * 2;
+                    run.bounds.size.y += d->outsideMargin * 2 * aspect;
                     run.bounds.pos.x  -= d->outsideMargin;
                 }                
-                const float aspect = (float) imgSize.y / (float) imgSize.x;
-                run.bounds.size.y = d->size.x * aspect;
                 run.visBounds = run.bounds;
                 const iInt2 maxSize = mulf_I2(imgSize, get_Window()->pixelRatio);
                 if (width_Rect(run.visBounds) > maxSize.x) {
diff --git a/src/media.c b/src/media.c
index 5240ab5d..e47c5278 100644
--- a/src/media.c
+++ b/src/media.c
@@ -87,6 +87,40 @@ void deinit_GmImage(iGmImage *d) {
     deinit_GmMediaProps_(&d->props);
 }
 
+static void applyImageStyle_(enum iImageStyle style, iInt2 size, uint8_t *imgData) {
+    if (style == original_ImageStyle) {
+        return;
+    }
+    iColor colorize = (iColor){ 255, 255, 255, 255};
+    float brighten = 0.0f;
+    if (style != grayscale_ImageStyle) {
+        colorize = get_Color(style == textColorized_ImageStyle ? tmParagraph_ColorId
+                                                               : tmPreformatted_ColorId);
+        /* Maximize contrast. */
+        const int colMax = iMax(iMax(colorize.r, colorize.g), colorize.b);
+        if (colMax >= 8) {
+            colorize.r = colorize.r * 255 / colMax;
+            colorize.g = colorize.g * 255 / colMax;
+            colorize.b = colorize.b * 255 / colMax;
+        }
+        else {
+            colorize = (iColor){ 255, 255, 255, 255};
+        }
+//        printf("colorize:%d %d %d\n", colorize.r, colorize.g, colorize.b);
+//        brighten = iClamp(1.0f - (colorize.r + colorize.g + colorize.b) / 600.0f, 0.0f, 0.5f); /* compensate loss of light */
+//        printf("bright:%f\n", brighten);
+    }
+    uint8_t *pos = imgData;
+    size_t numPixels = size.x * size.y;
+    while (numPixels-- > 0) {
+        iHSLColor hsl = hsl_Color((iColor){ pos[0], pos[1], pos[2], 255 });
+        pos[0] = powf((colorize.r * hsl.lum) / 255.0f, 1.0f - brighten) * 255;
+        pos[1] = powf((colorize.g * hsl.lum) / 255.0f, 1.0f - brighten) * 255;
+        pos[2] = powf((colorize.b * hsl.lum) / 255.0f, 1.0f - brighten) * 255;
+        pos += 4;
+    }
+}
+
 void makeTexture_GmImage(iGmImage *d) {
     iBlock *data     = &d->partialData;
     d->numBytes      = size_Block(data);
@@ -105,6 +139,7 @@ void makeTexture_GmImage(iGmImage *d) {
         d->texture = NULL;
     }
     else {
+        applyImageStyle_(prefs_App()->imageStyle, d->size, imgData);        
         /* TODO: Save some memory by checking if the alpha channel is actually in use. */
         iWindow *window  = get_Window();
         iInt2    texSize = d->size;
diff --git a/src/prefs.c b/src/prefs.c
index 13a95a3d..749accf8 100644
--- a/src/prefs.c
+++ b/src/prefs.c
@@ -62,6 +62,7 @@ void init_Prefs(iPrefs *d) {
     d->quoteIcon         = iTrue;
     d->centerShortDocs   = iTrue;
     d->plainTextWrap     = iTrue;
+    d->imageStyle        = original_ImageStyle;
     d->docThemeDark      = colorfulDark_GmDocumentTheme;
     d->docThemeLight     = white_GmDocumentTheme;
     d->saturation        = 1.0f;
diff --git a/src/prefs.h b/src/prefs.h
index 58c73bf7..21960646 100644
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -86,6 +86,7 @@ struct Impl_Prefs {
     iBool            quoteIcon;
     iBool            centerShortDocs;
     iBool            plainTextWrap;
+    enum iImageStyle imageStyle;
     /* Colors */
     enum iGmDocumentTheme docThemeDark;
     enum iGmDocumentTheme docThemeLight;
diff --git a/src/ui/util.c b/src/ui/util.c
index b6ecc7d5..8a42f75b 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -1831,6 +1831,23 @@ iWidget *makePreferences_Widget(void) {
             addRadioButton_(sats, "prefs.saturation.0", "0 %", "saturation.set arg:0");
         }
         addChildFlags_Widget(values, iClob(sats), arrangeHorizontal_WidgetFlag | arrangeSize_WidgetFlag);
+        /* Colorize images. */ {
+            addChild_Widget(headings, iClob(makeHeading_Widget("${prefs.imagestyle}")));
+            const iMenuItem imgStyles[] = {
+                { "${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.text}",      0, 0, format_CStr("imagestyle.set arg:%d", textColorized_ImageStyle) },
+                { "${prefs.imagestyle.preformat}", 0, 0, format_CStr("imagestyle.set arg:%d", preformatColorized_ImageStyle) },   
+            };
+            iLabelWidget *button = makeMenuButton_LabelWidget(
+                imgStyles[findWidestItemLabel_(imgStyles, iElemCount(imgStyles))].label,
+                imgStyles,
+                iElemCount(imgStyles));
+            setBackgroundColor_Widget(findChild_Widget(as_Widget(button), "menu"),
+                                      uiBackgroundMenu_ColorId);
+            setId_Widget(addChildFlags_Widget(values, iClob(button), alignLeft_WidgetFlag),
+                         "prefs.imagestyle");
+        }
     }
     /* Fonts. */ {
         setId_Widget(appendTwoColumnTabPage_Widget(tabs, "${heading.prefs.fonts}", '4', &headings, &values), "prefs.page.fonts");