Added horizontal and vertical flip commands

README.md

@@ -122,6 +122,7 @@ The following additional key commands are available in *image mode*:
                  (also with Ctrl-arrow keys)
 
     <,>          Rotate image (counter-)clockwise by 90 degrees
+    \,|          Flip image horizontally/vertically
 
     s            Toggle slideshow
     Ctrl-'-'     Decrease slideshow delay

commands.c

@@ -342,6 +342,21 @@ bool i_rotate(arg_t a) {
 	return false;
 }
 
+bool i_flip(arg_t a) {
+	flip_t flp = (flip_t) a;
+
+	if (mode == MODE_IMAGE) {
+		if (flp == FLIP_HORIZONTAL) {
+			img_flip_horizontal(&img);
+			return true;
+		} else if (flp == FLIP_VERTICAL) {
+			img_flip_vertical(&img);
+			return true;
+		}
+	}
+	return false;
+}
+
 bool i_toggle_antialias(arg_t a) {
 	if (mode == MODE_IMAGE) {
 		img_toggle_antialias(&img);

commands.h

@@ -61,6 +61,7 @@ bool i_set_zoom(arg_t);
 bool i_fit_to_win(arg_t);
 bool i_fit_to_img(arg_t);
 bool i_rotate(arg_t);
+bool i_flip(arg_t);
 bool i_toggle_slideshow(arg_t);
 bool i_adjust_slideshow(arg_t);
 bool i_reset_slideshow(arg_t);

config.def.h

@@ -113,6 +113,9 @@ static const keymap_t keys[] = {
 	{ false,  XK_less,          i_rotate,             (arg_t) DIR_LEFT },
 	{ false,  XK_greater,       i_rotate,             (arg_t) DIR_RIGHT },
 
+	{ false,  XK_backslash,     i_flip,               (arg_t) FLIP_HORIZONTAL },
+	{ false,  XK_bar,           i_flip,               (arg_t) FLIP_VERTICAL },
+
 	{ false,  XK_a,             i_toggle_antialias,   (arg_t) None },
 	{ false,  XK_A,             it_toggle_alpha,      (arg_t) None },
 

image.c

@@ -642,6 +642,26 @@ void img_rotate_right(img_t *img) {
 	img_rotate(img, 1);
 }
 
+void img_flip(img_t *img, int f) {
+	if (img == NULL || img->im == NULL || img->win == NULL)
+		return;
+
+	imlib_context_set_image(img->im);
+    if (f == 0)
+        imlib_image_flip_horizontal();
+    else
+        imlib_image_flip_vertical();
+	img->dirty = true;
+}
+
+void img_flip_horizontal(img_t *img) {
+    img_flip(img, 0);
+}
+
+void img_flip_vertical(img_t *img) {
+    img_flip(img, 1);
+}
+
 void img_toggle_antialias(img_t *img) {
 	if (img == NULL || img->im == NULL)
 		return;

image.h

@@ -76,9 +76,14 @@ bool img_move(img_t*, float, float);
 bool img_pan(img_t*, direction_t, int);
 bool img_pan_edge(img_t*, direction_t);
 
+void img_rotate(img_t*, int);
 void img_rotate_left(img_t*);
 void img_rotate_right(img_t*);
 
+void img_flip(img_t*, int);
+void img_flip_horizontal(img_t*);
+void img_flip_vertical(img_t*);
+
 void img_toggle_antialias(img_t*);
 
 bool img_frame_navigate(img_t*, int);

sxiv.1

@@ -238,6 +238,13 @@ Rotate image counter-clockwise by 90 degrees.
 .TP
 .B >
 Rotate image clockwise by 90 degrees.
+.SS Flip
+.TP
+.B \\\\
+Flip image horizontally.
+.TP
+.B |
+Flip image vertically.
 .SS Slideshow
 .TP
 .B s

types.h

@@ -23,6 +23,11 @@ typedef enum {
 	DIR_DOWN
 } direction_t;
 
+typedef enum {
+	FLIP_HORIZONTAL,
+	FLIP_VERTICAL
+} flip_t;
+
 typedef enum {
 	SCALE_DOWN,
 	SCALE_FIT,