text: font: replace x/y offsets with baseline attribute

When rendering underlines we need the baseline attribute. Therefore,
replace the unused x/y offsets with a baseline attribute.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

src/text.h

@@ -70,8 +70,6 @@ bool kmscon_font_attr_match(const struct kmscon_font_attr *a1,
 struct kmscon_glyph {
 	unsigned int ascent;
 	unsigned int descent;
-	unsigned int xoff;
-	unsigned int yoff;
 	struct uterm_video_buffer buf;
 };
 
@@ -79,6 +77,7 @@ struct kmscon_font {
 	unsigned long ref;
 	const struct kmscon_font_ops *ops;
 	struct kmscon_font_attr attr;
+	unsigned int baseline;
 	void *data;
 };
 

src/text_font_8x16.c

@@ -71,6 +71,7 @@ static int kmscon_font_8x16_init(struct kmscon_font *out,
 	out->attr.width = 8;
 	out->attr.height = 16;
 	kmscon_font_attr_normalize(&out->attr);
+	out->baseline = 4;
 
 	return 0;
 }