From ac771d288d5a34a10d193bd9352c8f5c744df20f Mon Sep 17 00:00:00 2001
From: wm4 <wm4@mplayer2.org>
Date: Sun, 23 Oct 2011 05:26:15 +0200
Subject: osd: enable line breaking for OSD text

OSD text wider than the window will be broken to fit the width. The line
breaking algorithm is naive and intended as temporary, until the OSD
render code is possibly replaced by "something better".

Newline characters are also considered.
---
 sub/sub.c | 98 +++++++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 67 insertions(+), 31 deletions(-)

(limited to 'sub')

diff --git a/sub/sub.c b/sub/sub.c
index efe648948c..744642dfdd 100644
--- a/sub/sub.c
+++ b/sub/sub.c
@@ -190,43 +190,79 @@ no_utf8:
   return c;
 }
 
+//if obj is NULL, don't render, and just return the metrics
+//sw, sh: screen width/height
+//out_w/out_h: return width/height of the text box (write-only)
+static void vo_update_text_osd_render(const char *cp, mp_osd_obj_t *obj,
+                                      int sw, int sh, int *out_w, int *out_h)
+{
+    int x = 0;
+    int y = 0;
+    int line_height = get_height('t', 0);
+    int w = 0;
+    int h = line_height;
+    int font;
+
+    while (*cp && h < sh && line_height > 0) {
+        const char* prev = cp;
+        uint16_t c = utf8_get_char(&cp);
+        int lf = (c == '\n');
+        int newx;
+        render_one_glyph(vo_font, c);
+        newx = x + vo_font->width[c];
+        if (lf || (newx > sw)) {
+            if (!lf)
+                cp = prev;
+            //can't put at least one char per line?
+            //rare but nasty corner case... simply exit and avoid endless loop
+            if (!lf && x == 0)
+                break;
+            y += h;
+            h = line_height;
+            w = FFMAX(x, w);
+            x = 0;
+            continue;
+        }
+        if (obj && (font = vo_font->font[c]) >= 0)
+            draw_alpha_buf(obj, obj->x + x, obj->y + y,
+                           vo_font->width[c],
+                           vo_font->pic_a[font]->h,
+                           vo_font->pic_b[font]->bmp + vo_font->start[c],
+                           vo_font->pic_a[font]->bmp + vo_font->start[c],
+                           vo_font->pic_a[font]->w);
+        x = newx + vo_font->charspace;
+        h = get_height(c, h);
+    }
+
+    y += h;
+    w = FFMAX(x, w) - vo_font->charspace;
+
+    *out_w = FFMAX(w, 0);
+    *out_h = y;
+}
+
 inline static void vo_update_text_osd(struct osd_state *osd, mp_osd_obj_t* obj,
                                       int dxs, int dys)
 {
 	const char *cp = osd->osd_text;
-	int x=20;
-	int h=0;
-	int font;
-
-        obj->bbox.x1=obj->x=x;
-        obj->bbox.y1=obj->y=10;
-
-        while (*cp){
-          uint16_t c=utf8_get_char(&cp);
-	  render_one_glyph(vo_font, c);
-	  x+=vo_font->width[c]+vo_font->charspace;
-	  h=get_height(c,h);
-        }
+    int w, h, sw, sh;
 
-	obj->bbox.x2=x-vo_font->charspace;
-	obj->bbox.y2=obj->bbox.y1+h;
-	obj->flags|=OSDFLAG_BBOX;
+    obj->bbox.x1 = obj->x = 20;
+    obj->bbox.y1 = obj->y = 10;
+    sw = dxs - obj->x;
+    sh = dys - obj->y;
 
-	alloc_buf(obj);
-
-	cp = osd->osd_text;
-	x = obj->x;
-        while (*cp){
-          uint16_t c=utf8_get_char(&cp);
-          if ((font=vo_font->font[c])>=0)
-            draw_alpha_buf(obj,x,obj->y,
-			   vo_font->width[c],
-			   vo_font->pic_a[font]->h,
-			   vo_font->pic_b[font]->bmp+vo_font->start[c],
-			   vo_font->pic_a[font]->bmp+vo_font->start[c],
-			   vo_font->pic_a[font]->w);
-          x+=vo_font->width[c]+vo_font->charspace;
-        }
+    //first pass: calculate obj bounding box
+    vo_update_text_osd_render(cp, NULL, sw, sh, &w, &h);
+
+    obj->bbox.x2 = obj->bbox.x1 + w;
+    obj->bbox.y2 = obj->bbox.y1 + h;
+    obj->flags |= OSDFLAG_BBOX;
+
+    alloc_buf(obj);
+
+    //second pass: actually draw the text
+    vo_update_text_osd_render(cp, obj, sw, sh, &w, &h);
 }
 
 #ifdef CONFIG_DVDNAV
-- 
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