text_style: add text_style_Merge()

include/vlc_text_style.h

@@ -144,6 +144,28 @@ VLC_API text_style_t * text_style_Copy( text_style_t *, const text_style_t * );
  */
 VLC_API text_style_t * text_style_Duplicate( const text_style_t * );
 
+/**
+ * Merge two styles using non default values
+ *
+ * Set b_override to true if you also want to overwrite non-defaults
+ */
+VLC_API void text_style_Merge( text_style_t *, const text_style_t *, bool b_override );
+
+inline void text_style_Reset( text_style_t *p_style )
+{
+    free(p_style->psz_fontname);
+    p_style->psz_fontname = NULL;
+    free(p_style->psz_monofontname);
+    p_style->psz_monofontname = NULL;
+    p_style->i_features = STYLE_NO_DEFAULTS;
+    p_style->i_style_flags = 0;
+    p_style->f_font_relsize = 0.0;
+    p_style->i_font_size = 0;
+    p_style->i_outline_width = 0;
+    p_style->i_shadow_width = 0;
+    p_style->i_spacing = -0;
+}
+
 /**
  * Delete a text style created by text_style_New or text_style_Duplicate
  */

src/libvlccore.sym

@@ -673,6 +673,7 @@ xml_Create
 text_style_Copy
 text_style_Delete
 text_style_Duplicate
+text_style_Merge
 text_style_New
 xml_Delete
 xml_ReaderCreate

src/misc/text_style.c

@@ -76,6 +76,54 @@ text_style_t *text_style_Copy( text_style_t *p_dst, const text_style_t *p_src )
     return p_dst;
 }
 
+#define MERGE(var, fflag) \
+    if( (p_src->i_features & fflag) && (b_override || !(p_dst->i_features & fflag)) )\
+        p_dst->var = p_src->var
+
+#define MERGE_SIZE(var) \
+    if( p_src->var > 0 && (b_override || p_dst->var <= 0) )\
+        p_dst->var = p_src->var
+
+void text_style_Merge( text_style_t *p_dst, const text_style_t *p_src, bool b_override )
+{
+    if( p_src->psz_fontname && (!p_dst->psz_fontname || b_override) )
+    {
+        free( p_dst->psz_fontname );
+        p_dst->psz_fontname = strdup( p_src->psz_fontname );
+    }
+
+    if( p_src->psz_monofontname && (!p_dst->psz_monofontname || b_override) )
+    {
+        free( p_dst->psz_monofontname );
+        p_dst->psz_monofontname = strdup( p_src->psz_monofontname );
+    }
+
+    if( p_src->i_features != STYLE_NO_DEFAULTS )
+    {
+        MERGE(i_font_color,         STYLE_HAS_FONT_COLOR);
+        MERGE(i_font_alpha,         STYLE_HAS_FONT_ALPHA);
+        MERGE(i_outline_color,      STYLE_HAS_OUTLINE_COLOR);
+        MERGE(i_outline_alpha,      STYLE_HAS_OUTLINE_ALPHA);
+        MERGE(i_shadow_color,       STYLE_HAS_SHADOW_COLOR);
+        MERGE(i_shadow_alpha,       STYLE_HAS_SHADOW_ALPHA);
+        MERGE(i_background_color,   STYLE_HAS_BACKGROUND_COLOR);
+        MERGE(i_background_alpha,   STYLE_HAS_BACKGROUND_ALPHA);
+        MERGE(i_karaoke_background_color, STYLE_HAS_K_BACKGROUND_COLOR);
+        MERGE(i_karaoke_background_alpha, STYLE_HAS_K_BACKGROUND_ALPHA);
+        p_dst->i_features |= p_src->i_features;
+        p_dst->i_style_flags |= p_src->i_style_flags;
+    }
+
+    MERGE_SIZE(f_font_relsize);
+    MERGE_SIZE(i_font_size);
+    MERGE_SIZE(i_outline_width);
+    MERGE_SIZE(i_shadow_width);
+    MERGE_SIZE(i_spacing);
+}
+
+#undef MERGE
+#undef MERGE_SIZE
+
 text_style_t *text_style_Duplicate( const text_style_t *p_src )
 {
     if( !p_src )