Attachment 6360 Details for Bug 7494 – Elide size-zero glyphs from calls to XRender functions.

[patch] Elide size-zero glyphs from calls to XRender functions.

7494.patch (text/plain), 3.61 KB, created by Carl Worth on 2006-07-27 00:07:05 UTC

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Creator: Carl Worth

Created: 2006-07-27 00:07:05 UTC

Size: 3.61 KB

patch

obsolete

>commit 2010753cc750ff804e373f1bdd4cd31def786368
>Author: Carl Worth <cworth@cworth.org>
>Date:   Wed Jul 26 15:48:56 2006 -0700
>
>    Elide size-zero glyphs from calls to XRender functions.
>    
>    There appears to be a bug in some X servers which is triggered by
>    rendering 1-bit glyphs with a size of 0x0 via the functions
>    XRenderAddGlyphs and XRenderCompositeText8 (and likely its variants).
>    
>    We avoid this bug by making a copy of the glyphs array which does not
>    include any of the 0x0 glyphs so that the X server never sees them.
>
>diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c
>index cac6787..2067c98 100644
>--- a/src/cairo-xlib-surface.c
>+++ b/src/cairo-xlib-surface.c
>@@ -2674,12 +2674,13 @@ _cairo_xlib_surface_show_glyphs (void   
>     cairo_surface_attributes_t attributes;
>     cairo_xlib_surface_t *src = NULL;
> 
>+    cairo_glyph_t *output_glyphs;
>     const cairo_glyph_t *glyphs_chunk;
>     int glyphs_remaining, chunk_size, max_chunk_size;
>     cairo_scaled_glyph_t *scaled_glyph;
>     cairo_xlib_surface_font_private_t *font_private;
> 
>-    int i;
>+    int i, o;
>     unsigned long max_index = 0;
> 
>     cairo_xlib_surface_show_glyphs_func_t show_glyphs_func;
>@@ -2723,6 +2724,13 @@ _cairo_xlib_surface_show_glyphs (void   
> 	(font_private != NULL && font_private->dpy != dst->dpy))
> 	return CAIRO_INT_STATUS_UNSUPPORTED;
> 
>+    /* We make a copy of the glyphs so that we can elide any 0x0
>+     * glyphs to workaround an X server bug, (present in at least Xorg
>+     * 7.1 without EXA). */
>+    output_glyphs = malloc (num_glyphs * sizeof (cairo_glyph_t));
>+    if (output_glyphs == NULL)
>+	return CAIRO_STATUS_NO_MEMORY;
>+
>     /* After passing all those tests, we're now committed to rendering
>      * these glyphs or to fail trying. We first upload any glyphs to
>      * the X server that it doesn't have already, then we draw
>@@ -2781,7 +2789,7 @@ _cairo_xlib_surface_show_glyphs (void   
>         goto BAIL;
> 
>     /* Send all unsent glyphs to the server, and count the max of the glyph indices */
>-    for (i = 0; i < num_glyphs; i++) {
>+    for (i = 0, o = 0; i < num_glyphs; i++) {
> 	if (glyphs[i].index > max_index)
> 	    max_index = glyphs[i].index;
> 	status = _cairo_scaled_glyph_lookup (scaled_font,
>@@ -2790,11 +2798,18 @@ _cairo_xlib_surface_show_glyphs (void   
> 					     &scaled_glyph);
> 	if (status != CAIRO_STATUS_SUCCESS)
> 	    goto BAIL;
>-	if (scaled_glyph->surface_private == NULL) {
>-	    _cairo_xlib_surface_add_glyph (dst->dpy, scaled_font, scaled_glyph);
>-	    scaled_glyph->surface_private = (void *) 1;
>+	/* Don't put any size-zero glyphs into output_glyphs to avoid
>+	 * an X server bug which stops rendering glyphs after the
>+	 * first size-zero glyph. */
>+	if (scaled_glyph->surface->width && scaled_glyph->surface->height) {
>+	    output_glyphs[o++] = glyphs[i];
>+	    if (scaled_glyph->surface_private == NULL) {
>+		_cairo_xlib_surface_add_glyph (dst->dpy, scaled_font, scaled_glyph);
>+		scaled_glyph->surface_private = (void *) 1;
>+	    }
> 	}
>     }
>+    num_glyphs = o;
> 
>     _cairo_xlib_surface_ensure_dst_picture (dst);
> 
>@@ -2811,7 +2826,7 @@ _cairo_xlib_surface_show_glyphs (void   
>     }
>     max_chunk_size /= sz_xGlyphElt;
> 
>-    for (glyphs_remaining = num_glyphs, glyphs_chunk = glyphs;
>+    for (glyphs_remaining = num_glyphs, glyphs_chunk = output_glyphs;
> 	 glyphs_remaining;
> 	 glyphs_remaining -= chunk_size, glyphs_chunk += chunk_size)
>     {
>@@ -2826,6 +2841,7 @@ _cairo_xlib_surface_show_glyphs (void   
> 
>   BAIL:
>     _cairo_scaled_font_thaw_cache (scaled_font);
>+    free (output_glyphs);
> 
>     if (src)
>         _cairo_pattern_release_surface (src_pattern, &src->base, &attributes);

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Attachments on bug 7494: 6319 | 6320 | 6321 | 6354 | 6359 | 6360

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