[cairo] PDF show glyphs

Adrian Johnson ajohnson at redneon.com
Sun Feb 11 06:20:08 PST 2007


Behdad Esfahbod wrote:
> Do you want to get this in for or past 1.4?  If 1.4, go ahead and commit
> it so we get a bit of testing.

I've done some more testing and updated the patch however I have not
committed it because it breaks three tests. These tests print a string
of glyphs. The test failures are the result of one or two glyphs
shifting left or right by 1 pixel.

-------------- next part --------------
>From 7502af0e8b1cb2900e78804dd4c746610b7534d3 Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson at redneon.com>
Date: Mon, 12 Feb 2007 00:16:55 +1030
Subject: [PATCH] PDF: Use TJ for showing glyphs

cairo-scale-font-subsets looks up the x_advance for
each glyph added to the subset. The x_advance is
returned to the PDF surface via the map_glyphs function.

The PDF surface looks for two or more glyphs with the same
Y coordinate and used the TJ operater to emit a single
string of glyphs without needing to reposition between
each glyph.
---
 src/cairo-pdf-surface.c                 |  113 ++++++++++++++++++++++++++-----
 src/cairo-ps-surface.c                  |    4 +-
 src/cairo-scaled-font-subsets-private.h |    4 +-
 src/cairo-scaled-font-subsets.c         |   29 +++++++--
 src/cairo-svg-surface.c                 |    4 +-
 5 files changed, 130 insertions(+), 24 deletions(-)

diff --git a/src/cairo-pdf-surface.c b/src/cairo-pdf-surface.c
index 1e5e521..cfea723 100644
--- a/src/cairo-pdf-surface.c
+++ b/src/cairo-pdf-surface.c
@@ -2835,6 +2835,8 @@ _cairo_pdf_surface_fill (void			*abstrac
     return status;
 }
 
+#define GLYPH_POSITION_TOLERANCE 0.001
+
 static cairo_int_status_t
 _cairo_pdf_surface_show_glyphs (void			*abstract_surface,
 				cairo_operator_t	 op,
@@ -2846,8 +2848,11 @@ _cairo_pdf_surface_show_glyphs (void			*
     cairo_pdf_surface_t *surface = abstract_surface;
     unsigned int current_subset_id = (unsigned int)-1;
     unsigned int font_id, subset_id, subset_glyph_index;
-    cairo_bool_t diagonal;
+    cairo_bool_t diagonal, in_TJ;
     cairo_status_t status;
+    double x_advance;
+    double Tlm_x = 0, Tlm_y = 0;
+    double Tm_x = 0;
     int i;
 
     if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
@@ -2868,34 +2873,110 @@ _cairo_pdf_surface_show_glyphs (void			*
     else
         diagonal = FALSE;
 
+    in_TJ = FALSE;
     for (i = 0; i < num_glyphs; i++) {
-	status = _cairo_scaled_font_subsets_map_glyph (surface->font_subsets,
-						       scaled_font, glyphs[i].index,
-						       &font_id, &subset_id, &subset_glyph_index);
+        status = _cairo_scaled_font_subsets_map_glyph (surface->font_subsets,
+                                                       scaled_font, glyphs[i].index,
+                                                       &font_id, &subset_id, &subset_glyph_index,
+                                                       &x_advance);
 	if (status)
-	    return status;
+            return status;
 
-	if (subset_id != current_subset_id)
-	    _cairo_output_stream_printf (surface->output,
-					 "/CairoFont-%d-%d 1 Tf\r\n",
-					 font_id, subset_id);
+	if (subset_id != current_subset_id) {
+            if (in_TJ) {
+                _cairo_output_stream_printf (surface->output, ">] TJ\r\n");
+                in_TJ = FALSE;
+            }
+            _cairo_output_stream_printf (surface->output,
+                                         "/CairoFont-%d-%d 1 Tf\r\n",
+                                         font_id, subset_id);
+        }
 
         if (subset_id != current_subset_id || !diagonal) {
             _cairo_output_stream_printf (surface->output,
-                                         "%f %f %f %f %f %f Tm <%02x> Tj\r\n",
+                                         "%f %f %f %f %f %f Tm\r\n",
                                          scaled_font->scale.xx,
                                          scaled_font->scale.yx,
                                          -scaled_font->scale.xy,
                                          -scaled_font->scale.yy,
                                          glyphs[i].x,
-                                         glyphs[i].y,
-                                         subset_glyph_index);
-	    current_subset_id = subset_id;
+                                         glyphs[i].y);
+            current_subset_id = subset_id;
+            Tlm_x = glyphs[i].x;
+            Tlm_y = glyphs[i].y;
+            Tm_x = Tlm_x;
+        }
+
+        if (diagonal) {
+            if (i < num_glyphs - 1 &&
+                fabs((glyphs[i].y - glyphs[i+1].y)/scaled_font->scale.yy) < GLYPH_POSITION_TOLERANCE &&
+                fabs((glyphs[i].x - glyphs[i+1].x)/scaled_font->scale.xx) < 10) {
+                if (!in_TJ) {
+                    if (i != 0) {
+                        _cairo_output_stream_printf (surface->output,
+                                                     "%f %f Td\r\n",
+                                                     (glyphs[i].x - Tlm_x)/scaled_font->scale.xx,
+                                                     (glyphs[i].y - Tlm_y)/-scaled_font->scale.yy);
+                        Tlm_x = glyphs[i].x;
+                        Tlm_y = glyphs[i].y;
+                        Tm_x = Tlm_x;
+                    }
+                    _cairo_output_stream_printf (surface->output,
+                                                 "[<%02x",
+                                                 subset_glyph_index);
+                    Tm_x += x_advance;
+                    in_TJ = TRUE;
+                } else {
+                    if (fabs((glyphs[i].x - Tm_x)/scaled_font->scale.xx) > GLYPH_POSITION_TOLERANCE)
+                    {
+                        double delta = glyphs[i].x - Tm_x;
+
+                        _cairo_output_stream_printf (surface->output,
+                                                     "> %f <",
+                                                     -1000.0*delta/scaled_font->scale.xx);
+                        Tm_x += delta;
+                    }
+                    _cairo_output_stream_printf (surface->output,
+                                                 "%02x",
+                                                 subset_glyph_index);
+                    Tm_x += x_advance;
+                }
+            }
+            else {
+                if (in_TJ) {
+                    if (fabs((glyphs[i].x - Tm_x)/scaled_font->scale.xx) > GLYPH_POSITION_TOLERANCE)
+                    {
+                        double delta = glyphs[i].x - Tm_x;
+
+                        _cairo_output_stream_printf (surface->output,
+                                                     "> %f <",
+                                                     -1000.0*delta/scaled_font->scale.xx);
+                        Tm_x += delta;
+                    }
+                    _cairo_output_stream_printf (surface->output,
+                                                 "%02x>] TJ\r\n",
+                                                 subset_glyph_index);
+                    Tm_x += x_advance;
+                    in_TJ = FALSE;
+                } else {
+                    if (i != 0) {
+                        _cairo_output_stream_printf (surface->output,
+                                                     "%f %f Td ",
+                                                     (glyphs[i].x - Tlm_x)/scaled_font->scale.xx,
+                                                     (glyphs[i].y - Tlm_x)/-scaled_font->scale.yy);
+                        Tlm_x = glyphs[i].x;
+                        Tlm_y = glyphs[i].y;
+                        Tm_x = Tlm_x;
+                    }
+                    _cairo_output_stream_printf (surface->output,
+                                                 "<%02x> Tj ",
+                                                 subset_glyph_index);
+                    Tm_x += x_advance;
+                }
+            }
         } else {
             _cairo_output_stream_printf (surface->output,
-                                         "%f %f Td <%02x> Tj\r\n",
-                                         (glyphs[i].x - glyphs[i-1].x)/scaled_font->scale.xx,
-                                         (glyphs[i].y - glyphs[i-1].y)/-scaled_font->scale.yy,
+                                         "<%02x> Tj\r\n",
                                          subset_glyph_index);
         }
     }
diff --git a/src/cairo-ps-surface.c b/src/cairo-ps-surface.c
index 3da530e..4b8b124 100644
--- a/src/cairo-ps-surface.c
+++ b/src/cairo-ps-surface.c
@@ -2150,6 +2150,7 @@ _cairo_ps_surface_show_glyphs (void
     unsigned int num_glyphs_unsigned, i, j, last, end;
     cairo_bool_t vertical, horizontal;
     cairo_output_stream_t *word_wrap;
+    double x_advance;
 
     if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
 	return _analyze_operation (surface, op, source);
@@ -2174,7 +2175,8 @@ _cairo_ps_surface_show_glyphs (void
                                                        scaled_font, glyphs[i].index,
                                                        &font_id,
                                                        &(glyph_ids[i].subset_id),
-                                                       &(glyph_ids[i].glyph_id));
+                                                       &(glyph_ids[i].glyph_id),
+                                                       &x_advance);
         if (status)
             goto fail;
     }
diff --git a/src/cairo-scaled-font-subsets-private.h b/src/cairo-scaled-font-subsets-private.h
index 88dbfbb..9b7e28d 100644
--- a/src/cairo-scaled-font-subsets-private.h
+++ b/src/cairo-scaled-font-subsets-private.h
@@ -78,6 +78,7 @@ _cairo_scaled_font_subsets_destroy (cair
  * @font_id_ret: return value giving the font ID of the mapped glyph
  * @subset_id_ret: return value giving the subset ID of the mapped glyph within the @font_id_ret
  * @subset_glyph_index_ret: return value giving the index of the mapped glyph within the @subset_id_ret subset
+ * @x_advance_ret: return value giving the user space X advance of the glyph
  *
  * Map a glyph from a #cairo_scaled_font to a new index within a
  * subset of that font. The mapping performed is from the tuple:
@@ -126,7 +127,8 @@ _cairo_scaled_font_subsets_map_glyph (ca
 				      unsigned long			 scaled_font_glyph_index,
 				      unsigned int			*font_id_ret,
 				      unsigned int			*subset_id_ret,
-				      unsigned int			*subset_glyph_index_ret);
+				      unsigned int			*subset_glyph_index_ret,
+                                      double                            *x_advance_ret);
 
 typedef void
 (*cairo_scaled_font_subset_callback_func_t) (cairo_scaled_font_subset_t	*font_subset,
diff --git a/src/cairo-scaled-font-subsets.c b/src/cairo-scaled-font-subsets.c
index 68a662a..d6e6404 100644
--- a/src/cairo-scaled-font-subsets.c
+++ b/src/cairo-scaled-font-subsets.c
@@ -69,6 +69,7 @@ typedef struct _cairo_sub_font_glyph {
 
     unsigned int subset_id;
     unsigned int subset_glyph_index;
+    double       x_advance;
 } cairo_sub_font_glyph_t;
 
 typedef struct _cairo_sub_font_collection {
@@ -102,7 +103,8 @@ _cairo_sub_font_glyphs_equal (const void
 static cairo_sub_font_glyph_t *
 _cairo_sub_font_glyph_create (unsigned long	scaled_font_glyph_index,
 			      unsigned int	subset_id,
-			      unsigned int	subset_glyph_index)
+			      unsigned int	subset_glyph_index,
+                              double            x_advance)
 {
     cairo_sub_font_glyph_t *sub_font_glyph;
 
@@ -113,6 +115,7 @@ _cairo_sub_font_glyph_create (unsigned l
     _cairo_sub_font_glyph_init_key (sub_font_glyph, scaled_font_glyph_index);
     sub_font_glyph->subset_id = subset_id;
     sub_font_glyph->subset_glyph_index = subset_glyph_index;
+    sub_font_glyph->x_advance = x_advance;
 
     return sub_font_glyph;
 }
@@ -230,10 +233,13 @@ static cairo_status_t
 _cairo_sub_font_map_glyph (cairo_sub_font_t	*sub_font,
 			   unsigned long	 scaled_font_glyph_index,
 			   unsigned int		*subset_id,
-			   unsigned int		*subset_glyph_index)
+			   unsigned int		*subset_glyph_index,
+                           double               *x_advance)
 {
     cairo_sub_font_glyph_t key, *sub_font_glyph;
     cairo_status_t status;
+    cairo_scaled_glyph_t *scaled_glyph;
+    double x, y;
 
     _cairo_sub_font_glyph_init_key (&key, scaled_font_glyph_index);
     if (! _cairo_hash_table_lookup (sub_font->sub_font_glyphs, &key.base,
@@ -246,9 +252,20 @@ _cairo_sub_font_map_glyph (cairo_sub_fon
 	    sub_font->num_glyphs_in_current_subset = 0;
 	}
 
+        status = _cairo_scaled_glyph_lookup (sub_font->scaled_font,
+                                             scaled_font_glyph_index,
+                                             CAIRO_SCALED_GLYPH_INFO_METRICS,
+                                             &scaled_glyph);
+	if (status)
+	    return status;
+
+        x = scaled_glyph->metrics.x_advance;
+        y = 0;
+        cairo_matrix_transform_distance (&sub_font->scaled_font->ctm, &x, &y);
 	sub_font_glyph = _cairo_sub_font_glyph_create (scaled_font_glyph_index,
 						       sub_font->current_subset,
-						       sub_font->num_glyphs_in_current_subset++);
+						       sub_font->num_glyphs_in_current_subset++,
+                                                       x);
 	if (sub_font_glyph == NULL)
 	    return CAIRO_STATUS_NO_MEMORY;
 
@@ -262,6 +279,7 @@ _cairo_sub_font_map_glyph (cairo_sub_fon
 
     *subset_id = sub_font_glyph->subset_id;
     *subset_glyph_index = sub_font_glyph->subset_glyph_index;
+    *x_advance = sub_font_glyph->x_advance;
 
     return CAIRO_STATUS_SUCCESS;
 }
@@ -344,7 +362,8 @@ _cairo_scaled_font_subsets_map_glyph (ca
 				      unsigned long			 scaled_font_glyph_index,
 				      unsigned int			*font_id,
 				      unsigned int			*subset_id,
-				      unsigned int			*subset_glyph_index)
+				      unsigned int			*subset_glyph_index,
+                                      double                            *x_advance)
 {
     cairo_sub_font_t key, *sub_font;
     cairo_status_t status;
@@ -368,7 +387,7 @@ _cairo_scaled_font_subsets_map_glyph (ca
     *font_id = sub_font->font_id;
 
     return _cairo_sub_font_map_glyph (sub_font, scaled_font_glyph_index,
-						  subset_id, subset_glyph_index);
+                                      subset_id, subset_glyph_index, x_advance);
 }
 
 cairo_private cairo_status_t
diff --git a/src/cairo-svg-surface.c b/src/cairo-svg-surface.c
index 5f25015..6f488e2 100644
--- a/src/cairo-svg-surface.c
+++ b/src/cairo-svg-surface.c
@@ -1618,6 +1618,7 @@ _cairo_svg_surface_show_glyphs (void			*
     cairo_path_fixed_t path;
     cairo_status_t status;
     unsigned int font_id, subset_id, subset_glyph_index;
+    double x_advance;
     int i;
 
     if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
@@ -1641,7 +1642,8 @@ _cairo_svg_surface_show_glyphs (void			*
     for (i = 0; i < num_glyphs; i++) {
 	status = _cairo_scaled_font_subsets_map_glyph (document->font_subsets,
 						       scaled_font, glyphs[i].index,
-						       &font_id, &subset_id, &subset_glyph_index);
+						       &font_id, &subset_id, &subset_glyph_index,
+                                                       &x_advance);
 	if (status) {
 	    glyphs += i;
 	    num_glyphs -= i;
-- 
1.4.3.4



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