[API} hb_buffer_get_glyph_{infos,positions}: Add length out parameter

Return the length, whenever we return an array.  Makes it easier on the
language bindings.

src/hb-buffer.cc

@@ -475,18 +475,26 @@ hb_buffer_get_length (hb_buffer_t *buffer)
 
 /* Return value valid as long as buffer not modified */
 hb_glyph_info_t *
-hb_buffer_get_glyph_infos (hb_buffer_t *buffer)
+hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
+                           unsigned int *length)
 {
+  if (length)
+    *length = buffer->len;
+
   return (hb_glyph_info_t *) buffer->info;
 }
 
 /* Return value valid as long as buffer not modified */
 hb_glyph_position_t *
-hb_buffer_get_glyph_positions (hb_buffer_t *buffer)
+hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
+                               unsigned int *length)
 {
   if (!buffer->have_positions)
     _hb_buffer_clear_positions (buffer);
 
+  if (length)
+    *length = buffer->len;
+
   return (hb_glyph_position_t *) buffer->pos;
 }
 

src/hb-buffer.h

@@ -160,11 +160,13 @@ hb_buffer_get_length (hb_buffer_t *buffer);
 
 /* Return value valid as long as buffer not modified */
 hb_glyph_info_t *
-hb_buffer_get_glyph_infos (hb_buffer_t *buffer);
+hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
+                           unsigned int *length);
 
 /* Return value valid as long as buffer not modified */
 hb_glyph_position_t *
-hb_buffer_get_glyph_positions (hb_buffer_t *buffer);
+hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
+                               unsigned int *length);
 
 
 HB_END_DECLS

src/hb-ot-layout-gpos-private.hh

@@ -1493,8 +1493,8 @@ void
 GPOS::position_finish (hb_buffer_t *buffer)
 {
   unsigned int i, j;
-  unsigned int len = hb_buffer_get_length (buffer);
-  hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer);
+  unsigned int len;
+  hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
   hb_direction_t direction = buffer->props.direction;
 
   /* Handle cursive connections:

src/hb-view.c

@@ -361,8 +361,8 @@ _hb_cr_text_glyphs (cairo_t *cr,
   hb_shape (hb_font, hb_face, hb_buffer, features, num_features);
 
   num_glyphs = hb_buffer_get_length (hb_buffer);
-  hb_glyph = hb_buffer_get_glyph_infos (hb_buffer);
-  hb_position = hb_buffer_get_glyph_positions (hb_buffer);
+  hb_glyph = hb_buffer_get_glyph_infos (hb_buffer, NULL);
+  hb_position = hb_buffer_get_glyph_positions (hb_buffer, NULL);
   cairo_glyphs = cairo_glyph_allocate (num_glyphs + 1);
   x = 0;
   for (i = 0; i < num_glyphs; i++)

test/test-buffer.c

@@ -126,11 +126,9 @@ test_buffer_contents (Fixture *fixture, gconstpointer user_data)
     return;
   }
 
-  len = hb_buffer_get_length (fixture->b);
+  glyphs = hb_buffer_get_glyph_infos (fixture->b, &len);
   g_assert_cmpint (len, ==, 5);
 
-  glyphs = hb_buffer_get_glyph_infos (fixture->b);
-
   for (i = 0; i < len; i++) {
     unsigned int cluster;
     cluster = 1+i;
@@ -155,8 +153,7 @@ test_buffer_positions (Fixture *fixture, gconstpointer user_data)
   hb_glyph_position_t *positions;
 
   /* Without shaping, positions should all be zero */
-  positions = hb_buffer_get_glyph_positions (fixture->b);
-  len = hb_buffer_get_length (fixture->b);
+  positions = hb_buffer_get_glyph_positions (fixture->b, &len);
   for (i = 0; i < len; i++) {
     g_assert_cmpint (0, ==, positions[i].x_advance);
     g_assert_cmpint (0, ==, positions[i].y_advance);