ref: 13217f25096025df83ddcabeff15651acd0f5d4d
parent: d53cf1df31fa7ca41f87645d25517b05a1111eb3
author: Graham Asher <[email protected]>
date: Thu Jul 18 11:59:23 EDT 2002
Added the incremental loading system for the TrueType driver. Tested using my own unit test code.
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -750,15 +750,18 @@
TT_Face face = (TT_Face)loader->face;
FT_ULong offset;
FT_Int contours_count;
- FT_UInt idx, num_points, count;
+ FT_UInt num_points, count;
FT_Fixed x_scale, y_scale;
FT_GlyphLoader gloader = loader->gloader;
FT_Bool opened_frame = 0;
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ struct FT_StreamRec_ inc_stream;
+#endif
/* check glyph index */
- idx = glyph_index;
- if ( idx >= (FT_UInt)face->root.num_glyphs )
+ glyph_index;
+ if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
{error = TT_Err_Invalid_Glyph_Index;
goto Exit;
@@ -777,16 +780,40 @@
/* get horizontal metrics */
{- FT_Short left_bearing;
- FT_UShort advance_width;
+ FT_Short left_bearing = 0;
+ FT_UShort advance_width = 0;
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ FT_Bool metrics_found = FALSE;
- Get_HMetrics( face, idx,
+ /* If this is an incrementally loaded font see if there are overriding metrics for this glyph. */
+ if (face->root.incremental_interface && face->root.incremental_interface->funcs->get_glyph_metrics)
+ {+ FT_Basic_Glyph_Metrics m;
+ error = face->root.incremental_interface->funcs->get_glyph_metrics(face->root.incremental_interface->object,
+ glyph_index,FALSE,&m,&metrics_found);
+ if (error)
+ goto Exit;
+ left_bearing = (FT_Short)m.bearing_x;
+ advance_width = (FT_UShort)m.advance;
+ }
+
+ if (!metrics_found)
+ Get_HMetrics( face, glyph_index,
+ (FT_Bool)!( loader->load_flags &
+ FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
+ &left_bearing,
+ &advance_width );
+
+#else
+ Get_HMetrics( face, glyph_index,
(FT_Bool)!( loader->load_flags &
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ),
&left_bearing,
&advance_width );
+#endif
+
loader->left_bearing = left_bearing;
loader->advance = advance_width;
@@ -797,12 +824,38 @@
}
}
- offset = face->glyph_locations[idx];
- count = 0;
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ /*
+ Set 'offset' to the start of the glyph program relative to the start of the 'glyf' table,
+ and 'count' to the length of the glyph program in bytes.
- if ( idx < (FT_UInt)face->num_locations - 1 )
- count = face->glyph_locations[idx + 1] - offset;
+ If we are loading glyph data via the incremental interface, set the loader stream to a memory
+ stream reading the data returned by the interface.
+ */
+ if (face->root.incremental_interface)
+ {+ FT_Data data;
+ error = face->root.incremental_interface->funcs->get_glyph_data(face->root.incremental_interface->object,
+ glyph_index,&data);
+ if (error)
+ goto Exit;
+ offset = 0;
+ count = data.length;
+ memset(&inc_stream,0,sizeof(inc_stream));
+ FT_Stream_OpenMemory(&inc_stream,data.pointer,data.length);
+ loader->stream = &inc_stream;
+ }
+ else
+#endif
+ {+ offset = face->glyph_locations[glyph_index];
+ count = 0;
+
+ if ( glyph_index < (FT_UInt)face->num_locations - 1 )
+ count = face->glyph_locations[glyph_index + 1] - offset;
+ }
+
if ( count == 0 )
{/* as described by Frederic Loyer, these are spaces, and */
@@ -1200,7 +1253,7 @@
}
- static void
+ static FT_Error
compute_glyph_metrics( TT_Loader loader,
FT_UInt glyph_index )
{@@ -1279,10 +1332,25 @@
FT_Pos left; /* scaled vertical left side bearing */
FT_Pos top; /* scaled vertical top side bearing */
FT_Pos advance; /* scaled vertical advance height */
+ FT_Bool metrics_found = FALSE;
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ /* If this is an incrementally loaded font see if there are overriding metrics for this glyph. */
+ if (face->root.incremental_interface && face->root.incremental_interface->funcs->get_glyph_metrics)
+ {+ FT_Basic_Glyph_Metrics m;
+ FT_Error error =
+ face->root.incremental_interface->funcs->get_glyph_metrics(face->root.incremental_interface->object,
+ glyph_index,TRUE,&m,&metrics_found);
+ if (error)
+ return error;
+ top_bearing = (FT_Short)m.bearing_y;
+ advance_height = (FT_UShort)m.advance;
+ }
+#endif
- /* Get the unscaled `tsb' and `ah' */
- if ( face->vertical_info &&
+ /* Get the unscaled top bearing and advance height. */
+ if ( !metrics_found && face->vertical_info &&
face->vertical.number_Of_VMetrics > 0 )
{/* Don't assume that both the vertical header and vertical */
@@ -1377,6 +1445,8 @@
/* set glyph dimensions */
glyph->metrics.width = bbox.xMax - bbox.xMin;
glyph->metrics.height = bbox.yMax - bbox.yMin;
+
+ return 0;
}
@@ -1498,14 +1568,19 @@
/* seek to the beginning of the glyph table. For Type 42 fonts */
/* the table might be accessed from a Postscript stream or something */
/* else... */
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ /* Don't look for the glyph table if this is an incremental font. */
+ if (!face->root.incremental_interface)
+#endif
+ {+ error = face->goto_table( face, TTAG_glyf, stream, 0 );
+ if ( error )
+ {+ FT_ERROR(( "TT_Load_Glyph: could not access glyph table\n" ));
+ goto Exit;
+ }
+ }
- error = face->goto_table( face, TTAG_glyf, stream, 0 );
- if ( error )
- {- FT_ERROR(( "TT_Load_Glyph: could not access glyph table\n" ));
- goto Exit;
- }
-
FT_MEM_SET( &loader, 0, sizeof ( loader ) );
/* update the glyph zone bounds */
@@ -1552,7 +1627,12 @@
loader.glyph = (FT_GlyphSlot)glyph;
loader.stream = stream;
- loader.glyf_offset = FT_STREAM_POS();
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ if (face->root.incremental_interface)
+ loader.glyf_offset = 0;
+ else
+#endif
+ loader.glyf_offset = FT_STREAM_POS();
#ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
--- a/src/truetype/ttobjs.c
+++ b/src/truetype/ttobjs.c
@@ -197,9 +197,15 @@
goto Exit;
if ( face->root.face_flags & FT_FACE_FLAG_SCALABLE )
- error = TT_Load_Locations( face, stream ) ||
- TT_Load_CVT ( face, stream ) ||
- TT_Load_Programs ( face, stream );
+ {+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+ if ( !face->root.incremental_interface )
+ error = TT_Load_Locations( face, stream );
+ if ( !error )
+#endif
+ error = TT_Load_CVT ( face, stream ) ||
+ TT_Load_Programs ( face, stream );
+ }
/* initialize standard glyph loading routines */
TT_Init_Glyph_Loading( face );