shithub: freetype+ttf2subf

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[smooth] Restore the span buffering for direct mode only.

The buffer size FT_MAX_GRAY_SPANS is set to 10 spans, which should be
enough to cover the entire scanline for simple glyphs in most cases:
each slightly slanted edge needs up to two spans, plus a filling span
in-between.  This is not new, we used to do it before cb4388783cecc.

* src/smooth/ftgrays.c (gray_TWorker): Add `spans' and `num_spans'.
(gray_hline, gray_sweep): Implement the span buffering.
(gray_raster_render): Use negative `num_spans' to avoid the direct
mode.

git/fs: mount .git/fs: mount/attach disallowed

--- a/ChangeLog

+++ b/ChangeLog

@@ -1,3 +1,17 @@

+2019-06-13  Alexei Podtelezhnikov  <[email protected]>

+

+	[smooth] Restore the span buffering for direct mode only.

+

+	The buffer size FT_MAX_GRAY_SPANS is set to 10 spans, which should be

+	enough to cover the entire scanline for simple glyphs in most cases:

+	each slightly slanted edge needs up to two spans, plus a filling span

+	in-between.  This is not new, we used to do it before cb4388783cecc.

+

+	* src/smooth/ftgrays.c (gray_TWorker): Add `spans' and `num_spans'.

+	(gray_hline, gray_sweep): Implement the span buffering.

+	(gray_raster_render): Use negative `num_spans' to avoid the direct

+	mode.

+

 2019-06-12  Alexei Podtelezhnikov  <[email protected]>

 	* include/freetype/ftmodapi.h (FT_DebugHook_Func): Return error.

--- a/src/smooth/ftgrays.c

+++ b/src/smooth/ftgrays.c

@@ -432,7 +432,10 @@

 #define FT_MAX_GRAY_POOL  ( 2048 / sizeof ( TCell ) )

 #endif

+  /* FT_Span buffer size for direct rendering only */

+#define FT_MAX_GRAY_SPANS  10

+

 #if defined( _MSC_VER )      /* Visual C++ (and Intel C++) */

   /* We disable the warning `structure was padded due to   */

   /* __declspec(align())' in order to compile cleanly with */

@@ -465,6 +468,8 @@

     FT_Raster_Span_Func  render_span;

     void*                render_span_data;

+    FT_Span              spans[FT_MAX_GRAY_SPANS];

+    int                  num_spans;

   } gray_TWorker, *gray_PWorker;

@@ -1226,16 +1231,21 @@

         coverage = 255;

     }

-    if ( ras.render_span )  /* for FT_RASTER_FLAG_DIRECT only */

+    if ( ras.num_spans >= 0 )  /* for FT_RASTER_FLAG_DIRECT only */

     {

-      FT_Span  span;

+      FT_Span*  span = ras.spans + ras.num_spans++;

-      span.x        = (short)x;

-      span.len      = (unsigned short)acount;

-      span.coverage = (unsigned char)coverage;

+      span->x        = (short)x;

+      span->len      = (unsigned short)acount;

+      span->coverage = (unsigned char)coverage;

-      ras.render_span( y, 1, &span, ras.render_span_data );

+      if ( ras.num_spans == FT_MAX_GRAY_SPANS )

+      {

+        /* flush the span buffer and reset the count */

+        ras.render_span( y, ras.num_spans, ras.spans, ras.render_span_data );

+        ras.num_spans = 0;

+      }

     }

     else

     {

@@ -1309,6 +1319,13 @@

       if ( cover != 0 )

         gray_hline( RAS_VAR_ x, y, cover, ras.max_ex - x );

+

+      if ( ras.num_spans > 0 )  /* for FT_RASTER_FLAG_DIRECT only */

+      {

+        /* flush the span buffer and reset the count */

+        ras.render_span( y, ras.num_spans, ras.spans, ras.render_span_data );

+        ras.num_spans = 0;

+      }

     }

   }

@@ -1778,6 +1795,7 @@

       ras.render_span      = (FT_Raster_Span_Func)params->gray_spans;

       ras.render_span_data = params->user;

+      ras.num_spans        = 0;

       ras.min_ex = params->clip_box.xMin;

       ras.min_ey = params->clip_box.yMin;

@@ -1807,6 +1825,7 @@

       ras.render_span      = (FT_Raster_Span_Func)NULL;

       ras.render_span_data = NULL;

+      ras.num_spans        = -1;  /* invalid */

       ras.min_ex = 0;

       ras.min_ey = 0;