Commit 460d23f1689f14f5812bfe4b322fd3f2a449905e
2010-04-05T08:46:26
Add new function `FT_Library_SetLcdFilterWeights'. This is based on code written by Lifter <http://unixforum.org/index.php?showuser=11691>. It fixes FreeDesktop bug #27386. * src/base/ftlcdfil.c (FT_Library_SetLcdFilterWeights): New function. * include/freetype/ftlcdfil.h: Updated. * docs/CHANGES: Updated.
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diff --git a/ChangeLog b/ChangeLog
index 1c62e16..a8fa18f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2010-04-05 Werner Lemberg <wl@gnu.org>
+
+ Add new function `FT_Library_SetLcdFilterWeights'.
+
+ This is based on code written by Lifter
+ <http://unixforum.org/index.php?showuser=11691>. It fixes
+ FreeDesktop bug #27386.
+
+ * src/base/ftlcdfil.c (FT_Library_SetLcdFilterWeights): New
+ function.
+
+ * include/freetype/ftlcdfil.h: Updated.
+
+ * docs/CHANGES: Updated.
+
2010-04-01 John Tytgat <John.Tytgat@esko.com>
Fix Savannah bug #29404.
diff --git a/docs/CHANGES b/docs/CHANGES
index 018d16c..761d92a 100644
--- a/docs/CHANGES
+++ b/docs/CHANGES
@@ -1,3 +1,13 @@
+CHANGES BETWEEN 2.3.12 and 2.3.13
+
+ I. IMPORTANT CHANGES
+
+ - A new function `FT_Library_SetLcdFilterWeights' is available to
+ adjust the filter weights set by `FT_Library_SetLcdFilter'.
+
+
+======================================================================
+
CHANGES BETWEEN 2.3.11 and 2.3.12
I. IMPORTANT CHANGES
@@ -3378,7 +3388,8 @@ Extensions support:
------------------------------------------------------------------------
-Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by
+Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+ 2010 by
David Turner, Robert Wilhelm, and Werner Lemberg.
This file is part of the FreeType project, and may only be used,
diff --git a/include/freetype/ftlcdfil.h b/include/freetype/ftlcdfil.h
index c6201b3..992a064 100644
--- a/include/freetype/ftlcdfil.h
+++ b/include/freetype/ftlcdfil.h
@@ -5,7 +5,7 @@
/* FreeType API for color filtering of subpixel bitmap glyphs */
/* (specification). */
/* */
-/* Copyright 2006, 2007, 2008 by */
+/* Copyright 2006, 2007, 2008, 2010 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
@@ -161,6 +161,47 @@ FT_BEGIN_HEADER
FT_Library_SetLcdFilter( FT_Library library,
FT_LcdFilter filter );
+
+ /**************************************************************************
+ *
+ * @func:
+ * FT_Library_SetLcdFilterWeights
+ *
+ * @description:
+ * Use this function to override the filter weights selected by
+ * @FT_Library_SetLcdFilter. By default, FreeType uses the quintuple
+ * (0x00, 0x55, 0x56, 0x55, 0x00) for FT_LCD_FILTER_LIGHT, and (0x10,
+ * 0x40, 0x70, 0x40, 0x10) for FT_LCD_FILTER_DEFAULT and
+ * FT_LCD_FILTER_LEGACY.
+ *
+ * @input:
+ * library ::
+ * A handle to the target library instance.
+ *
+ * weights ::
+ * A pointer to an array; the function copies the first five bytes and
+ * uses them to specify the filter weights.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * Due to *PATENTS* covering subpixel rendering, this function doesn't
+ * do anything except returning `FT_Err_Unimplemented_Feature' if the
+ * configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING is not
+ * defined in your build of the library, which should correspond to all
+ * default builds of FreeType.
+ *
+ * This function must be called after @FT_Library_SetLcdFilter to have
+ * any effect.
+ *
+ * @since:
+ * 2.3.13
+ */
+ FT_EXPORT( FT_Error )
+ FT_Library_SetLcdFilterWeights( FT_Library library,
+ unsigned char *weights );
+
/* */
diff --git a/src/base/ftlcdfil.c b/src/base/ftlcdfil.c
index 8064011..0da4ba1 100644
--- a/src/base/ftlcdfil.c
+++ b/src/base/ftlcdfil.c
@@ -4,7 +4,7 @@
/* */
/* FreeType API for color filtering of subpixel bitmap glyphs (body). */
/* */
-/* Copyright 2006, 2008, 2009 by */
+/* Copyright 2006, 2008, 2009, 2010 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
@@ -267,18 +267,31 @@
FT_EXPORT_DEF( FT_Error )
- FT_Library_SetLcdFilter( FT_Library library,
- FT_LcdFilter filter )
+ FT_Library_SetLcdFilterWeights( FT_Library library,
+ unsigned char *weights )
+ {
+ if ( !library || !weights )
+ return FT_Err_Invalid_Argument;
+
+ ft_memcpy( library->lcd_weights, weights, 5 );
+
+ return FT_Err_Ok;
+ }
+
+
+ FT_EXPORT_DEF( FT_Error )
+ FT_Library_SetLcdFilter( FT_Library library,
+ FT_LcdFilter filter )
{
static const FT_Byte light_filter[5] =
- { 0, 85, 86, 85, 0 };
+ { 0x00, 0x55, 0x56, 0x55, 0x00 };
/* the values here sum up to a value larger than 256, */
/* providing a cheap gamma correction */
static const FT_Byte default_filter[5] =
{ 0x10, 0x40, 0x70, 0x40, 0x10 };
- if ( library == NULL )
+ if ( !library )
return FT_Err_Invalid_Argument;
switch ( filter )
@@ -330,12 +343,24 @@
}
library->lcd_filter = filter;
- return 0;
+
+ return FT_Err_Ok;
}
#else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */
FT_EXPORT_DEF( FT_Error )
+ FT_Library_SetLcdFilterWeights( FT_Library library,
+ unsigned char *weights )
+ {
+ FT_UNUSED( library );
+ FT_UNUSED( weights );
+
+ return FT_Err_Unimplemented_Feature;
+ }
+
+
+ FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdFilter( FT_Library library,
FT_LcdFilter filter )
{