[freetype2] wl/freetype-ot-svg-from-scratch-new f27826c7a 1/6: Add the flag FT_CONFIG_OPTION_SVG.

[Werner Lemberg]

branch: wl/freetype-ot-svg-from-scratch-new
commit f27826c7a07ce33411abc9969eec3f17b63e4d64
Author: Moazin Khatti <moazinkhatri@gmail.com>
Commit: Werner Lemberg <wl@gnu.org>

    Add the flag FT_CONFIG_OPTION_SVG.
    
    This flag is going to be used to conditionally compile support for
    OT-SVG glyphs.  FreeType will do the parsing and rely on external
    hooks for rendering of OT-SVG glyphs.  A system installation of
    zlib is required for GZIP compressed glyphs.
    
    * devel/ftoption.h, include/freetype/config/ftoption.h
    (FT_CONFIG_OPTION_SVG): New flag.
---
 devel/ftoption.h                   | 28 ++++++++++++++++++++++++++++
 include/freetype/config/ftoption.h | 27 +++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/devel/ftoption.h b/devel/ftoption.h
index a99c4c97d..cd3d41d38 100644
--- a/devel/ftoption.h
+++ b/devel/ftoption.h
@@ -525,6 +525,20 @@ FT_BEGIN_HEADER
 #undef FT_CONFIG_OPTION_USE_MODULE_ERRORS
 
 
+  /**************************************************************************
+   *
+   * OpenType SVG Glyph Support
+   *
+   *   Setting this macro enables support for OpenType SVG glyphs.  By
+   *   default, FreeType can only fetch SVG documents.  However, it can also
+   *   render them if external rendering hook functions are plugged in at
+   *   runtime.
+   *
+   *   More details on the hooks can be found in file `otsvg.h`.
+   */
+#define FT_CONFIG_OPTION_SVG
+
+
   /**************************************************************************
    *
    * Error Strings
@@ -1004,6 +1018,20 @@ FT_BEGIN_HEADER
 #error "Invalid CFF darkening parameters!"
 #endif
 
+
+  /*
+   * OpenType SVG support needs system Zlib to do the decompression
+   * as the internal Zlib is not capable of doing that because of being
+   * outdated.
+   */
+#if defined( FT2_BUILD_LIBRARY )             && \
+    defined( FT_CONFIG_OPTION_SVG )          && \
+    !defined( FT_CONFIG_OPTION_SYSTEM_ZLIB )
+#pragma message "External installation of ZLIB is needed"
+#pragma message "to support GZIP compressed SVG documents"
+#endif
+
+
 FT_END_HEADER
 
 
diff --git a/include/freetype/config/ftoption.h 
b/include/freetype/config/ftoption.h
index 487b33364..dcf3f22f1 100644
--- a/include/freetype/config/ftoption.h
+++ b/include/freetype/config/ftoption.h
@@ -527,6 +527,20 @@ FT_BEGIN_HEADER
 #undef FT_CONFIG_OPTION_USE_MODULE_ERRORS
 
 
+  /**************************************************************************
+   *
+   * OpenType SVG Glyph Support
+   *
+   *   Setting this macro enables support for OpenType SVG glyphs.  By
+   *   default, FreeType can only fetch SVG documents.  However, it can also
+   *   render them if external rendering hook functions are plugged in at
+   *   runtime.
+   *
+   *   More details on the hooks can be found in file `otsvg.h`.
+   */
+#define FT_CONFIG_OPTION_SVG
+
+
   /**************************************************************************
    *
    * Error Strings
@@ -1006,6 +1020,19 @@ FT_BEGIN_HEADER
 #error "Invalid CFF darkening parameters!"
 #endif
 
+  /*
+   * OpenType SVG support needs system Zlib to do the decompression
+   * as the internal Zlib is not capable of doing that because of being
+   * outdated.
+   */
+#if defined( FT2_BUILD_LIBRARY )             && \
+    defined( FT_CONFIG_OPTION_SVG )          && \
+    !defined( FT_CONFIG_OPTION_SYSTEM_ZLIB )
+#pragma message "External installation of ZLIB is needed"
+#pragma message "to support GZIP compressed SVG documents"
+#endif
+
+
 FT_END_HEADER