From 1c55ca966f356030a863479459055c48e98ed1e5 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sat, 11 Jul 2015 20:33:15 +0200
Subject: directwrite: convert to C

Unfortunately, nobody ever tested the MinGW dwrite.h header in C. There
are multiple glaring mistakes, and the header doesn't even compile by
itself. The main issues are overloaded functions (which doesn't work
in C), and broken COBJMACROS defines.

dwrite.diff contains changes to dwrite.h which make libass work.
Warning: the patch lacks a required change to the DrawInlineObject
method of IDWriteTextRenderer (missing THIS_).

Additionally, these definitions would ideally be provided by dwrite.h:

DEFINE_GUID(IID_IDWriteFactory, 0xb859ee5a,0xd838,0x4b5b,0xa2,0xe8,0x1a,0xdc,0x7d,0x93,0xdb,0x48);
DEFINE_GUID(IID_IDWritePixelSnapping, 0xeaf3a2da,0xecf4,0x4d24,0xb6,0x44,0xb3,0x4f,0x68,0x42,0x02,0x4b);
DEFINE_GUID(IID_IDWriteTextRenderer, 0xef8a8135,0x5cc6,0x45fe,0x88,0x25,0xc5,0xa0,0x72,0x4e,0xb8,0x19);

Also, in order to make libass compile out of the box with current
MinGW/msys installations, a very stripped down in-tree copy of dwrite.h
is provided.
---
 configure.ac | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

(limited to 'configure.ac')

diff --git a/configure.ac b/configure.ac
index 61a8533..4c7e37d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,7 +9,6 @@ AC_CONFIG_HEADER([config.h])
 
 # Checks for programs.
 AC_PROG_CC
-AC_PROG_CXX
 AC_PROG_CPP
 AM_PROG_CC_C_O
 AM_PROG_AS
@@ -178,14 +177,12 @@ fi
 
 
 if test x$enable_directwrite != xno; then
-AC_LANG_PUSH([C++])
-CXXFLAGS="$CXXFLAGS -fno-rtti -fno-exceptions"
 # Linking to DirectWrite directly only works from Windows
 AC_MSG_CHECKING([for DIRECTWRITE])
 AC_LINK_IFELSE([
   AC_LANG_PROGRAM(
-    [[#include <dwrite.h>]],
-    [[DWRITE_FACTORY_TYPE_SHARED;]],)
+    [[#include <windows.h>]],
+    [[;]],)
   ], [
     AC_DEFINE(CONFIG_DIRECTWRITE, 1, [found DirectWrite])
     directwrite=true
@@ -194,7 +191,6 @@ AC_LINK_IFELSE([
     directwrite=false
     AC_MSG_RESULT([no])
   ])
-AC_LANG_POP([C++])
 fi
 AM_CONDITIONAL([DIRECTWRITE], [test x$directwrite = xtrue])
 
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