From 6689f9ebcb586333d059ace12ccff950bb6411b1 Mon Sep 17 00:00:00 2001
From: Dan Nicholson <dbn.lists@gmail.com>
Date: Wed, 5 Dec 2007 21:04:15 -0800
Subject: [PATCH] autoconf: Configure the osmesa channel size for OSMesa16 and
 OSMesa32

Allow the user to specify channel bits of 16 or 32 to enable OSMesa16 or
OSMesa32 instead of the default OSMesa. This option is controlled
through the option --with-osmesa-bits=BITS and is only honored when the
driver is osmesa.

The osdemos are not enabled in the 16 or 32 bit case because the
Makefile is currently hardcoded to link to -lOSMesa.
---
 configs/autoconf.in |  2 +-
 configure.ac        | 31 +++++++++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/configs/autoconf.in b/configs/autoconf.in
index 8cb1ba75b8d..a1896a64400 100644
--- a/configs/autoconf.in
+++ b/configs/autoconf.in
@@ -46,7 +46,7 @@ GL_LIB = GL
 GLU_LIB = GLU
 GLUT_LIB = glut
 GLW_LIB = GLw
-OSMESA_LIB = OSMesa
+OSMESA_LIB = @OSMESA_LIB@
 
 # Library names (actual file names)
 GL_LIB_NAME = @GL_LIB_NAME@
diff --git a/configure.ac b/configure.ac
index 9272b01dc58..db6a7850a46 100644
--- a/configure.ac
+++ b/configure.ac
@@ -328,6 +328,30 @@ if test "x$x11_osmesa" = xyes; then
     fi
 fi
 
+dnl Configure the channel bits for OSMesa (libOSMesa, libOSMesa16, ...)
+AC_ARG_WITH(osmesa-bits,
+    [AS_HELP_STRING([--with-osmesa-bits=BITS],
+        [OSMesa channel bits and library name: 8, 16, 32 @<:@default=8@:>@])],
+        osmesa_bits="$withval",
+        osmesa_bits=8)
+if test "$mesa_driver" != osmesa && test "x$osmesa_bits" != x8; then
+    AC_MSG_WARN([Ignoring OSMesa channel bits for non-OSMesa driver])
+    osmesa_bits=8
+fi
+case "x$osmesa_bits" in
+x8)
+    OSMESA_LIB=OSMesa
+    ;;
+x16|x32)
+    OSMESA_LIB="OSMesa$osmesa_bits"
+    DEFINES="$DEFINES -DCHAN_BITS=$osmesa_bits -DDEFAULT_SOFTWARE_DEPTH_BITS=31"
+    ;;
+*)
+    AC_MSG_ERROR([OSMesa bits '$osmesa_bits' is not a valid option])
+    ;;
+esac
+AC_SUBST(OSMESA_LIB)
+
 case "$mesa_driver" in
 osmesa)
     OSMESA_LIB_DEPS="-lm -lpthread"
@@ -355,8 +379,11 @@ if test "x$enable_glu" = xyes; then
 
     case "$mesa_driver" in
     osmesa)
-        # If GLU is available, we can build the osdemos
-        PROGRAM_DIRS="$PROGRAM_DIRS osdemos"
+        # If GLU is available and we have libOSMesa (not 16 or 32),
+        # we can build the osdemos
+        if test "$osmesa_bits" = 8; then
+            PROGRAM_DIRS="$PROGRAM_DIRS osdemos"
+        fi
 
         # Link libGLU to libOSMesa instead of libGL
         GLU_LIB_DEPS=""
-- 
2.30.2