From b95d252c347e14825cd61b28223040cfc5d0e7de Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 12 Nov 1999 02:07:56 +0000
Subject: [PATCH] added GL_EXT_texture_env_add extension

---
 include/GL/gl.h            | 13 ++++++++++++-
 src/mesa/main/extensions.c |  3 ++-
 src/mesa/main/texstate.c   | 17 ++++++++++++-----
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/include/GL/gl.h b/include/GL/gl.h
index 22477924dee..a0f71bed0b9 100644
--- a/include/GL/gl.h
+++ b/include/GL/gl.h
@@ -1,4 +1,4 @@
-/* $Id: gl.h,v 1.20 1999/11/11 17:48:32 brianp Exp $ */
+/* $Id: gl.h,v 1.21 1999/11/12 02:08:59 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -2308,6 +2308,17 @@ GLAPI void GLAPIENTRY glResizeBuffersMESA( void );
 
 
 
+/*
+ * GL_EXT_texture_env_add
+ */
+#ifndef GL_EXT_texture_env_add
+#define GL_EXT_texture_env_add 1
+
+/* No new tokens or functions */
+
+#endif /* GL_EXT_texture_env_add */
+
+
 
 
 #if defined(__BEOS__) || defined(__QUICKDRAW__)
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index c8b154d0613..98a7551191d 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -1,4 +1,4 @@
-/* $Id: extensions.c,v 1.12 1999/11/12 02:05:46 brianp Exp $ */
+/* $Id: extensions.c,v 1.13 1999/11/12 02:07:56 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -74,6 +74,7 @@ static struct { int enabled; const char *name; } default_extensions[] = {
    { DEFAULT_ON,     "GL_EXT_compiled_vertex_array" },
    { DEFAULT_OFF,    "GL_EXT_vertex_array_set" },
    { DEFAULT_ON,     "GL_EXT_clip_volume_hint" },
+   { DEFAULT_ON,     "GL_EXT_texture_env_add" },
 };
 
 
diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index 7e5ce3085a0..fa893e7f2d7 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -1,4 +1,4 @@
-/* $Id: texstate.c,v 1.5 1999/11/11 01:22:28 brianp Exp $ */
+/* $Id: texstate.c,v 1.6 1999/11/12 02:07:56 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -31,6 +31,7 @@
 #include "glheader.h"
 #include "context.h"
 #include "enums.h"
+#include "extensions.h"
 #include "macros.h"
 #include "matrix.h"
 #include "texobj.h"
@@ -84,10 +85,16 @@ _mesa_TexEnvfv( GLenum target, GLenum pname, const GLfloat *param )
    if (pname==GL_TEXTURE_ENV_MODE) {
       GLenum mode = (GLenum) (GLint) *param;
       switch (mode) {
-	 case GL_MODULATE:
-	 case GL_BLEND:
-	 case GL_DECAL:
-	 case GL_REPLACE:
+         case GL_ADD:
+            if (!gl_extension_is_enabled(ctx, "GL_EXT_texture_env_add")) {
+               gl_error(ctx, GL_INVALID_ENUM, "glTexEnv(param)");
+               return;
+            }
+            /* FALL-THROUGH */
+         case GL_MODULATE:
+         case GL_BLEND:
+         case GL_DECAL:
+         case GL_REPLACE:
 	    /* A small optimization for drivers */ 
 	    if (texUnit->EnvMode == mode)
                return;
-- 
2.30.2