From bf478280ebed8a60a5d007884d9817391e206987 Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 13 Apr 2001 00:13:51 +0000
Subject: [PATCH] added a work-around in _swrast_copy_texsubimage[123]d() to
 fix alpha channel problem in some DRI drivers (see comments)

---
 src/mesa/swrast/s_texstore.c | 50 +++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/src/mesa/swrast/s_texstore.c b/src/mesa/swrast/s_texstore.c
index 92afecf91db..f01dab5fdd3 100644
--- a/src/mesa/swrast/s_texstore.c
+++ b/src/mesa/swrast/s_texstore.c
@@ -1,4 +1,4 @@
-/* $Id: s_texstore.c,v 1.2 2001/03/28 20:40:52 gareth Exp $ */
+/* $Id: s_texstore.c,v 1.3 2001/04/13 00:13:51 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -274,6 +274,22 @@ _swrast_copy_texsubimage1d(GLcontext *ctx, GLenum target, GLint level,
          return;
       }
 
+      /*
+       * XXX this is a bit of a hack.  We need to be sure that the alpha
+       * channel is 1.0 if the internal texture format is not supposed to
+       * have an alpha channel.  This is because some drivers may store
+       * RGB textures as RGBA and the texutil.c code isn't smart enough
+       * to set the alpha channel to 1.0 in this situation.
+       */
+      if (texImage->Format == GL_LUMINANCE ||
+          texImage->Format == GL_RGB) {
+         const GLuint n = width * 4;
+         GLuint i;
+         for (i = 0; i < n; i += 4) {
+            image[i + 3] = CHAN_MAX;
+         }
+      }
+
       /* now call glTexSubImage1D to do the real work */
       (*ctx->Driver.TexSubImage1D)(ctx, target, level, xoffset, width,
                                    GL_RGBA, CHAN_TYPE, image,
@@ -326,6 +342,22 @@ _swrast_copy_texsubimage2d( GLcontext *ctx,
          return;
       }
 
+      /*
+       * XXX this is a bit of a hack.  We need to be sure that the alpha
+       * channel is 1.0 if the internal texture format is not supposed to
+       * have an alpha channel.  This is because some drivers may store
+       * RGB textures as RGBA and the texutil.c code isn't smart enough
+       * to set the alpha channel to 1.0 in this situation.
+       */
+      if (texImage->Format == GL_LUMINANCE ||
+          texImage->Format == GL_RGB) {
+         const GLuint n = width * height * 4;
+         GLuint i;
+         for (i = 0; i < n; i += 4) {
+            image[i + 3] = CHAN_MAX;
+         }
+      }
+
       /* now call glTexSubImage2D to do the real work */
       (*ctx->Driver.TexSubImage2D)(ctx, target, level,
                                    xoffset, yoffset, width, height,
@@ -380,6 +412,22 @@ _swrast_copy_texsubimage3d( GLcontext *ctx,
          return;
       }
 
+      /*
+       * XXX this is a bit of a hack.  We need to be sure that the alpha
+       * channel is 1.0 if the internal texture format is not supposed to
+       * have an alpha channel.  This is because some drivers may store
+       * RGB textures as RGBA and the texutil.c code isn't smart enough
+       * to set the alpha channel to 1.0 in this situation.
+       */
+      if (texImage->Format == GL_LUMINANCE ||
+          texImage->Format == GL_RGB) {
+         const GLuint n = width * height * 4;
+         GLuint i;
+         for (i = 0; i < n; i += 4) {
+            image[i + 3] = CHAN_MAX;
+         }
+      }
+
       /* now call glTexSubImage3D to do the real work */
       (*ctx->Driver.TexSubImage3D)(ctx, target, level,
                                    xoffset, yoffset, zoffset, width, height, 1,
-- 
2.30.2