mesa: Don't choose S3TC for generic compression if we can't compress.

If the app is asking us to do GL_COMPRESSED_RGBA, then the app obviously
doesn't have pre-compressed data to hand us.  So don't choose a storage
format that we won't actually be able to compress and store.

Fixes black screen in warzone2100 when libtxc_dxtn is not present.  Also
66 piglit tests.

NOTE: This is a candidate for the 9.2 branch.
Reported-by: Paul Wise <pabs@debian.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/main/texformat.c b/src/mesa/main/texformat.c
index fdbf69508c85af3a2d0c0e1dcceb024eb98d40f0..d3aa477361412161e748458c64ced6ceb8d3be83 100644 (file)
--- a/src/mesa/main/texformat.c
+++ b/src/mesa/main/texformat.c
@@ -239,7 +239,8 @@ _mesa_choose_tex_format(struct gl_context *ctx, GLenum target,
        * 1D ARRAY textures in S3TC format.
        */
       if (target != GL_TEXTURE_1D && target != GL_TEXTURE_1D_ARRAY) {
-         RETURN_IF_SUPPORTED(MESA_FORMAT_RGB_DXT1);
+         if (ctx->Mesa_DXTn)
+            RETURN_IF_SUPPORTED(MESA_FORMAT_RGB_DXT1);
          RETURN_IF_SUPPORTED(MESA_FORMAT_RGB_FXT1);
       }
       RETURN_IF_SUPPORTED(MESA_FORMAT_RGB888);
@@ -249,7 +250,8 @@ _mesa_choose_tex_format(struct gl_context *ctx, GLenum target,
    case GL_COMPRESSED_RGBA_ARB:
       /* We don't use texture compression for 1D and 1D array textures. */
       if (target != GL_TEXTURE_1D && target != GL_TEXTURE_1D_ARRAY) {
-         RETURN_IF_SUPPORTED(MESA_FORMAT_RGBA_DXT3); /* Not rgba_dxt1, see spec */
+         if (ctx->Mesa_DXTn)
+            RETURN_IF_SUPPORTED(MESA_FORMAT_RGBA_DXT3); /* Not rgba_dxt1, see spec */
          RETURN_IF_SUPPORTED(MESA_FORMAT_RGBA_FXT1);
       }
       RETURN_IF_SUPPORTED(MESA_FORMAT_RGBA8888);
@@ -547,12 +549,14 @@ _mesa_choose_tex_format(struct gl_context *ctx, GLenum target,
       RETURN_IF_SUPPORTED(MESA_FORMAT_SARGB8);
       break;
    case GL_COMPRESSED_SRGB_EXT:
-      RETURN_IF_SUPPORTED(MESA_FORMAT_SRGB_DXT1);
+      if (ctx->Mesa_DXTn)
+         RETURN_IF_SUPPORTED(MESA_FORMAT_SRGB_DXT1);
       RETURN_IF_SUPPORTED(MESA_FORMAT_SRGB8);
       RETURN_IF_SUPPORTED(MESA_FORMAT_SARGB8);
       break;
    case GL_COMPRESSED_SRGB_ALPHA_EXT:
-      RETURN_IF_SUPPORTED(MESA_FORMAT_SRGBA_DXT3); /* Not srgba_dxt1, see spec */
+      if (ctx->Mesa_DXTn)
+         RETURN_IF_SUPPORTED(MESA_FORMAT_SRGBA_DXT3); /* Not srgba_dxt1, see spec */
       RETURN_IF_SUPPORTED(MESA_FORMAT_SRGBA8);
       RETURN_IF_SUPPORTED(MESA_FORMAT_SARGB8);
       break;