mesa: Always use seamless cubemap filtering in GLES3

Appendix F.2 of the OpenGL ES 3.0.0 spec says:

    "OpenGL ES 3.0 requires that all cube map filtering be
    seamless. OpenGL ES 2.0 specified that a single cube map face be
    selected and used for filtering."

Setting the field only in the context will work fine with sampler
objects (and drivers that support AMD_seamless_cubemap_per_texture)
because seamless filtering is used if *either* the context or the
sampler enable it:

    "If TEXTURE_CUBE_MAP_SEAMLESS_ARB is emabled (sic) globally or the
    value of the texture's TEXTURE_CUBE_MAP_SEAMLESS_ARB parameter is
    TRUE, seamless cube map sampling is enabled..."

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Reported-by: Maxence Le Dore <maxence.ledore@gmail.com>
Thanked-by: Maxence Le Dore <maxence.ledore@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index dad69a8..ad80dcf 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -810,6 +810,14 @@ _mesa_init_texture(struct gl_context *ctx)
    ctx->Texture.CurrentUnit = 0;      /* multitexture */
    ctx->Texture._EnabledUnits = 0x0;
 
+   /* Appendix F.2 of the OpenGL ES 3.0 spec says:
+    *
+    *     "OpenGL ES 3.0 requires that all cube map filtering be
+    *     seamless. OpenGL ES 2.0 specified that a single cube map face be
+    *     selected and used for filtering."
+    */
+   ctx->Texture.CubeMapSeamless = _mesa_is_gles3(ctx);
+
    for (u = 0; u < Elements(ctx->Texture.Unit); u++)
       init_texture_unit(ctx, u);