intel: Use a system value for gl_FragCoord

It's kind-of an anomaly that the Intel drivers are still treating
gl_FragCoord as an input.  It also makes zero sense because we have to
special-case it in the back-end.

Because ANV is the only user of nir_lower_wpos_center, we go ahead and
just update it to look for nir_intrinsic_load_frag_coord as part of this
patch.

Reviewed-by: Kenneth Graunke <[email protected]>

2 files changed, 2 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 3783d1532e9..91053842aa1 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -621,6 +621,7 @@ brw_initialize_context_constants(struct brw_context *brw)
    if (devinfo->gen >= 5 || devinfo->is_g4x)
       ctx->Const.MaxClipPlanes = 8;
 
+   ctx->Const.GLSLFragCoordIsSysVal = true;
    ctx->Const.GLSLTessLevelsAsInputs = true;
    ctx->Const.PrimitiveRestartForPatches = true;
 
diff --git a/src/mesa/drivers/dri/i965/brw_program.c b/src/mesa/drivers/dri/i965/brw_program.c
index 0e91612d845..b69b032a9c2 100644
--- a/src/mesa/drivers/dri/i965/brw_program.c
+++ b/src/mesa/drivers/dri/i965/brw_program.c
@@ -262,6 +262,7 @@ brwProgramStringNotify(struct gl_context *ctx,
 
       if (newFP == curFP)
 	 brw->ctx.NewDriverState |= BRW_NEW_FRAGMENT_PROGRAM;
+      _mesa_program_fragment_position_to_sysval(&newFP->program);
       newFP->id = get_new_program_id(brw->screen);
 
       prog->nir = brw_create_nir(brw, NULL, prog, MESA_SHADER_FRAGMENT, true);