DRW: Fix matflag not being updated after first drawcall

This Fixes T61823: Flickering material problem with eevee

1 files changed, 33 insertions, 23 deletions

diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index 91e3befa8d6..53fbb8bb9cc 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -309,13 +309,43 @@ static void drw_call_calc_orco(Object *ob, float (*r_orcofacs)[3])
 	}
 }
 
+static void drw_call_state_update_matflag(DRWCallState *state, DRWShadingGroup *shgroup, Object *ob)
+{
+	uint16_t new_flags = ((state->matflag ^ shgroup->matflag) & shgroup->matflag);
+
+	/* HACK: Here we set the matflags bit to 1 when computing the value
+	 * so that it's not recomputed for other drawcalls.
+	 * This is the opposite of what draw_matrices_model_prepare() does. */
+	state->matflag |= shgroup->matflag;
+
+	/* Orco factors: We compute this at creation to not have to save the *ob_data */
+	if ((new_flags & DRW_CALL_ORCOTEXFAC) != 0) {
+		drw_call_calc_orco(ob, state->orcotexfac);
+	}
+
+	if ((new_flags & DRW_CALL_OBJECTINFO) != 0) {
+		state->objectinfo[0] = ob ? ob->index : 0;
+		uint random;
+#if 0 /* TODO(fclem) handle dupli objects */
+		if (GMS.dob) {
+			random = GMS.dob->random_id;
+		}
+		else
+#endif
+		{
+			random = BLI_hash_int_2d(BLI_hash_string(ob->id.name + 2), 0);
+		}
+		state->objectinfo[1] = random * (1.0f / (float)0xFFFFFFFF);
+	}
+}
+
 static DRWCallState *drw_call_state_create(DRWShadingGroup *shgroup, float (*obmat)[4], Object *ob)
 {
 	DRWCallState *state = BLI_mempool_alloc(DST.vmempool->states);
 	state->flag = 0;
 	state->cache_id = 0;
 	state->visibility_cb = NULL;
-	state->matflag = shgroup->matflag;
+	state->matflag = 0;
 
 	/* Matrices */
 	if (obmat != NULL) {
@@ -343,27 +373,7 @@ static DRWCallState *drw_call_state_create(DRWShadingGroup *shgroup, float (*obm
 		state->bsphere.radius = -1.0f;
 	}
 
-	/* Orco factors: We compute this at creation to not have to save the *ob_data */
-	if ((state->matflag & DRW_CALL_ORCOTEXFAC) != 0) {
-		drw_call_calc_orco(ob, state->orcotexfac);
-		state->matflag &= ~DRW_CALL_ORCOTEXFAC;
-	}
-
-	if ((state->matflag & DRW_CALL_OBJECTINFO) != 0) {
-		state->objectinfo[0] = ob ? ob->index : 0;
-		uint random;
-#if 0 /* TODO(fclem) handle dupli objects */
-		if (GMS.dob) {
-			random = GMS.dob->random_id;
-		}
-		else
-#endif
-		{
-			random = BLI_hash_int_2d(BLI_hash_string(ob->id.name + 2), 0);
-		}
-		state->objectinfo[1] = random * (1.0f / (float)0xFFFFFFFF);
-		state->matflag &= ~DRW_CALL_OBJECTINFO;
-	}
+	drw_call_state_update_matflag(state, shgroup, ob);
 
 	return state;
 }
@@ -375,7 +385,7 @@ static DRWCallState *drw_call_state_object(DRWShadingGroup *shgroup, float (*obm
 	}
 	else {
 		/* If the DRWCallState is reused, add necessary matrices. */
-		DST.ob_state->matflag |= shgroup->matflag;
+		drw_call_state_update_matflag(DST.ob_state, shgroup, ob);
 	}
 
 	return DST.ob_state;