Mesa (master): nvc0: don't enable early-z if alpha test is enabled

[Christoph Bumiller]

Module: Mesa
Branch: master
Commit: f0ee7d8bb46ac7694693f3fb8cd0f15c422f1bef
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f0ee7d8bb46ac7694693f3fb8cd0f15c422f1bef

Author: Christoph Bumiller <e0425955 at student.tuwien.ac.at>
Date:   Sun Mar 13 13:05:14 2011 +0100

nvc0: don't enable early-z if alpha test is enabled

Depth values are also written before the shader is executed, so if
early tests are enabled, fragments that failed the alpha test were
modifying the depth buffer, but they shouldn't.

---

 src/gallium/drivers/nvc0/nvc0_context.h        |    1 +
 src/gallium/drivers/nvc0/nvc0_shader_state.c   |    2 --
 src/gallium/drivers/nvc0/nvc0_state.c          |   14 ++++----------
 src/gallium/drivers/nvc0/nvc0_state_validate.c |   15 +++++++++++++++
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/gallium/drivers/nvc0/nvc0_context.h b/src/gallium/drivers/nvc0/nvc0_context.h
index 67c5a12..aac358e 100644
--- a/src/gallium/drivers/nvc0/nvc0_context.h
+++ b/src/gallium/drivers/nvc0/nvc0_context.h
@@ -79,6 +79,7 @@ struct nvc0_context {
       uint32_t instance_base;
       int32_t index_bias;
       boolean prim_restart;
+      boolean early_z;
       uint8_t num_vtxbufs;
       uint8_t num_vtxelts;
       uint8_t num_textures[5];
diff --git a/src/gallium/drivers/nvc0/nvc0_shader_state.c b/src/gallium/drivers/nvc0/nvc0_shader_state.c
index 79b5f3d..7294eaa 100644
--- a/src/gallium/drivers/nvc0/nvc0_shader_state.c
+++ b/src/gallium/drivers/nvc0/nvc0_shader_state.c
@@ -111,8 +111,6 @@ nvc0_fragprog_validate(struct nvc0_context *nvc0)
          return;
    nvc0_program_update_context_state(nvc0, fp, 4);
 
-   BEGIN_RING(chan, RING_3D(EARLY_FRAGMENT_TESTS), 1);
-   OUT_RING  (chan, fp->fp.early_z);
    BEGIN_RING(chan, RING_3D(SP_SELECT(5)), 2);
    OUT_RING  (chan, 0x51);
    OUT_RING  (chan, fp->code_base);
diff --git a/src/gallium/drivers/nvc0/nvc0_state.c b/src/gallium/drivers/nvc0/nvc0_state.c
index bbcac39..1815fe8 100644
--- a/src/gallium/drivers/nvc0/nvc0_state.c
+++ b/src/gallium/drivers/nvc0/nvc0_state.c
@@ -276,14 +276,11 @@ nvc0_zsa_state_create(struct pipe_context *pipe,
 
    so->pipe = *cso;
 
-   SB_IMMED_3D(so, DEPTH_WRITE_ENABLE, cso->depth.writemask);
-   SB_BEGIN_3D(so, DEPTH_TEST_ENABLE, 1);
+   SB_IMMED_3D(so, DEPTH_TEST_ENABLE, cso->depth.enabled);
    if (cso->depth.enabled) {
-      SB_DATA    (so, 1);
+      SB_IMMED_3D(so, DEPTH_WRITE_ENABLE, cso->depth.writemask);
       SB_BEGIN_3D(so, DEPTH_TEST_FUNC, 1);
       SB_DATA    (so, nvgl_comparison_op(cso->depth.func));
-   } else {
-      SB_DATA    (so, 0);
    }
 
    if (cso->stencil[0].enabled) {
@@ -315,15 +312,12 @@ nvc0_zsa_state_create(struct pipe_context *pipe,
    if (cso->stencil[0].enabled) {
       SB_IMMED_3D(so, STENCIL_TWO_SIDE_ENABLE, 0);
    }
-    
-   SB_BEGIN_3D(so, ALPHA_TEST_ENABLE, 1);
+
+   SB_IMMED_3D(so, ALPHA_TEST_ENABLE, cso->alpha.enabled);
    if (cso->alpha.enabled) {
-      SB_DATA    (so, 1);
       SB_BEGIN_3D(so, ALPHA_TEST_REF, 2);
       SB_DATA    (so, fui(cso->alpha.ref_value));
       SB_DATA    (so, nvgl_comparison_op(cso->alpha.func));
-   } else {
-      SB_DATA    (so, 0);
    }
 
    assert(so->size < (sizeof(so->state) / sizeof(so->state[0])));
diff --git a/src/gallium/drivers/nvc0/nvc0_state_validate.c b/src/gallium/drivers/nvc0/nvc0_state_validate.c
index c37a070..4daa968 100644
--- a/src/gallium/drivers/nvc0/nvc0_state_validate.c
+++ b/src/gallium/drivers/nvc0/nvc0_state_validate.c
@@ -387,6 +387,20 @@ nvc0_constbufs_validate(struct nvc0_context *nvc0)
    }
 }
 
+static void
+nvc0_validate_derived_1(struct nvc0_context *nvc0)
+{
+   struct nouveau_channel *chan = nvc0->screen->base.channel;
+   boolean early_z;
+
+   early_z = nvc0->fragprog->fp.early_z && !nvc0->zsa->pipe.alpha.enabled;
+
+   if (early_z != nvc0->state.early_z) {
+      nvc0->state.early_z = early_z;
+      IMMED_RING(chan, RING_3D(EARLY_FRAGMENT_TESTS), early_z);
+   }
+}
+
 static struct state_validate {
     void (*func)(struct nvc0_context *);
     uint32_t states;
@@ -406,6 +420,7 @@ static struct state_validate {
     { nvc0_tevlprog_validate,      NVC0_NEW_TEVLPROG },
     { nvc0_gmtyprog_validate,      NVC0_NEW_GMTYPROG },
     { nvc0_fragprog_validate,      NVC0_NEW_FRAGPROG },
+    { nvc0_validate_derived_1,     NVC0_NEW_FRAGPROG | NVC0_NEW_ZSA },
     { nvc0_constbufs_validate,     NVC0_NEW_CONSTBUF },
     { nvc0_validate_textures,      NVC0_NEW_TEXTURES },
     { nvc0_validate_samplers,      NVC0_NEW_SAMPLERS },