- Enable GEN6_WM_MSDISPMODE_PERSAMPLE, GEN6_WM_POSOFFSET_SAMPLE,
GEN6_WM_OMASK_TO_RENDER_TARGET as per extension's specification.
- Don't enable GEN6_WM_16_DISPATCH_ENABLE when GEN6_WM_MSDISPMODE_PERSAMPLE
is enabled. Refer SNB PRM Vol. 2, Part 1, Page 279 for details.
Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com>
---
src/mesa/drivers/dri/i965/gen6_wm_state.c | 67 +++++++++++++++++++++++++++++--
1 file changed, 64 insertions(+), 3 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/gen6_wm_state.c
b/src/mesa/drivers/dri/i965/gen6_wm_state.c
index c96a107..4bc25d6 100644
--- a/src/mesa/drivers/dri/i965/gen6_wm_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_wm_state.c
@@ -103,6 +103,7 @@ upload_wm_state(struct brw_context *brw)
/* _NEW_BUFFERS */
bool multisampled_fbo = ctx->DrawBuffer->Visual.samples > 1;
+ bool msdispmode_persample = false;
/* CACHE_NEW_WM_PROG */
if (brw->wm.prog_data->nr_params == 0) {
@@ -156,7 +157,17 @@ upload_wm_state(struct brw_context *brw)
/* CACHE_NEW_WM_PROG */
dw5 |= GEN6_WM_8_DISPATCH_ENABLE;
- if (brw->wm.prog_data->prog_offset_16)
+ msdispmode_persample =
+ ctx->Multisample.Enabled &&
+ (ctx->Multisample.SampleShading ||
+ brw->fragment_program->Base.InputsRead & VARYING_BIT_SAMPLE_ID ||
+ brw->fragment_program->Base.InputsRead & VARYING_BIT_SAMPLE_POS);
+
+ /* In case of non 1x (i.e 4x, 8x) multisampling with MDISPMODE_PERSAMPLE,
+ * only one of SIMD8 and SIMD16 should be enabled.
+ */
+ if (brw->wm.prog_data->prog_offset_16 &&
+ !(multisampled_fbo && msdispmode_persample))
dw5 |= GEN6_WM_16_DISPATCH_ENABLE;
/* CACHE_NEW_WM_PROG | _NEW_COLOR */
@@ -185,7 +196,10 @@ upload_wm_state(struct brw_context *brw)
/* _NEW_COLOR, _NEW_MULTISAMPLE */
if (fp->program.UsesKill || ctx->Color.AlphaEnabled ||
- ctx->Multisample.SampleAlphaToCoverage)
+ ctx->Multisample.SampleAlphaToCoverage ||
+ (ctx->Multisample.SampleShading &&
+ (fp->program.Base.OutputsWritten &
+ BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK))))
dw5 |= GEN6_WM_KILL_ENABLE;
if (brw_color_buffer_write_enabled(brw) ||
@@ -193,6 +207,19 @@ upload_wm_state(struct brw_context *brw)
dw5 |= GEN6_WM_DISPATCH_ENABLE;
}
+ /* From the SNB PRM, volume 2 part 1, page 278:
+ * "This bit is inserted in the PS payload header and made available to
+ * the DataPort (either via the message header or via header bypass) to
+ * indicate that oMask data (one or two phases) is included in Render
+ * Target Write messages. If present, the oMask data is used to mask off
+ * samples."
+ * TODO: [DevSNB:A0] This bit must be disabled in A Step.
+ */
+ if (ctx->Extensions.ARB_sample_shading &&
+ (brw->fragment_program->Base.OutputsWritten &
+ BITFIELD64_BIT(FRAG_RESULT_SAMPLE_MASK)))
+ dw5 |= GEN6_WM_OMASK_TO_RENDER_TARGET;
+
/* CACHE_NEW_WM_PROG */
dw6 |= brw->wm.prog_data->num_varying_inputs <<
GEN6_WM_NUM_SF_OUTPUTS_SHIFT;
@@ -202,12 +229,46 @@ upload_wm_state(struct brw_context *brw)
dw6 |= GEN6_WM_MSRAST_ON_PATTERN;
else
dw6 |= GEN6_WM_MSRAST_OFF_PIXEL;
- dw6 |= GEN6_WM_MSDISPMODE_PERPIXEL;
+
+ /* From arb_sample_shading specification:
+ * "If MULTISAMPLE or SAMPLE_SHADING_ARB is disabled, sample shading
+ * has no effect."
+ *
+ * "Using gl_SampleID in a fragment shader causes the entire shader
+ * to be evaluated per-sample."
+ * "Using gl_SamplePosition in a fragment shader causes the entire
+ * shader to be evaluated per-sample."
+ *
+ * I interprate the above four lines as enable the sample shading
+ * if fragment shader uses gl_SampleID or gl_SamplePosition.
+ */
+ if (msdispmode_persample)
+ dw6 |= GEN6_WM_MSDISPMODE_PERSAMPLE;
+ else
+ dw6 |= GEN6_WM_MSDISPMODE_PERPIXEL;
} else {
dw6 |= GEN6_WM_MSRAST_OFF_PIXEL;
dw6 |= GEN6_WM_MSDISPMODE_PERSAMPLE;
}
+ /* _NEW_MULTISAMPLE */
+ /* From the SNB PRM, volume 2 part 1, page 281:
+ * "If the PS kernel does not need the Position XY Offsets
+ * to compute a Position XY value, then this field should be
+ * programmed to POSOFFSET_NONE."
+ *
+ * "SW Recommendation: If the PS kernel needs the Position Offsets
+ * to compute a Position XY value, this field should match Position
+ * ZW Interpolation Mode to ensure a consistent position.xyzw
+ * computation."
+ * We only require XY sample offsets. So, this recommendation doesn't
+ * look useful at the moment. We might need this in future.
+ */
+ if (brw->fragment_program->Base.InputsRead & VARYING_BIT_SAMPLE_POS)
+ dw6 |= GEN6_WM_POSOFFSET_SAMPLE;
+ else
+ dw6 |= GEN6_WM_POSOFFSET_NONE;
+
BEGIN_BATCH(9);
OUT_BATCH(_3DSTATE_WM << 16 | (9 - 2));
OUT_BATCH(brw->wm.base.prog_offset);
--
1.8.1.4
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