radeonsi: explicitly choose center locations for 1xAA on Polaris

Unlike SC, the small primitive filter does not automatically use center
locations in 1xAA mode, so this is needed to avoid artifacts caused by
the small primitive filter discarding triangles that it shouldn't.

As a side effect of how the effective number of samples is now calculated,
this patch also avoids submitting the sample locations for line/poly smoothing
when they're not really needed.

Cc: 12.0 <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/gallium/drivers/radeon/cayman_msaa.c b/src/gallium/drivers/radeon/cayman_msaa.c
index 89c4937a2cc..33f1040185a 100644
--- a/src/gallium/drivers/radeon/cayman_msaa.c
+++ b/src/gallium/drivers/radeon/cayman_msaa.c
@@ -143,6 +143,13 @@ void cayman_init_msaa(struct pipe_context *ctx)
 void cayman_emit_msaa_sample_locs(struct radeon_winsys_cs *cs, int nr_samples)
 {
 	switch (nr_samples) {
+	default:
+	case 1:
+		radeon_set_context_reg(cs, CM_R_028BF8_PA_SC_AA_SAMPLE_LOCS_PIXEL_X0Y0_0, 0);
+		radeon_set_context_reg(cs, CM_R_028C08_PA_SC_AA_SAMPLE_LOCS_PIXEL_X1Y0_0, 0);
+		radeon_set_context_reg(cs, CM_R_028C18_PA_SC_AA_SAMPLE_LOCS_PIXEL_X0Y1_0, 0);
+		radeon_set_context_reg(cs, CM_R_028C28_PA_SC_AA_SAMPLE_LOCS_PIXEL_X1Y1_0, 0);
+		break;
 	case 2:
 		radeon_set_context_reg(cs, CM_R_028BF8_PA_SC_AA_SAMPLE_LOCS_PIXEL_X0Y0_0, eg_sample_locs_2x[0]);
 		radeon_set_context_reg(cs, CM_R_028C08_PA_SC_AA_SAMPLE_LOCS_PIXEL_X1Y0_0, eg_sample_locs_2x[1]);