[Mesa-dev] [PATCH 1/6] radv: fix interpolation at wrong place for offset interp

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

The code was interpolating at the offset from the sample,
not the offset from the center. Also fix for persample interpolation
modes we should force the pixel center to be at the sample.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/amd/common/ac_nir_to_llvm.c  | 6 ++++--
 src/amd/vulkan/radv_cmd_buffer.c | 1 -
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index a74b906..ca1416d 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -2884,10 +2884,12 @@ static LLVMValueRef visit_interp(struct nir_to_llvm_context *ctx,
 		location = INTERP_CENTROID;
 		break;
 	case nir_intrinsic_interp_var_at_sample:
-	case nir_intrinsic_interp_var_at_offset:
 		location = INTERP_SAMPLE;
 		src0 = get_src(ctx, instr->src[0]);
 		break;
+	case nir_intrinsic_interp_var_at_offset:
+		location = INTERP_CENTER;
+		src0 = get_src(ctx, instr->src[0]);
 	default:
 		break;
 	}
@@ -2910,7 +2912,7 @@ static LLVMValueRef visit_interp(struct nir_to_llvm_context *ctx,
 	interp_param = lookup_interp_param(ctx, instr->variables[0]->var->data.interpolation, location);
 	attr_number = LLVMConstInt(ctx->i32, input_index, false);
 
-	if (location == INTERP_SAMPLE) {
+	if (location == INTERP_SAMPLE || location == INTERP_CENTER) {
 		LLVMValueRef ij_out[2];
 		LLVMValueRef ddxy_out = emit_ddxy_interp(ctx, interp_param);
 
diff --git a/src/amd/vulkan/radv_cmd_buffer.c b/src/amd/vulkan/radv_cmd_buffer.c
index 4aa5df6..dd6deef 100644
--- a/src/amd/vulkan/radv_cmd_buffer.c
+++ b/src/amd/vulkan/radv_cmd_buffer.c
@@ -685,7 +685,6 @@ radv_emit_fragment_shader(struct radv_cmd_buffer *cmd_buffer,
 	radeon_set_context_reg(cmd_buffer->cs, R_0286D0_SPI_PS_INPUT_ADDR,
 			       ps->config.spi_ps_input_addr);
 
-	spi_baryc_cntl |= S_0286E0_POS_FLOAT_LOCATION(0);
 	radeon_set_context_reg(cmd_buffer->cs, R_0286D8_SPI_PS_IN_CONTROL,
 			       S_0286D8_NUM_INTERP(ps->info.fs.num_interp));
 
-- 
2.9.3