diff --git a/src/xenia/gpu/d3d12/d3d12_command_processor.cc b/src/xenia/gpu/d3d12/d3d12_command_processor.cc
index cfc9ba2e0..d4c1e24b2 100644
--- a/src/xenia/gpu/d3d12/d3d12_command_processor.cc
+++ b/src/xenia/gpu/d3d12/d3d12_command_processor.cc
@@ -1739,7 +1739,10 @@ void D3D12CommandProcessor::UpdateSystemConstantValues(
   float ndc_offset_x = (pa_cl_vte_cntl & (1 << 1)) ? 0.0f : -1.0f;
   float ndc_offset_y = (pa_cl_vte_cntl & (1 << 3)) ? 0.0f : 1.0f;
   float ndc_offset_z = gl_clip_space_def ? 0.5f : 0.0f;
-  float pixel_half_pixel_offset = 0.0f;
+  // Like in OpenGL - VPOS giving pixel centers.
+  // TODO(Triang3l): Check if ps_param_gen should give center positions in
+  // OpenGL mode on the Xbox 360.
+  float pixel_half_pixel_offset = 0.5f;
   if (FLAGS_d3d12_half_pixel_offset && !(pa_su_vtx_cntl & (1 << 0))) {
     // Signs are hopefully correct here, tested in GTA IV on both clearing
     // (without a viewport) and drawing things near the edges of the screen.
@@ -1757,7 +1760,8 @@ void D3D12CommandProcessor::UpdateSystemConstantValues(
     } else {
       ndc_offset_y -= 1.0f / 2560.0f;
     }
-    pixel_half_pixel_offset = -0.5f;
+    // Like in Direct3D 9 - VPOS giving the top-left corner.
+    pixel_half_pixel_offset = 0.0f;
   }
   dirty |= system_constants_.ndc_scale[0] != ndc_scale_x;
   dirty |= system_constants_.ndc_scale[1] != ndc_scale_y;
diff --git a/src/xenia/gpu/dxbc_shader_translator.cc b/src/xenia/gpu/dxbc_shader_translator.cc
index cba883287..6d1fffb37 100644
--- a/src/xenia/gpu/dxbc_shader_translator.cc
+++ b/src/xenia/gpu/dxbc_shader_translator.cc
@@ -961,10 +961,9 @@ void DxbcShaderTranslator::StartPixelShader() {
   ++stat_.dynamic_flow_control_count;
   // Write VPOS (without supersampling because SSAA is used to fake MSAA, and
   // at integer coordinates rather than half-pixel if needed) to XY.
-  system_constants_used_ |= (1ull << kSysConst_SSAAInvScale_Index) |
-                            (1ull << kSysConst_PixelHalfPixelOffset_Index);
-  shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_MAD) |
-                         ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(13));
+  system_constants_used_ |= 1ull << kSysConst_SSAAInvScale_Index;
+  shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_MUL) |
+                         ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(9));
   shader_code_.push_back(
       EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0011, 1));
   shader_code_.push_back(param_gen_value_temp);
@@ -978,6 +977,30 @@ void DxbcShaderTranslator::StartPixelShader() {
   shader_code_.push_back(cbuffer_index_system_constants_);
   shader_code_.push_back(uint32_t(CbufferRegister::kSystemConstants));
   shader_code_.push_back(kSysConst_SSAAInvScale_Vec);
+  ++stat_.instruction_count;
+  ++stat_.float_instruction_count;
+  // Floor VPOS so with AA, the resulting pixel corner/center is written, not
+  // the sample position (games likely don't expect it to be fractional).
+  shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ROUND_NI) |
+                         ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(5));
+  shader_code_.push_back(
+      EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0011, 1));
+  shader_code_.push_back(param_gen_value_temp);
+  shader_code_.push_back(
+      EncodeVectorSwizzledOperand(D3D10_SB_OPERAND_TYPE_TEMP, kSwizzleXYZW, 1));
+  shader_code_.push_back(param_gen_value_temp);
+  ++stat_.instruction_count;
+  ++stat_.float_instruction_count;
+  // If in OpenGL half-pixel offset mode, write the center of the pixel.
+  system_constants_used_ |= 1ull << kSysConst_PixelHalfPixelOffset_Index;
+  shader_code_.push_back(ENCODE_D3D10_SB_OPCODE_TYPE(D3D10_SB_OPCODE_ADD) |
+                         ENCODE_D3D10_SB_TOKENIZED_INSTRUCTION_LENGTH(9));
+  shader_code_.push_back(
+      EncodeVectorMaskedOperand(D3D10_SB_OPERAND_TYPE_TEMP, 0b0011, 1));
+  shader_code_.push_back(param_gen_value_temp);
+  shader_code_.push_back(
+      EncodeVectorSwizzledOperand(D3D10_SB_OPERAND_TYPE_TEMP, kSwizzleXYZW, 1));
+  shader_code_.push_back(param_gen_value_temp);
   shader_code_.push_back(
       EncodeVectorReplicatedOperand(D3D10_SB_OPERAND_TYPE_CONSTANT_BUFFER,
                                     kSysConst_PixelHalfPixelOffset_Comp, 3));