diff --git a/hlsl/phosphor.fx b/hlsl/phosphor.fx
index 6fa136b9eb2..aba572743ba 100644
--- a/hlsl/phosphor.fx
+++ b/hlsl/phosphor.fx
@@ -79,7 +79,7 @@ VS_OUTPUT vs_main(VS_INPUT Input)
 	
 	float2 InvTexSize = float2(1.0f / TargetWidth, 1.0f / TargetHeight);
 	Output.TexCoord = Input.TexCoord + 0.5f * InvTexSize; 
-	Output.PrevCoord = Output.TexCoord + 0.5f * InvTexSize;
+	Output.PrevCoord = Input.TexCoord + 0.5f * InvTexSize;
 	
 	return Output;
 }
diff --git a/hlsl/post.fx b/hlsl/post.fx
index d55e6a14ced..41e54118d95 100644
--- a/hlsl/post.fx
+++ b/hlsl/post.fx
@@ -116,6 +116,9 @@ uniform float RedFloor = 0.0f;
 uniform float GrnFloor = 0.0f;
 uniform float BluFloor = 0.0f;
 
+uniform float SnapX = 0.0f;
+uniform float SnapY = 0.0f;
+
 float4 ps_main(PS_INPUT Input) : COLOR
 {
 	float2 Ratios = float2(WidthRatio, HeightRatio);
@@ -125,7 +128,11 @@ float4 ps_main(PS_INPUT Input) : COLOR
 	float2 PinUnitCoord = (Input.TexCoord + PinViewpointOffset) * Ratios * 2.0f - 1.0f;
 	float PincushionR2 = pow(length(PinUnitCoord), 2.0f) / pow(length(Ratios), 2.0f);
 	float2 PincushionCurve = PinUnitCoord * PincushionAmount * PincushionR2;
-	float2 BaseCoord = Input.TexCoord;
+	float2 BaseCoord = Input.TexCoord + float2(0.0f, 0.0f / TargetHeight);
+	BaseCoord.y *= TargetHeight;
+	BaseCoord.y -= frac(BaseCoord.y);
+	BaseCoord.y += 0.5f;
+	BaseCoord.y /= TargetHeight;
 	BaseCoord -= 0.5f / Ratios;
 	BaseCoord *= 1.0f - PincushionAmount * Ratios * 0.2f; // Warning: Magic constant
 	BaseCoord += 0.5f / Ratios;
diff --git a/src/osd/windows/drawd3d.c b/src/osd/windows/drawd3d.c
index 7bd4dad57dd..512d6de9208 100644
--- a/src/osd/windows/drawd3d.c
+++ b/src/osd/windows/drawd3d.c
@@ -2976,6 +2976,8 @@ static void primitive_flush_pending(d3d_info *d3d)
 					(*d3dintf->effect.set_float)(curr_effect, "RedFloor", options->screen_red_floor);
 					(*d3dintf->effect.set_float)(curr_effect, "GrnFloor", options->screen_green_floor);
 					(*d3dintf->effect.set_float)(curr_effect, "BluFloor", options->screen_blue_floor);
+					(*d3dintf->effect.set_float)(curr_effect, "SnapX", d3d->hlsl_snap_width);
+					(*d3dintf->effect.set_float)(curr_effect, "SnapY", d3d->hlsl_snap_height);
 					(*d3dintf->effect.set_float)(curr_effect, "PincushionAmount", options->screen_pincushion);
 					(*d3dintf->effect.set_float)(curr_effect, "CurvatureAmount", options->screen_curvature);
 					(*d3dintf->effect.set_float)(curr_effect, "UseShadow", d3d->shadow_texture == NULL ? 0.0f : 1.0f);
@@ -3388,6 +3390,8 @@ static void primitive_flush_pending(d3d_info *d3d)
 
 					(*d3dintf->effect.set_texture)(curr_effect, "Diffuse", d3d->hlsltexture0[poly->texture->target_index]);
 
+					(*d3dintf->effect.set_float)(curr_effect, "SnapX", d3d->hlsl_snap_width);
+					(*d3dintf->effect.set_float)(curr_effect, "SnapY", d3d->hlsl_snap_height);
 					result = (*d3dintf->device.set_render_target)(d3d->device, 0, d3d->hlsl_snap_target);
 					if (result != D3D_OK) mame_printf_verbose("Direct3D: Error %08X during device set_render_target call\n", (int)result);
 
@@ -3407,6 +3411,9 @@ static void primitive_flush_pending(d3d_info *d3d)
 					d3d->hlsl_snap_rendered = true;
 				}
 
+				(*d3dintf->effect.set_float)(curr_effect, "SnapX", d3d->width);
+				(*d3dintf->effect.set_float)(curr_effect, "SnapY", d3d->height);
+
 				/* Scanlines and shadow mask */
 				curr_effect = d3d->post_effect;