GS: Sample LOD 0 explicitly in interlace shaders

Can't use normal sampling because the derivates are undefined in
non-uniform control flow (in MAD).

bin/resources/shaders/dx11/interlace.fx

@@ -23,7 +23,7 @@ float4 ps_main0(PS_INPUT input) : SV_Target0
 	const int vpos  = int(input.p.y); // vertical position of destination texture
 
 	if ((vpos & 1) == field)
-		return Texture.Sample(Sampler, input.t);
+		return Texture.SampleLevel(Sampler, input.t, 0);
 	else
 		discard;
 
@@ -34,7 +34,7 @@ float4 ps_main0(PS_INPUT input) : SV_Target0
 // Bob shader
 float4 ps_main1(PS_INPUT input) : SV_Target0
 {
-	return Texture.Sample(Sampler, input.t);
+	return Texture.SampleLevel(Sampler, input.t, 0);
 }
 
 
@@ -42,9 +42,9 @@ float4 ps_main1(PS_INPUT input) : SV_Target0
 float4 ps_main2(PS_INPUT input) : SV_Target0
 {
 	float2 vstep = float2(0.0f, ZrH.y);
-	float4 c0 = Texture.Sample(Sampler, input.t - vstep);
+	float4 c0 = Texture.SampleLevel(Sampler, input.t - vstep, 0);
-	float4 c1 = Texture.Sample(Sampler, input.t);
+	float4 c1 = Texture.SampleLevel(Sampler, input.t, 0);
-	float4 c2 = Texture.Sample(Sampler, input.t + vstep);
+	float4 c2 = Texture.SampleLevel(Sampler, input.t + vstep, 0);
 
 	return (c0 + c1 * 2 + c2) / 4;
 }
@@ -74,7 +74,7 @@ float4 ps_main3(PS_INPUT input) : SV_Target0
 	// if the index of current destination line belongs to the current fiels we update it, otherwise
 	// we leave the old line in the destination buffer
 	if ((optr.y >= 0.0f) && (optr.y < 0.5f) && ((vpos & 1) == field))
-		return Texture.Sample(Sampler, iptr);
+		return Texture.SampleLevel(Sampler, iptr, 0);
 	else
 		discard;
 
@@ -133,13 +133,13 @@ float4 ps_main4(PS_INPUT input) : SV_Target0
 
 	// calculating motion, only relevant for missing lines where the "center line" is pointed by p_t1
 
-	float4 hn = Texture.Sample(Sampler, p_t0 - lofs); // new high pixel
+	float4 hn = Texture.SampleLevel(Sampler, p_t0 - lofs, 0); // new high pixel
-	float4 cn = Texture.Sample(Sampler, p_t1);        // new center pixel
+	float4 cn = Texture.SampleLevel(Sampler, p_t1, 0);        // new center pixel
-	float4 ln = Texture.Sample(Sampler, p_t0 + lofs); // new low pixel
+	float4 ln = Texture.SampleLevel(Sampler, p_t0 + lofs, 0); // new low pixel
 
-	float4 ho = Texture.Sample(Sampler, p_t2 - lofs); // old high pixel
+	float4 ho = Texture.SampleLevel(Sampler, p_t2 - lofs, 0); // old high pixel
-	float4 co = Texture.Sample(Sampler, p_t3);        // old center pixel
+	float4 co = Texture.SampleLevel(Sampler, p_t3, 0);        // old center pixel
-	float4 lo = Texture.Sample(Sampler, p_t2 + lofs); // old low pixel
+	float4 lo = Texture.SampleLevel(Sampler, p_t2 + lofs, 0); // old low pixel
 
 	float3 mh = hn.rgb - ho.rgb; // high pixel motion
 	float3 mc = cn.rgb - co.rgb; // center pixel motion
@@ -164,7 +164,7 @@ float4 ps_main4(PS_INPUT input) : SV_Target0
 	if ((vpos & 1) == field)
 	{
 		// output coordinate present on current field
-		return Texture.Sample(Sampler, p_t0);
+		return Texture.SampleLevel(Sampler, p_t0, 0);
 	}
 	else if ((iptr.y > 0.5f - lofs.y) || (iptr.y < 0.0 + lofs.y))
 	{

bin/resources/shaders/opengl/interlace.glsl

@@ -19,7 +19,7 @@ void ps_main0()
 	int vpos  = int(gl_FragCoord.y); // vertical position of destination texture
 
 	if ((vpos & 1) == field)
-		SV_Target0 = texture(TextureSampler, PSin_t);
+		SV_Target0 = textureLod(TextureSampler, PSin_t, 0);
 	else
 		discard;
 }
@@ -28,7 +28,7 @@ void ps_main0()
 // Bob shader
 void ps_main1()
 {
-	SV_Target0 = texture(TextureSampler, PSin_t);
+	SV_Target0 = textureLod(TextureSampler, PSin_t, 0);
 }
 
 
@@ -36,9 +36,9 @@ void ps_main1()
 void ps_main2()
 {
 	vec2 vstep = vec2(0.0f, ZrH.y);
-	vec4 c0 = texture(TextureSampler, PSin_t - vstep);
+	vec4 c0 = textureLod(TextureSampler, PSin_t - vstep, 0);
-	vec4 c1 = texture(TextureSampler, PSin_t);
+	vec4 c1 = textureLod(TextureSampler, PSin_t, 0);
-	vec4 c2 = texture(TextureSampler, PSin_t + vstep);
+	vec4 c2 = textureLod(TextureSampler, PSin_t + vstep, 0);
 
 	SV_Target0 = (c0 + c1 * 2.0f + c2) / 4.0f;
 }
@@ -68,7 +68,7 @@ void ps_main3()
 	// if the index of current destination line belongs to the current fiels we update it, otherwise
 	// we leave the old line in the destination buffer
 	if ((optr.y >= 0.0f) && (optr.y < 0.5f) && ((vpos & 1) == field))
-		SV_Target0 = texture(TextureSampler, iptr);
+		SV_Target0 = textureLod(TextureSampler, iptr, 0);
 	else
 		discard;
 }
@@ -126,13 +126,13 @@ void ps_main4()
 	// calculating motion, only relevant for missing lines where the "center line" is pointed
 	// by p_t1
 
-	vec4 hn = texture(TextureSampler, p_t0 - lofs); // new high pixel
+	vec4 hn = textureLod(TextureSampler, p_t0 - lofs, 0); // new high pixel
-	vec4 cn = texture(TextureSampler, p_t1);        // new center pixel
+	vec4 cn = textureLod(TextureSampler, p_t1, 0);        // new center pixel
-	vec4 ln = texture(TextureSampler, p_t0 + lofs); // new low pixel
+	vec4 ln = textureLod(TextureSampler, p_t0 + lofs, 0); // new low pixel
 
-	vec4 ho = texture(TextureSampler, p_t2 - lofs); // old high pixel
+	vec4 ho = textureLod(TextureSampler, p_t2 - lofs, 0); // old high pixel
-	vec4 co = texture(TextureSampler, p_t3);        // old center pixel
+	vec4 co = textureLod(TextureSampler, p_t3, 0);        // old center pixel
-	vec4 lo = texture(TextureSampler, p_t2 + lofs); // old low pixel
+	vec4 lo = textureLod(TextureSampler, p_t2 + lofs, 0); // old low pixel
 
 	vec3 mh = hn.rgb - ho.rgb; // high pixel motion
 	vec3 mc = cn.rgb - co.rgb; // center pixel motion
@@ -158,7 +158,7 @@ void ps_main4()
 	if ((vpos & 1) == field)
 	{
 		// output coordinate present on current field
-		SV_Target0 = texture(TextureSampler, p_t0);
+		SV_Target0 = textureLod(TextureSampler, p_t0, 0);
 	}
 	else if ((iptr.y > 0.5f - lofs.y) || (iptr.y < 0.0 + lofs.y))
 	{

bin/resources/shaders/vulkan/interlace.glsl

@@ -35,7 +35,7 @@ void ps_main0()
 	const int vpos  = int(gl_FragCoord.y); // vertical position of destination texture
 
 	if ((vpos & 1) == field)
-		o_col0 = texture(samp0, v_tex);
+		o_col0 = textureLod(samp0, v_tex, 0);
 	else
 		discard;
 }
@@ -46,7 +46,7 @@ void ps_main0()
 #ifdef ps_main1
 void ps_main1()
 {
-	o_col0 = texture(samp0, v_tex);
+	o_col0 = textureLod(samp0, v_tex, 0);
 }
 #endif
 
@@ -56,9 +56,9 @@ void ps_main1()
 void ps_main2()
 {
 	vec2 vstep = vec2(0.0f, ZrH.y);
-	vec4 c0 = texture(samp0, v_tex - vstep);
+	vec4 c0 = textureLod(samp0, v_tex - vstep, 0);
-	vec4 c1 = texture(samp0, v_tex);
+	vec4 c1 = textureLod(samp0, v_tex, 0);
-	vec4 c2 = texture(samp0, v_tex + vstep);
+	vec4 c2 = textureLod(samp0, v_tex + vstep, 0);
 
 	o_col0 = (c0 + c1 * 2.0f + c2) / 4.0f;
 }
@@ -90,7 +90,7 @@ void ps_main3()
 	// if the index of current destination line belongs to the current fiels we update it, otherwise
 	// we leave the old line in the destination buffer
 	if ((optr.y >= 0.0f) && (optr.y < 0.5f) && ((vpos & 1) == field))
-		o_col0 = texture(samp0, iptr);
+		o_col0 = textureLod(samp0, iptr, 0);
 	else
 		discard;
 }
@@ -150,13 +150,13 @@ void ps_main4()
 
 	// calculating motion, only relevant for missing lines where the "center line" is pointed by p_t1
 
-	vec4 hn = texture(samp0, p_t0 - lofs); // new high pixel
+	vec4 hn = textureLod(samp0, p_t0 - lofs, 0); // new high pixel
-	vec4 cn = texture(samp0, p_t1);        // new center pixel
+	vec4 cn = textureLod(samp0, p_t1, 0);        // new center pixel
-	vec4 ln = texture(samp0, p_t0 + lofs); // new low pixel
+	vec4 ln = textureLod(samp0, p_t0 + lofs, 0); // new low pixel
 
-	vec4 ho = texture(samp0, p_t2 - lofs); // old high pixel
+	vec4 ho = textureLod(samp0, p_t2 - lofs, 0); // old high pixel
-	vec4 co = texture(samp0, p_t3);        // old center pixel
+	vec4 co = textureLod(samp0, p_t3, 0);        // old center pixel
-	vec4 lo = texture(samp0, p_t2 + lofs); // old low pixel
+	vec4 lo = textureLod(samp0, p_t2 + lofs, 0); // old low pixel
 
 	vec3 mh = hn.rgb - ho.rgb; // high pixel motion
 	vec3 mc = cn.rgb - co.rgb; // center pixel motion
@@ -181,7 +181,7 @@ void ps_main4()
 	if ((vpos & 1) == field) // output coordinate present on current field
 	{
 		// output coordinate present on current field
-		o_col0 = texture(samp0, p_t0);
+		o_col0 = textureLod(samp0, p_t0, 0);
 	}
 	else if ((iptr.y > 0.5f - lofs.y) || (iptr.y < 0.0 + lofs.y))
 	{

pcsx2/GS/Renderers/Metal/GSMTLShaderCommon.h

@@ -33,6 +33,10 @@ struct ConvertPSRes
 	{
 		return texture.sample(s, coord);
 	}
+	float4 sample_level(float2 coord, float lod)
+	{
+		return texture.sample(s, coord, level(lod));
+	}
 };
 
 struct ConvertPSDepthRes

pcsx2/GS/Renderers/Metal/interlace.metal

@@ -27,7 +27,7 @@ fragment float4 ps_interlace0(ConvertShaderData data [[stage_in]], ConvertPSRes
 	const int vpos  = int(data.p.y);      // vertical position of destination texture
 
 	if ((vpos & 1) == field)
-		return res.sample(data.t);
+		return res.sample_level(data.t, 0);
 	else
 		discard_fragment();
 
@@ -38,7 +38,7 @@ fragment float4 ps_interlace0(ConvertShaderData data [[stage_in]], ConvertPSRes
 // Bob shader
 fragment float4 ps_interlace1(ConvertShaderData data [[stage_in]], ConvertPSRes res)
 {
-	return res.sample(data.t);
+	return res.sample_level(data.t);
 }
 
 
@@ -47,9 +47,9 @@ fragment float4 ps_interlace2(ConvertShaderData data [[stage_in]], ConvertPSRes
 	constant GSMTLInterlacePSUniform& uniform [[buffer(GSMTLBufferIndexUniforms)]])
 {
 	float2 vstep = float2(0.0f, uniform.ZrH.y);
-	float4 c0 = res.sample(data.t - vstep);
+	float4 c0 = res.sample_level(data.t - vstep, 0);
-	float4 c1 = res.sample(data.t);
+	float4 c1 = res.sample_level(data.t, 0);
-	float4 c2 = res.sample(data.t + vstep);
+	float4 c2 = res.sample_level(data.t + vstep, 0);
 	return (c0 + c1 * 2.f + c2) / 4.f;
 }
 
@@ -79,7 +79,7 @@ fragment float4 ps_interlace3(ConvertShaderData data [[stage_in]], ConvertPSRes
 	// if the index of current destination line belongs to the current fiels we update it, otherwise
 	// we leave the old line in the destination buffer
 	if ((optr.y >= 0.0f) && (optr.y < 0.5f) && ((vpos & 1) == field))
-		return res.sample(iptr);
+		return res.sample_level(iptr, 0);
 	else
 		discard_fragment();
 
@@ -137,13 +137,13 @@ fragment float4 ps_interlace4(ConvertShaderData data [[stage_in]], ConvertPSRes
 
 	// calculating motion, only relevant for missing lines where the "center line" is pointed by p_t1
 
-	float4 hn = res.sample(p_t0 - lofs); // new high pixel
+	float4 hn = res.sample_level(p_t0 - lofs, 0); // new high pixel
-	float4 cn = res.sample(p_t1);        // new center pixel
+	float4 cn = res.sample_level(p_t1, 0);        // new center pixel
-	float4 ln = res.sample(p_t0 + lofs); // new low pixel
+	float4 ln = res.sample_level(p_t0 + lofs, 0); // new low pixel
 
-	float4 ho = res.sample(p_t2 - lofs); // old high pixel
+	float4 ho = res.sample_level(p_t2 - lofs, 0); // old high pixel
-	float4 co = res.sample(p_t3);        // old center pixel
+	float4 co = res.sample_level(p_t3, 0);        // old center pixel
-	float4 lo = res.sample(p_t2 + lofs); // old low pixel
+	float4 lo = res.sample_level(p_t2 + lofs, 0); // old low pixel
 
 	float3 mh = hn.rgb - ho.rgb;
 	float3 mc = cn.rgb - co.rgb;
@@ -168,7 +168,7 @@ fragment float4 ps_interlace4(ConvertShaderData data [[stage_in]], ConvertPSRes
 	if ((vpos & 1) == field)
 	{
 		// output coordinate present on current field
-		return res.sample(p_t0);
+		return res.sample_level(p_t0, 0);
 	}
 	else if ((iptr.y > 0.5f - lofs.y) || (iptr.y < 0.0 + lofs.y))
 	{