rsx: Implement pixel_center_origin decorator for WPOS

rpcs3/Emu/RSX/Common/buffer_stream.hpp

@@ -40,10 +40,15 @@ namespace utils
 	/**
 	 * Stream a 128 bits vector from src to dst.
 	 */
-	static inline
-		void stream_vector_from_memory(void* dst, void* src)
+	template <int Count = 1>
+	void stream_vector_from_memory(void* dst, void* src)
 	{
-		const __m128i vector = _mm_loadu_si128(reinterpret_cast<__m128i*>(src));
-		_mm_stream_si128(reinterpret_cast<__m128i*>(dst), vector);
+		auto _src = reinterpret_cast<__m128i*>(src);
+		auto _dst = reinterpret_cast<__m128i*>(dst);
+		for (int i = 0; i < Count; ++i, ++_src, ++_dst)
+		{
+			const __m128i vector = _mm_loadu_si128(_src);
+			_mm_stream_si128(_dst, vector);
+		}
 	}
 }

rpcs3/Emu/RSX/Core/RSXDrawCommands.cpp

@@ -664,7 +664,21 @@ namespace rsx
 
 	void draw_command_processor::fill_fragment_state_buffer(void* buffer, const RSXFragmentProgram& /*fragment_program*/) const
 	{
+#pragma pack(push, 1)
+		struct fragment_context_t
+		{
+			f32 fog_param0;
+			f32 fog_param1;
+			u32 rop_control;
+			f32 alpha_ref;
+			u32 fog_mode;
+			f32 wpos_scale;
+			f32 wpos_bias[2];
+		};
+#pragma pack(pop)
+
 		ROP_control_t rop_control{};
+		alignas(16) fragment_context_t payload{};
 
 		if (REGS(m_ctx)->alpha_test_enabled())
 		{
@@ -720,10 +734,6 @@ namespace rsx
 			}
 		}
 
-		const f32 fog0 = REGS(m_ctx)->fog_params_0();
-		const f32 fog1 = REGS(m_ctx)->fog_params_1();
-		const u32 fog_mode = static_cast<u32>(REGS(m_ctx)->fog_equation());
-
 		// Check if framebuffer is actually an XRGB format and not a WZYX format
 		switch (REGS(m_ctx)->surface_color())
 		{
@@ -745,21 +755,37 @@ namespace rsx
 		}
 
 		// Generate wpos coefficients
-		// wpos equation is now as follows:
+		// wpos equation is now as follows (ignoring pixel center offset):
 		// wpos.y = (frag_coord / resolution_scale) * ((window_origin!=top)?-1.: 1.) + ((window_origin!=top)? window_height : 0)
 		// wpos.x = (frag_coord / resolution_scale)
 		// wpos.zw = frag_coord.zw
 
+		payload.fog_param0 = REGS(m_ctx)->fog_params_0();
+		payload.fog_param1 = REGS(m_ctx)->fog_params_1();
+		payload.fog_mode = static_cast<u32>(REGS(m_ctx)->fog_equation());
+		payload.rop_control = rop_control.value;
+		payload.alpha_ref = REGS(m_ctx)->alpha_ref();
+
+
 		const auto window_origin = REGS(m_ctx)->shader_window_origin();
 		const u32 window_height = REGS(m_ctx)->shader_window_height();
+		const auto pixel_center = REGS(m_ctx)->pixel_center();
 		const f32 resolution_scale = (window_height <= static_cast<u32>(g_cfg.video.min_scalable_dimension)) ? 1.f : rsx::get_resolution_scale();
-		const f32 wpos_scale = (window_origin == rsx::window_origin::top) ? (1.f / resolution_scale) : (-1.f / resolution_scale);
-		const f32 wpos_bias = (window_origin == rsx::window_origin::top) ? 0.f : window_height;
-		const f32 alpha_ref = REGS(m_ctx)->alpha_ref();
 
-		u32* dst = static_cast<u32*>(buffer);
-		utils::stream_vector(dst, std::bit_cast<u32>(fog0), std::bit_cast<u32>(fog1), rop_control.value, std::bit_cast<u32>(alpha_ref));
-		utils::stream_vector(dst + 4, 0u, fog_mode, std::bit_cast<u32>(wpos_scale), std::bit_cast<u32>(wpos_bias));
+		payload.wpos_scale = (window_origin == rsx::window_origin::top) ? (1.f / resolution_scale) : (-1.f / resolution_scale);
+		payload.wpos_bias[0] = 0.f;
+		payload.wpos_bias[1] = (window_origin == rsx::window_origin::top) ? 0.f : window_height;
+
+		if (pixel_center == window_pixel_center::integer)
+		{
+			// We could technically fix this shader side, but...
+			// 1. We have full control over gl_FragCoord consumption, so fix it using our own pipeline as it is an emulated input.
+			// 2. Vulkan does not support pixel_center_integer decoration. SPIR-V modules only permit pixel center at half offset.
+			payload.wpos_bias[0] -= 0.5f;
+			payload.wpos_bias[1] -= 0.5f;
+		}
+
+		utils::stream_vector_from_memory<2>(buffer, &payload);
 	}
 
 	void draw_command_processor::fill_constants_instancing_buffer(rsx::io_buffer& indirection_table_buf, rsx::io_buffer& constants_data_array_buffer, const VertexProgramBase* prog) const

rpcs3/Emu/RSX/GL/GLFragmentProgram.cpp

@@ -175,10 +175,9 @@ void GLFragmentDecompilerThread::insertConstants(std::stringstream & OS)
 	"	float fog_param1;\n"
 	"	uint rop_control;\n"
 	"	float alpha_ref;\n"
-	"	uint reserved;\n"
 	"	uint fog_mode;\n"
 	"	float wpos_scale;\n"
-	"	float wpos_bias;\n"
+	"	vec2 wpos_bias;\n"
 	"};\n\n"
 
 	"layout(std140, binding = " << GL_FRAGMENT_TEXTURE_PARAMS_BIND_SLOT << ") uniform TextureParametersBuffer\n"

rpcs3/Emu/RSX/Program/GLSLSnippets/RSXProg/RSXDefines2.glsl

@@ -43,10 +43,9 @@ struct fragment_context_t
 	float fog_param1;
 	uint rop_control;
 	float alpha_ref;
-	uint reserved;
 	uint fog_mode;
 	float wpos_scale;
-	float wpos_bias;
+	vec2 wpos_bias;
 };
 
 )"

rpcs3/Emu/RSX/Program/GLSLSnippets/RSXProg/RSXFragmentPrologue.glsl

@@ -38,7 +38,7 @@ bool _fragment_discard = false;
 vec4 get_wpos()
 {
 	float abs_scale = abs(wpos_scale);
-	return (gl_FragCoord * vec4(abs_scale, wpos_scale, 1., 1.)) + vec4(0., wpos_bias, 0., 0.);
+	return (gl_FragCoord * vec4(abs_scale, wpos_scale, 1., 1.)) + vec4(wpos_bias, 0., 0.);
 }
 #endif
 

rpcs3/Emu/RSX/rsx_decode.h

@@ -3132,7 +3132,7 @@ struct registers_decoder<NV4097_SET_SHADER_WINDOW>
 			return to_window_origin(window_shader_origin_raw());
 		}
 
-		auto window_shader_pixel_center() const
+		auto pixel_center() const
 		{
 			return to_window_pixel_center(window_shader_pixel_center_raw());
 		}
@@ -3146,7 +3146,7 @@ struct registers_decoder<NV4097_SET_SHADER_WINDOW>
 	static void dump(std::string& out, const decoded_type& decoded)
 	{
 		fmt::append(out, "Viewport: height: %u origin: %s pixel center: %s", decoded.window_shader_height()
-			, decoded.window_shader_origin(), decoded.window_shader_pixel_center());
+			, decoded.window_shader_origin(), decoded.pixel_center());
 	}
 };
 

rpcs3/Emu/RSX/rsx_methods.h

@@ -226,9 +226,9 @@ namespace rsx
 			return decode<NV4097_SET_SHADER_WINDOW>().window_shader_origin();
 		}
 
-		window_pixel_center shader_window_pixel() const
+		window_pixel_center pixel_center() const
 		{
-			return decode<NV4097_SET_SHADER_WINDOW>().window_shader_pixel_center();
+			return decode<NV4097_SET_SHADER_WINDOW>().pixel_center();
 		}
 
 		u16 shader_window_height() const