From 57b9acec62420345a8affc66cba601cc3c603f06 Mon Sep 17 00:00:00 2001
From: kd-11 <karokidii@gmail.com>
Date: Mon, 23 Aug 2021 11:48:32 +0300
Subject: [PATCH] rsx: Implement indexed dynamic attribute load

---
 .../RSX/Program/FragmentProgramDecompiler.cpp | 45 +++++++++++++++++--
 .../RSX/Program/FragmentProgramDecompiler.h   |  1 +
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.cpp b/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.cpp
index 37cb986544..0c82856f55 100644
--- a/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.cpp
+++ b/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.cpp
@@ -550,14 +550,14 @@ template<typename T> std::string FragmentProgramDecompiler::GetSRC(T src)
 		// 4. [A0 + N] addressing can be applied to dynamically sample texture coordinates.
 		// - This is explained in NV_fragment_program2 specification page, Fragment Attributes section.
 		// - There is no instruction that writes to the address register directly, it is supposed to be the loop counter!
-		const u32 register_id = src2.use_index_reg ? (src2.addr_reg + 4) : dst.src_attr_reg_num;
+		u32 register_id = src2.use_index_reg ? (src2.addr_reg + 4) : dst.src_attr_reg_num;
 		const std::string reg_var = (register_id < std::size(reg_table))? reg_table[register_id] : "unk";
 		bool insert = true;
 
 		if (src2.use_index_reg && m_loop_count)
 		{
-			// TODO: Actually implement dynamic register indexing (kd-11)
-			rsx_log.error("Dynamic register indexing is unimplemented. Report this to developers!");
+			// Dynamically load the input
+			register_id = 0xFF;
 		}
 
 		switch (register_id)
@@ -621,6 +621,23 @@ template<typename T> std::string FragmentProgramDecompiler::GetSRC(T src)
 			}
 			break;
 		}
+		case 0xFF:
+		{
+			for (int i = 0; i < 10; ++i)
+			{
+				m_parr.AddParam(PF_PARAM_IN, getFloatTypeName(4), reg_table[i + 4]);
+			}
+
+			if (m_loop_count > 1)
+			{
+				rsx_log.error("Nested loop with indexed load was detected. Report this to developers!");
+			}
+
+			ret = fmt::format("_indexed_load(i%u + %u)", m_loop_count - 1, src2.addr_reg);
+			properties.has_dynamic_register_load = true;
+			insert = false;
+			break;
+		}
 		default:
 		{
 			// SSA (winding direction register)
@@ -911,6 +928,28 @@ std::string FragmentProgramDecompiler::BuildCode()
 		OS << "}\n\n";
 	}
 
+	if (properties.has_dynamic_register_load)
+	{
+		OS <<
+		"vec4 _indexed_load(int index)\n"
+		"{\n"
+		"	switch (index)\n"
+		"	{\n"
+		"		case 0: return tc0;\n"
+		"		case 1: return tc1;\n"
+		"		case 2: return tc2;\n"
+		"		case 3: return tc3;\n"
+		"		case 4: return tc4;\n"
+		"		case 5: return tc5;\n"
+		"		case 6: return tc6;\n"
+		"		case 7: return tc7;\n"
+		"		case 8: return tc8;\n"
+		"		case 9: return tc9;\n"
+		"	}\n"
+		"	return vec4(0., 0., 0., 1.);\n"
+		"}\n\n";
+	}
+
 	insertMainStart(OS);
 	OS << main << std::endl;
 	insertMainEnd(OS);
diff --git a/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.h b/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.h
index 2b8766754a..e55f6fc42d 100644
--- a/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.h
+++ b/rpcs3/Emu/RSX/Program/FragmentProgramDecompiler.h
@@ -287,6 +287,7 @@ public:
 		bool has_exp_tex_op = false;
 		bool has_pkg = false;
 		bool has_upg = false;
+		bool has_dynamic_register_load = false;
 	}
 	properties;