Merge pull request #494 from bunnei/shader-tex

gl_shader_decompiler: Implement TEX, fixes for TEXS.

src/video_core/engines/shader_bytecode.h

@@ -261,6 +261,19 @@ union Instruction {
         BitField<50, 1, u64> saturate_a;
     } conversion;
 
+    union {
+        BitField<31, 4, u64> component_mask;
+
+        bool IsComponentEnabled(size_t component) const {
+            return ((1 << component) & component_mask) != 0;
+        }
+    } tex;
+
+    union {
+        // TODO(bunnei): This is just a guess, needs to be verified
+        BitField<52, 1, u64> enable_g_component;
+    } texs;
+
     BitField<61, 1, u64> is_b_imm;
     BitField<60, 1, u64> is_b_gpr;
     BitField<59, 1, u64> is_c_gpr;
@@ -281,6 +294,7 @@ public:
         KIL,
         LD_A,
         ST_A,
+        TEX,
         TEXQ, // Texture Query
         TEXS, // Texture Fetch with scalar/non-vec4 source/destinations
         TLDS, // Texture Load with scalar/non-vec4 source/destinations
@@ -444,6 +458,7 @@ private:
             INST("111000110011----", Id::KIL, Type::Flow, "KIL"),
             INST("1110111111011---", Id::LD_A, Type::Memory, "LD_A"),
             INST("1110111111110---", Id::ST_A, Type::Memory, "ST_A"),
+            INST("1100000000111---", Id::TEX, Type::Memory, "TEX"),
             INST("1101111101001---", Id::TEXQ, Type::Memory, "TEXQ"),
             INST("1101100---------", Id::TEXS, Type::Memory, "TEXS"),
             INST("1101101---------", Id::TLDS, Type::Memory, "TLDS"),

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -896,6 +896,32 @@ private:
                                                   instr.gpr0);
                 break;
             }
+            case OpCode::Id::TEX: {
+                ASSERT_MSG(instr.attribute.fmt20.size == 4, "untested");
+                const std::string op_a = regs.GetRegisterAsFloat(instr.gpr8);
+                const std::string op_b = regs.GetRegisterAsFloat(instr.gpr8.Value() + 1);
+                const std::string sampler = GetSampler(instr.sampler);
+                const std::string coord = "vec2 coords = vec2(" + op_a + ", " + op_b + ");";
+                // Add an extra scope and declare the texture coords inside to prevent overwriting
+                // them in case they are used as outputs of the texs instruction.
+                shader.AddLine("{");
+                ++shader.scope;
+                shader.AddLine(coord);
+                const std::string texture = "texture(" + sampler + ", coords)";
+
+                size_t dest_elem{};
+                for (size_t elem = 0; elem < instr.attribute.fmt20.size; ++elem) {
+                    if (!instr.tex.IsComponentEnabled(elem)) {
+                        // Skip disabled components
+                        continue;
+                    }
+                    regs.SetRegisterToFloat(instr.gpr0, elem, texture, 1, 4, false, dest_elem);
+                    ++dest_elem;
+                }
+                --shader.scope;
+                shader.AddLine("}");
+                break;
+            }
             case OpCode::Id::TEXS: {
                 ASSERT_MSG(instr.attribute.fmt20.size == 4, "untested");
                 const std::string op_a = regs.GetRegisterAsFloat(instr.gpr8);
@@ -908,8 +934,23 @@ private:
                 ++shader.scope;
                 shader.AddLine(coord);
                 const std::string texture = "texture(" + sampler + ", coords)";
-                for (unsigned elem = 0; elem < instr.attribute.fmt20.size; ++elem) {
-                    regs.SetRegisterToFloat(instr.gpr0, elem, texture, 1, 4, false, elem);
+
+                // TEXS has two destination registers. RG goes into gpr0+0 and gpr0+1, and BA goes
+                // into gpr28+0 and gpr28+1
+                size_t offset{};
+                for (const auto& dest : {instr.gpr0.Value(), instr.gpr28.Value()}) {
+                    for (unsigned elem = 0; elem < 2; ++elem) {
+                        if (dest + elem >= Register::ZeroIndex) {
+                            // Skip invalid register values
+                            break;
+                        }
+                        regs.SetRegisterToFloat(dest, elem + offset, texture, 1, 4, false, elem);
+                        if (!instr.texs.enable_g_component) {
+                            // Skip the second component
+                            break;
+                        }
+                    }
+                    offset += 2;
                 }
                 --shader.scope;
                 shader.AddLine("}");