Merge pull request #1263 from FernandoS27/tex-mode

shader_decompiler:  Implemented (Partially) Texture Processing Modes

src/video_core/engines/shader_bytecode.h

@@ -254,6 +254,15 @@ enum class TextureQueryType : u64 {
     BorderColor = 22,
 };
 
+enum class TextureProcessMode : u64 {
+    None = 0,
+    LZ = 1,  // Unknown, appears to be the same as none.
+    LB = 2,  // Load Bias.
+    LL = 3,  // Load LOD (LevelOfDetail)
+    LBA = 6, // Load Bias. The A is unknown, does not appear to differ with LB
+    LLA = 7  // Load LOD. The A is unknown, does not appear to differ with LL
+};
+
 enum class IpaInterpMode : u64 { Linear = 0, Perspective = 1, Flat = 2, Sc = 3 };
 enum class IpaSampleMode : u64 { Default = 0, Centroid = 1, Offset = 2 };
 
@@ -573,6 +582,7 @@ union Instruction {
         BitField<28, 1, u64> array;
         BitField<29, 2, TextureType> texture_type;
         BitField<31, 4, u64> component_mask;
+        BitField<55, 3, TextureProcessMode> process_mode;
 
         bool IsComponentEnabled(size_t component) const {
             return ((1ull << component) & component_mask) != 0;

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -1853,15 +1853,47 @@ private:
                     coord = "vec2 coords = vec2(" + x + ", " + y + ");";
                     texture_type = Tegra::Shader::TextureType::Texture2D;
                 }
+                // TODO: make sure coordinates are always indexed to gpr8 and gpr20 is always bias
+                // or lod.
+                const std::string op_c = regs.GetRegisterAsFloat(instr.gpr20);
 
                 const std::string sampler = GetSampler(instr.sampler, texture_type, false);
                 // 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)";
+                std::string texture;
 
+                switch (instr.tex.process_mode) {
+                case Tegra::Shader::TextureProcessMode::None: {
+                    texture = "texture(" + sampler + ", coords)";
+                    break;
+                }
+                case Tegra::Shader::TextureProcessMode::LZ: {
+                    texture = "textureLod(" + sampler + ", coords, 0.0)";
+                    break;
+                }
+                case Tegra::Shader::TextureProcessMode::LB:
+                case Tegra::Shader::TextureProcessMode::LBA: {
+                    // TODO: Figure if A suffix changes the equation at all.
+                    texture = "texture(" + sampler + ", coords, " + op_c + ')';
+                    break;
+                }
+                case Tegra::Shader::TextureProcessMode::LL:
+                case Tegra::Shader::TextureProcessMode::LLA: {
+                    // TODO: Figure if A suffix changes the equation at all.
+                    texture = "textureLod(" + sampler + ", coords, " + op_c + ')';
+                    break;
+                }
+                default: {
+                    texture = "texture(" + sampler + ", coords)";
+                    LOG_CRITICAL(HW_GPU, "Unhandled texture process mode {}",
+                                 static_cast<u32>(instr.tex.process_mode.Value()));
+                    UNREACHABLE();
+                }
+                }
                 size_t dest_elem{};
                 for (size_t elem = 0; elem < 4; ++elem) {
                     if (!instr.tex.IsComponentEnabled(elem)) {