shader_decode: Implement TEXS (F32)

2 files changed, 217 insertions, 0 deletions

diff --git a/src/video_core/shader/decode/memory.cpp b/src/video_core/shader/decode/memory.cpp
index aea1a0675..1f458b6d7 100644
--- a/src/video_core/shader/decode/memory.cpp
+++ b/src/video_core/shader/decode/memory.cpp
@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <vector>
+
 #include "common/assert.h"
 #include "common/common_types.h"
 #include "video_core/engines/shader_bytecode.h"
@@ -13,6 +15,24 @@ using Tegra::Shader::Attribute;
 using Tegra::Shader::Instruction;
 using Tegra::Shader::OpCode;
 using Tegra::Shader::Register;
+using Tegra::Shader::TextureMiscMode;
+using Tegra::Shader::TextureProcessMode;
+using Tegra::Shader::TextureType;
+
+static std::size_t GetCoordCount(TextureType texture_type) {
+    switch (texture_type) {
+    case TextureType::Texture1D:
+        return 1;
+    case TextureType::Texture2D:
+        return 2;
+    case TextureType::Texture3D:
+    case TextureType::TextureCube:
+        return 3;
+    default:
+        UNIMPLEMENTED_MSG("Unhandled texture type: {}", static_cast<u32>(texture_type));
+        return 0;
+    }
+}
 
 u32 ShaderIR::DecodeMemory(BasicBlock& bb, u32 pc) {
     const Instruction instr = {program_code[pc]};
@@ -82,6 +102,27 @@ u32 ShaderIR::DecodeMemory(BasicBlock& bb, u32 pc) {
 
         break;
     }
+    case OpCode::Id::TEXS: {
+        Tegra::Shader::TextureType texture_type{instr.texs.GetTextureType()};
+        const bool is_array{instr.texs.IsArrayTexture()};
+        const bool depth_compare = instr.texs.UsesMiscMode(TextureMiscMode::DC);
+        const auto process_mode = instr.texs.GetTextureProcessMode();
+
+        if (instr.texs.UsesMiscMode(TextureMiscMode::NODEP)) {
+            LOG_WARNING(HW_GPU, "TEXS.NODEP implementation is incomplete");
+        }
+
+        const Node texture =
+            GetTexsCode(instr, texture_type, process_mode, depth_compare, is_array);
+
+        if (instr.texs.fp32_flag) {
+            WriteTexsInstructionFloat(bb, instr, texture);
+        } else {
+            UNIMPLEMENTED();
+            // WriteTexsInstructionHalfFloat(bb, instr, texture);
+        }
+        break;
+    }
     default:
         UNIMPLEMENTED_MSG("Unhandled memory instruction: {}", opcode->get().GetName());
     }
@@ -89,4 +130,162 @@ u32 ShaderIR::DecodeMemory(BasicBlock& bb, u32 pc) {
     return pc;
 }
 
+const Sampler& ShaderIR::GetSampler(const Tegra::Shader::Sampler& sampler, TextureType type,
+                                    bool is_array, bool is_shadow) {
+    const auto offset = static_cast<std::size_t>(sampler.index.Value());
+
+    // If this sampler has already been used, return the existing mapping.
+    const auto itr =
+        std::find_if(used_samplers.begin(), used_samplers.end(),
+                     [&](const Sampler& entry) { return entry.GetOffset() == offset; });
+    if (itr != used_samplers.end()) {
+        ASSERT(itr->GetType() == type && itr->IsArray() == is_array &&
+               itr->IsShadow() == is_shadow);
+        return *itr;
+    }
+
+    // Otherwise create a new mapping for this sampler
+    const std::size_t next_index = used_samplers.size();
+    const Sampler entry{offset, next_index, type, is_array, is_shadow};
+    return *used_samplers.emplace(entry).first;
+}
+
+void ShaderIR::WriteTexsInstructionFloat(BasicBlock& bb, Tegra::Shader::Instruction instr,
+                                         Node texture) {
+    // TEXS has two destination registers and a swizzle. The first two elements in the swizzle
+    // go into gpr0+0 and gpr0+1, and the rest goes into gpr28+0 and gpr28+1
+
+    MetaComponents meta;
+    std::array<Node, 4> dest;
+
+    std::size_t written_components = 0;
+    for (u32 component = 0; component < 4; ++component) {
+        if (!instr.texs.IsComponentEnabled(component)) {
+            continue;
+        }
+        meta.components_map[written_components] = static_cast<u32>(component);
+
+        if (written_components < 2) {
+            // Write the first two swizzle components to gpr0 and gpr0+1
+            dest[written_components] = GetRegister(instr.gpr0.Value() + written_components % 2);
+        } else {
+            ASSERT(instr.texs.HasTwoDestinations());
+            // Write the rest of the swizzle components to gpr28 and gpr28+1
+            dest[written_components] = GetRegister(instr.gpr28.Value() + written_components % 2);
+        }
+
+        ++written_components;
+    }
+
+    std::generate(dest.begin() + written_components, dest.end(), [&]() { return GetRegister(RZ); });
+
+    bb.push_back(Operation(OperationCode::AssignComposite, meta, texture, dest[0], dest[1], dest[2],
+                           dest[3]));
+}
+
+Node ShaderIR::GetTextureCode(Instruction instr, TextureType texture_type,
+                              TextureProcessMode process_mode, bool depth_compare, bool is_array,
+                              std::size_t bias_offset, std::vector<Node>&& coords) {
+    UNIMPLEMENTED_IF_MSG(
+        (texture_type == TextureType::Texture3D && (is_array || depth_compare)) ||
+            (texture_type == TextureType::TextureCube && is_array && depth_compare),
+        "This method is not supported.");
+
+    const auto& sampler = GetSampler(instr.sampler, texture_type, is_array, depth_compare);
+
+    const bool lod_needed = process_mode == TextureProcessMode::LZ ||
+                            process_mode == TextureProcessMode::LL ||
+                            process_mode == TextureProcessMode::LLA;
+
+    const bool gl_lod_supported =
+        !((texture_type == TextureType::Texture2D && is_array && depth_compare) ||
+          (texture_type == TextureType::TextureCube && !is_array && depth_compare));
+
+    const OperationCode read_method =
+        lod_needed && gl_lod_supported ? OperationCode::F4TextureLod : OperationCode::F4Texture;
+
+    const MetaTexture meta{sampler, static_cast<u32>(coords.size())};
+
+    std::vector<Node> params = std::move(coords);
+
+    if (process_mode != TextureProcessMode::None) {
+        if (process_mode == TextureProcessMode::LZ) {
+            if (gl_lod_supported) {
+                params.push_back(Immediate(0));
+            } else {
+                // Lod 0 is emulated by a big negative bias in scenarios that are not supported by
+                // GLSL
+                params.push_back(Immediate(-1000));
+            }
+        } else {
+            // If present, lod or bias are always stored in the register indexed by the gpr20 field
+            // with an offset depending on the usage of the other registers
+            params.push_back(GetRegister(instr.gpr20.Value() + bias_offset));
+        }
+    }
+
+    return Operation(read_method, meta, std::move(params));
+}
+
+Node ShaderIR::GetTexsCode(Instruction instr, TextureType texture_type,
+                           TextureProcessMode process_mode, bool depth_compare, bool is_array) {
+
+    const bool lod_bias_enabled = (process_mode != Tegra::Shader::TextureProcessMode::None &&
+                                   process_mode != Tegra::Shader::TextureProcessMode::LZ);
+
+    const auto [coord_count, total_coord_count] = ValidateAndGetCoordinateElement(
+        texture_type, depth_compare, is_array, lod_bias_enabled, 4, 4);
+    // If enabled arrays index is always stored in the gpr8 field
+    const u64 array_register = instr.gpr8.Value();
+    // First coordinate index is stored in gpr8 field or (gpr8 + 1) when arrays are used
+    const u64 coord_register = array_register + (is_array ? 1 : 0);
+    const u64 last_coord_register =
+        (is_array || !(lod_bias_enabled || depth_compare) || (coord_count > 2))
+            ? static_cast<u64>(instr.gpr20.Value())
+            : coord_register + 1;
+
+    std::vector<Node> coords;
+    for (std::size_t i = 0; i < coord_count; ++i) {
+        const bool last = (i == (coord_count - 1)) && (coord_count > 1);
+        coords.push_back(GetRegister(last ? last_coord_register : coord_register + i));
+    }
+
+    if (depth_compare) {
+        // Depth is always stored in the register signaled by gpr20
+        // or in the next register if lod or bias are used
+        const u64 depth_register = instr.gpr20.Value() + (lod_bias_enabled ? 1 : 0);
+        coords.push_back(GetRegister(depth_register));
+    }
+    if (is_array) {
+        coords.push_back(
+            Operation(OperationCode::ICastFloat, NO_PRECISE, GetRegister(array_register)));
+    }
+    // Fill ignored coordinates
+    while (coords.size() < total_coord_count) {
+        coords.push_back(Immediate(0));
+    }
+
+    return GetTextureCode(instr, texture_type, process_mode, depth_compare, is_array,
+                          (coord_count > 2 ? 1 : 0), std::move(coords));
+}
+
+std::tuple<std::size_t, std::size_t> ShaderIR::ValidateAndGetCoordinateElement(
+    TextureType texture_type, bool depth_compare, bool is_array, bool lod_bias_enabled,
+    std::size_t max_coords, std::size_t max_inputs) {
+
+    const std::size_t coord_count = GetCoordCount(texture_type);
+
+    std::size_t total_coord_count = coord_count + (is_array ? 1 : 0) + (depth_compare ? 1 : 0);
+    const std::size_t total_reg_count = total_coord_count + (lod_bias_enabled ? 1 : 0);
+    if (total_coord_count > max_coords || total_reg_count > max_inputs) {
+        UNIMPLEMENTED_MSG("Unsupported Texture operation");
+        total_coord_count = std::min(total_coord_count, max_coords);
+    }
+    // 1D.DC OpenGL is using a vec3 but 2nd component is ignored later.
+    total_coord_count +=
+        (depth_compare && !is_array && texture_type == TextureType::Texture1D) ? 1 : 0;
+
+    return {coord_count, total_coord_count};
+}
+
 } // namespace VideoCommon::Shader
\ No newline at end of file
diff --git a/src/video_core/shader/shader_ir.h b/src/video_core/shader/shader_ir.h
index 8223ff044..4716d4c90 100644
--- a/src/video_core/shader/shader_ir.h
+++ b/src/video_core/shader/shader_ir.h
@@ -675,6 +675,24 @@ private:
     /// Returns a condition code evaluated from internal flags
     Node GetConditionCode(Tegra::Shader::ConditionCode cc);
 
+    /// Accesses a texture sampler
+    const Sampler& GetSampler(const Tegra::Shader::Sampler& sampler,
+                              Tegra::Shader::TextureType type, bool is_array, bool is_shadow);
+
+    void WriteTexsInstructionFloat(BasicBlock& bb, Tegra::Shader::Instruction instr, Node texture);
+
+    Node GetTexsCode(Tegra::Shader::Instruction instr, Tegra::Shader::TextureType texture_type,
+                     Tegra::Shader::TextureProcessMode process_mode, bool depth_compare,
+                     bool is_array);
+
+    std::tuple<std::size_t, std::size_t> ValidateAndGetCoordinateElement(
+        Tegra::Shader::TextureType texture_type, bool depth_compare, bool is_array,
+        bool lod_bias_enabled, std::size_t max_coords, std::size_t max_inputs);
+
+    Node GetTextureCode(Tegra::Shader::Instruction instr, Tegra::Shader::TextureType texture_type,
+                        Tegra::Shader::TextureProcessMode process_mode, bool depth_compare,
+                        bool is_array, std::size_t bias_offset, std::vector<Node>&& coords);
+
     template <typename... T>
     inline Node Operation(OperationCode code, const T*... operands) {
         return StoreNode(OperationNode(code, operands...));