1 files changed, 221 insertions, 1 deletions
diff --git a/Source/Core/VideoCommon/OpcodeDecoding.h b/Source/Core/VideoCommon/OpcodeDecoding.h
index df1059f221..2d1632efc3 100644
--- a/Source/Core/VideoCommon/OpcodeDecoding.h
+++ b/Source/Core/VideoCommon/OpcodeDecoding.h
@@ -3,9 +3,17 @@
 
 #pragma once
 
+#include <type_traits>
+
+#include "Common/Assert.h"
 #include "Common/CommonTypes.h"
 #include "Common/EnumFormatter.h"
+#include "Common/Inline.h"
+#include "Common/Swap.h"
+#include "VideoCommon/CPMemory.h"
+#include "VideoCommon/VertexLoaderBase.h"
 
+struct CPState;
 class DataReader;
 
 namespace OpcodeDecoder
@@ -55,8 +63,220 @@ enum class Primitive : u8
 
 void Init();
 
+// Interface for the Run and RunCommand functions below.
+// The functions themselves are templates so that the compiler generates separate versions for each
+// callback (with the callback functions inlined), so the callback doesn't actually need to be
+// publicly inherited.
+// Compilers don't generate warnings for failed inlining with virtual functions, so this define
+// allows disabling the use of virtual functions to generate those warnings.  However, this means
+// that missing functions will generate errors on their use in RunCommand, instead of in the
+// subclass, which can be confusing.
+#define OPCODE_CALLBACK_USE_INHERITANCE
+
+#ifdef OPCODE_CALLBACK_USE_INHERITANCE
+#define OPCODE_CALLBACK(sig) DOLPHIN_FORCE_INLINE sig override
+#define OPCODE_CALLBACK_NOINLINE(sig) sig override
+#else
+#define OPCODE_CALLBACK(sig) DOLPHIN_FORCE_INLINE sig
+#define OPCODE_CALLBACK_NOINLINE(sig) sig
+#endif
+class Callback
+{
+#ifdef OPCODE_CALLBACK_USE_INHERITANCE
+public:
+  virtual ~Callback() = default;
+
+  // Called on any XF command.
+  virtual void OnXF(u16 address, u8 count, const u8* data) = 0;
+  // Called on any CP command.
+  // Subclasses should update the CP state with GetCPState().LoadCPReg(command, value) so that
+  // primitive commands decode properly.
+  virtual void OnCP(u8 command, u32 value) = 0;
+  // Called on any BP command.
+  virtual void OnBP(u8 command, u32 value) = 0;
+  // Called on any indexed XF load command.
+  virtual void OnIndexedLoad(CPArray array, u32 index, u16 address, u8 size) = 0;
+  // Called on any primitive command.
+  virtual void OnPrimitiveCommand(OpcodeDecoder::Primitive primitive, u8 vat, u32 vertex_size,
+                                  u16 num_vertices, const u8* vertex_data) = 0;
+  // Called on a display list.
+  virtual void OnDisplayList(u32 address, u32 size) = 0;
+  // Called on any NOP commands (which are all merged into a single call).
+  virtual void OnNop(u32 count) = 0;
+  // Called on an unknown opcode, or an opcode that is known but not implemented.
+  // data[0] is opcode.
+  virtual void OnUnknown(u8 opcode, const u8* data) = 0;
+
+  // Called on ANY command.  The first byte of data is the opcode.  Size will be at least 1.
+  // This function is called after one of the above functions is called.
+  virtual void OnCommand(const u8* data, u32 size) = 0;
+
+  // Get the current CP state.  Needed for vertex decoding; will also be mutated for CP commands.
+  virtual CPState& GetCPState() = 0;
+#endif
+};
+
+namespace detail
+{
+// Main logic; split so that the main RunCommand can call OnCommand with the returned size.
+template <typename T, typename = std::enable_if_t<std::is_base_of_v<Callback, T>>>
+static DOLPHIN_FORCE_INLINE u32 RunCommand(const u8* data, u32 available, T& callback)
+{
+  if (available < 1)
+    return 0;
+
+  const Opcode cmd = static_cast<Opcode>(data[0]);
+
+  switch (cmd)
+  {
+  case Opcode::GX_NOP:
+  {
+    u32 count = 1;
+    while (count < available && static_cast<Opcode>(data[count]) == Opcode::GX_NOP)
+      count++;
+    callback.OnNop(count);
+    return count;
+  }
+
+  case Opcode::GX_LOAD_CP_REG:
+  {
+    if (available < 6)
+      return 0;
+
+    const u8 cmd2 = data[1];
+    const u32 value = Common::swap32(&data[2]);
+
+    callback.OnCP(cmd2, value);
+
+    return 6;
+  }
+
+  case Opcode::GX_LOAD_XF_REG:
+  {
+    if (available < 5)
+      return 0;
+
+    const u32 cmd2 = Common::swap32(&data[1]);
+    const u16 base_address = cmd2 & 0xffff;
+
+    const u16 stream_size_temp = cmd2 >> 16;
+    ASSERT(stream_size_temp < 16);
+    const u8 stream_size = (stream_size_temp & 0xf) + 1;
+
+    if (available < u32(5 + stream_size * 4))
+      return 0;
+
+    callback.OnXF(base_address, stream_size, &data[5]);
+
+    return 5 + stream_size * 4;
+  }
+
+  case Opcode::GX_LOAD_INDX_A:  // Used for position matrices
+  case Opcode::GX_LOAD_INDX_B:  // Used for normal matrices
+  case Opcode::GX_LOAD_INDX_C:  // Used for postmatrices
+  case Opcode::GX_LOAD_INDX_D:  // Used for lights
+  {
+    if (available < 5)
+      return 0;
+
+    const u32 value = Common::swap32(&data[1]);
+
+    const u32 index = value >> 16;
+    const u16 address = value & 0xFFF;  // TODO: check mask
+    const u8 size = ((value >> 12) & 0xF) + 1;
+
+    // Map the command byte to its ref array.
+    // GX_LOAD_INDX_A (32 = 8*4) . CPArray::XF_A (4+8 = 12)
+    // GX_LOAD_INDX_B (40 = 8*5) . CPArray::XF_B (5+8 = 13)
+    // GX_LOAD_INDX_C (48 = 8*6) . CPArray::XF_C (6+8 = 14)
+    // GX_LOAD_INDX_D (56 = 8*7) . CPArray::XF_D (7+8 = 15)
+    const auto ref_array = static_cast<CPArray>((static_cast<u8>(cmd) / 8) + 8);
+
+    callback.OnIndexedLoad(ref_array, index, address, size);
+    return 5;
+  }
+
+  case Opcode::GX_CMD_CALL_DL:
+  {
+    if (available < 9)
+      return 0;
+
+    const u32 address = Common::swap32(&data[1]);
+    const u32 size = Common::swap32(&data[5]);
+
+    callback.OnDisplayList(address, size);
+    return 9;
+  }
+
+  case Opcode::GX_LOAD_BP_REG:
+  {
+    if (available < 5)
+      return 0;
+
+    const u8 cmd2 = data[1];
+    const u32 value = Common::swap24(&data[2]);
+
+    callback.OnBP(cmd2, value);
+
+    return 5;
+  }
+
+  default:
+    if (cmd >= Opcode::GX_PRIMITIVE_START && cmd <= Opcode::GX_PRIMITIVE_END)
+    {
+      if (available < 3)
+        return 0;
+
+      const u8 cmdbyte = static_cast<u8>(cmd);
+      const OpcodeDecoder::Primitive primitive = static_cast<OpcodeDecoder::Primitive>(
+          (cmdbyte & OpcodeDecoder::GX_PRIMITIVE_MASK) >> OpcodeDecoder::GX_PRIMITIVE_SHIFT);
+      const u8 vat = cmdbyte & OpcodeDecoder::GX_VAT_MASK;
+
+      const u32 vertex_size = VertexLoaderBase::GetVertexSize(callback.GetCPState().vtx_desc,
+                                                              callback.GetCPState().vtx_attr[vat]);
+      const u16 num_vertices = Common::swap16(&data[1]);
+
+      if (available < 3 + num_vertices * vertex_size)
+        return 0;
+
+      callback.OnPrimitiveCommand(primitive, vat, vertex_size, num_vertices, &data[3]);
+
+      return 3 + num_vertices * vertex_size;
+    }
+  }
+
+  callback.OnUnknown(static_cast<u8>(cmd), data);
+  return 1;
+}
+}  // namespace detail
+
+template <typename T, typename = std::enable_if_t<std::is_base_of_v<Callback, T>>>
+DOLPHIN_FORCE_INLINE u32 RunCommand(const u8* data, u32 available, T& callback)
+{
+  const u32 size = detail::RunCommand(data, available, callback);
+  if (size > 0)
+  {
+    callback.OnCommand(data, size);
+  }
+  return size;
+}
+
+template <typename T, typename = std::enable_if_t<std::is_base_of_v<Callback, T>>>
+DOLPHIN_FORCE_INLINE u32 Run(const u8* data, u32 available, T& callback)
+{
+  u32 size = 0;
+  while (size < available)
+  {
+    const u32 command_size = RunCommand(&data[size], available - size, callback);
+    if (command_size == 0)
+      break;
+    size += command_size;
+  }
+  return size;
+}
+
 template <bool is_preprocess = false>
-u8* Run(DataReader src, u32* cycles, bool in_display_list);
+u8* RunFifo(DataReader src, u32* cycles);
 
 }  // namespace OpcodeDecoder