// Copyright 2010 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#pragma once

#include <memory>
#include <vector>

#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"

class DataReader;
class NativeVertexFormat;
class PointerWrap;
struct PortableVertexDeclaration;

enum PrimitiveType
{
  PRIMITIVE_POINTS,
  PRIMITIVE_LINES,
  PRIMITIVE_TRIANGLES,
};

struct Slope
{
  float dfdx;
  float dfdy;
  float f0;
  bool dirty;
};

class VertexManagerBase
{
private:
  // 3 pos
  static constexpr u32 SMALLEST_POSSIBLE_VERTEX = sizeof(float) * 3;
  // 3 pos, 3*3 normal, 2*u32 color, 8*4 tex, 1 posMat
  static constexpr u32 LARGEST_POSSIBLE_VERTEX = sizeof(float) * 45 + sizeof(u32) * 2;

  static constexpr u32 MAX_PRIMITIVES_PER_COMMAND = 65535;

public:
  static constexpr u32 MAXVBUFFERSIZE =
      ROUND_UP_POW2(MAX_PRIMITIVES_PER_COMMAND * LARGEST_POSSIBLE_VERTEX);

  // We may convert triangle-fans to triangle-lists, almost 3x as many indices.
  static constexpr u32 MAXIBUFFERSIZE = ROUND_UP_POW2(MAX_PRIMITIVES_PER_COMMAND * 3);

  VertexManagerBase();
  // needs to be virtual for DX11's dtor
  virtual ~VertexManagerBase();

  DataReader PrepareForAdditionalData(int primitive, u32 count, u32 stride, bool cullall);
  void FlushData(u32 count, u32 stride);

  void Flush();

  virtual NativeVertexFormat*
  CreateNativeVertexFormat(const PortableVertexDeclaration& vtx_decl) = 0;

  void DoState(PointerWrap& p);

protected:
  virtual void vDoState(PointerWrap& p) {}
  PrimitiveType m_current_primitive_type = PrimitiveType::PRIMITIVE_POINTS;

  virtual void ResetBuffer(u32 stride) = 0;

  u8* m_cur_buffer_pointer = nullptr;
  u8* m_base_buffer_pointer = nullptr;
  u8* m_end_buffer_pointer = nullptr;

  u32 GetRemainingSize() const;
  static u32 GetRemainingIndices(int primitive);

  Slope m_zslope = {};
  void CalculateZSlope(NativeVertexFormat* format);

  bool m_cull_all = false;

private:
  bool m_is_flushed = true;

  virtual void vFlush(bool useDstAlpha) = 0;

  virtual void CreateDeviceObjects() {}
  virtual void DestroyDeviceObjects() {}
};

extern std::unique_ptr<VertexManagerBase> g_vertex_manager;