/* SPDX-License-Identifier: GPL-2.0-or-later */

/**
 * Shared structures, enums & defines between C++ and GLSL.
 * Can also include some math functions but they need to be simple enough to be valid in both
 * language.
 */

#ifndef USE_GPU_SHADER_CREATE_INFO
#  pragma once

#  include "BLI_memory_utils.hh"
#  include "DRW_gpu_wrapper.hh"

// #  include "eevee_defines.hh"

#  include "GPU_shader_shared.h"

namespace blender::eevee {

using draw::Framebuffer;
using draw::SwapChain;
using draw::Texture;
using draw::TextureFromPool;

#endif

#define UBO_MIN_MAX_SUPPORTED_SIZE 1 << 14

/* -------------------------------------------------------------------- */
/** \name Camera
 * \{ */

enum eCameraType : uint32_t {
  CAMERA_PERSP = 0u,
  CAMERA_ORTHO = 1u,
  CAMERA_PANO_EQUIRECT = 2u,
  CAMERA_PANO_EQUISOLID = 3u,
  CAMERA_PANO_EQUIDISTANT = 4u,
  CAMERA_PANO_MIRROR = 5u
};

static inline bool is_panoramic(eCameraType type)
{
  return type > CAMERA_ORTHO;
}

struct CameraData {
  /* View Matrices of the camera, not from any view! */
  float4x4 persmat;
  float4x4 persinv;
  float4x4 viewmat;
  float4x4 viewinv;
  float4x4 winmat;
  float4x4 wininv;
  /** Camera UV scale and bias. Also known as `viewcamtexcofac`. */
  float2 uv_scale;
  float2 uv_bias;
  /** Panorama parameters. */
  float2 equirect_scale;
  float2 equirect_scale_inv;
  float2 equirect_bias;
  float fisheye_fov;
  float fisheye_lens;
  /** Clipping distances. */
  float clip_near;
  float clip_far;
  /** Film pixel filter radius. */
  float filter_size;
  eCameraType type;
};
BLI_STATIC_ASSERT_ALIGN(CameraData, 16)

/** \} */

/* -------------------------------------------------------------------- */
/** \name VelocityModule
 * \{ */

#define VELOCITY_INVALID 512.0

enum eVelocityStep : uint32_t {
  STEP_PREVIOUS = 0,
  STEP_NEXT = 1,
  STEP_CURRENT = 2,
};

struct VelocityObjectIndex {
  /** Offset inside #VelocityObjectBuf for each timestep. Indexed using eVelocityStep. */
  int3 ofs;
  /** Temporary index to copy this to the #VelocityIndexBuf. */
  uint resource_id;

#ifdef __cplusplus
  VelocityObjectIndex() : ofs(-1, -1, -1), resource_id(-1){};
#endif
};
BLI_STATIC_ASSERT_ALIGN(VelocityObjectIndex, 16)

struct VelocityGeometryIndex {
  /** Offset inside #VelocityGeometryBuf for each timestep. Indexed using eVelocityStep. */
  int3 ofs;
  /** If true, compute deformation motion blur. */
  bool1 do_deform;
  /** Length of data inside #VelocityGeometryBuf for each timestep. Indexed using eVelocityStep. */
  int3 len;

  int _pad0;

#ifdef __cplusplus
  VelocityGeometryIndex() : ofs(-1, -1, -1), do_deform(false), len(-1, -1, -1), _pad0(1){};
#endif
};
BLI_STATIC_ASSERT_ALIGN(VelocityGeometryIndex, 16)

struct VelocityIndex {
  VelocityObjectIndex obj;
  VelocityGeometryIndex geo;
};
BLI_STATIC_ASSERT_ALIGN(VelocityGeometryIndex, 16)

/** \} */

/* -------------------------------------------------------------------- */
/** \name Ray-Tracing
 * \{ */

enum eClosureBits : uint32_t {
  /** NOTE: These are used as stencil bits. So we are limited to 8bits. */
  CLOSURE_DIFFUSE = (1u << 0u),
  CLOSURE_SSS = (1u << 1u),
  CLOSURE_REFLECTION = (1u << 2u),
  CLOSURE_REFRACTION = (1u << 3u),
  /* Non-stencil bits. */
  CLOSURE_TRANSPARENCY = (1u << 8u),
  CLOSURE_EMISSION = (1u << 9u),
  CLOSURE_HOLDOUT = (1u << 10u),
  CLOSURE_VOLUME = (1u << 11u),
  CLOSURE_AMBIENT_OCCLUSION = (1u << 12u),
};

/** \} */

/* -------------------------------------------------------------------- */
/** \name Utility Texture
 * \{ */

#define UTIL_TEX_SIZE 64
#define UTIL_BTDF_LAYER_COUNT 16
/* Scale and bias to avoid interpolation of the border pixel.
 * Remap UVs to the border pixels centers. */
#define UTIL_TEX_UV_SCALE ((UTIL_TEX_SIZE - 1.0f) / UTIL_TEX_SIZE)
#define UTIL_TEX_UV_BIAS (0.5f / UTIL_TEX_SIZE)

#define UTIL_BLUE_NOISE_LAYER 0
#define UTIL_LTC_MAT_LAYER 1
#define UTIL_LTC_MAG_LAYER 2
#define UTIL_BSDF_LAYER 2
#define UTIL_BTDF_LAYER 3
#define UTIL_DISK_INTEGRAL_LAYER 3
#define UTIL_DISK_INTEGRAL_COMP 2

#ifndef __cplusplus
/* Fetch texel. Wrapping if above range. */
float4 utility_tx_fetch(sampler2DArray util_tx, float2 texel, float layer)
{
  return texelFetch(util_tx, int3(int2(texel) % UTIL_TEX_SIZE, layer), 0);
}

/* Sample at uv position. Filtered & Wrapping enabled. */
float4 utility_tx_sample(sampler2DArray util_tx, float2 uv, float layer)
{
  return textureLod(util_tx, float3(uv, layer), 0.0);
}
#endif

/** \} */

#ifdef __cplusplus

using CameraDataBuf = draw::UniformBuffer<CameraData>;
using VelocityIndexBuf = draw::StorageArrayBuffer<VelocityIndex, 16>;
using VelocityObjectBuf = draw::StorageArrayBuffer<float4x4, 16>;
using VelocityGeometryBuf = draw::StorageArrayBuffer<float4, 16, true>;

}  // namespace blender::eevee
#endif