gpu_texture_private.hh

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/* SPDX-FileCopyrightText: 2020 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#pragma once
 
#include "BLI_assert.h"
 
#include "GPU_vertex_buffer.hh"
 
#include "gpu_framebuffer_private.hh"
 
namespace blender {
namespace gpu {
 
enum eGPUTextureFormatFlag {
  /* The format has a depth component and can be used as depth attachment. */
  GPU_FORMAT_DEPTH = (1 << 0),
  /* The format has a stencil component and can be used as stencil attachment. */
  GPU_FORMAT_STENCIL = (1 << 1),
  /* The format represent non-normalized integers data, either signed or unsigned. */
  GPU_FORMAT_INTEGER = (1 << 2),
  /* The format is using normalized integers, either signed or unsigned. */
  GPU_FORMAT_NORMALIZED_INTEGER = (1 << 3),
  /* The format represent floating point data, either signed or unsigned. */
  GPU_FORMAT_FLOAT = (1 << 4),
  /* The format is using block compression. */
  GPU_FORMAT_COMPRESSED = (1 << 5),
  /* The format is using sRGB encoded storage. */
  GPU_FORMAT_SRGB = (1 << 6),
  /* The format can store negative values. */
  GPU_FORMAT_SIGNED = (1 << 7),
 
  GPU_FORMAT_DEPTH_STENCIL = (GPU_FORMAT_DEPTH | GPU_FORMAT_STENCIL),
};
 
ENUM_OPERATORS(eGPUTextureFormatFlag, GPU_FORMAT_SIGNED)
 
enum eGPUTextureType {
  GPU_TEXTURE_1D = (1 << 0),
  GPU_TEXTURE_2D = (1 << 1),
  GPU_TEXTURE_3D = (1 << 2),
  GPU_TEXTURE_CUBE = (1 << 3),
  GPU_TEXTURE_ARRAY = (1 << 4),
  GPU_TEXTURE_BUFFER = (1 << 5),
 
  GPU_TEXTURE_1D_ARRAY = (GPU_TEXTURE_1D | GPU_TEXTURE_ARRAY),
  GPU_TEXTURE_2D_ARRAY = (GPU_TEXTURE_2D | GPU_TEXTURE_ARRAY),
  GPU_TEXTURE_CUBE_ARRAY = (GPU_TEXTURE_CUBE | GPU_TEXTURE_ARRAY),
};
 
ENUM_OPERATORS(eGPUTextureType, GPU_TEXTURE_BUFFER)
 
/* Format types for samplers within the shader.
 * This covers the sampler format type permutations within GLSL/MSL. */
enum eGPUSamplerFormat {
  GPU_SAMPLER_TYPE_FLOAT = 0,
  GPU_SAMPLER_TYPE_INT = 1,
  GPU_SAMPLER_TYPE_UINT = 2,
  /* Special case for depth, as these require differing dummy formats. */
  GPU_SAMPLER_TYPE_DEPTH = 3,
  GPU_SAMPLER_TYPE_MAX = 4
};
 
ENUM_OPERATORS(eGPUSamplerFormat, GPU_SAMPLER_TYPE_UINT)
 
#ifndef NDEBUG
#  define DEBUG_NAME_LEN 64
#else
#  define DEBUG_NAME_LEN 8
#endif
 
/* Maximum number of FBOs a texture can be attached to. */
#define GPU_TEX_MAX_FBO_ATTACHED 32
 
class Texture {
 public:
  GPUSamplerState sampler_state = GPUSamplerState::default_sampler();
  int refcount = 1;
  int src_w = 0, src_h = 0;
#ifndef GPU_NO_USE_PY_REFERENCES
  void **py_ref = nullptr;
#endif
 
 protected:
  /* ---- Texture format (immutable after init). ---- */
  int w_, h_, d_;
  eGPUTextureFormat format_;
  eGPUTextureFormatFlag format_flag_;
  eGPUTextureType type_;
  eGPUTextureUsage gpu_image_usage_flags_;
 
  /* TODO(fclem): Should become immutable and the need for mipmaps should be specified upfront. */
  int mipmaps_ = -1;
  int mip_min_ = 0, mip_max_ = 0;
 
  char name_[DEBUG_NAME_LEN];
 
  GPUAttachmentType fb_attachment_[GPU_TEX_MAX_FBO_ATTACHED];
  FrameBuffer *fb_[GPU_TEX_MAX_FBO_ATTACHED];
 
 public:
  Texture(const char *name);
  virtual ~Texture();
 
  /* Return true on success. */
  bool init_1D(int w, int layers, int mip_len, eGPUTextureFormat format);
  bool init_2D(int w, int h, int layers, int mip_len, eGPUTextureFormat format);
  bool init_3D(int w, int h, int d, int mip_len, eGPUTextureFormat format);
  bool init_cubemap(int w, int layers, int mip_len, eGPUTextureFormat format);
  bool init_buffer(VertBuf *vbo, eGPUTextureFormat format);
  bool init_view(GPUTexture *src,
                 eGPUTextureFormat format,
                 eGPUTextureType type,
                 int mip_start,
                 int mip_len,
                 int layer_start,
                 int layer_len,
                 bool cube_as_array,
                 bool use_stencil);
 
  virtual void generate_mipmap() = 0;
  virtual void copy_to(Texture *tex) = 0;
  virtual void clear(eGPUDataFormat format, const void *data) = 0;
  virtual void swizzle_set(const char swizzle_mask[4]) = 0;
  virtual void mip_range_set(int min, int max) = 0;
  virtual void *read(int mip, eGPUDataFormat format) = 0;
 
  void attach_to(FrameBuffer *fb, GPUAttachmentType type);
  void detach_from(FrameBuffer *fb);
  void update(eGPUDataFormat format, const void *data);
 
  void usage_set(eGPUTextureUsage usage_flags);
 
  virtual void update_sub(
      int mip, int offset[3], int extent[3], eGPUDataFormat format, const void *data) = 0;
  virtual void update_sub(int offset[3],
                          int extent[3],
                          eGPUDataFormat format,
                          GPUPixelBuffer *pixbuf) = 0;
 
  /* TODO(fclem): Legacy. Should be removed at some point. */
  virtual uint gl_bindcode_get() const = 0;
  int width_get() const
  {
    return w_;
  }
  int height_get() const
  {
    return h_;
  }
  int depth_get() const
  {
    return d_;
  }
  eGPUTextureUsage usage_get() const
  {
    return gpu_image_usage_flags_;
  }
 
  void mip_size_get(int mip, int r_size[3]) const
  {
    /* TODO: assert if lvl is below the limit of 1px in each dimension. */
    int div = 1 << mip;
    r_size[0] = max_ii(1, w_ / div);
 
    if (type_ == GPU_TEXTURE_1D_ARRAY) {
      r_size[1] = h_;
    }
    else if (h_ > 0) {
      r_size[1] = max_ii(1, h_ / div);
    }
 
    if (type_ & (GPU_TEXTURE_ARRAY | GPU_TEXTURE_CUBE)) {
      r_size[2] = d_;
    }
    else if (d_ > 0) {
      r_size[2] = max_ii(1, d_ / div);
    }
  }
 
  int mip_width_get(int mip) const
  {
    return max_ii(1, w_ / (1 << mip));
  }
  int mip_height_get(int mip) const
  {
    return (type_ == GPU_TEXTURE_1D_ARRAY) ? h_ : max_ii(1, h_ / (1 << mip));
  }
  int mip_depth_get(int mip) const
  {
    return (type_ & (GPU_TEXTURE_ARRAY | GPU_TEXTURE_CUBE)) ? d_ : max_ii(1, d_ / (1 << mip));
  }
 
  /* Return number of dimension taking the array type into account. */
  int dimensions_count() const
  {
    const int array = (type_ & GPU_TEXTURE_ARRAY) ? 1 : 0;
    switch (type_ & ~GPU_TEXTURE_ARRAY) {
      case GPU_TEXTURE_BUFFER:
        return 1;
      case GPU_TEXTURE_1D:
        return 1 + array;
      case GPU_TEXTURE_2D:
        return 2 + array;
      case GPU_TEXTURE_CUBE:
      case GPU_TEXTURE_3D:
      default:
        return 3;
    }
  }
  /* Return number of array layer (or face layer) for texture array or 1 for the others. */
  int layer_count() const
  {
    switch (type_) {
      case GPU_TEXTURE_1D_ARRAY:
        return h_;
      case GPU_TEXTURE_2D_ARRAY:
      case GPU_TEXTURE_CUBE_ARRAY:
        return d_;
      default:
        return 1;
    }
  }
 
  int mip_count() const
  {
    return mipmaps_;
  }
 
  eGPUTextureFormat format_get() const
  {
    return format_;
  }
  eGPUTextureFormatFlag format_flag_get() const
  {
    return format_flag_;
  }
  eGPUTextureType type_get() const
  {
    return type_;
  }
  GPUAttachmentType attachment_type(int slot) const
  {
    switch (format_) {
      case GPU_DEPTH_COMPONENT32F:
      case GPU_DEPTH_COMPONENT24:
      case GPU_DEPTH_COMPONENT16:
        BLI_assert(slot == 0);
        return GPU_FB_DEPTH_ATTACHMENT;
      case GPU_DEPTH24_STENCIL8:
      case GPU_DEPTH32F_STENCIL8:
        BLI_assert(slot == 0);
        return GPU_FB_DEPTH_STENCIL_ATTACHMENT;
      default:
        /* Valid color attachment formats. */
        return GPU_FB_COLOR_ATTACHMENT0 + slot;
 
      case GPU_RGB16F:
      case GPU_RGBA16_SNORM:
      case GPU_RGBA8_SNORM:
      case GPU_RGB32F:
      case GPU_RGB32I:
      case GPU_RGB32UI:
      case GPU_RGB16_SNORM:
      case GPU_RGB16I:
      case GPU_RGB16UI:
      case GPU_RGB16:
      case GPU_RGB8_SNORM:
      case GPU_RGB8:
      case GPU_RGB8I:
      case GPU_RGB8UI:
      case GPU_RG16_SNORM:
      case GPU_RG8_SNORM:
      case GPU_R16_SNORM:
      case GPU_R8_SNORM:
      case GPU_SRGB8_A8_DXT1:
      case GPU_SRGB8_A8_DXT3:
      case GPU_SRGB8_A8_DXT5:
      case GPU_RGBA8_DXT1:
      case GPU_RGBA8_DXT3:
      case GPU_RGBA8_DXT5:
      case GPU_SRGB8:
      case GPU_RGB9_E5:
        BLI_assert_msg(0, "Texture cannot be attached to a framebuffer because of its type");
        return GPU_FB_COLOR_ATTACHMENT0;
    }
  }
 
 protected:
  virtual bool init_internal() = 0;
  virtual bool init_internal(VertBuf *vbo) = 0;
  virtual bool init_internal(GPUTexture *src,
                             int mip_offset,
                             int layer_offset,
                             bool use_stencil) = 0;
};
 
/* Syntactic sugar. */
static inline GPUTexture *wrap(Texture *vert)
{
  return reinterpret_cast<GPUTexture *>(vert);
}
static inline Texture *unwrap(GPUTexture *vert)
{
  return reinterpret_cast<Texture *>(vert);
}
static inline const Texture *unwrap(const GPUTexture *vert)
{
  return reinterpret_cast<const Texture *>(vert);
}
 
/* GPU pixel Buffer. */
class PixelBuffer {
 protected:
  size_t size_ = 0;
 
 public:
  PixelBuffer(size_t size) : size_(size){};
  virtual ~PixelBuffer(){};
 
  virtual void *map() = 0;
  virtual void unmap() = 0;
  virtual int64_t get_native_handle() = 0;
  virtual size_t get_size() = 0;
};
 
/* Syntactic sugar. */
static inline GPUPixelBuffer *wrap(PixelBuffer *pixbuf)
{
  return reinterpret_cast<GPUPixelBuffer *>(pixbuf);
}
static inline PixelBuffer *unwrap(GPUPixelBuffer *pixbuf)
{
  return reinterpret_cast<PixelBuffer *>(pixbuf);
}
static inline const PixelBuffer *unwrap(const GPUPixelBuffer *pixbuf)
{
  return reinterpret_cast<const PixelBuffer *>(pixbuf);
}
 
#undef DEBUG_NAME_LEN
 
inline size_t to_bytesize(eGPUTextureFormat format)
{
  switch (format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA8UI:
    case GPU_RGBA8I:
    case GPU_RGBA8:
      return (4 * 8) / 8;
    case GPU_RGBA32UI:
    case GPU_RGBA32I:
    case GPU_RGBA32F:
      return (4 * 32) / 8;
    case GPU_RGBA16UI:
    case GPU_RGBA16I:
    case GPU_RGBA16F:
    case GPU_RGBA16:
      return (4 * 16) / 8;
    case GPU_RG8UI:
    case GPU_RG8I:
    case GPU_RG8:
      return (2 * 8) / 8;
    case GPU_RG32UI:
    case GPU_RG32I:
    case GPU_RG32F:
      return (2 * 32) / 8;
    case GPU_RG16UI:
    case GPU_RG16I:
    case GPU_RG16F:
    case GPU_RG16:
      return (2 * 16) / 8;
    case GPU_R8UI:
    case GPU_R8I:
    case GPU_R8:
      return 8 / 8;
    case GPU_R32UI:
    case GPU_R32I:
    case GPU_R32F:
      return 32 / 8;
    case GPU_R16UI:
    case GPU_R16I:
    case GPU_R16F:
    case GPU_R16:
      return 16 / 8;
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
    case GPU_RGB10_A2UI:
      return (3 * 10 + 2) / 8;
    case GPU_R11F_G11F_B10F:
      return (11 + 11 + 10) / 8;
    case GPU_DEPTH32F_STENCIL8:
      /* 32-bit depth, 8 bits stencil, and 24 unused bits. */
      return (32 + 8 + 24) / 8;
    case GPU_DEPTH24_STENCIL8:
      return (24 + 8) / 8;
    case GPU_SRGB8_A8:
      return (3 * 8 + 8) / 8;
 
    /* Texture only formats. */
    case GPU_RGB16F:
    case GPU_RGB16_SNORM:
    case GPU_RGB16I:
    case GPU_RGB16UI:
    case GPU_RGB16:
      return (3 * 16) / 8;
    case GPU_RGBA16_SNORM:
      return (4 * 16) / 8;
    case GPU_RGBA8_SNORM:
      return (4 * 8) / 8;
    case GPU_RGB32F:
    case GPU_RGB32I:
    case GPU_RGB32UI:
      return (3 * 32) / 8;
    case GPU_RGB8_SNORM:
    case GPU_RGB8:
    case GPU_RGB8I:
    case GPU_RGB8UI:
      return (3 * 8) / 8;
    case GPU_RG16_SNORM:
      return (2 * 16) / 8;
    case GPU_RG8_SNORM:
      return (2 * 8) / 8;
    case GPU_R16_SNORM:
      return (1 * 16) / 8;
    case GPU_R8_SNORM:
      return (1 * 8) / 8;
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      /* Incorrect but actual size is fractional. */
      return 1;
    case GPU_SRGB8:
      return (3 * 8) / 8;
    case GPU_RGB9_E5:
      return (3 * 9 + 5) / 8;
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
      return 32 / 8;
    case GPU_DEPTH_COMPONENT24:
      /* Depth component 24 uses 3 bytes to store the depth value, and reserved 1 byte for
       * alignment. */
      return (24 + 8) / 8;
    case GPU_DEPTH_COMPONENT16:
      return 16 / 8;
  }
  BLI_assert_unreachable();
  return 0;
}
 
inline size_t to_block_size(eGPUTextureFormat data_type)
{
  switch (data_type) {
    case GPU_SRGB8_A8_DXT1:
    case GPU_RGBA8_DXT1:
      return 8;
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      return 16;
    default:
      BLI_assert_msg(0, "Texture format is not a compressed format");
      return 0;
  }
}
 
inline eGPUTextureFormatFlag to_format_flag(eGPUTextureFormat format)
{
  switch (format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA8UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RGBA8I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGBA8:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RGBA32UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RGBA32I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGBA32F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RGBA16UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RGBA16I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGBA16F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RGBA16:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RG8UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RG8I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RG8:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RG32UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RG32I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RG32F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RG16UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RG16I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RG16F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RG16:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_R8UI:
      return GPU_FORMAT_INTEGER;
    case GPU_R8I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_R8:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_R32UI:
      return GPU_FORMAT_INTEGER;
    case GPU_R32I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_R32F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_R16UI:
      return GPU_FORMAT_INTEGER;
    case GPU_R16I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_R16F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_R16:
      return GPU_FORMAT_NORMALIZED_INTEGER;
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RGB10_A2UI:
      return GPU_FORMAT_INTEGER;
    case GPU_R11F_G11F_B10F:
      return GPU_FORMAT_FLOAT;
    case GPU_DEPTH32F_STENCIL8:
    case GPU_DEPTH24_STENCIL8:
      return GPU_FORMAT_DEPTH_STENCIL;
    case GPU_SRGB8_A8:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SRGB;
 
    /* Texture only formats. */
    case GPU_RGB16F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RGB16_SNORM:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB16I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB16UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RGB16:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RGBA16_SNORM:
    case GPU_RGBA8_SNORM:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB32F:
      return GPU_FORMAT_FLOAT | GPU_FORMAT_SIGNED;
    case GPU_RGB32I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB32UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RGB8_SNORM:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB8:
      return GPU_FORMAT_NORMALIZED_INTEGER;
    case GPU_RGB8I:
      return GPU_FORMAT_INTEGER | GPU_FORMAT_SIGNED;
    case GPU_RGB8UI:
      return GPU_FORMAT_INTEGER;
    case GPU_RG16_SNORM:
    case GPU_RG8_SNORM:
    case GPU_R16_SNORM:
    case GPU_R8_SNORM:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SIGNED;
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_COMPRESSED | GPU_FORMAT_SRGB;
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_COMPRESSED;
    case GPU_SRGB8:
      return GPU_FORMAT_NORMALIZED_INTEGER | GPU_FORMAT_SRGB;
    case GPU_RGB9_E5:
      return GPU_FORMAT_FLOAT;
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
    case GPU_DEPTH_COMPONENT24:
    case GPU_DEPTH_COMPONENT16:
      return GPU_FORMAT_DEPTH;
  }
  BLI_assert_unreachable();
  return GPU_FORMAT_FLOAT;
}
 
inline int to_component_len(eGPUTextureFormat format)
{
  switch (format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA8UI:
    case GPU_RGBA8I:
    case GPU_RGBA8:
    case GPU_RGBA32UI:
    case GPU_RGBA32I:
    case GPU_RGBA32F:
    case GPU_RGBA16UI:
    case GPU_RGBA16I:
    case GPU_RGBA16F:
    case GPU_RGBA16:
      return 4;
    case GPU_RG8UI:
    case GPU_RG8I:
    case GPU_RG8:
    case GPU_RG32UI:
    case GPU_RG32I:
    case GPU_RG32F:
    case GPU_RG16UI:
    case GPU_RG16I:
    case GPU_RG16F:
    case GPU_RG16:
      return 2;
    case GPU_R8UI:
    case GPU_R8I:
    case GPU_R8:
    case GPU_R32UI:
    case GPU_R32I:
    case GPU_R32F:
    case GPU_R16UI:
    case GPU_R16I:
    case GPU_R16F:
    case GPU_R16:
      return 1;
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
    case GPU_RGB10_A2UI:
      return 4;
    case GPU_R11F_G11F_B10F:
      return 3;
    case GPU_DEPTH32F_STENCIL8:
    case GPU_DEPTH24_STENCIL8:
      /* Only count depth component. */
      return 1;
    case GPU_SRGB8_A8:
      return 4;
 
    /* Texture only formats. */
    case GPU_RGB16F:
    case GPU_RGB16_SNORM:
    case GPU_RGB16I:
    case GPU_RGB16UI:
    case GPU_RGB16:
      return 3;
    case GPU_RGBA16_SNORM:
    case GPU_RGBA8_SNORM:
      return 4;
    case GPU_RGB32F:
    case GPU_RGB32I:
    case GPU_RGB32UI:
    case GPU_RGB8_SNORM:
    case GPU_RGB8:
    case GPU_RGB8I:
    case GPU_RGB8UI:
      return 3;
    case GPU_RG16_SNORM:
    case GPU_RG8_SNORM:
      return 2;
    case GPU_R16_SNORM:
    case GPU_R8_SNORM:
      return 1;
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      return 4;
    case GPU_SRGB8:
    case GPU_RGB9_E5:
      return 3;
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
    case GPU_DEPTH_COMPONENT24:
    case GPU_DEPTH_COMPONENT16:
      return 1;
  }
  BLI_assert_unreachable();
  return 1;
}
 
inline size_t to_bytesize(eGPUDataFormat data_format)
{
  switch (data_format) {
    case GPU_DATA_UBYTE:
      return 1;
    case GPU_DATA_HALF_FLOAT:
      return 2;
    case GPU_DATA_FLOAT:
    case GPU_DATA_INT:
    case GPU_DATA_UINT:
      return 4;
    case GPU_DATA_UINT_24_8:
    case GPU_DATA_10_11_11_REV:
    case GPU_DATA_2_10_10_10_REV:
      return 4;
  }
  BLI_assert_unreachable();
  return 0;
}
 
inline size_t to_bytesize(eGPUTextureFormat tex_format, eGPUDataFormat data_format)
{
  /* Special case for compacted types.
   * Standard component len calculation does not apply, as the texture formats contain multiple
   * channels, but associated data format contains several compacted components. */
  if ((tex_format == GPU_R11F_G11F_B10F && data_format == GPU_DATA_10_11_11_REV) ||
      ((tex_format == GPU_RGB10_A2 || tex_format == GPU_RGB10_A2UI) &&
       data_format == GPU_DATA_2_10_10_10_REV))
  {
    return 4;
  }
 
  return to_component_len(tex_format) * to_bytesize(data_format);
}
 
/* Definitely not complete, edit according to the gl specification. */
constexpr inline bool validate_data_format(eGPUTextureFormat tex_format,
                                           eGPUDataFormat data_format)
{
  switch (tex_format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA32UI:
    case GPU_RG32UI:
    case GPU_R32UI:
      return ELEM(data_format, GPU_DATA_UINT);
    case GPU_RGBA16UI:
    case GPU_RG16UI:
    case GPU_R16UI:
      return ELEM(data_format, GPU_DATA_UINT); /* Also GPU_DATA_USHORT if needed. */
    case GPU_RGBA8UI:
    case GPU_RG8UI:
    case GPU_R8UI:
      return ELEM(data_format, GPU_DATA_UINT, GPU_DATA_UBYTE);
 
    case GPU_RGBA32I:
    case GPU_RG32I:
    case GPU_R32I:
      return ELEM(data_format, GPU_DATA_INT);
    case GPU_RGBA16I:
    case GPU_RG16I:
    case GPU_R16I:
      return ELEM(data_format, GPU_DATA_INT); /* Also GPU_DATA_SHORT if needed. */
    case GPU_RGBA8I:
    case GPU_RG8I:
    case GPU_R8I:
      return ELEM(data_format, GPU_DATA_INT); /* Also GPU_DATA_BYTE if needed. */
 
    case GPU_RGBA32F:
    case GPU_RG32F:
    case GPU_R32F:
      return ELEM(data_format, GPU_DATA_FLOAT);
    case GPU_RGBA16F:
    case GPU_RG16F:
    case GPU_R16F:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_HALF_FLOAT);
    case GPU_RGBA16:
    case GPU_RG16:
    case GPU_R16:
      return ELEM(data_format, GPU_DATA_FLOAT); /* Also GPU_DATA_USHORT if needed. */
    case GPU_RGBA8:
    case GPU_RG8:
    case GPU_R8:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_UBYTE);
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
    case GPU_RGB10_A2UI:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_2_10_10_10_REV);
    case GPU_R11F_G11F_B10F:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_10_11_11_REV);
    case GPU_DEPTH32F_STENCIL8:
      /* Should have its own type. For now, we rely on the backend to do the conversion. */
      ATTR_FALLTHROUGH;
    case GPU_DEPTH24_STENCIL8:
      return ELEM(data_format, GPU_DATA_UINT_24_8, GPU_DATA_UINT);
    case GPU_SRGB8_A8:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_UBYTE);
 
    /* Texture only formats. */
    case GPU_RGB32UI:
      return ELEM(data_format, GPU_DATA_UINT);
    case GPU_RGB16UI:
      return ELEM(data_format, GPU_DATA_UINT); /* Also GPU_DATA_SHORT if needed. */
    case GPU_RGB8UI:
      return ELEM(data_format, GPU_DATA_UINT); /* Also GPU_DATA_BYTE if needed. */
    case GPU_RGB32I:
      return ELEM(data_format, GPU_DATA_INT);
    case GPU_RGB16I:
      return ELEM(data_format, GPU_DATA_INT); /* Also GPU_DATA_USHORT if needed. */
    case GPU_RGB8I:
      return ELEM(data_format, GPU_DATA_INT, GPU_DATA_UBYTE);
    case GPU_RGB16:
      return ELEM(data_format, GPU_DATA_FLOAT); /* Also GPU_DATA_USHORT if needed. */
    case GPU_RGB8:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_UBYTE);
    case GPU_RGBA16_SNORM:
    case GPU_RGB16_SNORM:
    case GPU_RG16_SNORM:
    case GPU_R16_SNORM:
      return ELEM(data_format, GPU_DATA_FLOAT); /* Also GPU_DATA_SHORT if needed. */
    case GPU_RGBA8_SNORM:
    case GPU_RGB8_SNORM:
    case GPU_RG8_SNORM:
    case GPU_R8_SNORM:
      return ELEM(data_format, GPU_DATA_FLOAT); /* Also GPU_DATA_BYTE if needed. */
    case GPU_RGB32F:
      return ELEM(data_format, GPU_DATA_FLOAT);
    case GPU_RGB16F:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_HALF_FLOAT);
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      /* TODO(fclem): GPU_DATA_COMPRESSED for each compression? Wouldn't it be overkill?
       * For now, expect format to be set to float. */
      return ELEM(data_format, GPU_DATA_FLOAT);
    case GPU_SRGB8:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_UBYTE);
    case GPU_RGB9_E5:
      return ELEM(data_format, GPU_DATA_FLOAT);
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
    case GPU_DEPTH_COMPONENT24:
    case GPU_DEPTH_COMPONENT16:
      return ELEM(data_format, GPU_DATA_FLOAT, GPU_DATA_UINT);
  }
  BLI_assert_unreachable();
  return data_format == GPU_DATA_FLOAT;
}
 
/* Return default data format for an internal texture format. */
inline eGPUDataFormat to_data_format(eGPUTextureFormat tex_format)
{
  switch (tex_format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA32UI:
    case GPU_RG32UI:
    case GPU_R32UI:
    case GPU_RGBA16UI:
    case GPU_RG16UI:
    case GPU_R16UI:
    case GPU_RGBA8UI:
    case GPU_RG8UI:
    case GPU_R8UI:
      return GPU_DATA_UINT;
 
    case GPU_RGBA32I:
    case GPU_RG32I:
    case GPU_R32I:
    case GPU_RGBA16I:
    case GPU_RG16I:
    case GPU_R16I:
    case GPU_RGBA8I:
    case GPU_RG8I:
    case GPU_R8I:
      return GPU_DATA_INT;
 
    case GPU_RGBA32F:
    case GPU_RG32F:
    case GPU_R32F:
    case GPU_RGBA16F:
    case GPU_RG16F:
    case GPU_R16F:
    case GPU_RGBA16:
    case GPU_RG16:
    case GPU_R16:
    case GPU_RGBA8:
    case GPU_RG8:
    case GPU_R8:
      return GPU_DATA_FLOAT;
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
    case GPU_RGB10_A2UI:
      return GPU_DATA_2_10_10_10_REV;
    case GPU_R11F_G11F_B10F:
      return GPU_DATA_10_11_11_REV;
    case GPU_DEPTH32F_STENCIL8:
      /* Should have its own type. For now, we rely on the backend to do the conversion. */
      ATTR_FALLTHROUGH;
    case GPU_DEPTH24_STENCIL8:
      return GPU_DATA_UINT_24_8;
    case GPU_SRGB8_A8:
      return GPU_DATA_FLOAT;
 
    /* Texture only formats. */
    case GPU_RGB32UI:
    case GPU_RGB16UI:
    case GPU_RGB8UI:
      return GPU_DATA_UINT;
    case GPU_RGB32I:
    case GPU_RGB16I:
    case GPU_RGB8I:
      return GPU_DATA_INT;
    case GPU_RGB16:
    case GPU_RGB8:
      return GPU_DATA_FLOAT;
    case GPU_RGBA16_SNORM:
    case GPU_RGB16_SNORM:
    case GPU_RG16_SNORM:
    case GPU_R16_SNORM:
      return GPU_DATA_FLOAT;
    case GPU_RGBA8_SNORM:
    case GPU_RGB8_SNORM:
    case GPU_RG8_SNORM:
    case GPU_R8_SNORM:
      return GPU_DATA_FLOAT;
    case GPU_RGB32F:
    case GPU_RGB16F:
      return GPU_DATA_FLOAT;
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
      /* TODO(fclem): GPU_DATA_COMPRESSED for each compression? Wouldn't it be overkill?
       * For now, expect format to be set to float. */
      return GPU_DATA_FLOAT;
    case GPU_SRGB8:
      return GPU_DATA_FLOAT;
    case GPU_RGB9_E5:
      return GPU_DATA_FLOAT;
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
    case GPU_DEPTH_COMPONENT24:
    case GPU_DEPTH_COMPONENT16:
      return GPU_DATA_FLOAT;
  }
  BLI_assert_unreachable();
  return GPU_DATA_FLOAT;
}
 
inline eGPUFrameBufferBits to_framebuffer_bits(eGPUTextureFormat tex_format)
{
  switch (tex_format) {
    /* Formats texture & render-buffer */
    case GPU_RGBA32UI:
    case GPU_RG32UI:
    case GPU_R32UI:
    case GPU_RGBA16UI:
    case GPU_RG16UI:
    case GPU_R16UI:
    case GPU_RGBA8UI:
    case GPU_RG8UI:
    case GPU_R8UI:
    case GPU_RGBA32I:
    case GPU_RG32I:
    case GPU_R32I:
    case GPU_RGBA16I:
    case GPU_RG16I:
    case GPU_R16I:
    case GPU_RGBA8I:
    case GPU_RG8I:
    case GPU_R8I:
    case GPU_RGBA32F:
    case GPU_RG32F:
    case GPU_R32F:
    case GPU_RGBA16F:
    case GPU_RG16F:
    case GPU_R16F:
    case GPU_RGBA16:
    case GPU_RG16:
    case GPU_R16:
    case GPU_RGBA8:
    case GPU_RG8:
    case GPU_R8:
      return GPU_COLOR_BIT;
 
    /* Special formats texture & render-buffer */
    case GPU_RGB10_A2:
    case GPU_RGB10_A2UI:
    case GPU_R11F_G11F_B10F:
    case GPU_SRGB8_A8:
      return GPU_COLOR_BIT;
    case GPU_DEPTH32F_STENCIL8:
    case GPU_DEPTH24_STENCIL8:
      return GPU_DEPTH_BIT | GPU_STENCIL_BIT;
 
    /* Depth Formats. */
    case GPU_DEPTH_COMPONENT32F:
    case GPU_DEPTH_COMPONENT24:
    case GPU_DEPTH_COMPONENT16:
      return GPU_DEPTH_BIT;
 
    /* Texture only formats. */
    case GPU_RGB32UI:
    case GPU_RGB16UI:
    case GPU_RGB8UI:
    case GPU_RGB32I:
    case GPU_RGB16I:
    case GPU_RGB8I:
    case GPU_RGB16:
    case GPU_RGB8:
    case GPU_RGBA16_SNORM:
    case GPU_RGB16_SNORM:
    case GPU_RG16_SNORM:
    case GPU_R16_SNORM:
    case GPU_RGBA8_SNORM:
    case GPU_RGB8_SNORM:
    case GPU_RG8_SNORM:
    case GPU_R8_SNORM:
    case GPU_RGB32F:
    case GPU_RGB16F:
      BLI_assert_msg(0, "This texture format is not compatible with framebuffer attachment.");
      return GPU_COLOR_BIT;
 
    /* Special formats, texture only. */
    case GPU_SRGB8_A8_DXT1:
    case GPU_SRGB8_A8_DXT3:
    case GPU_SRGB8_A8_DXT5:
    case GPU_RGBA8_DXT1:
    case GPU_RGBA8_DXT3:
    case GPU_RGBA8_DXT5:
    case GPU_SRGB8:
    case GPU_RGB9_E5:
      BLI_assert_msg(0, "This texture format is not compatible with framebuffer attachment.");
      return GPU_COLOR_BIT;
  }
  BLI_assert_unreachable();
  return GPU_COLOR_BIT;
}
 
static inline eGPUTextureFormat to_texture_format(const GPUVertFormat *format)
{
  if (format->attr_len == 0) {
    BLI_assert_msg(0, "Incorrect vertex format for buffer texture");
    return GPU_DEPTH_COMPONENT24;
  }
  switch (format->attrs[0].comp_len) {
    case 1:
      switch (format->attrs[0].comp_type) {
        case GPU_COMP_I8:
          return GPU_R8I;
        case GPU_COMP_U8:
          return GPU_R8UI;
        case GPU_COMP_I16:
          return GPU_R16I;
        case GPU_COMP_U16:
          return GPU_R16UI;
        case GPU_COMP_I32:
          return GPU_R32I;
        case GPU_COMP_U32:
          return GPU_R32UI;
        case GPU_COMP_F32:
          return GPU_R32F;
        default:
          break;
      }
      break;
    case 2:
      switch (format->attrs[0].comp_type) {
        case GPU_COMP_I8:
          return GPU_RG8I;
        case GPU_COMP_U8:
          return GPU_RG8UI;
        case GPU_COMP_I16:
          return GPU_RG16I;
        case GPU_COMP_U16:
          return GPU_RG16UI;
        case GPU_COMP_I32:
          return GPU_RG32I;
        case GPU_COMP_U32:
          return GPU_RG32UI;
        case GPU_COMP_F32:
          return GPU_RG32F;
        default:
          break;
      }
      break;
    case 3:
      /* Not supported until GL 4.0 */
      break;
    case 4:
      switch (format->attrs[0].comp_type) {
        case GPU_COMP_I8:
          return GPU_RGBA8I;
        case GPU_COMP_U8:
          return GPU_RGBA8UI;
        case GPU_COMP_I16:
          return GPU_RGBA16I;
        case GPU_COMP_U16:
          /* NOTE: Checking the fetch mode to select the right GPU texture format. This can be
           * added to other formats as well. */
          switch (format->attrs[0].fetch_mode) {
            case GPU_FETCH_INT:
              return GPU_RGBA16UI;
            case GPU_FETCH_INT_TO_FLOAT_UNIT:
              return GPU_RGBA16;
            case GPU_FETCH_INT_TO_FLOAT:
              return GPU_RGBA16F;
            case GPU_FETCH_FLOAT:
              return GPU_RGBA16F;
          }
        case GPU_COMP_I32:
          return GPU_RGBA32I;
        case GPU_COMP_U32:
          return GPU_RGBA32UI;
        case GPU_COMP_F32:
          return GPU_RGBA32F;
        default:
          break;
      }
      break;
    default:
      break;
  }
  BLI_assert_msg(0, "Unsupported vertex format for buffer texture");
  return GPU_DEPTH_COMPONENT24;
}
 
}  // namespace gpu
}  // namespace blender