vk_memory_layout.hh

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#pragma once
 
#include "gpu_shader_create_info.hh"
 
namespace blender::gpu {
 
struct Std140 {
  static uint32_t component_mem_size(const shader::Type type);
  static uint32_t element_alignment(const shader::Type type, bool is_array);
  static uint32_t element_components_len(const shader::Type type);
  static uint32_t array_components_len(const shader::Type type);
  static uint32_t inner_row_padding(const shader::Type type);
};
 
struct Std430 {
  static uint32_t component_mem_size(const shader::Type type);
  static uint32_t element_alignment(const shader::Type type, bool is_array);
  static uint32_t element_components_len(const shader::Type type);
  static uint32_t array_components_len(const shader::Type type);
  static uint32_t inner_row_padding(const shader::Type type);
};
 
template<typename LayoutT> static uint32_t element_stride(const shader::Type type)
{
  return LayoutT::element_components_len(type) * LayoutT::component_mem_size(type);
}
 
template<typename LayoutT> static uint32_t array_stride(const shader::Type type)
{
  return LayoutT::array_components_len(type) * LayoutT::component_mem_size(type);
}
 
template<typename LayoutT>
static void align(const shader::Type &type, const int32_t array_size, uint32_t *r_offset)
{
  uint32_t alignment = LayoutT::element_alignment(type, array_size != 0);
  uint32_t alignment_mask = alignment - 1;
  uint32_t offset = *r_offset;
  if ((offset & alignment_mask) != 0) {
    offset &= ~alignment_mask;
    offset += alignment;
    *r_offset = offset;
  }
}
 
template<typename LayoutT>
static void reserve(const shader::Type type, int32_t array_size, uint32_t *r_offset)
{
  uint32_t size = array_size == 0 ? element_stride<LayoutT>(type) :
                                    array_stride<LayoutT>(type) * array_size;
  *r_offset += size;
}
 
template<typename LayoutT> static void align_end_of_struct(uint32_t *r_offset)
{
  align<LayoutT>(shader::Type::VEC4, 0, r_offset);
}
 
}  // namespace blender::gpu