vaiorabbit/06_bump_sdl2_metal.rb

## 06_bump_sdl2_metal.rb
# coding: utf-8
#
# Ref.: bgfx/examples/06-bump/bump.cpp
#       https://github.com/vaiorabbit/sdl2-bindings
#
require 'rmath3d/rmath3d'
require 'sdl2'
require_relative '../../bindings/ruby/bgfx.rb'
require_relative './logo.rb'
require_relative './utils.rb'

include SDL2
include RMath3D

SDL2.load_lib(SampleUtils.sdl2_dll_path())
Bgfx.load_lib(SampleUtils.bgfx_dll_path())

################################################################################

class PosNormalTangentTexcoordVertex < FFI::Struct
  @@ms_layout = Bgfx_vertex_layout_t.new

  def self.ms_layout
    @@ms_layout
  end

  layout(
    :m_x, :float,
    :m_y, :float,
    :m_z, :float,
    :m_normal, :uint32,
    :m_tangent, :uint32,
    :m_u, :int16,
    :m_v, :int16
  )

  def self.init()
    Bgfx::bgfx_vertex_layout_begin(@@ms_layout, Bgfx::RendererType::Noop)
    Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Position, 3, Bgfx::AttribType::Float, false, false)
    Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Normal, 4, Bgfx::AttribType::Uint8, true, true)
    Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Tangent, 4, Bgfx::AttribType::Uint8, true, true)
    Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::TexCoord0, 2, Bgfx::AttribType::Int16, true, true)
    Bgfx::bgfx_vertex_layout_end(@@ms_layout)
  end
end

# Ref: Array of Structs https://github.com/ffi/ffi/wiki/Structs

cubeVerticesSrc = [
    [-1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0,  1.0), 0,      0,      0 ],
    [ 1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0,  1.0), 0, 0x7fff,      0 ],
    [-1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0,  1.0), 0,      0, 0x7fff ],
    [ 1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0,  1.0), 0, 0x7fff, 0x7fff ],
    [-1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0, -1.0), 0,      0,      0 ],
    [ 1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0, -1.0), 0, 0x7fff,      0 ],
    [-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0, -1.0), 0,      0, 0x7fff ],
    [ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  0.0, -1.0), 0, 0x7fff, 0x7fff ],
    [-1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  1.0,  0.0), 0,      0,      0 ],
    [ 1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0,  1.0,  0.0), 0, 0x7fff,      0 ],
    [-1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  1.0,  0.0), 0,      0, 0x7fff ],
    [ 1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0,  1.0,  0.0), 0, 0x7fff, 0x7fff ],
    [-1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0,  0.0), 0,      0,      0 ],
    [ 1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0,  0.0), 0, 0x7fff,      0 ],
    [-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0,  0.0), 0,      0, 0x7fff ],
    [ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0,  0.0), 0, 0x7fff, 0x7fff ],
    [ 1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8( 1.0,  0.0,  0.0), 0,      0,      0 ],
    [ 1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8( 1.0,  0.0,  0.0), 0, 0x7fff,      0 ],
    [ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 1.0,  0.0,  0.0), 0,      0, 0x7fff ],
    [ 1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8( 1.0,  0.0,  0.0), 0, 0x7fff, 0x7fff ],
    [-1.0, -1.0,  1.0, BgfxUtils.encode_normal_rgba8(-1.0,  0.0,  0.0), 0,      0,      0 ],
    [-1.0,  1.0,  1.0, BgfxUtils.encode_normal_rgba8(-1.0,  0.0,  0.0), 0, 0x7fff,      0 ],
    [-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8(-1.0,  0.0,  0.0), 0,      0, 0x7fff ],
    [-1.0,  1.0, -1.0, BgfxUtils.encode_normal_rgba8(-1.0,  0.0,  0.0), 0, 0x7fff, 0x7fff ],
]

$s_cubeVertices = FFI::MemoryPointer.new(PosNormalTangentTexcoordVertex, cubeVerticesSrc.length)
cubeVertices = cubeVerticesSrc.length.times.collect do |i|
  PosNormalTangentTexcoordVertex.new($s_cubeVertices + i * PosNormalTangentTexcoordVertex.size)
end

cubeVertices.each_with_index do |c, i|
  c[:m_x], c[:m_y], c[:m_z], c[:m_normal], c[:m_tangent], c[:m_u], c[:m_v] = *cubeVerticesSrc[i]
end


cubeIndicesSrc = [
  0,  2,  1,
  1,  2,  3,
  4,  5,  6,
  5,  7,  6,

  8, 10,  9,
  9, 10, 11,
  12, 13, 14,
  13, 15, 14,

  16, 18, 17,
  17, 18, 19,
  20, 21, 22,
  21, 23, 22,
]
$s_cubeIndices = FFI::MemoryPointer.new(:uint16, cubeIndicesSrc.length).write_array_of_ushort(cubeIndicesSrc)


################################################################################

$m_vbh = nil # Bgfx_dynamic_vertex_buffer_handle_t
$m_ibh = nil # Bgfx_dynamic_index_buffer_handle_t
$m_program = nil # Bgfx_shader_handle_t
$s_texColor = nil # Bgfx_uniform_handle_t
$s_texNormal = nil # Bgfx_uniform_handle_t
$u_lightPosRadius = nil # Bgfx_uniform_handle_t
$u_lightRgbInnerR = nil # Bgfx_uniform_handle_t
$m_numLights = 4 # uint16
$m_textureColor = nil # Bgfx_texture_handle_t
$m_textureNormal = nil # Bgfx_texture_handle_t

if __FILE__ == $0
  success = SDL_Init(SDL_INIT_VIDEO)
  exit if success < 0

  SDL_SetHint(SDL_HINT_RENDER_DRIVER, "metal")

  window_width = 1280
  window_height = 720
  window = SDL_CreateWindow("ruby-bgfx : 06-bump", 0, 0, window_width, window_height, 0)

  renderer = SDL_CreateRenderer(window, -1, 0)
  if renderer == nil
    pp "Failed to initialize SDL"
    exit
  end

  nwh =  FFI::Pointer.new(:pointer, SampleUtils.native_window_handle(window))
  pd = Bgfx_platform_data_t.new
  pd[:ndt] = nil
  pd[:nwh] = nwh
  pd[:context]      = nil
  pd[:backBuffer]   = nil
  pd[:backBufferDS] = nil
  Bgfx::bgfx_set_platform_data(pd)

  init = Bgfx_init_t.new
  init[:type] = Bgfx::RendererType::Metal
  init[:vendorId] = Bgfx::Pci_Id_None
  init[:resolution][:width] = window_width
  init[:resolution][:height] = window_height
  init[:resolution][:reset] = Bgfx::Reset_Vsync
  init[:limits][:maxEncoders] = 1
  init[:limits][:transientVbSize] = 6<<20
  init[:limits][:transientIbSize] = 2<<20
  bgfx_init_success = Bgfx::bgfx_init(init)
  pp "Failed to initialize Bgfx" unless bgfx_init_success

  #Bgfx::bgfx_set_debug(Bgfx::Debug_None)
  #Bgfx::bgfx_set_debug(Bgfx::Debug_Wireframe)
  Bgfx::bgfx_set_debug(Bgfx::Debug_Stats)
  Bgfx::bgfx_set_view_clear(0, Bgfx::Clear_Color|Bgfx::Clear_Depth, 0x303080ff, 1.0, 0)

  PosNormalTangentTexcoordVertex.init()

  BgfxUtils.calc_tangents($s_cubeVertices, $s_cubeVertices.size / $s_cubeVertices.type_size, PosNormalTangentTexcoordVertex.ms_layout, cubeIndicesSrc)

  $m_vbh = Bgfx::bgfx_create_vertex_buffer(
    Bgfx::bgfx_make_ref($s_cubeVertices, $s_cubeVertices.size),
    PosNormalTangentTexcoordVertex.ms_layout,
    Bgfx::Buffer_None
  )

  $m_ibh = Bgfx::bgfx_create_index_buffer(
    Bgfx::bgfx_make_ref($s_cubeIndices, $s_cubeIndices.size),
    Bgfx::Buffer_None
  )

  $s_texColor  = Bgfx::bgfx_create_uniform("s_texColor",  Bgfx::UniformType::Sampler, -1)
  $s_texNormal = Bgfx::bgfx_create_uniform("s_texNormal", Bgfx::UniformType::Sampler, -1)
  $u_lightPosRadius = Bgfx::bgfx_create_uniform("u_lightPosRadius", Bgfx::UniformType::Vec4, $m_numLights)
  $u_lightRgbInnerR = Bgfx::bgfx_create_uniform("u_lightRgbInnerR", Bgfx::UniformType::Vec4, $m_numLights)
  $m_textureColor = BgfxUtils.load_texture("textures/fieldstone-rgba.dds")
  $m_textureNormal = BgfxUtils.load_texture("textures/fieldstone-n.dds")

  $m_program = BgfxUtils.load_program("vs_bump", "fs_bump")

  eye = RVec3.new(0.0, 0.0, -7.0)
  at  = RVec3.new(0.0, 0.0, 0.0)
  up  = RVec3.new(0.0,  1.0,  0.0)
  mtxLookAt = RMtx4.new.lookAtRH( eye, at, up )
  view = FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxLookAt.to_a)

  mtxProj = RMtx4.new.perspectiveFovRH( 60.0*Math::PI/180.0, window_width.to_f/window_height.to_f, 0.1, 100.0 ) # TODO bgfx::getCaps()->homogeneousDepth
  proj =  FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxProj.to_a)

  time_prev = SDL_GetTicks()
  time_crnt = time_prev
  time = 0.0

  event = SDL_Event.new
  done = false
  while not done
    while SDL_PollEvent(event) != 0
      # 'type' and 'timestamp' are common members for all SDL Event structs.
      event_type = event[:common][:type]
      event_timestamp = event[:common][:timestamp]

      case event_type
      when SDL_KEYDOWN
        if event[:key][:keysym][:sym] == SDL2::SDLK_ESCAPE
          done = true
        end
      end
    end

    Bgfx::bgfx_reset(window_width, window_height, Bgfx::Reset_None, Bgfx::TextureFormat::Count)

    time_crnt = SDL_GetTicks()
    time += (time_crnt-time_prev).to_f * 0.001
    time_prev = time_crnt

    Bgfx::bgfx_set_view_transform(0, view, proj)
    Bgfx::bgfx_set_view_rect(0, 0, 0, window_width, window_height)
    Bgfx::bgfx_touch(0)

    light_pos_radius = Array.new(4) { Array.new(4, 0.0) }
    $m_numLights.times do |ii|
      light_pos_radius[ii][0] = Math.sin( (time*(0.1 + ii*0.17) + ii*(0.5 * Math::PI) * 1.37 ) )*3.0
      light_pos_radius[ii][1] = Math.cos( (time*(0.2 + ii*0.29) + ii*(0.5 * Math::PI) * 1.49 ) )*3.0
      light_pos_radius[ii][2] = -2.5
      light_pos_radius[ii][3] = 3.0
    end

    Bgfx::bgfx_set_uniform($u_lightPosRadius, light_pos_radius.flatten!.pack("F16"), $m_numLights)

    light_rgb_inner_r = [
      [ 1.0, 0.7, 0.2, 0.8 ],
      [ 0.7, 0.2, 1.0, 0.8 ],
      [ 0.2, 1.0, 0.7, 0.8 ],
      [ 1.0, 0.4, 0.2, 0.8 ],
    ]

    Bgfx::bgfx_set_uniform($u_lightRgbInnerR, light_rgb_inner_r.flatten!.pack("F16"), $m_numLights)

    state = 0 | Bgfx::State_Write_Rgb | Bgfx::State_Write_A | Bgfx::State_Write_Z | Bgfx::State_Depth_Test_Less | Bgfx::State_Msaa

    3.times do |yy|
      3.times do |xx|
        mtxTransform = RMtx4.new.translation(-3.0 + xx * 3.0, -3.0 + yy * 3.0, 0.0) * RMtx4.new.rotationY(time * 0.03 + yy * 0.37) * RMtx4.new.rotationX(time * 0.23 + xx * 0.21)
        mtx = FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxTransform.to_a)
        Bgfx::bgfx_set_transform(mtx, 1)
        Bgfx::bgfx_set_vertex_buffer(0, $m_vbh, 0, 0xffffffff) # 0xffffffff == UINT32_MAX
        Bgfx::bgfx_set_index_buffer($m_ibh, 0, 0xffffffff) # 0xffffffff == UINT32_MAX
        Bgfx::bgfx_set_texture(0, $s_texColor,  $m_textureColor, 0xffffffff) # 0xffffffff == UINT32_MAX
        Bgfx::bgfx_set_texture(1, $s_texNormal, $m_textureNormal, 0xffffffff) # 0xffffffff == UINT32_MAX
        Bgfx::bgfx_set_state(state, 0)

        Bgfx::bgfx_submit(0, $m_program, 0, Bgfx::Discard_All)
      end
    end

    Bgfx::bgfx_frame(false)
  end

  if bgfx_init_success
    Bgfx::bgfx_destroy_uniform($s_texColor)
    Bgfx::bgfx_destroy_uniform($s_texNormal)
    Bgfx::bgfx_destroy_uniform($u_lightPosRadius)
    Bgfx::bgfx_destroy_uniform($u_lightRgbInnerR)
    Bgfx::bgfx_destroy_texture($m_textureNormal)
    Bgfx::bgfx_destroy_texture($m_textureColor)

    Bgfx::bgfx_destroy_program($m_program)
    Bgfx::bgfx_destroy_vertex_buffer($m_vbh)
    Bgfx::bgfx_destroy_index_buffer($m_ibh)

    Bgfx::bgfx_shutdown()
  end

  SDL_DestroyWindow(window)
  SDL_Quit()
end

## utils.rb
require 'ffi'
require 'sdl2'
require 'rmath3d/rmath3d'

module BgfxUtils

  ################################################################################

  def self.load_shader(name, runtime_path = "../runtime/")

    shader_path = case Bgfx::bgfx_get_renderer_type()
                  when Bgfx::RendererType::OpenGL
                    "shaders/glsl/"
                  when Bgfx::RendererType::Metal
                    "shaders/metal/"
                  else
                    $stderr.puts "You should not be here!"
                  end

    file_path = runtime_path + shader_path + name + ".bin"

    shader_binary = IO.binread(file_path)
    shader_mem = FFI::MemoryPointer.from_string(shader_binary)
    handle = Bgfx::bgfx_create_shader(Bgfx::bgfx_make_ref(shader_mem, shader_mem.size))
    Bgfx::bgfx_set_shader_name(handle, name, 0x7fffffff) # 0x7fffffff == INT32_MAX

    return handle
  end

  def self.load_program(vs_name, fs_name, runtime_path = "../runtime/")
    vsh = load_shader(vs_name, runtime_path)
    fsh = fs_name != nil ? load_shader(fs_name, runtime_path) : Bgfx::Bgfx_Invalid_Handle
    return Bgfx::bgfx_create_program(vsh, fsh, true)
  end

  ################################################################################

  def self.load_texture(name, runtime_path = "../runtime/")
    texture_raw = IO.binread(runtime_path + name)
    texture_mem = FFI::MemoryPointer.from_string(texture_raw)

    return Bgfx::bgfx_create_texture(
      Bgfx::bgfx_make_ref(texture_mem, texture_mem.size),
      Bgfx::Texture_None|Bgfx::Sampler_None,
      0,
      nil
    )
  end

  ################################################################################

  def self.to_unorm(_value, _scale)
    ((_value.clamp(0.0, 1.0) * _scale) + 0.5).floor
  end

  # usage) pp BgfxUtils.encode_normal_rgba8(0.0, 1.0, 0.0).to_s(16) => "8080ff80"
  def self.encode_normal_rgba8(_x, _y = 0.0, _z = 0.0, _w = 0.0)
    to_unorm = lambda { |_value, _scale| ((_value.clamp(0.0, 1.0) * _scale) + 0.5).floor }
    src = [
      _x * 0.5 + 0.5,
      _y * 0.5 + 0.5,
      _z * 0.5 + 0.5,
      _w * 0.5 + 0.5,
    ]
    dst = [
      to_unorm(src[0], 255.0),
      to_unorm(src[1], 255.0),
      to_unorm(src[2], 255.0),
      to_unorm(src[3], 255.0),
    ]
    return dst.pack("C4").unpack1("L")
  end

  ################################################################################

  class PosTexcoord
    def initialize
      @m_pos = FFI::MemoryPointer.new(:float, 4)
      @m_texcoord = FFI::MemoryPointer.new(:float, 4)
    end
    def m_x; @m_pos[0]; end
    def m_y; @m_pos[1]; end
    def m_z; @m_pos[2]; end
    def m_u; @m_texcoord[0]; end
    def m_v; @m_texcoord[1]; end
  end

  def self.calc_tangents(_vertices, _numVertices, _layout, _indices)

    tangents = Array.new (2 * _numVertices) { RVec3.new }
    v0 = PosTexcoord.new
    v1 = PosTexcoord.new
    v2 = PosTexcoord.new

    num = _indices.length / 3
    num.times do |ii|
      indices = _indices[ii * 3, 3]
      i0 = indices[0]
      i1 = indices[1]
      i2 = indices[2]

      Bgfx::bgfx_vertex_unpack(v0.m_x, Bgfx::Attrib::Position, _layout, _vertices, i0)
      Bgfx::bgfx_vertex_unpack(v0.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i0)

      Bgfx::bgfx_vertex_unpack(v1.m_x, Bgfx::Attrib::Position, _layout, _vertices, i1)
      Bgfx::bgfx_vertex_unpack(v1.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i1)

      Bgfx::bgfx_vertex_unpack(v2.m_x, Bgfx::Attrib::Position, _layout, _vertices, i2)
      Bgfx::bgfx_vertex_unpack(v2.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i2)

      bax = v1.m_x.read_float - v0.m_x.read_float
      bay = v1.m_y.read_float - v0.m_y.read_float
      baz = v1.m_z.read_float - v0.m_z.read_float
      bau = v1.m_u.read_float - v0.m_u.read_float
      bav = v1.m_v.read_float - v0.m_v.read_float

      cax = v2.m_x.read_float - v0.m_x.read_float
      cay = v2.m_y.read_float - v0.m_y.read_float
      caz = v2.m_z.read_float - v0.m_z.read_float
      cau = v2.m_u.read_float - v0.m_u.read_float
      cav = v2.m_v.read_float - v0.m_v.read_float

      det = (bau * cav - bav * cau)
      invDet = 1.0 / det

      tx = (bax * cav - cax * bav) * invDet
      ty = (bay * cav - cay * bav) * invDet
      tz = (baz * cav - caz * bav) * invDet

      bx = (cax * bau - bax * cau) * invDet
      by = (cay * bau - bay * cau) * invDet
      bz = (caz * bau - baz * cau) * invDet

      3.times do |jj|
        tanu = tangents[indices[jj] + 0]
        tanv = tangents[indices[jj] + 1]
        tanu[0] += tx
        tanu[1] += ty
        tanu[2] += tz
        tanv[0] += bx
        tanv[1] += by
        tanv[2] += bz
      end
    end

    nxyzw = FFI::MemoryPointer.new(:float, 4)
    tangent = FFI::MemoryPointer.new(:float, 4)
    _numVertices.times do |ii|
      tanu = tangents[ii + 0]
      tanv = tangents[ii + 1]

      Bgfx::bgfx_vertex_unpack(nxyzw, Bgfx::Attrib::Normal, _layout, _vertices, ii)

      normal = RVec3.new(*nxyzw.read_array_of_float(3))
      ndt    = RVec3.dot(normal, tanu)
      nxt    = RVec3.cross(normal, tanu);
      tmp    = (tanu - (ndt * normal)).normalize!

      tangent.write_array_of_float([*tmp.to_a, RVec3.dot(nxt, tanv) < 0 ? -1.0 : 1.0])
      Bgfx::bgfx_vertex_pack(tangent, true, Bgfx::Attrib::Tangent, _layout, _vertices, ii)
    end
  end

end

####################################################################################################

module SampleUtils

  ################################################################################

  def self.sdl2_dll_path
    path = case RUBY_PLATFORM
           when /mswin|msys|mingw|cygwin/
             Dir.pwd + '/' + 'SDL2.dll'
           when /darwin/
             '/usr/local/lib/libSDL2.dylib'
           when /linux/
             './libSDL2.so'
           else
             raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
           end
    return path
  end

  ################################################################################

  def self.bgfx_dll_path
    path = case RUBY_PLATFORM
           when /mswin|msys|mingw|cygwin/
             Dir.pwd + '/bgfx-shared-libDebug.dll'
           when /darwin/
             './libbgfx-shared-libDebug.dylib'
           when /linux/
             './libbgfx-shared-libDebug.so'
           else
             raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
           end
    return path
  end

  ################################################################################

  def self.native_window_handle(sdl2_window)
    nwh = case RUBY_PLATFORM
          when /mswin|msys|mingw|cygwin/
            wminfo = SDL_SysWMinfo_win.new # TODO Windows
            if SDL_GetWindowWMInfo(sdl2_window, wminfo) == SDL_TRUE
              wminfo[:info][:win][:window]
            else
              nil
            end
          when /darwin/
            wminfo = SDL_SysWMinfo_cocoa.new # TODO Windows
            if SDL_GetWindowWMInfo(sdl2_window, wminfo) == SDL_TRUE
              wminfo[:info][:cocoa][:window]
            else
              nil
            end
          when /linux/
            raise RuntimeError, "Not supported yet: #{RUBY_PLATFORM}"
          else
            raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
          end
    return nwh
  end

end
	# coding: utf-8
	#
	# Ref.: bgfx/examples/06-bump/bump.cpp
	# https://github.com/vaiorabbit/sdl2-bindings
	#
	require 'rmath3d/rmath3d'
	require 'sdl2'
	require_relative '../../bindings/ruby/bgfx.rb'
	require_relative './logo.rb'
	require_relative './utils.rb'

	include SDL2
	include RMath3D

	SDL2.load_lib(SampleUtils.sdl2_dll_path())
	Bgfx.load_lib(SampleUtils.bgfx_dll_path())

	################################################################################

	class PosNormalTangentTexcoordVertex < FFI::Struct
	@@ms_layout = Bgfx_vertex_layout_t.new

	def self.ms_layout
	@@ms_layout
	end

	layout(
	:m_x, :float,
	:m_y, :float,
	:m_z, :float,
	:m_normal, :uint32,
	:m_tangent, :uint32,
	:m_u, :int16,
	:m_v, :int16
	)

	def self.init()
	Bgfx::bgfx_vertex_layout_begin(@@ms_layout, Bgfx::RendererType::Noop)
	Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Position, 3, Bgfx::AttribType::Float, false, false)
	Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Normal, 4, Bgfx::AttribType::Uint8, true, true)
	Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::Tangent, 4, Bgfx::AttribType::Uint8, true, true)
	Bgfx::bgfx_vertex_layout_add(@@ms_layout, Bgfx::Attrib::TexCoord0, 2, Bgfx::AttribType::Int16, true, true)
	Bgfx::bgfx_vertex_layout_end(@@ms_layout)
	end
	end

	# Ref: Array of Structs https://github.com/ffi/ffi/wiki/Structs

	cubeVerticesSrc = [
	[-1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, 1.0), 0, 0, 0 ],
	[ 1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, 1.0), 0, 0x7fff, 0 ],
	[-1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, 1.0), 0, 0, 0x7fff ],
	[ 1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, 1.0), 0, 0x7fff, 0x7fff ],
	[-1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, -1.0), 0, 0, 0 ],
	[ 1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, -1.0), 0, 0x7fff, 0 ],
	[-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, -1.0), 0, 0, 0x7fff ],
	[ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 0.0, -1.0), 0, 0x7fff, 0x7fff ],
	[-1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 1.0, 0.0), 0, 0, 0 ],
	[ 1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, 1.0, 0.0), 0, 0x7fff, 0 ],
	[-1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 1.0, 0.0), 0, 0, 0x7fff ],
	[ 1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, 1.0, 0.0), 0, 0x7fff, 0x7fff ],
	[-1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0, 0.0), 0, 0, 0 ],
	[ 1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0, 0.0), 0, 0x7fff, 0 ],
	[-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0, 0.0), 0, 0, 0x7fff ],
	[ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 0.0, -1.0, 0.0), 0, 0x7fff, 0x7fff ],
	[ 1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8( 1.0, 0.0, 0.0), 0, 0, 0 ],
	[ 1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8( 1.0, 0.0, 0.0), 0, 0x7fff, 0 ],
	[ 1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8( 1.0, 0.0, 0.0), 0, 0, 0x7fff ],
	[ 1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8( 1.0, 0.0, 0.0), 0, 0x7fff, 0x7fff ],
	[-1.0, -1.0, 1.0, BgfxUtils.encode_normal_rgba8(-1.0, 0.0, 0.0), 0, 0, 0 ],
	[-1.0, 1.0, 1.0, BgfxUtils.encode_normal_rgba8(-1.0, 0.0, 0.0), 0, 0x7fff, 0 ],
	[-1.0, -1.0, -1.0, BgfxUtils.encode_normal_rgba8(-1.0, 0.0, 0.0), 0, 0, 0x7fff ],
	[-1.0, 1.0, -1.0, BgfxUtils.encode_normal_rgba8(-1.0, 0.0, 0.0), 0, 0x7fff, 0x7fff ],
	]

	$s_cubeVertices = FFI::MemoryPointer.new(PosNormalTangentTexcoordVertex, cubeVerticesSrc.length)
	cubeVertices = cubeVerticesSrc.length.times.collect do \|i\|
	PosNormalTangentTexcoordVertex.new($s_cubeVertices + i * PosNormalTangentTexcoordVertex.size)
	end

	cubeVertices.each_with_index do \|c, i\|
	c[:m_x], c[:m_y], c[:m_z], c[:m_normal], c[:m_tangent], c[:m_u], c[:m_v] = *cubeVerticesSrc[i]
	end


	cubeIndicesSrc = [
	0, 2, 1,
	1, 2, 3,
	4, 5, 6,
	5, 7, 6,

	8, 10, 9,
	9, 10, 11,
	12, 13, 14,
	13, 15, 14,

	16, 18, 17,
	17, 18, 19,
	20, 21, 22,
	21, 23, 22,
	]
	$s_cubeIndices = FFI::MemoryPointer.new(:uint16, cubeIndicesSrc.length).write_array_of_ushort(cubeIndicesSrc)


	################################################################################

	$m_vbh = nil # Bgfx_dynamic_vertex_buffer_handle_t
	$m_ibh = nil # Bgfx_dynamic_index_buffer_handle_t
	$m_program = nil # Bgfx_shader_handle_t
	$s_texColor = nil # Bgfx_uniform_handle_t
	$s_texNormal = nil # Bgfx_uniform_handle_t
	$u_lightPosRadius = nil # Bgfx_uniform_handle_t
	$u_lightRgbInnerR = nil # Bgfx_uniform_handle_t
	$m_numLights = 4 # uint16
	$m_textureColor = nil # Bgfx_texture_handle_t
	$m_textureNormal = nil # Bgfx_texture_handle_t

	if __FILE__ == $0
	success = SDL_Init(SDL_INIT_VIDEO)
	exit if success < 0

	SDL_SetHint(SDL_HINT_RENDER_DRIVER, "metal")

	window_width = 1280
	window_height = 720
	window = SDL_CreateWindow("ruby-bgfx : 06-bump", 0, 0, window_width, window_height, 0)

	renderer = SDL_CreateRenderer(window, -1, 0)
	if renderer == nil
	pp "Failed to initialize SDL"
	exit
	end

	nwh = FFI::Pointer.new(:pointer, SampleUtils.native_window_handle(window))
	pd = Bgfx_platform_data_t.new
	pd[:ndt] = nil
	pd[:nwh] = nwh
	pd[:context] = nil
	pd[:backBuffer] = nil
	pd[:backBufferDS] = nil
	Bgfx::bgfx_set_platform_data(pd)

	init = Bgfx_init_t.new
	init[:type] = Bgfx::RendererType::Metal
	init[:vendorId] = Bgfx::Pci_Id_None
	init[:resolution][:width] = window_width
	init[:resolution][:height] = window_height
	init[:resolution][:reset] = Bgfx::Reset_Vsync
	init[:limits][:maxEncoders] = 1
	init[:limits][:transientVbSize] = 6<<20
	init[:limits][:transientIbSize] = 2<<20
	bgfx_init_success = Bgfx::bgfx_init(init)
	pp "Failed to initialize Bgfx" unless bgfx_init_success

	#Bgfx::bgfx_set_debug(Bgfx::Debug_None)
	#Bgfx::bgfx_set_debug(Bgfx::Debug_Wireframe)
	Bgfx::bgfx_set_debug(Bgfx::Debug_Stats)
	Bgfx::bgfx_set_view_clear(0, Bgfx::Clear_Color\|Bgfx::Clear_Depth, 0x303080ff, 1.0, 0)

	PosNormalTangentTexcoordVertex.init()

	BgfxUtils.calc_tangents($s_cubeVertices, $s_cubeVertices.size / $s_cubeVertices.type_size, PosNormalTangentTexcoordVertex.ms_layout, cubeIndicesSrc)

	$m_vbh = Bgfx::bgfx_create_vertex_buffer(
	Bgfx::bgfx_make_ref($s_cubeVertices, $s_cubeVertices.size),
	PosNormalTangentTexcoordVertex.ms_layout,
	Bgfx::Buffer_None
	)

	$m_ibh = Bgfx::bgfx_create_index_buffer(
	Bgfx::bgfx_make_ref($s_cubeIndices, $s_cubeIndices.size),
	Bgfx::Buffer_None
	)

	$s_texColor = Bgfx::bgfx_create_uniform("s_texColor", Bgfx::UniformType::Sampler, -1)
	$s_texNormal = Bgfx::bgfx_create_uniform("s_texNormal", Bgfx::UniformType::Sampler, -1)
	$u_lightPosRadius = Bgfx::bgfx_create_uniform("u_lightPosRadius", Bgfx::UniformType::Vec4, $m_numLights)
	$u_lightRgbInnerR = Bgfx::bgfx_create_uniform("u_lightRgbInnerR", Bgfx::UniformType::Vec4, $m_numLights)
	$m_textureColor = BgfxUtils.load_texture("textures/fieldstone-rgba.dds")
	$m_textureNormal = BgfxUtils.load_texture("textures/fieldstone-n.dds")

	$m_program = BgfxUtils.load_program("vs_bump", "fs_bump")

	eye = RVec3.new(0.0, 0.0, -7.0)
	at = RVec3.new(0.0, 0.0, 0.0)
	up = RVec3.new(0.0, 1.0, 0.0)
	mtxLookAt = RMtx4.new.lookAtRH( eye, at, up )
	view = FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxLookAt.to_a)

	mtxProj = RMtx4.new.perspectiveFovRH( 60.0*Math::PI/180.0, window_width.to_f/window_height.to_f, 0.1, 100.0 ) # TODO bgfx::getCaps()->homogeneousDepth
	proj = FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxProj.to_a)

	time_prev = SDL_GetTicks()
	time_crnt = time_prev
	time = 0.0

	event = SDL_Event.new
	done = false
	while not done
	while SDL_PollEvent(event) != 0
	# 'type' and 'timestamp' are common members for all SDL Event structs.
	event_type = event[:common][:type]
	event_timestamp = event[:common][:timestamp]

	case event_type
	when SDL_KEYDOWN
	if event[:key][:keysym][:sym] == SDL2::SDLK_ESCAPE
	done = true
	end
	end
	end

	Bgfx::bgfx_reset(window_width, window_height, Bgfx::Reset_None, Bgfx::TextureFormat::Count)

	time_crnt = SDL_GetTicks()
	time += (time_crnt-time_prev).to_f * 0.001
	time_prev = time_crnt

	Bgfx::bgfx_set_view_transform(0, view, proj)
	Bgfx::bgfx_set_view_rect(0, 0, 0, window_width, window_height)
	Bgfx::bgfx_touch(0)

	light_pos_radius = Array.new(4) { Array.new(4, 0.0) }
	$m_numLights.times do \|ii\|
	light_pos_radius[ii][0] = Math.sin( (time(0.1 + ii0.17) + ii(0.5 Math::PI) * 1.37 ) )*3.0
	light_pos_radius[ii][1] = Math.cos( (time(0.2 + ii0.29) + ii(0.5 Math::PI) * 1.49 ) )*3.0
	light_pos_radius[ii][2] = -2.5
	light_pos_radius[ii][3] = 3.0
	end

	Bgfx::bgfx_set_uniform($u_lightPosRadius, light_pos_radius.flatten!.pack("F16"), $m_numLights)

	light_rgb_inner_r = [
	[ 1.0, 0.7, 0.2, 0.8 ],
	[ 0.7, 0.2, 1.0, 0.8 ],
	[ 0.2, 1.0, 0.7, 0.8 ],
	[ 1.0, 0.4, 0.2, 0.8 ],
	]

	Bgfx::bgfx_set_uniform($u_lightRgbInnerR, light_rgb_inner_r.flatten!.pack("F16"), $m_numLights)

	state = 0 \| Bgfx::State_Write_Rgb \| Bgfx::State_Write_A \| Bgfx::State_Write_Z \| Bgfx::State_Depth_Test_Less \| Bgfx::State_Msaa

	3.times do \|yy\|
	3.times do \|xx\|
	mtxTransform = RMtx4.new.translation(-3.0 + xx * 3.0, -3.0 + yy * 3.0, 0.0) * RMtx4.new.rotationY(time * 0.03 + yy * 0.37) * RMtx4.new.rotationX(time * 0.23 + xx * 0.21)
	mtx = FFI::MemoryPointer.new(:float, 16).write_array_of_float(mtxTransform.to_a)
	Bgfx::bgfx_set_transform(mtx, 1)
	Bgfx::bgfx_set_vertex_buffer(0, $m_vbh, 0, 0xffffffff) # 0xffffffff == UINT32_MAX
	Bgfx::bgfx_set_index_buffer($m_ibh, 0, 0xffffffff) # 0xffffffff == UINT32_MAX
	Bgfx::bgfx_set_texture(0, $s_texColor, $m_textureColor, 0xffffffff) # 0xffffffff == UINT32_MAX
	Bgfx::bgfx_set_texture(1, $s_texNormal, $m_textureNormal, 0xffffffff) # 0xffffffff == UINT32_MAX
	Bgfx::bgfx_set_state(state, 0)

	Bgfx::bgfx_submit(0, $m_program, 0, Bgfx::Discard_All)
	end
	end

	Bgfx::bgfx_frame(false)
	end

	if bgfx_init_success
	Bgfx::bgfx_destroy_uniform($s_texColor)
	Bgfx::bgfx_destroy_uniform($s_texNormal)
	Bgfx::bgfx_destroy_uniform($u_lightPosRadius)
	Bgfx::bgfx_destroy_uniform($u_lightRgbInnerR)
	Bgfx::bgfx_destroy_texture($m_textureNormal)
	Bgfx::bgfx_destroy_texture($m_textureColor)

	Bgfx::bgfx_destroy_program($m_program)
	Bgfx::bgfx_destroy_vertex_buffer($m_vbh)
	Bgfx::bgfx_destroy_index_buffer($m_ibh)

	Bgfx::bgfx_shutdown()
	end

	SDL_DestroyWindow(window)
	SDL_Quit()
	end
	require 'ffi'
	require 'sdl2'
	require 'rmath3d/rmath3d'

	module BgfxUtils

	################################################################################

	def self.load_shader(name, runtime_path = "../runtime/")

	shader_path = case Bgfx::bgfx_get_renderer_type()
	when Bgfx::RendererType::OpenGL
	"shaders/glsl/"
	when Bgfx::RendererType::Metal
	"shaders/metal/"
	else
	$stderr.puts "You should not be here!"
	end

	file_path = runtime_path + shader_path + name + ".bin"

	shader_binary = IO.binread(file_path)
	shader_mem = FFI::MemoryPointer.from_string(shader_binary)
	handle = Bgfx::bgfx_create_shader(Bgfx::bgfx_make_ref(shader_mem, shader_mem.size))
	Bgfx::bgfx_set_shader_name(handle, name, 0x7fffffff) # 0x7fffffff == INT32_MAX

	return handle
	end

	def self.load_program(vs_name, fs_name, runtime_path = "../runtime/")
	vsh = load_shader(vs_name, runtime_path)
	fsh = fs_name != nil ? load_shader(fs_name, runtime_path) : Bgfx::Bgfx_Invalid_Handle
	return Bgfx::bgfx_create_program(vsh, fsh, true)
	end

	################################################################################

	def self.load_texture(name, runtime_path = "../runtime/")
	texture_raw = IO.binread(runtime_path + name)
	texture_mem = FFI::MemoryPointer.from_string(texture_raw)

	return Bgfx::bgfx_create_texture(
	Bgfx::bgfx_make_ref(texture_mem, texture_mem.size),
	Bgfx::Texture_None\|Bgfx::Sampler_None,
	0,
	nil
	)
	end

	################################################################################

	def self.to_unorm(_value, _scale)
	((_value.clamp(0.0, 1.0) * _scale) + 0.5).floor
	end

	# usage) pp BgfxUtils.encode_normal_rgba8(0.0, 1.0, 0.0).to_s(16) => "8080ff80"
	def self.encode_normal_rgba8(_x, _y = 0.0, _z = 0.0, _w = 0.0)
	to_unorm = lambda { \|_value, _scale\| ((_value.clamp(0.0, 1.0) * _scale) + 0.5).floor }
	src = [
	_x * 0.5 + 0.5,
	_y * 0.5 + 0.5,
	_z * 0.5 + 0.5,
	_w * 0.5 + 0.5,
	]
	dst = [
	to_unorm(src[0], 255.0),
	to_unorm(src[1], 255.0),
	to_unorm(src[2], 255.0),
	to_unorm(src[3], 255.0),
	]
	return dst.pack("C4").unpack1("L")
	end

	################################################################################

	class PosTexcoord
	def initialize
	@m_pos = FFI::MemoryPointer.new(:float, 4)
	@m_texcoord = FFI::MemoryPointer.new(:float, 4)
	end
	def m_x; @m_pos[0]; end
	def m_y; @m_pos[1]; end
	def m_z; @m_pos[2]; end
	def m_u; @m_texcoord[0]; end
	def m_v; @m_texcoord[1]; end
	end

	def self.calc_tangents(_vertices, _numVertices, _layout, _indices)

	tangents = Array.new (2 * _numVertices) { RVec3.new }
	v0 = PosTexcoord.new
	v1 = PosTexcoord.new
	v2 = PosTexcoord.new

	num = _indices.length / 3
	num.times do \|ii\|
	indices = _indices[ii * 3, 3]
	i0 = indices[0]
	i1 = indices[1]
	i2 = indices[2]

	Bgfx::bgfx_vertex_unpack(v0.m_x, Bgfx::Attrib::Position, _layout, _vertices, i0)
	Bgfx::bgfx_vertex_unpack(v0.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i0)

	Bgfx::bgfx_vertex_unpack(v1.m_x, Bgfx::Attrib::Position, _layout, _vertices, i1)
	Bgfx::bgfx_vertex_unpack(v1.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i1)

	Bgfx::bgfx_vertex_unpack(v2.m_x, Bgfx::Attrib::Position, _layout, _vertices, i2)
	Bgfx::bgfx_vertex_unpack(v2.m_u, Bgfx::Attrib::TexCoord0, _layout, _vertices, i2)

	bax = v1.m_x.read_float - v0.m_x.read_float
	bay = v1.m_y.read_float - v0.m_y.read_float
	baz = v1.m_z.read_float - v0.m_z.read_float
	bau = v1.m_u.read_float - v0.m_u.read_float
	bav = v1.m_v.read_float - v0.m_v.read_float

	cax = v2.m_x.read_float - v0.m_x.read_float
	cay = v2.m_y.read_float - v0.m_y.read_float
	caz = v2.m_z.read_float - v0.m_z.read_float
	cau = v2.m_u.read_float - v0.m_u.read_float
	cav = v2.m_v.read_float - v0.m_v.read_float

	det = (bau * cav - bav * cau)
	invDet = 1.0 / det

	tx = (bax * cav - cax * bav) * invDet
	ty = (bay * cav - cay * bav) * invDet
	tz = (baz * cav - caz * bav) * invDet

	bx = (cax * bau - bax * cau) * invDet
	by = (cay * bau - bay * cau) * invDet
	bz = (caz * bau - baz * cau) * invDet

	3.times do \|jj\|
	tanu = tangents[indices[jj] + 0]
	tanv = tangents[indices[jj] + 1]
	tanu[0] += tx
	tanu[1] += ty
	tanu[2] += tz
	tanv[0] += bx
	tanv[1] += by
	tanv[2] += bz
	end
	end

	nxyzw = FFI::MemoryPointer.new(:float, 4)
	tangent = FFI::MemoryPointer.new(:float, 4)
	_numVertices.times do \|ii\|
	tanu = tangents[ii + 0]
	tanv = tangents[ii + 1]

	Bgfx::bgfx_vertex_unpack(nxyzw, Bgfx::Attrib::Normal, _layout, _vertices, ii)

	normal = RVec3.new(*nxyzw.read_array_of_float(3))
	ndt = RVec3.dot(normal, tanu)
	nxt = RVec3.cross(normal, tanu);
	tmp = (tanu - (ndt * normal)).normalize!

	tangent.write_array_of_float([*tmp.to_a, RVec3.dot(nxt, tanv) < 0 ? -1.0 : 1.0])
	Bgfx::bgfx_vertex_pack(tangent, true, Bgfx::Attrib::Tangent, _layout, _vertices, ii)
	end
	end

	end

	####################################################################################################

	module SampleUtils

	################################################################################

	def self.sdl2_dll_path
	path = case RUBY_PLATFORM
	when /mswin\|msys\|mingw\|cygwin/
	Dir.pwd + '/' + 'SDL2.dll'
	when /darwin/
	'/usr/local/lib/libSDL2.dylib'
	when /linux/
	'./libSDL2.so'
	else
	raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
	end
	return path
	end

	################################################################################

	def self.bgfx_dll_path
	path = case RUBY_PLATFORM
	when /mswin\|msys\|mingw\|cygwin/
	Dir.pwd + '/bgfx-shared-libDebug.dll'
	when /darwin/
	'./libbgfx-shared-libDebug.dylib'
	when /linux/
	'./libbgfx-shared-libDebug.so'
	else
	raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
	end
	return path
	end

	################################################################################

	def self.native_window_handle(sdl2_window)
	nwh = case RUBY_PLATFORM
	when /mswin\|msys\|mingw\|cygwin/
	wminfo = SDL_SysWMinfo_win.new # TODO Windows
	if SDL_GetWindowWMInfo(sdl2_window, wminfo) == SDL_TRUE
	wminfo[:info][:win][:window]
	else
	nil
	end
	when /darwin/
	wminfo = SDL_SysWMinfo_cocoa.new # TODO Windows
	if SDL_GetWindowWMInfo(sdl2_window, wminfo) == SDL_TRUE
	wminfo[:info][:cocoa][:window]
	else
	nil
	end
	when /linux/
	raise RuntimeError, "Not supported yet: #{RUBY_PLATFORM}"
	else
	raise RuntimeError, "Unknown OS: #{RUBY_PLATFORM}"
	end
	return nwh
	end

	end