Method TexSubImage

src/lua/LuaTextures.cpp:1064–1106

int LuaTextureMgr::TexSubImage(lua_State* L) {
  const LuaTexture* texture = CheckLuaTexture(L, 1);
  if (!texture->IsWritable()) {
    return luaL_pushnil(L);
  }

  TextureData texData;
  if (!texData.Parse(L, 2)) {
    return luaL_pushnil(L);
  }

  const GLenum target = (GLenum)luaL_optint(L, 3, texture->GetTarget());
  const GLint  level  = (GLint) luaL_optint(L, 4, 0);
  const GLint  x      = (GLint) luaL_optint(L, 5, 0);
  const GLint  y      = (GLint) luaL_optint(L, 6, 0);

  if (!OpenGLPassState::PushAttrib(GL_TEXTURE_BIT)) {
    return luaL_pushnil(L); // exceeded the attrib stack depth
  }

  if (!texture->Bind()) {
    OpenGLPassState::PopAttrib();
    lua_pushboolean(L, false);
    return 1;
  }

  glGetError(); // clear the error
  glTexSubImage2D(target, level, x, y,
                  texData.xsize, texData.ysize,
                  texData.format, texData.type, texData.data);

  const GLenum errgl = glGetError();
  OpenGLPassState::PopAttrib();

  if (errgl != GL_NO_ERROR) {
    lua_pushboolean(L, false);
    lua_pushinteger(L, errgl);
    return 2;
  }

  lua_pushboolean(L, true);
  return 1;
}


int LuaTextureMgr::CopyToTexture(lua_State* L) {