//snippe 1

GLuint texture = 0;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexStorage2D(GL_TEXTURE_2D, 10, GL_RGBA8, 512, 512);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 512, 512, GL_RGBA, GL_UNSIGNED_BYTE, image_buffer);
glGenerateMipmap(GL_TEXTURE_2D);

//snippe 2

GLuint texture = 0;
glGenTextures(1, &texture);
glTextureImage2DEXT(texture, GL_TEXTURE_2D, 0, GL_RGBA8, 512, 512, 0, GL_RGBA, GL_UNSIGNED_BYTE, image_buffer);
glGenerateTextureMipmapEXT(texture, GL_TEXTURE_2D);

//snippe 3

GLuint texture = 0;
glGenTextures(1, &texture);
glTextureStorage2DEXT(texture, GL_TEXTURE_2D, 10, GL_RGBA8, 512, 512);
glTextureSubImage2DEXT(texture, GL_TEXTURE_2D, 0, 0, 0, 512, 512, GL_RGBA, GL_UNSIGNED_BYTE, image_buffer);
glBindTexture(GL_TEXTURE_2D, texture);
glGenerateMipmap(GL_TEXTURE_2D);

//snippe 4

GLuint texture = 0;
glGenTextures(1, &texture);
glTextureStorage2DEXT(texture, GL_TEXTURE_2D, 10, GL_RGBA8, 512, 512);
glTextureSubImage2DEXT(texture, GL_TEXTURE_2D, 0, 0, 0, 512, 512, GL_RGBA, GL_UNSIGNED_BYTE, image_buffer);
glBindTexture(GL_TEXTURE_2D, texture); //for some reason
glGenerateTextureMipmapEXT(texture, GL_TEXTURE_2D);