https://www.khronos.org/registry/OpenGL-Refpages/es3.0/html/glRenderbufferStorage.xhtml

https://www.khronos.org/registry/OpenGL-Refpages/es3.0/html/glRenderbufferStorageMultisample.xhtml

glRenderbufferStorage — establish data storage, format and dimensions of a renderbuffer object's image

有点像descriptor

bind前后用 sample

//渲染缓冲区作为颜色缓冲区

glGenRenderbuffers（1，& colorBuffer）;

glBindRenderbuffer（GL_RENDERBUFFER，colorBuffer）;

glRenderbufferStorage（GL_RENDERBUFFER，GL_RGBA，width，height）;

glBindRenderbuffer（GL_RENDERBUFFER，0）;

//将渲染缓冲区作为颜色缓冲区附加到fbo

glFramebufferRenderbuffer（GL_FRAMEBUFFER，GL_COLOR_ATTACHMENT0，GL_RENDERBUFFER，colorBuffer）;

有了扩展就可以用glRenderbufferStorageMultisample 作为ogles上msaa stay in tile 的解决方案（memoryless）

kGL_EXT_multisampled_render_to_texture

kGL_IMG_multisampled_render_to_texture

kGL_APPLE_framebuffer_multisample（apple现在用metal

kGL_NV_framebuffer_multisample kGL_NV_framebuffer_blit