帧缓冲区：FBO - MartinRGB/GLES30_ProgrammingGuide_NDK GitHub Wiki

简单流程如下

生成材质时:

   // Setup FBO
   glGenFramebuffers ( 1, &userData->fbo );
   glBindFramebuffer ( GL_FRAMEBUFFER, userData->fbo );
   
   // Gen Texture2D and attach to FBO
   userData->textureHeight = userData->textureWidth = 400;
   glGenTextures ( 4, &userData->textureID );
   glBindTexture ( GL_TEXTURE_2D, userData->textureID );

   glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGBA,userData->textureWidth, userData->textureHeight, 
                  0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
   // Set the filtering mode
   glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
   glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
   glFramebufferTexture2D ( GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 
                               GL_TEXTURE_2D, userData->colorTexId[i], 0 );

   glDrawBuffers ( 4, attachments );

   // Restore the original framebuffer
   glBindFramebuffer ( GL_FRAMEBUFFER, 0 );

绘制时:

// FIRST: use MRTs to output four colors to four buffers
   glBindFramebuffer ( GL_FRAMEBUFFER, userData->fbo );
   glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

   //not necessary ,only in this snippets
   glDrawBuffers ( 4, attachments );
   
   //Draw something here;
   ....

   // Restore the default framebuffer
   glBindFramebuffer ( GL_DRAW_FRAMEBUFFER, 0 );

关闭后:

   ...
   glDeleteFramebuffers ( 1, &userData->fbo );