android - I receive INVALID OPERATION when I use glBlitFramebuffer to implement MSAA -

perhaps have stupid problems. i'll appreciate if reply them. problems based on android environment , opengl es.

1. how verified whether has opened msaa or not ? if draw gl_points points size 50, there small squares. if enabled 4x msaa, can small squares become round points ?

2. i tried best enable msaa fbo , blitfbo. draw nothing , there error invalid_operation after glblitframebuffer() calling.

here complete projects mentioed above:https://github.com/enoch-liu/gl

and following key codes:

void renderer::multisampleantialiasing() {     glgenrenderbuffers(1, &m_mscolor);     glbindrenderbuffer(gl_renderbuffer, m_mscolor);     glrenderbufferstoragemultisample(gl_renderbuffer, 4, gl_rgba8, m_width, m_height);     checkglerror("genmscolorbuffer");      glgenframebuffers(1, &m_msfbo);     glbindframebuffer(gl_framebuffer, m_msfbo);       glframebufferrenderbuffer(gl_framebuffer, gl_color_attachment0, gl_renderbuffer, m_mscolor);     checkglerror("fborbo,colorattachment");      glgenrenderbuffers(1, &m_msdepth);     glbindrenderbuffer(gl_renderbuffer, m_msdepth);     glrenderbufferstoragemultisample(gl_renderbuffer, 4, gl_depth_component16, m_width, m_height);     checkglerror("gendepthbuffer");      glframebufferrenderbuffer(gl_framebuffer, gl_depth_attachment, gl_renderbuffer, m_msdepth);     checkglerror("depthbuffer,renderbuffer");     glenum drawbufs[] = {gl_color_attachment0};     gldrawbuffers(1, drawbufs);     checkglerror("drawbuffer");      if(glcheckframebufferstatus(gl_framebuffer) != gl_framebuffer_complete) {         log_error("failed make complete framebuffer object %x", glcheckframebufferstatus(gl_framebuffer));     } }   void renderer::drawframe() {     //log_info("drawframe %d x %d", width, height);     static float r=0.9f;     static float g=0.2f;     static float b=0.2f;      log_info("xxx %d, %d", m_width,m_height);     if (openmsaa)     {         glbindframebuffer(gl_framebuffer, m_msfbo);         glbindrenderbuffer(gl_renderbuffer, m_mscolor);         checkglerror("bindtwobuffers");     }      glviewport(0,0,m_width,m_height);     glscissor(0,0,m_width,m_height);      glclearcolor(r, g, b, 1.0f);     glclear(gl_color_buffer_bit | gl_depth_buffer_bit);     gldisable(gl_depth_test);      const glfloat landscapeorientationmatrix[16] = {             1.0f, 0.0f, 0.0f, 0.0f,             0.0f, 1.0f, 0.0f, 0.0f,             0.0f, 0.0f, 0.0f, 0.0f,             0.0f, 0.0f, 0.0f, 1.0f };     const glfloat color[4] = {             1.0f, 0.0f, 0.0f, 1.0f     };     gluseprogram( m_program );     gluniformmatrix4fv(m_umvp, 1, gl_false, landscapeorientationmatrix);     gluniform4fv(m_ucolor, 1, color);     m_p = glgetattriblocation(m_program, "vposition");     m_p1 = glgetattriblocation(m_program, "vposition1");      glenablevertexattribarray( m_p );     glvertexattribpointer( m_p , 3, gl_float, false, 3 * sizeof( float ), squarecoords);      gldrawarrays(gl_points, 0, 4);     gldisablevertexattribarray( m_p );     glflush();     checkglerror("before blit");     if (openmsaa)     {         glbindframebuffer(gl_read_framebuffer, m_msfbo);         checkglerror("bindreadbuffer");         glbindframebuffer(gl_draw_framebuffer, 0);         checkglerror("bindframebuffer");         glblitframebuffer(0, 0, m_width, m_height, 0, 0, m_width, m_height, gl_color_buffer_bit, gl_nearest);         checkglerror("blitframebuffercolor");         glblitframebuffer(0, 0, m_width, m_height, 0, 0, m_width, m_height, gl_depth_buffer_bit, gl_nearest);         checkglerror("blitframebufferdepth");         glbindframebuffer(gl_read_framebuffer, 0);         glbindframebuffer(gl_draw_framebuffer, 0);     } } 

the framebuffer complete.

the internal format of depth buffers have match: https://www.opengl.org/discussion_boards/showthread.php/173275-alternative-to-glblitframebuffer%28%29

looking @ github project not configuring depth buffer @ all. project:

const eglint attribs[] = {  //        egl_surface_type, egl_window_bit,          egl_renderable_type, egl_opengl_es2_bit,          egl_surface_type, egl_pbuffer_bit,          egl_blue_size, 8,          egl_green_size, 8,          egl_red_size, 8,          egl_alpha_size, 8,          egl_sample_buffers, 1,          egl_samples, 4,          egl_none  };