Function main

test/browser/webgl_create_context.cpp:77–206

}

int main() {
  bool first = true;
  EmscriptenWebGLContextAttributes attrs;
  int depth = 0;
  int stencil = 0;
  int antialias = 0;
#ifndef NO_DEPTH
  for(depth = 0; depth <= 1; ++depth)
#endif
#ifndef NO_STENCIL
  for(stencil = 0; stencil <= 1; ++stencil)
#endif
#ifndef NO_ANTIALIAS
  for(antialias = 0; antialias <= 1; ++antialias)
#endif
  {
    emscripten_webgl_init_context_attributes(&attrs);
    attrs.depth = depth;
    attrs.stencil = stencil;
    attrs.antialias = antialias;
    printf("Requesting depth: %d, stencil: %d, antialias: %d\n", depth, stencil, antialias);

    EM_ASM(
      var canvas2 = document.createElement('canvas');
      Module['canvas'].parentElement.appendChild(canvas2);
      canvas2.id = 'customCanvas';
    );

    assert(emscripten_webgl_get_current_context() == 0);
    EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context = emscripten_webgl_create_context("#customCanvas", &attrs);
    assert(context > 0); // Must have received a valid context.
    EMSCRIPTEN_RESULT res = emscripten_webgl_make_context_current(context);
    assert(res == EMSCRIPTEN_RESULT_SUCCESS);
    assert(emscripten_webgl_get_current_context() == context);

    // Let's try enabling all extensions.
    const char *extensions = (const char*)glGetString(GL_EXTENSIONS);
    std::vector<std::string> exts = split(extensions, ' ');
    for(size_t i = 0; i < exts.size(); ++i)
    {
      bool supported = emscripten_webgl_enable_extension(context, exts[i].c_str());
      printf("%s\n", exts[i].c_str());
      assert(supported);
    }

    int drawingBufferWidth = -1;
    int drawingBufferHeight = -1;
    res = emscripten_webgl_get_drawing_buffer_size(context, &drawingBufferWidth, &drawingBufferHeight);
    assert(res == EMSCRIPTEN_RESULT_SUCCESS);
    printf("drawingBufferWidth x Height: %dx%d\n", drawingBufferWidth, drawingBufferHeight);
    assert(drawingBufferWidth == 300);
    assert(drawingBufferHeight == 150);

    // Try with a simple glClear() that we got a context.
    glClearColor(1.f, 0.f, 0.f, 1.f);
    glClear(GL_COLOR_BUFFER_BIT);
    unsigned char pixels[4];
    glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixels);