OpenGL behaves differently in ubuntu and windows

Question

I am using wxGLContext and wxGLCanvas for 3D visualization. I initialized opengl like this

SetCurrent(*canvas);
glEnable(GL_BLEND);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_COLOR_MATERIAL);

and draw the objects

glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-w, w, -h, h, -10.0f, 10.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
quad = gluNewQuadric();
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL);
//draw the objects
gluDeleteQuadric(quad);
glFlush();

The problem is that this code works fine in windows, but in ubuntu the objects clipped by the objects which are located in back. The glFrontFace is correct for all objects, but clipping is wrong.

Maybe you get a context without a depth buffer? `wxGLContext` probably has a way to explicitly request a depth buffer when creating a context. — HolyBlackCat, Oct 16 '19 at 10:40
You are very smart. Thank you a lot. I used this attribute int AttribList[] = {WX_GL_DOUBLEBUFFER, WX_GL_DEPTH_SIZE, 16, 0}; — Mohammad Nakhaee, Oct 16 '19 at 12:21

score 0 · Accepted Answer · answered Oct 18 '19 at 09:14

As HolyBlackCat mentioned in the comments, the problem was depth buffer for the wxGLContext. It works by using WX_GL_DEPTH_SIZE 8 and 16, but not 32.

Although, I still do not know, how windows can handle it without error, I corrected some lines as follows

int AttribList[] = {WX_GL_DOUBLEBUFFER, WX_GL_DEPTH_SIZE, 16, 0};
wxGLCanvas* glc = new wxGLCanvas(parent, wxID_ANY, AttribList,
                                 wxDefaultPosition, wxDefaultSize,
                                 wxFULL_REPAINT_ON_RESIZE);

and now it works for both OSs.

OpenGL behaves differently in ubuntu and windows

1 Answers1