3 replies to this topic

[flame_warrior]

Hi, I am just learning OpenGL. The code is right out of the OpenGL superbible. // Simple.c // The Simplest OpenGL program with GLUT // OpenGL SuperBible, 2nd Edition // Richard S. Wright Jr. #include #include // Called to draw scene void RenderScene(void) { // Clear the window with current clearing color glClear(GL_COLOR_BUFFER_BIT); // Flush drawing commands glFinish(); } // Setup the rendering state void SetupRC(void) { glClearColor(0.0f, 0.0f, 1.0f, 1.0f); } // Main program entry point void main(void) { glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutCreateWindow("Simple"); glutDisplayFunc(RenderScene); SetupRC(); glutMainLoop(); } When I compile this I get a transparent window. If I use glutSwapBuffers() and GLUT_DOUBLE, I get black background and not blue background ? Thank you.

[Redge]

first point, you''re windows isn''t transparent, it had been initialised with what you have in your video memory. if you move your windows, you will see...

second point, I don''t know. Are you sure the alpha value is 1.0f ? perhaps it''s 0.0f
you use GLUT_RGB, perhaps it should be GLUT_RGBA or something like that? or try to use glClearColor3f(glFloat R, glFloat G, glFloat B) I think this function exist.

Redge

[grady]

I think that should be glutInitDisplayMode(GLUT_SINGLE|GL_RGB);

maybe you need to call glFlush(); after glFinish();

and you need a glClearColor(1.0f, 1.0f, 1.0f, 1.0f); i think

[zedzeek]

i dont see a resize function. theres a minimum num of functions that are needed in each glut program + IIRC resize is one of them

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