How is OpenGL formed

is the switch from fixed rendering pipeline to VBOs & shaders a big one in terms of performance? Also will it be hard to comprehend coming from doing only fixed rendering pipeline methods?


scene_render = GL11.glGenLists(1);
       
GL11.glNewList(scene_render, GL11.GL_COMPILE_AND_EXECUTE);
GL11.glLineWidth(1);
Map.render();
GL11.glEndList();
       
GL11.glDeleteLists(scene_render,1);

So i was experimenting with display lists and my result was a lost of ~20 fps vs no displays. Is that suppose to happen like that?

Also for doing window -> world coordinates would making a ray from:

GLU.gluUnProject((float)(x), (float)(y), 0f, modelview, projection, viewport, posOrg);
GLU.gluUnProject((float)(x), (float)(y), 1f, modelview, projection, viewport, posEnd);

work and then do some collision code?