bool
Stencil2Test::test_stencil(int method)
{
bool pass;
glEnable(GL_STENCIL_TEST);
//============================================================
// No depth testing
glDisable(GL_DEPTH_TEST);
glClear(GL_COLOR_BUFFER_BIT |
GL_STENCIL_BUFFER_BIT |
GL_DEPTH_BUFFER_BIT);
// set stencil buffer vals to 5
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_REPLACE, GL_REPLACE, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
5, ~0); // ref, mask
if (pass)
pass = render_test(5, 5);
reset_stencil_state(method);
if (!pass)
return false;
// incr front val to 6, decr back val to 4
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_INCR, GL_DECR, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
5, ~0); // ref, mask
if (pass)
pass = render_test(6, 4);
reset_stencil_state(method);
if (!pass)
return false;
// if front==6, keep
// if back<6, replace with zero
// final: front=6, back=0
pass = set_stencil_state(method,
GL_KEEP, GL_ZERO, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_KEEP, GL_KEEP, // z pass
GL_EQUAL, GL_LESS, // stencil func
6, ~0); // ref, mask
if (pass)
pass = render_test(6, 0);
reset_stencil_state(method);
if (!pass)
return false;
// if front!=10, keep, else decr
// if back<10, keep, else incr
// final: front=6, back=1
pass = set_stencil_state(method,
GL_DECR, GL_INCR, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_KEEP, GL_KEEP, // z pass
GL_NOTEQUAL, GL_LESS, // stencil func
10, ~0); // ref, mask
if (pass)
pass = render_test(6, 1);
reset_stencil_state(method);
if (!pass)
return false;
if (method != ATI) {
// if front!=10, keep, else decr
// if back<10, keep, else incr
// final: front=6, back=1
pass = set_stencil_state(method,
GL_DECR, GL_INCR, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_REPLACE, GL_REPLACE, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
0xf6, 0xf1, // ref
0xff, 0xff, // mask
0x60, 0x10); // writeMask
if (pass)
pass = render_test(0x66, 0x11);
reset_stencil_state(method);
if (!pass)
return false;
}
// reset write mask for clear
set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_REPLACE, GL_REPLACE, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
0, 0,
~0, ~0,
~0, ~0);
//============================================================
// Now begin tests with depth test
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glClear(GL_COLOR_BUFFER_BIT |
GL_STENCIL_BUFFER_BIT |
GL_DEPTH_BUFFER_BIT);
// set stencil buffer vals to 7, set Z values
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_REPLACE, GL_REPLACE, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
7, ~0); // ref, mask
if (pass)
pass = render_test(7, 7);
reset_stencil_state(method);
if (!pass)
return false;
// GL_LESS test should fail everywhere
// decr front to 5, incr back to 2
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_DECR, GL_INCR, // z fail
GL_KEEP, GL_KEEP, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
99, ~0); // ref, mask
if (pass)
pass = render_test(6, 8);
reset_stencil_state(method);
if (!pass)
return false;
// set depth test = GL_EQUAL
// Z test should pass everywhere
// set front to 3
// decr back to 7
glDepthFunc(GL_EQUAL);
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_REPLACE, GL_DECR, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
3, ~0); // ref, mask
if (pass)
pass = render_test(3, 7);
reset_stencil_state(method);
if (!pass)
return false;
// incr front to 4 (by z pass), decr back to 6 (by stencil fail)
pass = set_stencil_state(method,
GL_DECR, GL_INCR, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_INCR, GL_DECR, // z pass
GL_EQUAL, GL_NOTEQUAL, // stencil func
3, ~0); // ref, mask
if (pass)
pass = render_test(4, 6);
reset_stencil_state(method);
if (!pass)
return false;
//============================================================
// Disable depth test
glDisable(GL_DEPTH_TEST);
// test stencil value mask
// only test bit 1 in stencil values
// if !(front&0x2 == 15&0x2), decr to 3 (should happen)
// if !(back&0x2 == 15&0x2), incr to 7 (should not happen)
pass = set_stencil_state(method,
GL_DECR, GL_INCR, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_KEEP, GL_KEEP, // z pass
GL_EQUAL, GL_EQUAL, // stencil func
15, 0x2); // ref, mask
if (pass)
pass = render_test(3, 6);
reset_stencil_state(method);
if (!pass)
return false;
//============================================================
// Test common two-sided stencil modes for shadow volume rendering
// Requires stencil +/- wrap feature.
if (!have_stencil_wrap())
return true;
glClear(GL_COLOR_BUFFER_BIT |
GL_STENCIL_BUFFER_BIT |
GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
// "traditional / Z-pass" method:
// front face: incr on zpass
// back face: decr on zpass
// both front and back Z-test should pass here
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_KEEP, GL_KEEP, // z fail
GL_INCR_WRAP_EXT, GL_DECR_WRAP_EXT, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
0, ~0); // ref, mask
if (pass)
pass = render_test(1, stencilMax);
reset_stencil_state(method);
if (!pass)
return false;
// "Z-fail" method:
// front face: decr on zfail
// back face: incr on zfail
// both front and back Z-test should fail here
pass = set_stencil_state(method,
GL_KEEP, GL_KEEP, // stencil fail
GL_DECR_WRAP_EXT, GL_INCR_WRAP_EXT, // z fail
GL_KEEP, GL_KEEP, // z pass
GL_ALWAYS, GL_ALWAYS, // stencil func
0, ~0); // ref, mask
if (pass)
pass = render_test(0, 0);
reset_stencil_state(method);
if (!pass)
return false;
return true;
}
int main(int argc, char ** argv) {
m = import_object("teapot.3dt");
if(argc < 2) {
return render_test();
} else return read_file(argv[1]);
}
