Re: VDP Tests
Posted: Wed Dec 30, 2015 8:03 pm
Thanks for that video.
Sadly those who are not familar with VDP don't understand some things...
This tests made in that way that it requiring some interaction with user. It's not like some of other tests where it does self-diagnostic.
Tests with two rects filled with same colors confirm that VDP output consists of DAC from 4 bit Red, 4 bit Green, 4 Bit Blue, and highlight/shaddow stuff only does some simple arithmetics.
Tests with fast mode-switches should be recorded from screen, not from capture-card. Just because modern capture-cards does same unknown stuff like LCD does. I doubt if any of them does simulate full CRT behavior.
Tests with color ID and sprites stuff... You should know that there at least three "special" color id-s: 0 (transparent), E (shadow, IIRC), F (highlight, IIRC). That's reason why there is control of color id. Maybe I'm wrong and only 3E, 3F does that, but... anyway it does matter. But in your recording you stop at 3 color id, and it does not show cases.
Actually, I was assuming that one who will use this test, will first roll across all color ID's, then change first setting, and roll again, then change first setting into second position, and so on... until all combinations will be tested. And during that, one will do same in some emulator, and compare screens each time, to figure out difference in behavior. Or just somehow record all "testdata". Maybe I could put much more visual data on same screen, to make easier to save all testdata by separate screenshots, but I pick easier way.
Sadly those who are not familar with VDP don't understand some things...
This tests made in that way that it requiring some interaction with user. It's not like some of other tests where it does self-diagnostic.
Tests with two rects filled with same colors confirm that VDP output consists of DAC from 4 bit Red, 4 bit Green, 4 Bit Blue, and highlight/shaddow stuff only does some simple arithmetics.
Tests with fast mode-switches should be recorded from screen, not from capture-card. Just because modern capture-cards does same unknown stuff like LCD does. I doubt if any of them does simulate full CRT behavior.
Tests with color ID and sprites stuff... You should know that there at least three "special" color id-s: 0 (transparent), E (shadow, IIRC), F (highlight, IIRC). That's reason why there is control of color id. Maybe I'm wrong and only 3E, 3F does that, but... anyway it does matter. But in your recording you stop at 3 color id, and it does not show cases.
Actually, I was assuming that one who will use this test, will first roll across all color ID's, then change first setting, and roll again, then change first setting into second position, and so on... until all combinations will be tested. And during that, one will do same in some emulator, and compare screens each time, to figure out difference in behavior. Or just somehow record all "testdata". Maybe I could put much more visual data on same screen, to make easier to save all testdata by separate screenshots, but I pick easier way.