JamesD Posted November 15, 2016 Share Posted November 15, 2016 WOW! 5 Quote Link to comment Share on other sites More sharing options...
JamesD Posted November 15, 2016 Author Share Posted November 15, 2016 The download http://www.pouet.net/prod.php?which=68387 Quote Link to comment Share on other sites More sharing options...
CatPix Posted November 16, 2016 Share Posted November 16, 2016 The smooth scrolling is very impressive Quote Link to comment Share on other sites More sharing options...
+CXK Posted November 16, 2016 Share Posted November 16, 2016 Beautiful!! Quote Link to comment Share on other sites More sharing options...
Austin Posted November 16, 2016 Share Posted November 16, 2016 Wow, that's impressive. It looks and seems to play great if the video is anything to go by. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted November 17, 2016 Share Posted November 17, 2016 Neat! Quote Link to comment Share on other sites More sharing options...
JamesD Posted November 17, 2016 Author Share Posted November 17, 2016 The Amstrad has a 16 color graphics mode. If I understand correctly, it's 4 bits per pixel 160×200 mode. If that is the case, that means the screen takes up almost 16K.That screen scroll has to be some seriously unrolled code!Since the table is taller than the screen, they must be copying from a full image of the table to the screen.That would mean it takes over 32K for the screen and full table image in RAM.But I'm just guessing. Quote Link to comment Share on other sites More sharing options...
carlsson Posted November 17, 2016 Share Posted November 17, 2016 Not sure about number of colours on screen at the same time, but the palette consists of 3^3 = 27 distinct colours arranged as RGB in the expected range of 00, 80, FF. It means one level of grey, but also a lot of bright colours very close to eachother. Quote Link to comment Share on other sites More sharing options...
TMR Posted November 17, 2016 Share Posted November 17, 2016 That screen scroll has to be some seriously unrolled code! You're right about the memory use, but the scrolling relies on the CPC's ability to change the start address of the screen memory; if memory serves it's timing specific to get right and the 16K block "wraps" so the calculations are a bit fiddly, but a simplified version is used for games like Mission Genocide or Warhawk do their scrolling. Since the table is taller than the screen, they must be copying from a full image of the table to the screen. That would mean it takes over 32K for the screen and full table image in RAM. The original PD tables are 512 pixels high so it'll be more like 40K for the table itself and i'd expect the collision map to be quite chunky too. 1 Quote Link to comment Share on other sites More sharing options...
emkay Posted November 17, 2016 Share Posted November 17, 2016 The smooth scrolling is very impressive Impressive scrolling? Have you seen "Edge Grinder" for the CPC yet? That is imressive Quote Link to comment Share on other sites More sharing options...
emkay Posted November 17, 2016 Share Posted November 17, 2016 (edited) Not sure about number of colours on screen at the same time, but the palette consists of 3^3 = 27 distinct colours arranged as RGB in the expected range of 00, 80, FF. It means one level of grey, but also a lot of bright colours very close to eachother. 16 colours out of 27, giving you the choice of using nicely fitting colours on the screen. For game graphics a well chosen decision Edited November 17, 2016 by emkay Quote Link to comment Share on other sites More sharing options...
JamesD Posted November 18, 2016 Author Share Posted November 18, 2016 Impressive scrolling? Have you seen "Edge Grinder" for the CPC yet? That is imressive Quote Link to comment Share on other sites More sharing options...
TMR Posted November 18, 2016 Share Posted November 18, 2016 16 colours out of 27, giving you the choice of using nicely fitting colours on the screen. For game graphics a well chosen decision It's a bit "swings and roundabouts" really; having sixteen colours with arbitrary placement is obviously a plus, but it means handling twice the screen RAM of most other 8-bits; software sprites need more data and take longer to render, double buffering the display takes half the RAM on a 64K machine and the hardware scrolling being discussed here wasn't documented. There are some very poor examples of scrolling because brute force was used to shift the video memory. Impressive scrolling? Have you seen "Edge Grinder" for the CPC yet? That is imressive From what the author told me, Edge Grinder isn't compatible with every model of CPC (it relies on an undocumented feature of the CRTC which is also present on the BBC Micro but, to my knowledge, is never used there for similar reasons) along with a variation of the same technique behind PD. It's not much different to using LMS on the Atari 8-bit, except the screen RAM isn't contiguous so there's some juggling of numbers needed to get the memory addresses for each new row/column. Quote Link to comment Share on other sites More sharing options...
Asmusr Posted November 18, 2016 Share Posted November 18, 2016 It's incredible what you can squeeze out of a CPC now compared to back in the days when Sorcery was the gold standard. Quote Link to comment Share on other sites More sharing options...
CatPix Posted November 18, 2016 Share Posted November 18, 2016 Impressive scrolling? Have you seen "Edge Grinder" for the CPC yet? That is imressive Nope, but I have acquired some new tapes for the CPC recently and well, any smooth scrolling will impress me now Quote Link to comment Share on other sites More sharing options...
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