Vamiga: Clock app graphics errors

[dirkwhoffmann]

Todo: Find out if it's a line Blitter or a copy Blitter issue.

[mithrendal]

I bet its neither the blitter line nor the blitter copy operation. I think it is the blitter fill operation, which is not working as expected.

have a look here:
http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_guide/node0122.html

But I could also be wrong... It is just a feeling.

[dirkwhoffmann]

Yes, that's right, but the fill operation is not stand-alone. It is either part of a line operation or a copy operation. I hope it's the copy operation, because vAmiga doesn't support this, yet. The line Blitter is from WinFellow and hopefully correct and complete (I prefer not to touch that code 😬).

[mithrendal]

Oh boy, that fill mode was so far ahead in the days back then. It was 1987 clearly a machine from th future ... 😄

[dirkwhoffmann]

Yes, emulators are time-machines. It's been ages since I looked at the Workbench graphics in detail. I have to admit that it really looks a little primitive 😯.

[mithrendal]

But I can't see where it copys inside the clock window. I only see lines ... In fact it is a vector drawing of a analog clock. If you stretch it, it will adapt to the windows new size. Isn't this all done with lines only ? I know you don't want to touch it, but the more I think about it, the more I tend to bet it is the missing line Blitter fill mode. Hopefully I am wrong though 😳

[dirkwhoffmann]

I've run the clock with debug output enabled and captured the following:

There are about 50 blit operation for drawing a single watch face. The ones marked with "D" are descending copy blits and the ones marked with "E" are those with exclusive-fill on. Hence, the bug is most likely caused by my copy Blitter code (which doesn't support fill modes yet). That's good news, because it means that I don't have to fully understand the WinFellow line Blitter code.

[dirkwhoffmann]

[mithrendal]

This clock is really iconic art. Must have been advised by Andy Warhol I think... looks still very modern

[dirkwhoffmann]

This clock is really iconic art

This morning I first had this 😅:

Too modern for the 80s. On the other hand, it could be interpreted as a digital version of Dalí's melting clock. Maybe I should declare it as art and sell it 🤔.

[mithrendal]

Mhhm I am not sure about this one. This one looks more like a mosaic of a clock in an ancient roman bath. 😃
_Mosaics have a long history, starting in Mesopotamia in the 3rd millennium BC. Pebble mosaics were made in Tiryns in Mycenean Greece; mosaics with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome._

[mithrendal]

Dirk, the process you are going through resembles the process of unearthing precious ancient treasures out of the mud and cleaning them afterwards. These treasures look first a bit damaged and broken, in a thoughtful and carefully process they have to be cleaned and put into the same sparkling shape they have been thousand years ago.