if(XPCTRL & XPCTRL_XP_EN)
      {
       DisplayFB ^= 1;

       DrawingBlock = 0;
       DrawingActive = true;
       DrawingCounter = 1120 * 4;
       DrawingFB = DisplayFB ^ 1;
      }

• Attachment: buffertest_220728051801.vb
  (Size: 1.00KB, Downloaded 32 time(s))

[Updated on: Tue, 09 August 2022 23:12]

• Attachment: xprsttest_220728180347.vb
  (Size: 2.00KB, Downloaded 39 time(s))

[Updated on: Tue, 09 August 2022 23:12]

[Updated on: Wed, 03 August 2022 19:01]

Administrator wrote on Wed, 03 August 2022 16:19

Could you be more specific about what unfixed Mednafen should look like after pressing a button with buffertest_220728051801.vb? Are you saying that no change is visible at all when pressing a button, or the change that does show is wrong?

Going back and retrying myself, it looks like I was wrong-- while a patched Mednafen and hardware displays a smooth rolling animation from one pattern to another, an unpatched Mednafen will animate, but with tearing artifacts, looking a bit like this:



Mea culpa! I think what happened there was I was testing on a fresh install of 1.29.0, which didn't have my controls configured.

Quote:

Also, did you directly check that framebuffer 1, instead of framebuffer 0, is the one displayed after reset/power-on, before any drawing occurs?

I did not. I just now wrote a pair of ROMs (attached) testing that case, and before any drawing occurs, indeed framebuffer 0 is what is drawn. fb1test_220804013829.vb clears framebuffer 1 to a solid color, whereas fb1test_220804014304.vb clears framebuffer 0 to a solid color. On hardware, fb1test_220804013829.vb displays garbage and Mednafen displays black, whereas fb1test_220804014304.vb displays a consistent bright pattern on both hardware and Mednafen. Seems that enabling drawing is mucking with the internal framebuffer pointers.

• Attachment: buffertest_220728051801_unpatched.png
  (Size: 3.87KB, Downloaded 168 time(s))

• Attachment: fb1test_220804013829.vb
  (Size: 1.00KB, Downloaded 34 time(s))

• Attachment: fb1test_220804014304.vb
  (Size: 1.00KB, Downloaded 36 time(s))

• Attachment: mednafen-vb-vip-fb-flip.patch
  (Size: 0.67KB, Downloaded 36 time(s))

• Attachment: vip-flip-test.patch
  (Size: 0.82KB, Downloaded 42 time(s))

• Attachment: fb1test_220810024452 (XPRST once).vb
  (Size: 1.00KB, Downloaded 34 time(s))

• Attachment: vip-fb-flip.patch
  (Size: 0.76KB, Downloaded 34 time(s))

• Attachment: fb1test_220811052209 (XPRST twice).vb
  (Size: 1.00KB, Downloaded 33 time(s))

• Attachment: fb1test_220811060844 (4 nops).vb
  (Size: 1.00KB, Downloaded 35 time(s))

• Attachment: fb1test_220811060653 (5 nops).vb
  (Size: 1.00KB, Downloaded 36 time(s))