Part of DHR screen visible when 40 column text activated about apple2js HOT 2 CLOSED

I tested this following the repro steps above and I can repro it only with the GL renderer on. With the GL renderer off, it looks fine:

Looking at the margins for text mode in the original report, it looks like text mode is actually not centered, but about 1/2 a character off. Measuring the image as best I can on the top scan line:

• Left edge to DHGR start: 82 - 24 = 58 px
• Left edge to text start: 94 - 24 = 70 px
• Right edge to text end: 1206 - 1138  = 68 px

Looking at gl.ts, I think the discrepancy comes from how putImageData is called. At line 783, the x, y is set for the first pixel of the screen based on the mode. NTSC_DETAILS comes from line 471 of screenEmu.js.

It looks like the easy fix is just to erase everything before calling putImageData.

from apple2js.

The one 80 column row difference between 80 column and 40 column mode is present in real hardware, so apple2shader is attempting to replicate that, but it's oblivious to transitions between the two. Clearing the image buffer when that transition happens should be sufficient.

from apple2js.