80486DX2-66/86Box-fork
1
0
Fork 0
Code Issues Pull Requests Activity

Add note about bytes_skip calculation

Browse Source
This commit is contained in:
Cacodemon345
2024-02-07 01:40:15 +06:00
parent df91185e75
commit 1808498370
1 changed files with 3 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/video/vid_c&t_69000.c
View File

@@ -1160,8 +1160,9 @@ chips_69000_setup_bitblt(chips_69000_t* chips)
if (chips->bitblt_running.bitblt.bitblt_control & (1 << 10)) {
if (!(chips->bitblt_running.bitblt.bitblt_control & (1 << 12))) {
//pclog("source_span = %d, dest_span = %d\n", chips->bitblt_running.bitblt.source_span, chips->bitblt_running.bitblt.destination_span);
//pclog("destination_width = %d (qword aligned = %d), skip left = %d\n", chips->bitblt_running.bitblt.destination_width, (chips->bitblt_running.bitblt.destination_width + 7) & ~7, chips->bitblt_running.bitblt.source_addr);
/* Yes, the NT 4.0 and Linux drivers will send this many amount of bytes to the video adapter on quadword-boundary-crossing image blits.
This weird calculation is intended and deliberate.
*/
if ((chips->bitblt_running.bitblt.source_addr + (chips->bitblt_running.bitblt.destination_width)) > ((chips->bitblt_running.bitblt.destination_width + 7) & ~7))
chips->bitblt_running.bytes_skip = 8 + (((chips->bitblt_running.bitblt.destination_width + 7) & ~7) - chips->bitblt_running.bitblt.destination_width);
}