Opened 6 months ago

Last modified 5 months ago

#12039 new defect

SCUMM: MM (C64) - Graphical glitch with alien in telescope

Reported by: dp304 Owned by:
Priority: normal Component: Engine: SCUMM
Version: Keywords:
Cc: Game: Maniac Mansion

Description

Debian 10 x86_64
ScummVM 2.0.0
Maniac Mansion C64/English

The graphics are corrupted when the alien appears in the telescope, see screenshot.

To reproduce: load the attached save game, and use really powerful telescope.

This may be due to a corruption in the disk image, but apparently disk images from different download sources are identical in this regard: in MANIAC2.D64, at offset 0x29fff (i.e. within the pic map of Room 35), there is a 0x4B value, which should rather be 0x82.

(Btw. this would also cause a buffer overrun by 24 bytes in ScummVM, if it weren't for the extra space allocated for GdiV1::_V1.picMap. To make it safer, there should be x<size checks in GdiV1::decodeV1Gfx() before all three occurrences of writing to dst[x], which would log a warning about incorrect encoding and return from the function if x is too large.)

Attachments (2)

scummvm00000.png (2.2 KB ) - added by dp304 6 months ago.
maniac-c64.s08 (6.5 KB ) - added by dp304 6 months ago.

Download all attachments as: .zip

Change History (3)

by dp304, 6 months ago

Attachment: scummvm00000.png added

by dp304, 6 months ago

Attachment: maniac-c64.s08 added

comment:1 by dp304, 5 months ago

Summary: MMC64: Graphical glitch with alien in telescopeSCUMM: MM (C64) - Graphical glitch with alien in telescope
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