Opened 14 months ago

Closed 3 months ago

Last modified 3 months ago

#10686 closed defect (fixed)

WME: Sprite background is not fully transparent if AlphaColor is set

Reported by: lolbot-iichan Owned by: lolbot-iichan
Priority: normal Component: Engine: Wintermute
Keywords: has-pull-request Cc: somaen, lolbot-iichan, tobiatesan
Game: Wintermute

Description

Discovered this issue at FoxTail game, that is using dinamic lighting on PNG sprites with transparent background.

I have exctacted sprite lighting source code and made a simple test game to demonstrate this issue without running FoxTail which is not fully supported by ScummVM yet: https://github.com/tobiatesan/wme_testsuite/tree/master/light_test/packages

Screenshots are attached. Resulting colot difference is not big (like #FFDED5 vs #FFDAD5), however you could see and feel this rectangle moving around character sprite both in test game and FoxTail.

Tested on latest ScummVM from dev branch and ScummVM 2.1.0git3428-gc518691d7c (Aug 12 2018 19:04:49).

Attachments (2)

light_test_scummvm.png (24.9 KB ) - added by lolbot-iichan 14 months ago.
light_test_wintermute.png (23.9 KB ) - added by lolbot-iichan 14 months ago.

Download all attachments as: .zip

Change History (7)

by lolbot-iichan, 14 months ago

Attachment: light_test_scummvm.png added

by lolbot-iichan, 14 months ago

Attachment: light_test_wintermute.png added

comment:1 by lolbot-iichan, 14 months ago

Game: Wintermute

comment:2 by lolbot-iichan, 4 months ago

Owner: set to somaen
Resolution: fixed
Status: newpending

comment:3 by Filippos Karapetis <bluegr@…>, 4 months ago

In c4dc251f:

GRAPHICS: Fix fully transparent pixel blit

In BLEND_NORMAL mode with color != 0xffffffff, blending fully
transparent pixel was resulted in slightly modifying some background
colors, because old value X was a bit different from new value (X*255>>8).

This fixes defect #10686 WME: Sprite background is not fully transparent
if AlphaColor is set

comment:4 by lolbot-iichan, 3 months ago

Owner: changed from somaen to lolbot-iichan
Status: pendingclosed

comment:5 by lolbot-iichan, 3 months ago

Keywords: has-pull-request added
Note: See TracTickets for help on using tickets.