Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
03447 Graphics Minor Always Sep 23, 2009, 02:09 Apr 26, 2014, 18:14
Tester sigmaxix View Status Public Platform MAMEUI
Assigned To Phil Bennett Resolution Fixed OS Windows Vista/7 (64-bit)
Status [?] Resolved Driver vegas.cpp
Version 0.134 Fixed in Version 0.154 Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 03447: gauntdl, gauntdl24, gauntleg, gauntleg12: Texture with alpha channel is not drawn properly.
Description Rendering problem.

Texture with an alpha channel, such as trees, branches, posts, enemy weapons, and walkway rails, hide the objects and items behind them. This does not happen on the arcade.

The invisible color often creates a "blurry square" around 2D-props that hides any items or sprites behind them.

One example is at the beginning of level 1-3, where the giant tree hides a barrel and "poison food".
Steps To Reproduce Level 1-3 [Mountain Realm > Cliffs] big tree.
Ice Domain > Level 1 behind fences.
Forest > Level 1, hanging vines.
Additional Information
Github Commit
Flags Verified with Original
Regression Version
Affected Sets / Systems gauntdl, gauntdl24, gauntleg, gauntleg12
Attached Files
png file icon Graphical.png (372,419 bytes) Sep 23, 2009, 02:09
png file icon Hidden.png (512,608 bytes) Sep 23, 2009, 07:49
parent of 05629ResolvedPhil Bennett hangplt, hangpltu, thrilld: Voodoo 3D graphics have no palette 
User avatar
Sep 23, 2009, 07:44
edited on: Sep 23, 2009, 07:51
As stated in 02853, only gauntleg12 works in 0.134. I used it for confirmation.

And this is a FAQ, MAME doesn't use Direct3D or any other OS dependent graphic routine. What you select is how Windows draws the final image on the screen by the drawing options (ddraw, gdi, d3d), so it doesn't affect the internal emulation screen created by MAME at all. I fixed the report.
User avatar
Sep 23, 2009, 11:07
I'd like to mention, please, that in the future if posting snapshots to use MAME's mechanism for snapshots (F12). Taking a processed picture like above isn't the proper way to report graphical issues. Thank you.
User avatar
Phil Bennett
Apr 26, 2014, 18:14
These 'sprites' are drawn with alpha-testing (passing values > 0) and alpha-blending enabled. The alpha test was not operating on the correct input source, so fully transparent pixels would not be discarded and those passing the depth test would subsequently occlude any geometry rendered behind the sprite.

The alpha test is now performed on the output of the alpha combiner and not on the iterated/texture/fixed alpha value (a_other).