07586: Artwork: screen combined with multiply-blend does not work on BGFX D3D9

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
07586	Graphics	Minor	Always	Mar 7, 2020, 17:56	Feb 1, 2023, 19:47

Tester	hap	View Status	Public	Platform	MAME (Official Binary)
Assigned To	Ryan Holtz	Resolution	Fixed	OS
Status [?]	Resolved			Driver
Version	0.219	Fixed in Version	0.252	Build	64-bit
		Fixed in Git Commit	5671484	Github Pull Request #	#10858

Summary	07586: Artwork: screen combined with multiply-blend does not work on BGFX D3D9
Description	Artwork: screen combined with multiply-blend does not work on BGFX D3D9. With MAME's layout artwork system, when blending the screen by multiplying with another element, in some cases(which exactly?), it does not work properly with BGFX D3D9. Exact cause is unsure, symptom is severe: a blank screen element. But it only happens with this backend, so I'll leave bug severity on Minor.
Steps To Reproduce	mame64.exe ccmk5 -video bgfx -bgfx_backend d3d9 Also, see attachment pacman.zip for a simplified layout test that will result in a black screen. mame64.exe pacman -video bgfx -bgfx_backend d3d9 It also happens with neogeo cropped/stretched view. I hoped to be able to fix it by removing the multiply blending, but it still did not work. See mslug.zip attachment for my try, where cropped screen does work, but stretched screen still gives a black screen. In other words, it is not caused only by multiply-blend.
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Attached Files	pacman.zip (390 bytes) Mar 7, 2020, 18:18 Uploaded by hap
Attached Files	mslug.zip (458 bytes) Mar 7, 2020, 18:39 Uploaded by hap