View source for Sprite Masking and Overflow Test ROM

[[File:Gens-gs-r7plus-vdp-to-cpp-86948622-SpriteMaskingTestRom.png|320px|right]]
[[sonic:Nemesis|Nemesis]]<nowiki>'</nowiki> '''Sprite Masking and Overflow Test ROM''' is a test ROM used to verify the emulation of several [[Sega Mega Drive]] VDP quirks, including sprite limits.

==Tests==

The following tests are performed by the Sprite Masking and Overflow Test ROM.

Terminology:
* H32 == 256x224 display mode
* H40 == 320x224 display mode.
* Sprite mask: A sprite with X=0.

Tests:

# Max Sprites Per Line: 16 in H32, 20 in H40.
# Max Sprite Dots - Basic: Up to 256 sprite dots in H32; 320 in H40.
# Max Sprite Dots - Complex: Same as previous, except it verifies that sprites are cut off in the middle.
# Sprite Mask: Verifies that lower-priority sprites are masked if a sprite mask exists and is not the first sprite on the line.
# Sprite Mask S1: Verifies that lower-priority sprites are *not* masked if a sprite mask exists and is the first sprite on the line.
# Mask S1 On Dot Overflow: Verifies that sprite masks at the beginning of the line are ineffective if sprite dot overflow occurs on the previous line.
# Mask S1,X=1 S2,X=0: Verifies that the non-existent sprite masking "Mode 2" is not implemented.
# Mask S1,X=40 S2,X=0: Same as previous.
# Max Sprites Per Frame: 64 in H32, 80 in H40.

For tests with two results, the left result indicates that the minimum boundary is respected, and the right result indicates that the maximum boundary is respected.

Test #6 is conditional on test #5 passing. If test #5 passes, then test #6 passing is an error (indicated by a red line underneath "PASS").

==Downloads==
{{Multidownload
 |file1=SpriteMaskingTestRom.bin.gz
 |filename1=Sprite Masking and Test ROM
 |filesize1=3 KB
 |file2=SpriteMaskingTestRomSrc.zip
 |filename2=Sprite Masking and Test ROM (source code)
 |filesize2=4 KB
}}

==Test results==
===Hardware===

===Emulators===
Note: Using latest versions of emulators, unless otherwise stated.{{#vardefine:screenwidth|120}}
{| class="prettytable sortable"
!Emulator
!Release date
!class="unsortable"|H32 Mode
!class="unsortable"|H40 Mode
!class="unsortable"|Comments
|-
|[[AGES]]
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|-
|[[BizHawk]]
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|[[BlastEm]]
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|[[D-DGen]]
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|[[DebuGens]]
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|[[DGen]]
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|[[DrMD]]
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|-
|[[DualGens]]
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|-
|[[Exodus]]
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|-
|[[FB Alpha]]
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|-
|[[GenaDrive]]
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|-
|[[Genecyst]]
|1998-08-18
|{{bobscreen|SMaOTR H32 Genecyst.png|width={{#var:screenwidth}}}}
|{{bobscreen|SMaOTR H40 Genecyst.png|width={{#var:screenwidth}}}}
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|-
|[[GenEm]] (DOS)
|1997-05-20
|{{bobscreen|SMaOTR H32 GenEm.png|width={{#var:screenwidth}}}}
|{{bobscreen|SMaOTR H40 GenEm.png|width={{#var:screenwidth}}}}
|Images are cropped to 320x200.
|-
|[[Generator (emulator)]]
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|-
|[[Genesis Plus]]
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|-
|[[Genesis Plus GX]]
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|-
|[[Genesis4iphone]]
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|-
|[[Genital]]
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|-
|[[Gens]]
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|-
|[[Gens (Nick o'DIMM)]]
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|-
|[[Gens (XPort)]]
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|-
|[[Gens KMod]]
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|-
|[[Gens Plus!]]
|2005-08-06
|{{bobscreen|SMaOTR H32 GensPlus.png|width={{#var:screenwidth}}}}
|{{bobscreen|SMaOTR H40 GensPlus.png|width={{#var:screenwidth}}}}
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|-
|[[Gens Re-Recording]]
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|-
|[[Gens Tracer]]
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|-
|[[Gens X]]
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|-
|[[Gens/GS]]
|2009-11-22
|{{bobscreen|SMaOTR H32 GensGS.png|width={{#var:screenwidth}}}}
|{{bobscreen|Gens-gs-r7plus-vdp-to-cpp-86948622-SpriteMaskingTestRom.png|width={{#var:screenwidth}}}}
|
|-
|[[Gens/GS II]]
|2016
|{{bobscreen|SMaOTR H32 GensGS.png|width={{#var:screenwidth}}}}
|{{bobscreen|Gens-gs-r7plus-vdp-to-cpp-86948622-SpriteMaskingTestRom.png|width={{#var:screenwidth}}}}
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|-
|[[Gens32]]
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|-
|[[Gensoid]]
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|-
|[[Genux]]
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|-
|[[GigaDrive (GP32)]]
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|-
|[[HazeMD]]
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|-
|[[Higan]]
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|-
|[[IDC Log Gens]]
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|-
|[[JEnesis]]
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|-
|[[JEnesisDS]]
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|-
|[[Kega]]
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|-
|[[Kega (emulator)]]
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|-
|[[Kega Fusion]]
|2010-03-07
|{{bobscreen|SMaOTR H32 KegaFusion.png|width={{#var:screenwidth}}}}
|{{bobscreen|SMaOTR H40 KegaFusion.png|width={{#var:screenwidth}}}}
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|-
|[[Kega Lazarus]]
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|-
|[[KGen]]
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|-
|[[KGen98]]
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|-
|[[Mednafen]]
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|-
|[[Megadrive Emulator]]
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|-
|[[Megasis]]
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|-
|[[Mimic]]
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|-
|[[NeoGenesis]]
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|-
|[[PGen]]
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|-
|[[PicoDrive]]
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|-
|[[PicoDrive (Windows)]]
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|-
|[[PicoDriveDS]]
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|-
|[[PSPGenesis]]
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|-
|[[Regen]]
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|-
|[[RetroCopy]]
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|-
|[[RetroDrive]]
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|-
|[[SegaEMU]]
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|-
|[[SGens]]
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|-
|[[St0rm]]
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|-
|[[VGen]]
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|-
|[[Xe]]
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|[[Xega]]
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|[[Xenesis]]
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|}

==External links==
* [http://gendev.spritesmind.net/forum/viewtopic.php?p=8364 http://gendev.spritesmind.net/forum/viewtopic.php?p=8364] Original topic discussing emulation sprite masking, along with the post of the Test ROM

[[Category:Emulation]]