04856: pc_sjetm: Corrupt start screen

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
04856	Graphics	Minor	Always	May 23, 2012, 00:47	Dec 3, 2018, 08:56

Tester	M.A.S.H.	View Status	Public	Platform	MAME (Self-compiled)
Assigned To		Resolution	Open	OS	Windows XP
Status [?]	Confirmed			Driver	nintendo/playch10.cpp
Version	0.146	Fixed in Version		Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	04856: pc_sjetm: Corrupt start screen
Description	Since MAME 0.108u1 (!) there is one corrupt screen right after insert coin in Solar Jetman.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version	0.108u1
Affected Sets / Systems	pc_sjetm

Attached Files	pc_sjetm.gif (16,450 bytes) May 23, 2012, 00:47 Uploaded by M.A.S.H.

No.15865 M.A.S.H. Senior Tester Dec 3, 2018, 08:56	MAME 0.204 src\devices\video\ppu2c0x.cpp line 787: // The sprite collision acts funny on the last pixel of a scanline. // The various scanline latches update while the last few pixels // are being drawn. Since we don't do cycle-by-cycle PPU emulation, // we fudge it a bit here so that sprite 0 collisions are detected // when, e.g., sprite x is 254, sprite y is 29 and we're rendering // at the end of scanline 28. // Battletoads needs this level of precision to be playable. if ((sprite_index == 0) && (sprite_xpos == 254)) { sprite_ypos--; /* set the "sprite 0 hit" flag if appropriate */ if (line_priority[sprite_xpos] & 0x02) m_regs[PPU_STATUS] \|= PPU_STATUS_SPRITE0_HIT; } This extra collision hack for the NES game Battletoads (MESS) breaks Solar Jetman. It was added in MAME 0.108u1 == Regression Version

No.15865

M.A.S.H.

Senior Tester

Dec 3, 2018, 08:56

MAME 0.204

src\devices\video\ppu2c0x.cpp line 787:

// The sprite collision acts funny on the last pixel of a scanline.
// The various scanline latches update while the last few pixels
// are being drawn. Since we don't do cycle-by-cycle PPU emulation,
// we fudge it a bit here so that sprite 0 collisions are detected
// when, e.g., sprite x is 254, sprite y is 29 and we're rendering
// at the end of scanline 28.
// Battletoads needs this level of precision to be playable.
if ((sprite_index == 0) && (sprite_xpos == 254))
{
sprite_ypos--;
/* set the "sprite 0 hit" flag if appropriate */
if (line_priority[sprite_xpos] & 0x02)
m_regs[PPU_STATUS] |= PPU_STATUS_SPRITE0_HIT;
}

This extra collision hack for the NES game Battletoads (MESS) breaks Solar Jetman.
It was added in MAME 0.108u1 == Regression Version