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skyfox.cpp : Background pattern adjustment compared to PCB strictly. (#5979)

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sasuke-arcade 2019-11-30 00:59:26 +09:00 committed by hap
parent 75836c7ed7
commit 90866c6a35
1 changed files with 14 additions and 10 deletions
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24
src/mame/video/skyfox.cpp
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@ -192,9 +192,10 @@ void skyfox_state::draw_background(bitmap_ind16 &bitmap, const rectangle &clipre
{
uint8_t *rom = memregion("gfx2")->base();
/* Flashing stops until the first star moves after turning on the power */
bool shining = (m_bg_ctrl & 0x8);
/* Maybe star pattern change. This will change at some intervals or when restart */
/* Blinking stops until the first star moves after turning on the power */
bool blinking = (m_bg_ctrl & 0x8);
/* Star pattern change. This will change at when all star clusters to out of screen or when player restart.
When it changes, will change color of star clusters. */
int pattern = (m_bg_ctrl & 0x6) >> 1;
for (int i = 0; i < 0x1000; i++)
@ -206,16 +207,19 @@ void skyfox_state::draw_background(bitmap_ind16 &bitmap, const rectangle &clipre
/* ROM offset of star pattern */
int offs = (i * 2) % 0x2000 + pattern * 0x2000;
/* Looks like good, but was written with intuition, Probably not perfect */
/* Adjusted with 1 pixel accuracy compared to PCB.
Confirmed that pixel and color pattern match in the "1UP START" screen. */
int pen = rom[offs];
int x = rom[offs + 1] * 2 + ((i >> 4) & 1) + pos;
int y = (i >> 4);
x += 0x60; // Adjustment based on PCB display
int x = rom[offs + 1] * 2 + pos + 0x5b;
int y = (i >> 4) + 1;
// When flipscreen is enabled, direction of background scroll is reversed by the in-game subroutine.
// This PCB seems does not support background flip.
/* When flipscreen is enabled, scroll direction is flipped by only in-game subroutine.
This PCB seems does not support background flip. */
if (((m_bg_ctrl >> 4) & 3) != (pen & 3) || !shining)
/* This looks perfect at first glance.
but when strict compared on "1UP START" screen,
it seems the blinking pattern in each star may be different. */
if (((m_bg_ctrl >> 4) & 3) != (pen & 3) || !blinking)
bitmap.pix16(y % 256, x % 512) = pen;
}
}