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// license:BSD-3-Clause
// copyright-holders:Takahiro Nogi
/***************************************************************************
Video Hardware for MAGMAX.
Driver by Takahiro Nogi (nogi@kt.rim.or.jp) 1999/11/05 -
Additional tweaking by Jarek Burczynski
***************************************************************************/
#include "emu.h"
#include "includes/magmax.h"
/***************************************************************************
Convert the color PROMs into a more useable format.
Mag Max has three 256x4 palette PROMs (one per gun), connected to the
RGB output this way:
bit 3 -- 220 ohm resistor -- RED/GREEN/BLUE
-- 470 ohm resistor -- RED/GREEN/BLUE
-- 1 kohm resistor -- RED/GREEN/BLUE
bit 0 -- 2.2kohm resistor -- RED/GREEN/BLUE
***************************************************************************/
void magmax_state::palette(palette_device &palette) const
{
const uint8_t *color_prom = memregion("proms")->base();
// create a lookup table for the palette
for (int i = 0; i < 0x100; i++)
{
int const r = pal4bit(color_prom[i + 0x000]);
int const g = pal4bit(color_prom[i + 0x100]);
int const b = pal4bit(color_prom[i + 0x200]);
palette.set_indirect_color(i, rgb_t(r, g, b));
}
// color_prom now points to the beginning of the lookup table
color_prom += 0x300;
// characters use colors 0-0x0f
for (int i = 0; i < 0x10; i++)
palette.set_pen_indirect(i, i);
// sprites use colors 0x10-0x1f, color 0x1f being transparent
for (int i = 0; i < 0x100; i++)
{
uint8_t const ctabentry = (color_prom[i] & 0x0f) | 0x10;
palette.set_pen_indirect(i + 0x10, ctabentry);
}
// background uses all colors (no lookup table)
for (int i = 0; i < 0x100; i++)
palette.set_pen_indirect(i + 0x110, i);
}
void magmax_state::video_start()
{
uint8_t * prom14D = memregion("user2")->base();
// Set up save state
save_item(NAME(m_flipscreen));
m_prom_tab = std::make_unique<uint32_t[]>(256);
m_screen->register_screen_bitmap(m_bitmap);
// Allocate temporary bitmap
for (int i = 0; i < 256; i++)
{
int v = (prom14D[i] << 4) + prom14D[i + 0x100];
m_prom_tab[i] = ((v&0x1f)<<8) | ((v&0x10)<<10) | ((v&0xe0)>>1); /*convert data into more useful format*/
}
}
uint32_t magmax_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
// bit 2 flip screen
m_flipscreen = *m_vreg & 0x04;
// copy the background graphics
if (*m_vreg & 0x40) // background disable
bitmap.fill(0, cliprect);
else
{
uint32_t scroll_h = (*m_scroll_x) & 0x3fff;
uint32_t scroll_v = (*m_scroll_y) & 0xff;
// clear background-over-sprites bitmap
m_bitmap.fill(0);
for (int v = 2*8; v < 30*8; v++) // only for visible area
{
uint16_t line_data[256];
uint32_t map_v_scr_100 = (scroll_v + v) & 0x100;
uint32_t rom18D_addr = ((scroll_v + v) & 0xf8) + (map_v_scr_100<<5);
uint32_t rom15F_addr = (((scroll_v + v) & 0x07)<<2) + (map_v_scr_100<<5);
uint32_t map_v_scr_1fe_6 =((scroll_v + v) & 0x1fe)<<6;
pen_t pen_base = 0x110 + 0x20 + (map_v_scr_100>>1);
for (int h = 0; h < 0x100; h++)
{
uint32_t LS283 = scroll_h + h;
if (!map_v_scr_100)
{
if (h & 0x80)
LS283 = LS283 + (m_rom18B[ map_v_scr_1fe_6 + (h ^ 0xff) ] ^ 0xff);
else
LS283 = LS283 + m_rom18B[ map_v_scr_1fe_6 + h ] + 0xff01;
}
uint32_t prom_data = m_prom_tab[ (LS283 >> 6) & 0xff ];
rom18D_addr &= 0x20f8;
rom18D_addr += (prom_data & 0x1f00) + ((LS283 & 0x38) >>3);
rom15F_addr &= 0x201c;
rom15F_addr += (m_rom18B[0x4000 + rom18D_addr ]<<5) + ((LS283 & 0x6)>>1);
rom15F_addr += (prom_data & 0x4000);
uint32_t graph_color = (prom_data & 0x0070);
uint32_t graph_data = m_rom18B[0x8000 + rom15F_addr];
if ((LS283 & 1))
graph_data >>= 4;
graph_data &= 0x0f;
line_data[h] = pen_base + graph_color + graph_data;
// priority: background over sprites
if (map_v_scr_100 && ((graph_data & 0x0c)==0x0c))
m_bitmap.pix(v, h) = line_data[h];
}
if (m_flipscreen)
{
uint16_t line_data_flip_x[256];
for (int i = 0; i < 256; i++)
line_data_flip_x[i] = line_data[255-i];
draw_scanline16(bitmap, 0, 255-v, 256, line_data_flip_x, nullptr);
}
else
draw_scanline16(bitmap, 0, v, 256, line_data, nullptr);
}
}
// draw the sprites
for (int offs = 0; offs < m_spriteram.bytes()/2; offs += 4)
{
int sy = m_spriteram[offs] & 0xff;
if (sy)
{
int code = m_spriteram[offs + 1] & 0xff;
int attr = m_spriteram[offs + 2] & 0xff;
int color = (attr & 0xf0) >> 4;
int flipx = attr & 0x04;
int flipy = attr & 0x08;
int sx = (m_spriteram[offs + 3] & 0xff) - 0x80 + 0x100 * (attr & 0x01);
sy = 239 - sy;
if (m_flipscreen)
{
sx = 255-16 - sx;
sy = 239 - sy;
flipx = !flipx;
flipy = !flipy;
}
if (code & 0x80) // sprite bankswitch
code += (*m_vreg & 0x30) * 0x8;
m_gfxdecode->gfx(1)->transmask(bitmap, cliprect,
code,
color,
flipx, flipy,
sx, sy,
m_palette->transpen_mask(*m_gfxdecode->gfx(1), color, 0x1f));
}
}
if (!(*m_vreg & 0x40)) // background disable
copybitmap_trans(bitmap, m_bitmap, m_flipscreen, m_flipscreen, 0, 0, cliprect, 0);
// draw the foreground characters
for (int offs = 32*32-1; offs >= 0; offs -= 1)
{
//int page = (*m_vreg>>3) & 0x1;
int code = m_videoram[offs /*+ page*/] & 0xff;
if (code)
{
int sx = (offs % 32);
int sy = (offs / 32);
if (m_flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
}
m_gfxdecode->gfx(0)->transpen(bitmap, cliprect,
code,
0,
m_flipscreen, m_flipscreen,
8 * sx, 8 * sy, 0x0f);
}
}
return 0;
}
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