// license:BSD-3-Clause
// copyright-holders:Paul Hampson
/***************************************************************************
Video Hardware for Championship V'ball by Paul Hampson
Generally copied from China Gate by Paul Hampson
"Mainly copied from video of Double Dragon (bootleg) & Double Dragon II"
***************************************************************************/
#include "emu.h"
#include "cpu/m6502/m6502.h"
#include "includes/vball.h"
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
TILEMAP_MAPPER_MEMBER(vball_state::background_scan)
{
/* logical (col,row) -> memory offset */
return (col & 0x1f) + ((row & 0x1f) << 5) + ((col & 0x20) << 5) + ((row & 0x20) <<6);
}
TILE_GET_INFO_MEMBER(vball_state::get_bg_tile_info)
{
uint8_t code = m_videoram[tile_index];
uint8_t attr = m_attribram[tile_index];
SET_TILE_INFO_MEMBER(0,
code + ((attr & 0x1f) << 8) + (m_gfxset<<8),
(attr >> 5) & 0x7,
0);
}
void vball_state::video_start()
{
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(vball_state::get_bg_tile_info)), tilemap_mapper_delegate(*this, FUNC(vball_state::background_scan)), 8, 8, 64, 64);
m_bg_tilemap->set_scroll_rows(32);
m_gfxset=0;
m_bgprombank=0xff;
m_spprombank=0xff;
save_item(NAME(m_scrollx_hi));
save_item(NAME(m_scrolly_hi));
save_item(NAME(m_scrollx_lo));
save_item(NAME(m_gfxset));
save_item(NAME(m_scrollx));
save_item(NAME(m_bgprombank));
save_item(NAME(m_spprombank));
}
WRITE8_MEMBER(vball_state::videoram_w)
{
m_videoram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(vball_state::attrib_w)
{
m_attribram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
void vball_state::bgprombank_w( int bank )
{
int i;
uint8_t* color_prom;
if (bank==m_bgprombank) return;
color_prom = memregion("proms")->base() + bank*0x80;
for (i=0;i<128;i++, color_prom++) {
m_palette->set_pen_color(i,pal4bit(color_prom[0] >> 0),pal4bit(color_prom[0] >> 4),
pal4bit(color_prom[0x800] >> 0));
}
m_bgprombank=bank;
}
void vball_state::spprombank_w( int bank )
{
int i;
uint8_t* color_prom;
if (bank==m_spprombank) return;
color_prom = memregion("proms")->base()+0x400 + bank*0x80;
for (i=128;i<256;i++,color_prom++) {
m_palette->set_pen_color(i,pal4bit(color_prom[0] >> 0),pal4bit(color_prom[0] >> 4),
pal4bit(color_prom[0x800] >> 0));
}
m_spprombank=bank;
}
#define DRAW_SPRITE( order, sx, sy ) gfx->transpen(bitmap,\
cliprect, \
(which+order),color,flipx,flipy,sx,sy,0);
void vball_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
{
gfx_element *gfx = m_gfxdecode->gfx(1);
uint8_t *src = m_spriteram;
int i;
/* 240-Y S|X|CLR|WCH WHICH 240-X
xxxxxxxx x|x|xxx|xxx xxxxxxxx xxxxxxxx
*/
for (i = 0;i < m_spriteram.bytes();i += 4)
{
int attr = src[i+1];
int which = src[i+2]+((attr & 0x07)<<8);
int sx = ((src[i+3] + 8) & 0xff) - 7;
int sy = 240 - src[i];
int size = (attr & 0x80) >> 7;
int color = (attr & 0x38) >> 3;
int flipx = ~attr & 0x40;
int flipy = 0;
int dy = -16;
if (flip_screen())
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
dy = -dy;
}
switch (size)
{
case 0: /* normal */
DRAW_SPRITE(0,sx,sy);
break;
case 1: /* double y */
DRAW_SPRITE(0,sx,sy + dy);
DRAW_SPRITE(1,sx,sy);
break;
}
}
}
#undef DRAW_SPRITE
uint32_t vball_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
int i;
m_bg_tilemap->set_scrolly(0,m_scrolly_hi + *m_scrolly_lo);
/*To get linescrolling to work properly, we must ignore the 1st two scroll values, no idea why! -SJE */
for (i = 2; i < 256; i++) {
m_bg_tilemap->set_scrollx(i,m_scrollx[i-2]);
//logerror("scrollx[%d] = %d\n",i,m_scrollx[i]);
}
m_bg_tilemap->draw(screen, bitmap, cliprect, 0,0);
draw_sprites(bitmap,cliprect);
return 0;
}