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AmigActive 10
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AACD 10.iso
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vidhrdw
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xevious.c
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C/C++ Source or Header
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2000-05-04
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10KB
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385 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
unsigned char *xevious_fg_videoram,*xevious_fg_colorram;
unsigned char *xevious_bg_videoram,*xevious_bg_colorram;
extern unsigned char *spriteram,*spriteram_2,*spriteram_3;
extern size_t spriteram_size;
static struct tilemap *fg_tilemap,*bg_tilemap;
/* scroll position controller write (CUSTOM 13-1J on seet 7B) */
static int flipscreen;
/***************************************************************************
Convert the color PROMs into a more useable format.
Xevious has three 256x4 palette PROMs (one per gun) and four 512x4 lookup
table PROMs (two for sprites, two for background tiles; foreground
characters map directly to a palette color without using a PROM).
The palette PROMs are 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 xevious_vh_convert_color_prom(unsigned char *palette, unsigned short *colortable,const unsigned char *color_prom)
{
int i;
#define TOTAL_COLORS(gfxn) (Machine->gfx[gfxn]->total_colors * Machine->gfx[gfxn]->color_granularity)
#define COLOR(gfxn,offs) (colortable[Machine->drv->gfxdecodeinfo[gfxn].color_codes_start + offs])
for (i = 0;i < 128;i++)
{
int bit0,bit1,bit2,bit3;
/* red component */
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
bit3 = (color_prom[0] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
/* green component */
bit0 = (color_prom[256] >> 0) & 0x01;
bit1 = (color_prom[256] >> 1) & 0x01;
bit2 = (color_prom[256] >> 2) & 0x01;
bit3 = (color_prom[256] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
/* blue component */
bit0 = (color_prom[2*256] >> 0) & 0x01;
bit1 = (color_prom[2*256] >> 1) & 0x01;
bit2 = (color_prom[2*256] >> 2) & 0x01;
bit3 = (color_prom[2*256] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
color_prom++;
}
/* color 0x80 is used by sprites to mark transparency */
*(palette++) = 0;
*(palette++) = 0;
*(palette++) = 0;
color_prom += 128; /* the bottom part of the PROM is unused */
color_prom += 2*256;
/* color_prom now points to the beginning of the lookup table */
/* background tiles */
for (i = 0;i < TOTAL_COLORS(1);i++)
{
COLOR(1,i) = (color_prom[0] & 0x0f) | ((color_prom[TOTAL_COLORS(1)] & 0x0f) << 4);
color_prom++;
}
color_prom += TOTAL_COLORS(1);
/* sprites */
for (i = 0;i < TOTAL_COLORS(2);i++)
{
int c = (color_prom[0] & 0x0f) | ((color_prom[TOTAL_COLORS(2)] & 0x0f) << 4);
if (c & 0x80) COLOR(2,i) = c & 0x7f;
else COLOR(2,i) = 0x80; /* transparent */
color_prom++;
}
color_prom += TOTAL_COLORS(2);
/* foreground characters */
for (i = 0;i < TOTAL_COLORS(0);i++)
{
if (i % 2 == 0) COLOR(0,i) = 0x80; /* transparent */
else COLOR(0,i) = i / 2;
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static void get_fg_tile_info(int tile_index)
{
unsigned char attr = xevious_fg_colorram[tile_index];
SET_TILE_INFO(0,xevious_fg_videoram[tile_index],
((attr & 0x03) << 4) | ((attr & 0x3c) >> 2))
tile_info.flags = TILE_FLIPYX((attr & 0xc0) >> 6);
}
static void get_bg_tile_info(int tile_index)
{
unsigned char code = xevious_bg_videoram[tile_index];
unsigned char attr = xevious_bg_colorram[tile_index];
SET_TILE_INFO(1,code + ((attr & 0x01) << 8),
((attr & 0x3c) >> 2) | ((code & 0x80) >> 3) | ((attr & 0x03) << 5))
tile_info.flags = TILE_FLIPYX((attr & 0xc0) >> 6);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int xevious_vh_start(void)
{
bg_tilemap = tilemap_create(get_bg_tile_info,tilemap_scan_rows,TILEMAP_OPAQUE, 8,8,64,32);
fg_tilemap = tilemap_create(get_fg_tile_info,tilemap_scan_rows,TILEMAP_TRANSPARENT,8,8,64,32);
if (!bg_tilemap || !fg_tilemap)
return 1;
fg_tilemap->transparent_pen = 0;
return 0;
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE_HANDLER( xevious_fg_videoram_w )
{
if (xevious_fg_videoram[offset] != data)
{
xevious_fg_videoram[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap,offset);
}
}
WRITE_HANDLER( xevious_fg_colorram_w )
{
if (xevious_fg_colorram[offset] != data)
{
xevious_fg_colorram[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap,offset);
}
}
WRITE_HANDLER( xevious_bg_videoram_w )
{
if (xevious_bg_videoram[offset] != data)
{
xevious_bg_videoram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap,offset);
}
}
WRITE_HANDLER( xevious_bg_colorram_w )
{
if (xevious_bg_colorram[offset] != data)
{
xevious_bg_colorram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap,offset);
}
}
WRITE_HANDLER( xevious_vh_latch_w )
{
int reg;
data = data + ((offset&0x01)<<8); /* A0 -> D8 */
reg = (offset&0xf0)>>4;
switch (reg)
{
case 0:
if (flipscreen)
tilemap_set_scrollx(bg_tilemap,0,data-312);
else
tilemap_set_scrollx(bg_tilemap,0,data+20);
break;
case 1:
tilemap_set_scrollx(fg_tilemap,0,data+32);
break;
case 2:
tilemap_set_scrolly(bg_tilemap,0,data+16);
break;
case 3:
tilemap_set_scrolly(fg_tilemap,0,data+18);
break;
case 7: /* DISPLAY XY FLIP ?? */
flipscreen = data & 1;
tilemap_set_flip(ALL_TILEMAPS,flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
break;
default:
logerror("CRTC WRITE REG: %x Data: %03x\n",reg, data);
break;
}
}
/*
background pattern data
colorram mapping
b000-bfff background attribute
bit 0-1 COL:palette set select
bit 2-5 AN :color select
bit 6 AFF:Y flip
bit 7 PFF:X flip
c000-cfff background pattern name
bit 0-7 PP0-7
seet 8A
2 +-------+
COL0,1 --------------------------------------->|backg. |
1 |color |
PP7------------------------------------------->|replace|
4 | ROM | 6
AN0-3 ---------------------------------------->| 4H |-----> color code 6 bit
1 +-----------+ +--------+ | 4F |
COL0 ---->|B8 ROM 3C| 16 |custom | 2 | |
8 | |----->|shifter |------>| |
PP0-7 ---->|B0-7 ROM 3D| |16->2*8 | | |
+-----------+ +--------+ +-------+
font rom controller
1 +--------+ +--------+
ANF --->| ROM | 8 |shift | 1
8 | 3B |---->|reg |-----> font data
PP0-7 --->| | |8->1*8 |
+--------+ +--------+
font color ( not use color map )
2 |
COL0-1 --->| color code 6 bit
4 |
AN0-3 --->|
sprite
ROM 3M,3L color reprace table for sprite
*/
/***************************************************************************
Display refresh
***************************************************************************/
static void draw_sprites(struct osd_bitmap *bitmap)
{
int offs,sx,sy;
for (offs = 0;offs < spriteram_size;offs += 2)
{
if ((spriteram[offs + 1] & 0x40) == 0) /* I'm not sure about this one */
{
int bank,code,color,flipx,flipy;
if (spriteram_3[offs] & 0x80)
{
bank = 4;
code = spriteram[offs] & 0x3f;
}
else
{
bank = 2 + ((spriteram[offs] & 0x80) >> 7);
code = spriteram[offs] & 0x7f;
}
color = spriteram[offs + 1] & 0x7f;
flipx = spriteram_3[offs] & 4;
flipy = spriteram_3[offs] & 8;
if (flipscreen)
{
flipx = !flipx;
flipy = !flipy;
}
sx = spriteram_2[offs + 1] - 40 + 0x100*(spriteram_3[offs + 1] & 1);
sy = 28*8-spriteram_2[offs]-1;
if (spriteram_3[offs] & 2) /* double height (?) */
{
if (spriteram_3[offs] & 1) /* double width, double height */
{
code &= 0x7c;
drawgfx(bitmap,Machine->gfx[bank],
code+3,color,flipx,flipy,
flipx ? sx : sx+16,flipy ? sy-16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
drawgfx(bitmap,Machine->gfx[bank],
code+1,color,flipx,flipy,
flipx ? sx : sx+16,flipy ? sy : sy-16,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
}
code &= 0x7d;
drawgfx(bitmap,Machine->gfx[bank],
code+2,color,flipx,flipy,
flipx ? sx+16 : sx,flipy ? sy-16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
drawgfx(bitmap,Machine->gfx[bank],
code,color,flipx,flipy,
flipx ? sx+16 : sx,flipy ? sy : sy-16,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
}
else if (spriteram_3[offs] & 1) /* double width */
{
code &= 0x7e;
drawgfx(bitmap,Machine->gfx[bank],
code,color,flipx,flipy,
flipx ? sx+16 : sx,flipy ? sy-16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
drawgfx(bitmap,Machine->gfx[bank],
code+1,color,flipx,flipy,
flipx ? sx : sx+16,flipy ? sy-16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
}
else /* normal */
{
drawgfx(bitmap,Machine->gfx[bank],
code,color,flipx,flipy,sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,0x80);
}
}
}
}
void xevious_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
tilemap_update(ALL_TILEMAPS);
tilemap_render(ALL_TILEMAPS);
tilemap_draw(bitmap,bg_tilemap,0);
draw_sprites(bitmap);
tilemap_draw(bitmap,fg_tilemap,0);
}