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AmigActive 10
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AACD 10.iso
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vidhrdw
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appoooh.c
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C/C++ Source or Header
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2000-04-04
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8KB
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307 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
#define CHR1_OFST 0x00 /* palette page of char set #1 */
#define CHR2_OFST 0x10 /* palette page of char set #2 */
unsigned char *appoooh_videoram2;
unsigned char *appoooh_colorram2;
unsigned char *appoooh_spriteram2;
static unsigned char *dirtybuffer2;
static struct osd_bitmap *tmpbitmap2;
static int scroll_x;
static int flipscreen;
static int priority;
/***************************************************************************
Convert the color PROMs into a more useable format.
Palette information of appoooh is not known.
The palette decoder of Bank Panic was used for this driver.
Because these hardware is similar.
***************************************************************************/
void appoooh_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 < Machine->drv->total_colors;i++)
{
int bit0,bit1,bit2;
/* red component */
bit0 = (*color_prom >> 0) & 0x01;
bit1 = (*color_prom >> 1) & 0x01;
bit2 = (*color_prom >> 2) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* green component */
bit0 = (*color_prom >> 3) & 0x01;
bit1 = (*color_prom >> 4) & 0x01;
bit2 = (*color_prom >> 5) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* blue component */
bit0 = 0;
bit1 = (*color_prom >> 6) & 0x01;
bit2 = (*color_prom >> 7) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
color_prom++;
}
/* color_prom now points to the beginning of the lookup table */
/* charset #1 lookup table */
for (i = 0;i < TOTAL_COLORS(0);i++)
COLOR(0,i) = (*(color_prom++) & 0x0f)|CHR1_OFST;
/* charset #2 lookup table */
for (i = 0;i < TOTAL_COLORS(1);i++)
COLOR(1,i) = (*(color_prom++) & 0x0f)|CHR2_OFST;
/* TODO: the driver currently uses only 16 of the 32 color codes. */
/* 16-31 might be unused, but there might be a palette bank selector */
/* to use them somewhere in the game. */
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int appoooh_vh_start(void)
{
if (generic_vh_start() != 0)
return 1;
if ((dirtybuffer2 = malloc(videoram_size)) == 0)
{
generic_vh_stop();
return 1;
}
memset(dirtybuffer2,1,videoram_size);
if ((tmpbitmap2 = osd_create_bitmap(Machine->drv->screen_width,Machine->drv->screen_height)) == 0)
{
free(dirtybuffer2);
generic_vh_stop();
return 1;
}
return 0;
}
WRITE_HANDLER( appoooh_scroll_w )
{
scroll_x = data;
}
/***************************************************************************
Stop the video hardware emulation.
***************************************************************************/
void appoooh_vh_stop(void)
{
free(dirtybuffer2);
osd_free_bitmap(tmpbitmap2);
generic_vh_stop();
}
WRITE_HANDLER( appoooh_videoram2_w )
{
if (appoooh_videoram2[offset] != data)
{
dirtybuffer2[offset] = 1;
appoooh_videoram2[offset] = data;
}
}
WRITE_HANDLER( appoooh_colorram2_w )
{
if (appoooh_colorram2[offset] != data)
{
dirtybuffer2[offset] = 1;
appoooh_colorram2[offset] = data;
}
}
WRITE_HANDLER( appoooh_out_w )
{
/* bit 0 controls NMI */
if (data & 0x01) interrupt_enable_w(0,1);
else interrupt_enable_w(0,0);
/* bit 1 flip screen */
if ((data & 0x02) != flipscreen)
{
flipscreen = data & 0x02;
memset(dirtybuffer,1,videoram_size);
memset(dirtybuffer2,1,videoram_size);
}
/* bits 2-3 unknown */
/* bits 4-5 are playfield/sprite priority */
/* TODO: understand how this works, currently the only thing I do is draw */
/* the front layer behind sprites when priority == 0, and invert the sprite */
/* order when priority == 1 */
priority = (data & 0x30) >> 4;
/* bit 6 ROM bank select */
{
unsigned char *RAM = memory_region(REGION_CPU1);
cpu_setbank(1,&RAM[data&0x40 ? 0x10000 : 0x0a000]);
}
/* bit 7 unknown (used) */
}
static void appoooh_draw_sprites(struct osd_bitmap *dest_bmp,
const struct GfxElement *gfx,
unsigned char *sprite)
{
int offs;
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
int sy = 256-16-sprite[offs+0];
int code = (sprite[offs+1]>>2) + ((sprite[offs+2]>>5) & 0x07)*0x40;
int color = sprite[offs+2]&0x0f; /* TODO: bit 4 toggles continuously, what is it? */
int sx = sprite[offs+3];
int flipx = sprite[offs+1]&0x01;
if(sx>=248) sx -= 256;
if (flipscreen)
{
sx = 239- sx;
sy = 255- sy;
flipx = !flipx;
}
drawgfx( dest_bmp, gfx,
code,
color,
flipx,flipscreen,
sx, sy,
&Machine->drv->visible_area,
TRANSPARENCY_PEN , 0);
}
}
/***************************************************************************
Draw the game screen in the given osd_bitmap.
Do NOT call osd_update_display() from this function, it will be called by
the main emulation engine.
***************************************************************************/
void appoooh_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs;
int scroll;
/* for every character in the Video RAM, check if it has been modified */
/* since last time and update it accordingly. */
for (offs = videoram_size - 1;offs >= 0;offs--)
{
/* char set #1 */
if (dirtybuffer[offs])
{
int sx,sy,code,flipx;
dirtybuffer[offs] = 0;
sx = offs % 32;
sy = offs / 32;
code = videoram[offs] + 256 * ((colorram[offs]>>5) & 7);
flipx = colorram[offs] & 0x10;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
}
drawgfx(tmpbitmap,Machine->gfx[0],
code,
colorram[offs]&0x0f,
flipx,flipscreen,
8*sx,8*sy,
0,TRANSPARENCY_NONE,0);
}
/* char set #2 */
if (dirtybuffer2[offs])
{
int sx,sy,code,flipx;
dirtybuffer2[offs] = 0;
sx = offs % 32;
sy = offs / 32;
code = appoooh_videoram2[offs] + 256 * ((appoooh_colorram2[offs]>>5) & 0x07);
flipx = appoooh_colorram2[offs] & 0x10;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
}
drawgfx(tmpbitmap2,Machine->gfx[1],
code,
appoooh_colorram2[offs]&0x0f,
flipx,flipscreen,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
}
scroll = -scroll_x;
scroll = 0;
/* copy the temporary bitmaps to the screen */
copybitmap(bitmap,tmpbitmap2,0,0,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
if (priority == 0) /* fg behind sprites */
copyscrollbitmap(bitmap,tmpbitmap,1,&scroll,0,0,&Machine->drv->visible_area,TRANSPARENCY_COLOR,CHR1_OFST);
/* draw sprites */
if (priority == 1)
{
/* sprite set #1 */
appoooh_draw_sprites( bitmap, Machine->gfx[2],spriteram);
/* sprite set #2 */
appoooh_draw_sprites( bitmap, Machine->gfx[3],appoooh_spriteram2);
}
else
{
/* sprite set #2 */
appoooh_draw_sprites( bitmap, Machine->gfx[3],appoooh_spriteram2);
/* sprite set #1 */
appoooh_draw_sprites( bitmap, Machine->gfx[2],spriteram);
}
if (priority != 0) /* fg in front of sprites */
copyscrollbitmap(bitmap,tmpbitmap,1,&scroll,0,0,&Machine->drv->visible_area,TRANSPARENCY_COLOR,CHR1_OFST);
}