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AmigActive 10
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AACD 10.iso
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AACD
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MAME
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vidhrdw
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citycon.c
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C/C++ Source or Header
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2000-04-23
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7KB
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296 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *citycon_charlookup;
unsigned char *citycon_scroll;
static struct osd_bitmap *tmpbitmap2;
static int bg_image,dirty_background;
static unsigned char dirtylookup[32];
static int flipscreen;
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int citycon_vh_start(void)
{
if ((dirtybuffer = malloc(videoram_size)) == 0)
return 1;
memset(dirtybuffer,1,videoram_size);
dirty_background = 1;
/* CityConnection has a virtual screen 4 times as large as the visible screen */
if ((tmpbitmap = osd_new_bitmap(4 * Machine->drv->screen_width,Machine->drv->screen_height,Machine->scrbitmap->depth)) == 0)
{
free(dirtybuffer);
return 1;
}
/* And another one for background */
if ((tmpbitmap2 = osd_new_bitmap(4 * Machine->drv->screen_width,Machine->drv->screen_height,Machine->scrbitmap->depth)) == 0)
{
osd_free_bitmap(tmpbitmap);
free(dirtybuffer);
return 1;
}
return 0;
}
/***************************************************************************
Stop the video hardware emulation.
***************************************************************************/
void citycon_vh_stop(void)
{
free(dirtybuffer);
osd_free_bitmap(tmpbitmap);
osd_free_bitmap(tmpbitmap2);
}
WRITE_HANDLER( citycon_charlookup_w )
{
if (citycon_charlookup[offset] != data)
{
citycon_charlookup[offset] = data;
dirtylookup[offset / 8] = 1;
}
}
WRITE_HANDLER( citycon_background_w )
{
/* bits 4-7 control the background image */
if (bg_image != (data >> 4))
{
bg_image = data >> 4;
dirty_background = 1;
}
/* bit 0 flips screen */
/* it is also used to multiplex player 1 and player 2 controls */
if (flipscreen != (data & 1))
{
flipscreen = data & 1;
memset(dirtybuffer,1,videoram_size);
dirty_background = 1;
}
/* bits 1-3 are unknown */
if ((data & 0x0e) != 0) logerror("background register = %02x\n",data);
}
READ_HANDLER( citycon_in_r )
{
return readinputport(flipscreen);
}
/***************************************************************************
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 citycon_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs;
palette_init_used_colors();
for (offs = videoram_size - 1;offs >= 0;offs--)
{
int code,color;
code = memory_region(REGION_GFX4)[0x1000 * bg_image + offs];
color = memory_region(REGION_GFX4)[0xc000 + 0x100 * bg_image + code],
memset(&palette_used_colors[256 + 16 * color],PALETTE_COLOR_USED,16);
}
for (offs = 0;offs < 256;offs++)
{
int color;
color = citycon_charlookup[offs];
palette_used_colors[512 + 4 * color] = PALETTE_COLOR_TRANSPARENT;
memset(&palette_used_colors[512 + 4 * color + 1],PALETTE_COLOR_USED,3);
}
for (offs = spriteram_size-4;offs >= 0;offs -= 4)
{
int color;
color = spriteram[offs + 2] & 0x0f;
memset(&palette_used_colors[16 * color + 1],PALETTE_COLOR_USED,15);
}
if (palette_recalc())
{
memset(dirtybuffer,1,videoram_size);
dirty_background = 1;
}
/* Create the background */
if (dirty_background)
{
dirty_background = 0;
for (offs = videoram_size - 1;offs >= 0;offs--)
{
int sx,sy,code;
sy = offs / 32;
sx = (offs % 32) + (sy & 0x60);
sy = sy & 31;
if (flipscreen)
{
sx = 127 - sx;
sy = 31 - sy;
}
code = memory_region(REGION_GFX4)[0x1000 * bg_image + offs];
drawgfx(tmpbitmap2,Machine->gfx[3 + bg_image],
code,
memory_region(REGION_GFX4)[0xc000 + 0x100 * bg_image + code],
flipscreen,flipscreen,
8*sx,8*sy,
0,TRANSPARENCY_NONE,0);
}
}
/* copy the temporary bitmap to the screen */
{
int scroll;
if (flipscreen)
scroll = 256 + ((citycon_scroll[0]*256+citycon_scroll[1]) >> 1);
else
scroll = -((citycon_scroll[0]*256+citycon_scroll[1]) >> 1);
copyscrollbitmap(bitmap,tmpbitmap2,1,&scroll,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* 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--)
{
int sx,sy;
sy = offs / 32;
sx = (offs % 32) + (sy & 0x60);
sy = sy & 0x1f;
if (dirtybuffer[offs] || dirtylookup[sy])
{
int i;
struct rectangle clip;
dirtybuffer[offs] = 0;
if (flipscreen)
{
sx = 127 - sx;
sy = 31 - sy;
}
clip.min_x = 8*sx;
clip.max_x = 8*sx+7;
/* City Connection controls the color code for each _scanline_, not */
/* for each character as happens in most games. Therefore, we have to draw */
/* the character eight times, each time clipped to one line and using */
/* the color code for that scanline */
for (i = 0;i < 8;i++)
{
clip.min_y = 8*sy + i;
clip.max_y = 8*sy + i;
drawgfx(tmpbitmap,Machine->gfx[0],
videoram[offs],
citycon_charlookup[flipscreen ? (255 - 8*sy - i) : 8*sy + i],
flipscreen,flipscreen,
8*sx,8*sy,
&clip,TRANSPARENCY_NONE,0);
}
}
}
/* copy the temporary bitmap to the screen */
{
int i,scroll[32];
if (flipscreen)
{
for (i = 0;i < 6;i++)
scroll[31-i] = 256;
for (i = 6;i < 32;i++)
scroll[31-i] = 256 + (citycon_scroll[0]*256+citycon_scroll[1]);
}
else
{
for (i = 0;i < 6;i++)
scroll[i] = 0;
for (i = 6;i < 32;i++)
scroll[i] = -(citycon_scroll[0]*256+citycon_scroll[1]);
}
copyscrollbitmap(bitmap,tmpbitmap,32,scroll,0,0,
&Machine->drv->visible_area,TRANSPARENCY_PEN,palette_transparent_pen);
}
for (offs = spriteram_size-4;offs >= 0;offs -= 4)
{
int sx,sy,flipx;
sx = spriteram[offs + 3];
sy = 239 - spriteram[offs];
flipx = ~spriteram[offs + 2] & 0x10;
if (flipscreen)
{
sx = 240 - sx;
sy = 238 - sy;
flipx = !flipx;
}
drawgfx(bitmap,Machine->gfx[spriteram[offs + 1] & 0x80 ? 2 : 1],
spriteram[offs + 1] & 0x7f,
spriteram[offs + 2] & 0x0f,
flipx,flipscreen,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
for (offs = 0;offs < 32;offs++)
dirtylookup[offs] = 0;
}