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AmigActive 10
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AACD 10.iso
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vidhrdw
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suprloco.c
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C/C++ Source or Header
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2000-05-04
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7KB
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295 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
extern unsigned char *spriteram;
extern size_t spriteram_size;
unsigned char *suprloco_videoram;
static struct tilemap *bg_tilemap;
static int flipscreen;
static int control;
#define SPR_Y_TOP 0
#define SPR_Y_BOTTOM 1
#define SPR_X 2
#define SPR_COL 3
#define SPR_SKIP_LO 4
#define SPR_SKIP_HI 5
#define SPR_GFXOFS_LO 6
#define SPR_GFXOFS_HI 7
/***************************************************************************
Convert the color PROMs into a more useable format.
I'm not sure about the resistor values, I'm using the Galaxian ones.
***************************************************************************/
void suprloco_vh_convert_color_prom(unsigned char *palette, unsigned short *colortable,const unsigned char *color_prom)
{
int i;
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++;
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static void get_tile_info(int tile_index)
{
unsigned char attr = suprloco_videoram[2*tile_index+1];
SET_TILE_INFO(0,suprloco_videoram[2*tile_index] | ((attr & 0x03) << 8),(attr & 0x1c) >> 2)
tile_info.priority = (attr & 0x20) >> 5;
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int suprloco_vh_start(void)
{
bg_tilemap = tilemap_create(get_tile_info,tilemap_scan_rows,TILEMAP_OPAQUE,8,8,32,32);
if (!bg_tilemap)
return 1;
tilemap_set_scroll_rows(bg_tilemap,32);
return 0;
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE_HANDLER( suprloco_videoram_w )
{
if (suprloco_videoram[offset] != data)
{
suprloco_videoram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap,offset/2);
}
}
static int suprloco_scrollram[32];
WRITE_HANDLER( suprloco_scrollram_w )
{
int adj = flipscreen ? -8 : 8;
suprloco_scrollram[offset] = data;
tilemap_set_scrollx(bg_tilemap,offset, data - adj);
}
READ_HANDLER( suprloco_scrollram_r )
{
return suprloco_scrollram[offset];
}
WRITE_HANDLER( suprloco_control_w )
{
/* There is probably a palette select in here */
/* Bit 0 - coin counter A */
/* Bit 1 - coin counter B (only used if coinage differs from A) */
/* Bit 2-3 - probably unused */
/* Bit 4 - ??? pulsated when loco turns "super" */
/* Bit 5 - ??? */
/* Bit 6 - probably unused */
/* Bit 7 - flip screen */
if ((control & 0x10) != (data & 0x10))
{
/*logerror("Bit 4 = %d\n", (data >> 4) & 1); */
}
if ((control & 0x20) != (data & 0x20))
{
/*logerror("Bit 5 = %d\n", (data >> 5) & 1); */
}
coin_counter_w(0, data & 0x01);
coin_counter_w(1, data & 0x02);
flipscreen = data & 0x80;
tilemap_set_flip(ALL_TILEMAPS,flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
tilemap_set_scrolly(bg_tilemap,0,flipscreen ? -32 : 0);
control = data;
}
READ_HANDLER( suprloco_control_r )
{
return control;
}
/***************************************************************************
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.
***************************************************************************/
INLINE void draw_pixel(struct osd_bitmap *bitmap,int x,int y,int color)
{
if (flipscreen)
{
x = bitmap->width - x - 1;
y = bitmap->height - y - 1;
}
if (x < Machine->drv->visible_area.min_x ||
x > Machine->drv->visible_area.max_x ||
y < Machine->drv->visible_area.min_y ||
y > Machine->drv->visible_area.max_y)
return;
plot_pixel(bitmap, x, y, color);
}
static void render_sprite(struct osd_bitmap *bitmap,int spr_number)
{
int sx,sy,col,row,height,src,adjy,dy;
unsigned char *spr_reg;
unsigned short *spr_palette;
short skip; /* bytes to skip before drawing each row (can be negative) */
spr_reg = spriteram + 0x10 * spr_number;
src = spr_reg[SPR_GFXOFS_LO] + (spr_reg[SPR_GFXOFS_HI] << 8);
skip = spr_reg[SPR_SKIP_LO] + (spr_reg[SPR_SKIP_HI] << 8);
height = spr_reg[SPR_Y_BOTTOM] - spr_reg[SPR_Y_TOP];
spr_palette = Machine->remapped_colortable + 0x10 * spr_reg[SPR_COL];
sx = spr_reg[SPR_X];
sy = spr_reg[SPR_Y_TOP] + 1;
if (!flipscreen)
{
adjy = sy;
dy = 1;
}
else
{
adjy = sy + height + 30; /* some of the sprites are still off by a pixel */
dy = -1;
}
for (row = 0;row < height;row++,adjy+=dy)
{
int color1,color2,flipx;
UINT8 data;
UINT8 *gfx;
src += skip;
col = 0;
/* get pointer to packed sprite data */
gfx = &(memory_region(REGION_GFX2)[src & 0x7fff]);
flipx = src & 0x8000; /* flip x */
while (1)
{
if (flipx) /* flip x */
{
data = *gfx--;
color1 = data & 0x0f;
color2 = data >> 4;
}
else
{
data = *gfx++;
color1 = data >> 4;
color2 = data & 0x0f;
}
if (color1 == 15) break;
if (color1)
draw_pixel(bitmap,sx+col, adjy,spr_palette[color1]);
if (color2 == 15) break;
if (color2)
draw_pixel(bitmap,sx+col+1,adjy,spr_palette[color2]);
col += 2;
}
}
}
void draw_sprites(struct osd_bitmap *bitmap)
{
int spr_number;
unsigned char *spr_reg;
for (spr_number = 0;spr_number < (spriteram_size >> 4);spr_number++)
{
spr_reg = spriteram + 0x10 * spr_number;
if (spr_reg[SPR_X] != 0xff)
render_sprite(bitmap,spr_number);
}
}
void suprloco_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,bg_tilemap,1);
}