/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
UINT8 *tp84_videoram2, *tp84_colorram2;
static int col0;
/*
sprites are multiplexed, so we have to buffer the spriteram
scanline by scanline.
*/
static UINT8 *sprite_mux_buffer;
static int scanline;
static tilemap *bg_tilemap, *fg_tilemap;
/*
-The colortable is divided in 2 part:
-The characters colors
-The sprites colors
-The characters colors are indexed like this:
-2 bits from the characters
-4 bits from the attribute in colorram
-2 bits from col0 (d3-d4)
-3 bits from col0 (d0-d1-d2)
-So, there is 2048 bytes for the characters
-The sprites colors are indexed like this:
-4 bits from the sprites (16 colors)
-4 bits from the attribute of the sprites
-3 bits from col0 (d0-d1-d2)
-So, there is 2048 bytes for the sprites
*/
/*
The RGB signals are generated by 3 proms 256X4 (prom 2C, 2D and 1E)
The resistors values are:
1K ohm
470 ohm
220 ohm
100 ohm
*/
PALETTE_INIT( tp84 )
{
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,bit3,r,g,b;
/* 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;
r = 0x0e * bit0 + 0x1f * bit1 + 0x42 * bit2 + 0x90 * bit3;
/* green component */
bit0 = (color_prom[machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[machine->drv->total_colors] >> 3) & 0x01;
g = 0x0e * bit0 + 0x1f * bit1 + 0x42 * bit2 + 0x90 * bit3;
/* blue component */
bit0 = (color_prom[2*machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[2*machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[2*machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[2*machine->drv->total_colors] >> 3) & 0x01;
b = 0x0e * bit0 + 0x1f * bit1 + 0x42 * bit2 + 0x90 * bit3;
palette_set_color(machine,i,MAKE_RGB(r,g,b));
color_prom++;
}
color_prom += 2*machine->drv->total_colors;
/* color_prom now points to the beginning of the lookup table */
/* characters use colors 128-255 */
for (i = 0;i < TOTAL_COLORS(0)/8;i++)
{
int j;
for (j = 0;j < 8;j++)
COLOR(0,i+256*j) = *color_prom + 128 + 16*j;
color_prom++;
}
/* sprites use colors 0-127 */
for (i = 0;i < TOTAL_COLORS(1)/8;i++)
{
int j;
for (j = 0;j < 8;j++)
{
if (*color_prom) COLOR(1,i+256*j) = *color_prom + 16*j;
else COLOR(1,i+256*j) = 0; /* preserve transparency */
}
color_prom++;
}
}
WRITE8_HANDLER( tp84_videoram_w )
{
videoram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap, offset);
}
WRITE8_HANDLER( tp84_colorram_w )
{
colorram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap, offset);
}
WRITE8_HANDLER( tp84_videoram2_w )
{
tp84_videoram2[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap, offset);
}
WRITE8_HANDLER( tp84_colorram2_w )
{
tp84_colorram2[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap, offset);
}
WRITE8_HANDLER( tp84_scroll_x_w )
{
tilemap_set_scrollx(bg_tilemap, 0, data);
}
WRITE8_HANDLER( tp84_scroll_y_w )
{
tilemap_set_scrolly(bg_tilemap, 0, data);
}
WRITE8_HANDLER( tp84_flipscreen_x_w )
{
flip_screen_x_set(data & 0x01);
}
WRITE8_HANDLER( tp84_flipscreen_y_w )
{
flip_screen_y_set(data & 0x01);
}
/*****
col0 is a register to index the color Proms
*****/
WRITE8_HANDLER( tp84_col0_w )
{
if (col0 != data)
{
col0 = data;
tilemap_mark_all_tiles_dirty(ALL_TILEMAPS);
}
}
/* Return the current video scan line */
READ8_HANDLER( tp84_scanline_r )
{
return scanline;
}
static TILE_GET_INFO( get_bg_tile_info )
{
int coloffs = ((col0 & 0x18) << 1) + ((col0 & 0x07) << 6);
int attr = colorram[tile_index];
int code = videoram[tile_index] + ((attr & 0x30) << 4);
int color = (attr & 0x0f) + coloffs;
int flags = ((attr & 0x40) ? TILE_FLIPX : 0) | ((attr & 0x80) ? TILE_FLIPY : 0);
SET_TILE_INFO(0, code, color, flags);
}
static TILE_GET_INFO( get_fg_tile_info )
{
int coloffs = ((col0 & 0x18) << 1) + ((col0 & 0x07) << 6);
int attr = tp84_colorram2[tile_index];
int code = tp84_videoram2[tile_index]+ ((attr & 0x30) << 4);
int color = (attr & 0x0f) + coloffs;
int flags = ((attr & 0x40) ? TILE_FLIPX : 0) | ((attr & 0x80) ? TILE_FLIPY : 0) | TILE_FORCE_LAYER0;
SET_TILE_INFO(0, code, color, flags);
}
VIDEO_START( tp84 )
{
bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows,
TILEMAP_TYPE_PEN, 8, 8, 32, 32);
fg_tilemap = tilemap_create(get_fg_tile_info, tilemap_scan_rows,
TILEMAP_TYPE_PEN, 8, 8, 32, 32);
tilemap_set_transparent_pen(fg_tilemap, 0);
sprite_mux_buffer = auto_malloc(256 * spriteram_size);
}
static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect)
{
const gfx_element *gfx = machine->gfx[1];
int offs;
int line;
int coloffset = ((col0&0x07) << 4);
for (line = cliprect->min_y; line <= cliprect->max_y; line++)
{
UINT8 *sr;
rectangle clip = *cliprect;
sr = sprite_mux_buffer + line * spriteram_size;
clip.min_y = clip.max_y = line;
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
int code,color,sx,sy,flipx,flipy;
sx = sr[offs];
sy = 240 - sr[offs + 3];
if (sy > line-16 && sy <= line)
{
code = sr[offs + 1];
color = (sr[offs + 2] & 0x0f) + coloffset;
flipx = ~sr[offs + 2] & 0x40;
flipy = sr[offs + 2] & 0x80;
drawgfx(bitmap,gfx,
code,
color,
flipx,flipy,
sx,sy,
&clip,TRANSPARENCY_COLOR,0);
}
}
}
}
VIDEO_UPDATE( tp84 )
{
rectangle clip;
tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
draw_sprites(machine, bitmap, cliprect);
/* draw top fg_tilemap status layer part */
clip.min_x = machine->screen[0].visarea.min_x;
clip.max_x = machine->screen[0].visarea.min_x+15;
clip.min_y = machine->screen[0].visarea.min_y;
clip.max_y = machine->screen[0].visarea.max_y;
tilemap_draw(bitmap, &clip, fg_tilemap, 0, 0);
/* the middle part of fg_tilemap seems to be used as normal ram and is skipped */
/* draw bottom fg_tilemap status layer part */
clip.min_x = machine->screen[0].visarea.max_x-15;
clip.max_x = machine->screen[0].visarea.max_x;
clip.min_y = machine->screen[0].visarea.min_y;
clip.max_y = machine->screen[0].visarea.max_y;
tilemap_draw(bitmap, &clip, fg_tilemap, 0, 0);
return 0;
}
INTERRUPT_GEN( tp84_6809_interrupt )
{
scanline = 255 - cpu_getiloops();
memcpy(sprite_mux_buffer + scanline * spriteram_size,spriteram,spriteram_size);
if (scanline == 255)
irq0_line_hold();
}