/**********************************************************************
Signetics 2636 video chip
Copyright Nicola Salmoria and the MAME Team.
Visit http://mamedev.org for licensing and usage restrictions.
PVI REGISTER DESCRIPTION
------------------------
| bit |R/W| description
byte | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| | |
FC0 | size 4| size 3| size 2| size 1| W | size of the 4 objects(=sprites)
| | |
FC1 | |C1 |C2 |C3 |C1 |C2 |C3 | W | colors of the 4 objects
| | color 1 | color 2 | |
FC2 | |C1 |C2 |C3 |C1 |C2 |C3 | W |
| | color 3 | color 4 | |
| | |
FC3 | |sh |pos| W | 1=shape 0=position
| | | display format and position
FC4 | (free) | |
FC5 | (free) | |
| | |
FC6 | |C1 |C2 |C3 |BG |scrn colr | W | background lock and color
| |backg colr |enb|C1 |C2 |C3 | | 3="enable"
| | |
FC7 | sound | W | squarewave output
| | |
FC8 | N1 | N2 | W | range of the 4 display digits
FC9 | N3 | N4 | W |
| | |
|obj/backgrnd |complete object| R |
FCA | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | |
| | |
FCB | |VR-| object collisions | R | Composition of object and back-
| |LE |1/2|1/3|1/3|1/4|2/4|3/4| | ground,collision detection and
| | | object display as a state display
| | | for the status register.Set VRLE.
| | | wait for VRST.Read out or transmit
| | | [copy?] all bits until reset by
| | | VRST.
| | |
FCC | PORT1 | R | PORT1 and PORT2 for the range of
FCD | PORT2 | | the A/D conversion.Cleared by VRST
FCE | (free) | |
FCF | (free) | |
Size control by byte FC0
bit matrix
|0|0| 8x10
|0|1| 16x20
|1|0| 32x40
|1|1| 64x80
CE1 and not-CE2 are outputs from the PVI.$E80..$EFF also controls the
analog multiplexer.
SPRITES
-------
each object field: (=sprite data structure)
0 \ 10 bytes of bitmap (Each object is 8 pixels wide.)
9 /
A HC horizontal object coordinate
B HCB horizontal duplicate coordinate
C VC vertical object coordinate
D VCB vertical duplicate coordinate
*************************************************************/
#include "driver.h"
#include "s2636.h"
/*************************************
*
* Constants
*
*************************************/
#define SPRITE_WIDTH (8)
#define SPRITE_HEIGHT (10)
static const int sprite_offsets[4] = { 0x00, 0x10, 0x20, 0x40 };
/*************************************
*
* Internal S2636 data structure
*
*************************************/
struct _s2636_t
{
UINT8 *work_ram;
int y_offset;
int x_offset;
mame_bitmap *bitmap;
mame_bitmap *collision_bitmap;
};
/*************************************
*
* Configuration
*
*************************************/
s2636_t *s2636_config(UINT8 *work_ram, int screen_height, int screen_width, int y_offset, int x_offset)
{
s2636_t *s2636;
/* allocate the object that holds the state */
s2636 = auto_malloc(sizeof(*s2636));
s2636->work_ram = work_ram;
s2636->y_offset = y_offset;
s2636->x_offset = x_offset;
s2636->bitmap = auto_bitmap_alloc(screen_width, screen_height, BITMAP_FORMAT_INDEXED16);
s2636->collision_bitmap = auto_bitmap_alloc(screen_width, screen_height, BITMAP_FORMAT_INDEXED16);
return s2636;
}
/*************************************
*
* Draw a sprite
*
*************************************/
static void draw_sprite(UINT8 *gfx, int color, int y, int x, int expand,
int or_mode, mame_bitmap *bitmap, const rectangle *cliprect)
{
int sy;
/* for each row */
for (sy = 0; sy < SPRITE_HEIGHT; sy++)
{
int sx;
/* for each pixel on the row */
for (sx = 0; sx < SPRITE_WIDTH; sx++)
{
int ey;
/* each pixel can be expanded */
for (ey = 0; ey <= expand; ey++)
{
int ex;
for (ex = 0; ex <= expand; ex++)
{
/* compute effective destination pixel */
int ty = y + sy * (expand + 1) + ey;
int tx = x + sx * (expand + 1) + ex;
/* get out if outside the drawing region */
if ((tx < cliprect->min_x) ||
(tx > cliprect->max_x) ||
(ty < cliprect->min_y) ||
(ty > cliprect->max_y))
continue;
/* get out if current image bit is transparent */
if (((gfx[sy] << sx) & 0x80) == 0x00)
continue;
if (or_mode)
*BITMAP_ADDR16(bitmap, ty, tx) = 0x08 | *BITMAP_ADDR16(bitmap, ty, tx) | color;
else
*BITMAP_ADDR16(bitmap, ty, tx) = 0x08 | color;
}
}
}
}
}
/*************************************
*
* Collision detection
*
*************************************/
static int check_collision(s2636_t *s2636, int spriteno1, int spriteno2, const rectangle *cliprect)
{
int checksum = 0;
UINT8* attr1 = &s2636->work_ram[sprite_offsets[spriteno1]];
UINT8* attr2 = &s2636->work_ram[sprite_offsets[spriteno2]];
/* TODO: does not check shadow sprites yet */
fillbitmap(s2636->collision_bitmap, 0, cliprect);
if ((attr1[0x0a] != 0xff) && (attr2[0x0a] != 0xff))
{
int x, y;
int x1 = attr1[0x0a] + s2636->x_offset;
int y1 = attr1[0x0c] + s2636->y_offset;
int x2 = attr2[0x0a] + s2636->x_offset;
int y2 = attr2[0x0c] + s2636->y_offset;
int expand1 = (s2636->work_ram[0xc0] >> (spriteno1 << 1)) & 0x03;
int expand2 = (s2636->work_ram[0xc0] >> (spriteno2 << 1)) & 0x03;
/* draw first sprite */
draw_sprite(attr1, 1, y1, x1, expand1, FALSE, s2636->collision_bitmap, cliprect);
/* get fingerprint */
for (x = x1; x < x1 + SPRITE_WIDTH; x++)
for (y = y1; y < y1 + SPRITE_HEIGHT; y++)
{
if ((x < cliprect->min_x) ||
(x > cliprect->max_x) ||
(y < cliprect->min_y) ||
(y > cliprect->max_y))
continue;
checksum = checksum + *BITMAP_ADDR16(s2636->collision_bitmap, y, x);
}
/* black out second sprite */
draw_sprite(attr2, 0, y2, x2, expand2, FALSE, s2636->collision_bitmap, cliprect);
/* remove fingerprint */
for (x = x1; x < x1 + SPRITE_WIDTH; x++)
for (y = y1; y < y1 + SPRITE_HEIGHT; y++)
{
if ((x < cliprect->min_x) ||
(x > cliprect->max_x) ||
(y < cliprect->min_y) ||
(y > cliprect->max_y))
continue;
checksum = checksum - *BITMAP_ADDR16(s2636->collision_bitmap, y, x);
}
}
return (checksum != 0);
}
/*************************************
*
* Main drawing
*
*************************************/
mame_bitmap *s2636_update(s2636_t *s2636, const rectangle *cliprect)
{
UINT8 collision = 0;
int spriteno;
fillbitmap(s2636->bitmap, 0, cliprect);
for (spriteno = 0; spriteno < 4; spriteno++)
{
int color, expand, x, y;
UINT8* attr = &s2636->work_ram[sprite_offsets[spriteno]];
/* get out if sprite is turned off */
if (attr[0x0a] == 0xff)
continue;
x = attr[0x0a] + s2636->x_offset;
y = attr[0x0c] + s2636->y_offset;
color = (s2636->work_ram[0xc1 + (spriteno >> 1)] >> ((spriteno & 1) ? 0 : 3)) & 0x07;
expand = (s2636->work_ram[0xc0] >> (spriteno << 1)) & 0x03;
draw_sprite(attr, color, y, x, expand, TRUE, s2636->bitmap, cliprect);
/* bail if no shadow sprites */
if ((attr[0x0b] == 0xff) || (attr[0x0d] == 0xfe))
continue;
x = attr[0x0b] + s2636->x_offset;
while (y < 0xff)
{
y = y + SPRITE_HEIGHT + attr[0x0d];
draw_sprite(attr, color, y, x, expand, TRUE, s2636->bitmap, cliprect);
}
}
/* collision detection */
if (check_collision(s2636, 0, 1, cliprect)) collision |= 0x20;
if (check_collision(s2636, 0, 2, cliprect)) collision |= 0x10;
if (check_collision(s2636, 0, 3, cliprect)) collision |= 0x08;
if (check_collision(s2636, 1, 2, cliprect)) collision |= 0x04;
if (check_collision(s2636, 1, 3, cliprect)) collision |= 0x02;
if (check_collision(s2636, 2, 3, cliprect)) collision |= 0x01;
s2636->work_ram[0xcb] = collision;
return s2636->bitmap;
}