home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
AmigActive 10
/
AACD 10.iso
/
AACD
/
Games
/
MAME
/
src
/
vidhrdw
/
offtwall.c
< prev
next >
Wrap
C/C++ Source or Header
|
2000-04-04
|
10KB
|
367 lines
/***************************************************************************
vidhrdw/offtwall.c
Functions to emulate the video hardware of the machine.
****************************************************************************
Playfield encoding
------------------
1 16-bit word is used
Word 1:
Bits 13-15 = palette
Bits 0-12 = image number
Motion Object encoding
----------------------
4 16-bit words are used
Word 1:
Bits 0-7 = link to the next motion object
Word 2:
Bits 0-11 = image index
Word 3:
Bits 7-15 = horizontal position
Bits 0-3 = motion object palette
Word 4:
Bits 7-15 = vertical position
Bits 4-6 = horizontal size of the object, in tiles
Bit 3 = horizontal flip
Bits 0-2 = vertical size of the object, in tiles
***************************************************************************/
#include "driver.h"
#include "machine/atarigen.h"
#include "vidhrdw/generic.h"
#define XCHARS 42
#define YCHARS 30
#define XDIM (XCHARS*8)
#define YDIM (YCHARS*8)
/*************************************
*
* Prototypes
*
*************************************/
static const UINT8 *update_palette(void);
static void pf_color_callback(const struct rectangle *clip, const struct rectangle *tiles, const struct atarigen_pf_state *state, void *data);
static void pf_render_callback(const struct rectangle *clip, const struct rectangle *tiles, const struct atarigen_pf_state *state, void *data);
static void mo_color_callback(const UINT16 *data, const struct rectangle *clip, void *param);
static void mo_render_callback(const UINT16 *data, const struct rectangle *clip, void *param);
/*************************************
*
* Video system start
*
*************************************/
int offtwall_vh_start(void)
{
static struct atarigen_mo_desc mo_desc =
{
256, /* maximum number of MO's */
8, /* number of bytes per MO entry */
2, /* number of bytes between MO words */
0, /* ignore an entry if this word == 0xffff */
0, 0, 0xff, /* link = (data[linkword] >> linkshift) & linkmask */
0 /* render in reverse link order */
};
static struct atarigen_pf_desc pf_desc =
{
8, 8, /* width/height of each tile */
64, 64, /* number of tiles in each direction */
1 /* non-scrolling */
};
/* initialize the playfield */
if (atarigen_pf_init(&pf_desc))
return 1;
/* initialize the motion objects */
if (atarigen_mo_init(&mo_desc))
{
atarigen_pf_free();
return 1;
}
return 0;
}
/*************************************
*
* Video system shutdown
*
*************************************/
void offtwall_vh_stop(void)
{
atarigen_pf_free();
atarigen_mo_free();
}
/*************************************
*
* Playfield RAM write handler
*
*************************************/
WRITE_HANDLER( offtwall_playfieldram_w )
{
int oldword = READ_WORD(&atarigen_playfieldram[offset]);
int newword = COMBINE_WORD(oldword, data);
if (oldword != newword)
{
WRITE_WORD(&atarigen_playfieldram[offset], newword);
atarigen_pf_dirty[(offset & 0x1fff) / 2] = 0xff;
}
/* handle the latch, but only write the upper byte */
if (offset < 0x2000 && atarigen_video_control_state.latch1 != -1)
offtwall_playfieldram_w(offset + 0x2000, atarigen_video_control_state.latch1 | 0x00ff0000);
}
/*************************************
*
* Periodic scanline updater
*
*************************************/
void offtwall_scanline_update(int scanline)
{
/* update the playfield */
if (scanline == 0)
atarigen_video_control_update(&atarigen_playfieldram[0x1f00]);
/* update the MOs from the SLIP table */
atarigen_mo_update_slip_512(atarigen_spriteram, atarigen_video_control_state.sprite_yscroll, scanline, &atarigen_playfieldram[0x1f80]);
}
/*************************************
*
* Main refresh
*
*************************************/
void offtwall_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
/* remap if necessary */
if (update_palette())
memset(atarigen_pf_dirty, 0xff, atarigen_playfieldram_size / 4);
/* update playfield */
atarigen_pf_process(pf_render_callback, bitmap, &Machine->drv->visible_area);
/* render the motion objects */
atarigen_mo_process(mo_render_callback, bitmap);
/* update onscreen messages */
atarigen_update_messages();
}
/*************************************
*
* Palette management
*
*************************************/
static const UINT8 *update_palette(void)
{
UINT16 mo_map[16], pf_map[16];
int i, j;
/* reset color tracking */
memset(mo_map, 0, sizeof(mo_map));
memset(pf_map, 0, sizeof(pf_map));
palette_init_used_colors();
/* update color usage for the playfield */
atarigen_pf_process(pf_color_callback, pf_map, &Machine->drv->visible_area);
/* update color usage for the mo's */
atarigen_mo_process(mo_color_callback, mo_map);
/* rebuild the playfield palette */
for (i = 0; i < 16; i++)
{
UINT16 used = pf_map[i];
if (used)
for (j = 0; j < 16; j++)
if (used & (1 << j))
palette_used_colors[0x200 + i * 16 + j] = PALETTE_COLOR_USED;
}
/* rebuild the motion object palette */
for (i = 0; i < 16; i++)
{
UINT16 used = mo_map[i];
if (used)
{
palette_used_colors[0x100 + i * 16 + 0] = PALETTE_COLOR_TRANSPARENT;
for (j = 1; j < 16; j++)
if (used & (1 << j))
palette_used_colors[0x100 + i * 16 + j] = PALETTE_COLOR_USED;
}
}
return palette_recalc();
}
/*************************************
*
* Playfield palette
*
*************************************/
static void pf_color_callback(const struct rectangle *clip, const struct rectangle *tiles, const struct atarigen_pf_state *state, void *param)
{
const unsigned int *usage = Machine->gfx[0]->pen_usage;
UINT16 *colormap = param;
int x, y;
/* standard loop over tiles */
for (x = tiles->min_x; x != tiles->max_x; x = (x + 1) & 63)
for (y = tiles->min_y; y != tiles->max_y; y = (y + 1) & 63)
{
int offs = x * 64 + y;
int data1 = READ_WORD(&atarigen_playfieldram[offs * 2]);
int data2 = READ_WORD(&atarigen_playfieldram[offs * 2 + 0x2000]);
int code = data1 & 0x7fff;
int color = (data2 >> 8) & 15;
/* mark the colors used by this tile */
colormap[color] |= usage[code];
}
}
/*************************************
*
* Playfield rendering
*
*************************************/
static void pf_render_callback(const struct rectangle *clip, const struct rectangle *tiles, const struct atarigen_pf_state *state, void *param)
{
const struct GfxElement *gfx = Machine->gfx[0];
struct osd_bitmap *bitmap = param;
int x, y;
/* standard loop over tiles */
for (x = tiles->min_x; x != tiles->max_x; x = (x + 1) & 63)
for (y = tiles->min_y; y != tiles->max_y; y = (y + 1) & 63)
{
int offs = x * 64 + y;
/* update only if dirty */
if (atarigen_pf_dirty[offs])
{
int data1 = READ_WORD(&atarigen_playfieldram[offs * 2]);
int data2 = READ_WORD(&atarigen_playfieldram[offs * 2 + 0x2000]);
int color = (data2 >> 8) & 15;
int hflip = data1 & 0x8000;
int code = data1 & 0x7fff;
drawgfx(atarigen_pf_bitmap, gfx, code, 0x10 + color, hflip, 0, 8 * x, 8 * y, 0, TRANSPARENCY_NONE, 0);
atarigen_pf_dirty[offs] = 0;
}
}
/* then blast the result */
copybitmap(bitmap, atarigen_pf_bitmap, 0, 0, 0, 0, clip, TRANSPARENCY_NONE, 0);
}
/*************************************
*
* Motion object palette
*
*************************************/
static void mo_color_callback(const UINT16 *data, const struct rectangle *clip, void *param)
{
const unsigned int *usage = Machine->gfx[0]->pen_usage;
UINT16 *colormap = param;
int code = data[1] & 0x7fff;
int color = data[2] & 0x000f;
int hsize = ((data[3] >> 4) & 7) + 1;
int vsize = (data[3] & 7) + 1;
int tiles = hsize * vsize;
UINT16 temp = 0;
int i;
for (i = 0; i < tiles; i++)
temp |= usage[code++];
colormap[color] |= temp;
}
/*************************************
*
* Motion object rendering
*
*************************************/
static void mo_render_callback(const UINT16 *data, const struct rectangle *clip, void *param)
{
const struct GfxElement *gfx = Machine->gfx[0];
struct osd_bitmap *bitmap = param;
struct rectangle pf_clip;
/* extract data from the various words */
int hflip = data[1] & 0x8000;
int code = data[1] & 0x7fff;
int xpos = (data[2] >> 7) - atarigen_video_control_state.sprite_xscroll;
int color = data[2] & 0x000f;
int ypos = -(data[3] >> 7) - atarigen_video_control_state.sprite_yscroll;
int hsize = ((data[3] >> 4) & 7) + 1;
int vsize = (data[3] & 7) + 1;
/* adjust for height */
ypos -= vsize * 8;
/* adjust the final coordinates */
xpos &= 0x1ff;
ypos &= 0x1ff;
if (xpos >= XDIM) xpos -= 0x200;
if (ypos >= YDIM) ypos -= 0x200;
/* determine the bounding box */
atarigen_mo_compute_clip_8x8(pf_clip, xpos, ypos, hsize, vsize, clip);
/* draw the motion object */
atarigen_mo_draw_8x8(bitmap, gfx, code, color, hflip, 0, xpos, ypos, hsize, vsize, clip, TRANSPARENCY_PEN, 0);
}