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AmigActive 10
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AACD 10.iso
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vidhrdw
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firetrap.c
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C/C++ Source or Header
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2000-05-04
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11KB
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410 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *firetrap_bg1videoram,*firetrap_bg2videoram;
unsigned char *firetrap_videoram,*firetrap_colorram;
unsigned char *firetrap_scroll1x,*firetrap_scroll1y;
unsigned char *firetrap_scroll2x,*firetrap_scroll2y;
size_t firetrap_bgvideoram_size;
size_t firetrap_videoram_size;
static unsigned char *dirtybuffer2;
static struct osd_bitmap *tmpbitmap2;
static int flipscreen;
/***************************************************************************
Convert the color PROMs into a more useable format.
Fire Trap has one 256x8 and one 256x4 palette PROMs.
I don't know for sure how the palette PROMs are connected to the RGB
output, but it's probably the usual:
bit 7 -- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 2.2kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
-- 1 kohm resistor -- RED
bit 0 -- 2.2kohm resistor -- RED
bit 3 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 1 kohm resistor -- BLUE
bit 0 -- 2.2kohm resistor -- BLUE
***************************************************************************/
void firetrap_vh_convert_color_prom(unsigned char *palette, unsigned short *colortable,const unsigned char *color_prom)
{
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 < 256;i++)
{
int bit0,bit1,bit2,bit3;
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
bit3 = (color_prom[0] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[0] >> 4) & 0x01;
bit1 = (color_prom[0] >> 5) & 0x01;
bit2 = (color_prom[0] >> 6) & 0x01;
bit3 = (color_prom[0] >> 7) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[256] >> 0) & 0x01;
bit1 = (color_prom[256] >> 1) & 0x01;
bit2 = (color_prom[256] >> 2) & 0x01;
bit3 = (color_prom[256] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
color_prom++;
}
/* reserve the last color for the transparent pen (none of the game colors can have */
/* these RGB components) */
*(palette++) = 1;
*(palette++) = 1;
*(palette++) = 1;
/* characters use colors 0-63 */
for (i = 0;i < TOTAL_COLORS(0);i++)
COLOR(0,i) = i;
/* background #1 tiles use colors 128-191 */
for (i = 0;i < TOTAL_COLORS(1);i++)
{
if (i % Machine->gfx[1]->color_granularity == 0)
COLOR(1,i) = 256; /* transparent */
else COLOR(1,i) = i + 128;
}
/* background #2 tiles use colors 192-255 */
for (i = 0;i < TOTAL_COLORS(5);i++)
COLOR(5,i) = i + 192;
/* sprites use colors 64-127 */
for (i = 0;i < TOTAL_COLORS(9);i++)
COLOR(9,i) = i + 64;
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int firetrap_vh_start(void)
{
if ((dirtybuffer = malloc(firetrap_bgvideoram_size)) == 0)
{
return 1;
}
memset(dirtybuffer,1,firetrap_bgvideoram_size);
/* the background area is twice as wide and twice as tall as the screen */
if ((tmpbitmap = osd_create_bitmap(2*Machine->drv->screen_width,2*Machine->drv->screen_height)) == 0)
{
free(dirtybuffer);
return 1;
}
if ((dirtybuffer2 = malloc(firetrap_bgvideoram_size)) == 0)
{
osd_free_bitmap(tmpbitmap);
free(dirtybuffer);
return 1;
}
memset(dirtybuffer2,1,firetrap_bgvideoram_size);
/* the background area is twice as wide and twice as tall as the screen */
if ((tmpbitmap2 = osd_create_bitmap(2*Machine->drv->screen_width,2*Machine->drv->screen_height)) == 0)
{
osd_free_bitmap(tmpbitmap);
free(dirtybuffer2);
free(dirtybuffer);
generic_vh_stop();
return 1;
}
return 0;
}
/***************************************************************************
Stop the video hardware emulation.
***************************************************************************/
void firetrap_vh_stop(void)
{
osd_free_bitmap(tmpbitmap);
osd_free_bitmap(tmpbitmap2);
free(dirtybuffer);
free(dirtybuffer2);
}
WRITE_HANDLER( firetrap_bg1videoram_w )
{
if (firetrap_bg1videoram[offset] != data)
{
dirtybuffer[offset] = 1;
firetrap_bg1videoram[offset] = data;
}
}
WRITE_HANDLER( firetrap_bg2videoram_w )
{
if (firetrap_bg2videoram[offset] != data)
{
dirtybuffer2[offset] = 1;
firetrap_bg2videoram[offset] = data;
}
}
WRITE_HANDLER( firetrap_flipscreen_w )
{
if (flipscreen != (data & 1))
{
flipscreen = data & 1;
memset(dirtybuffer,1,firetrap_bgvideoram_size);
memset(dirtybuffer2,1,firetrap_bgvideoram_size);
}
}
/***************************************************************************
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 firetrap_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs;
/* for every character in the Video RAM, check if it has been modified */
/* since last time and update it accordingly. */
for (offs = firetrap_bgvideoram_size - 1;offs >= 0;offs--)
{
if ((offs & 0x100) == 0)
{
if (dirtybuffer[offs] || dirtybuffer[offs+0x100])
{
int sx,sy,flipx,flipy;
dirtybuffer[offs] = dirtybuffer[offs+0x100] = 0;
sx = (offs / 16) & 0x0f;
sy = 31 - offs % 16;
if (offs & 0x200) sy -= 16;
if (offs & 0x400) sx += 16;
flipx = firetrap_bg1videoram[offs+0x100] & 0x08;
flipy = firetrap_bg1videoram[offs+0x100] & 0x04;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(tmpbitmap,Machine->gfx[1 + (firetrap_bg1videoram[offs+0x100] & 0x03)],
firetrap_bg1videoram[offs],
(firetrap_bg1videoram[offs+0x100] & 0x30) >> 4,
flipx,flipy,
16*sx,16*sy,
0,TRANSPARENCY_NONE,0);
}
if (dirtybuffer2[offs] || dirtybuffer2[offs+0x100])
{
int sx,sy,flipx,flipy;
dirtybuffer2[offs] = dirtybuffer2[offs+0x100] = 0;
sx = (offs / 16) & 0x0f;
sy = 31 - offs % 16;
if (offs & 0x200) sy -= 16;
if (offs & 0x400) sx += 16;
flipx = firetrap_bg2videoram[offs+0x100] & 0x08;
flipy = firetrap_bg2videoram[offs+0x100] & 0x04;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(tmpbitmap2,Machine->gfx[5 + (firetrap_bg2videoram[offs+0x100] & 0x03)],
firetrap_bg2videoram[offs],
(firetrap_bg2videoram[offs+0x100] & 0x30) >> 4,
flipx,flipy,
16*sx,16*sy,
0,TRANSPARENCY_NONE,0);
}
}
}
/* copy the background graphics */
{
int scrollx,scrolly;
if (flipscreen)
{
scrolly = -(firetrap_scroll2x[0] + 256 * firetrap_scroll2x[1]);
scrollx = 256 + (firetrap_scroll2y[0] + 256 * firetrap_scroll2y[1]);
}
else
{
scrolly = 256 + (firetrap_scroll2x[0] + 256 * firetrap_scroll2x[1]);
scrollx = -(firetrap_scroll2y[0] + 256 * firetrap_scroll2y[1]);
}
copyscrollbitmap(bitmap,tmpbitmap2,1,&scrollx,1,&scrolly,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
if (flipscreen)
{
scrolly = -(firetrap_scroll1x[0] + 256 * firetrap_scroll1x[1]);
scrollx = 256 + (firetrap_scroll1y[0] + 256 * firetrap_scroll1y[1]);
}
else
{
scrolly = 256 + (firetrap_scroll1x[0] + 256 * firetrap_scroll1x[1]);
scrollx = -(firetrap_scroll1y[0] + 256 * firetrap_scroll1y[1]);
}
copyscrollbitmap(bitmap,tmpbitmap,1,&scrollx,1,&scrolly,&Machine->drv->visible_area,TRANSPARENCY_COLOR,256);
}
/* Draw the sprites. */
for (offs = 0;offs < spriteram_size; offs += 4)
{
// if (spriteram[offs] & 0x20)
{
int sx,sy,flipx,flipy,code,color;
/* the meaning of bit 3 of [offs] is unknown */
sy = spriteram[offs];
sx = spriteram[offs + 2];
code = spriteram[offs + 3] + 4 * (spriteram[offs + 1] & 0xc0);
color = ((spriteram[offs + 1] & 0x08) >> 2) | (spriteram[offs + 1] & 0x01);
flipx = spriteram[offs + 1] & 0x04;
flipy = spriteram[offs + 1] & 0x02;
if (flipscreen)
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
if (spriteram[offs + 1] & 0x10) /* double width */
{
if (flipscreen) sy -= 16;
drawgfx(bitmap,Machine->gfx[9],
code & ~1,
color,
flipx,flipy,
sx,flipy ? sy : sy + 16,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
drawgfx(bitmap,Machine->gfx[9],
code | 1,
color,
flipx,flipy,
sx,flipy ? sy + 16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
/* redraw with wraparound */
drawgfx(bitmap,Machine->gfx[9],
code & ~1,
color,
flipx,flipy,
sx - 256,flipy ? sy : sy + 16,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
drawgfx(bitmap,Machine->gfx[9],
code | 1,
color,
flipx,flipy,
sx - 256,flipy ? sy + 16 : sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
else
{
drawgfx(bitmap,Machine->gfx[9],
code,
color,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
/* redraw with wraparound */
drawgfx(bitmap,Machine->gfx[9],
code,
color,
flipx,flipy,
sx - 256,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}
}
/* draw the frontmost playfield. They are characters, but draw them as sprites */
for (offs = firetrap_videoram_size - 1;offs >= 0;offs--)
{
int sx,sy;
sx = offs / 32;
sy = 31 - offs % 32;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
}
drawgfx(bitmap,Machine->gfx[0],
firetrap_videoram[offs] + 256 * (firetrap_colorram[offs] & 0x01),
(firetrap_colorram[offs] & 0xf0) >> 4,
flipscreen,flipscreen,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}