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AmigActive 10
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AACD 10.iso
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vidhrdw
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fastfred.c
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C/C++ Source or Header
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2000-04-23
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8KB
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282 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
extern unsigned char *galaxian_attributesram;
static const unsigned char *fastfred_color_prom;
static struct rectangle spritevisiblearea =
{
2*8, 32*8-1,
2*8, 30*8-1
};
static struct rectangle spritevisibleareaflipx =
{
0*8, 30*8-1,
2*8, 30*8-1
};
static unsigned char character_bank[2];
static unsigned char color_bank[2];
static int flipscreenx, flipscreeny;
static int canspritesflipx = 0;
void jumpcoas_init_machine(void)
{
canspritesflipx = 1;
}
/***************************************************************************
Convert the color PROMs into a more useable format.
bit 0 -- 1 kohm resistor -- RED/GREEN/BLUE
-- 470 ohm resistor -- RED/GREEN/BLUE
-- 220 ohm resistor -- RED/GREEN/BLUE
bit 3 -- 100 ohm resistor -- RED/GREEN/BLUE
***************************************************************************/
static void convert_color(int i, int* r, int* g, int* b)
{
int bit0, bit1, bit2, bit3;
const unsigned char *prom = fastfred_color_prom;
int total = Machine->drv->total_colors;
bit0 = (prom[i + 0*total] >> 0) & 0x01;
bit1 = (prom[i + 0*total] >> 1) & 0x01;
bit2 = (prom[i + 0*total] >> 2) & 0x01;
bit3 = (prom[i + 0*total] >> 3) & 0x01;
*r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (prom[i + 1*total] >> 0) & 0x01;
bit1 = (prom[i + 1*total] >> 1) & 0x01;
bit2 = (prom[i + 1*total] >> 2) & 0x01;
bit3 = (prom[i + 1*total] >> 3) & 0x01;
*g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (prom[i + 2*total] >> 0) & 0x01;
bit1 = (prom[i + 2*total] >> 1) & 0x01;
bit2 = (prom[i + 2*total] >> 2) & 0x01;
bit3 = (prom[i + 2*total] >> 3) & 0x01;
*b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
}
void fastfred_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])
fastfred_color_prom = color_prom; /* we'll need this later */
for (i = 0;i < Machine->drv->total_colors;i++)
{
int r,g,b;
convert_color(i, &r, &g, &b);
*(palette++) = r;
*(palette++) = g;
*(palette++) = b;
}
/* characters and sprites use the same palette */
for (i = 0;i < TOTAL_COLORS(0);i++)
{
int color;
if (!(i & 0x07))
{
color = 0;
}
else
{
color = i;
}
COLOR(0,i) = COLOR(1,i) = color;
}
}
WRITE_HANDLER( fastfred_character_bank_select_w )
{
if (character_bank[offset] != data)
{
character_bank[offset] = data & 1;
memset(dirtybuffer, 1, videoram_size);
//if (offset==1) logerror("CharBank = %02X\n", (character_bank[1] << 1) | character_bank[0]);
}
}
WRITE_HANDLER( fastfred_color_bank_select_w )
{
if (color_bank[offset] != data)
{
color_bank[offset] = data & 1;
memset(dirtybuffer, 1, videoram_size);
//if (offset==1) logerror("ColorBank = %02X\n", (color_bank[1] << 1) | color_bank[0]);
}
}
WRITE_HANDLER( fastfred_background_color_w )
{
int r,g,b;
//logerror("Background color = %02X\n", data);
convert_color(data, &r, &g, &b);
palette_change_color(0,r,g,b);
}
WRITE_HANDLER( fastfred_flipx_w )
{
if (flipscreenx != (data & 1))
{
flipscreenx = data & 1;
memset(dirtybuffer,1,videoram_size);
}
}
WRITE_HANDLER( fastfred_flipy_w )
{
if (flipscreeny != (data & 1))
{
flipscreeny = data & 1;
memset(dirtybuffer,1,videoram_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 fastfred_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs, charbank, colorbank;
if (palette_recalc())
memset(dirtybuffer,1,videoram_size);
charbank = ((character_bank[1] << 9) | (character_bank[0] << 8));
colorbank = ((color_bank[1] << 4) | (color_bank[0] << 3));
for (offs = videoram_size - 1;offs >= 0;offs--)
{
int color;
if (dirtybuffer[offs])
{
int sx,sy;
dirtybuffer[offs] = 0;
sx = offs % 32;
sy = offs / 32;
color = colorbank | (galaxian_attributesram[2 * sx + 1] & 0x07);
if (flipscreenx) sx = 31 - sx;
if (flipscreeny) sy = 31 - sy;
drawgfx(tmpbitmap,Machine->gfx[0],
charbank | videoram[offs],
color,
flipscreenx,flipscreeny,
8*sx,8*sy,
0,TRANSPARENCY_NONE,0);
}
}
/* copy the temporary bitmap to the screen */
{
int i, scroll[32];
if (flipscreenx)
{
for (i = 0;i < 32;i++)
{
scroll[31-i] = -galaxian_attributesram[2 * i];
if (flipscreeny) scroll[31-i] = -scroll[31-i];
}
}
else
{
for (i = 0;i < 32;i++)
{
scroll[i] = -galaxian_attributesram[2 * i];
if (flipscreeny) scroll[i] = -scroll[i];
}
}
copyscrollbitmap(bitmap,tmpbitmap,0,0,32,scroll,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* Draw the sprites */
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
int code,sx,sy,flipx,flipy;
sx = (spriteram[offs + 3] + 1) & 0xff; /* ??? */
sy = 240 - spriteram[offs];
if (canspritesflipx)
{
// Jump Coaster
code = spriteram[offs + 1] & 0x3f;
flipx = ~spriteram[offs + 1] & 0x40;
flipy = spriteram[offs + 1] & 0x80;
}
else
{
// Fast Freddie
code = spriteram[offs + 1] & 0x7f;
flipx = 0;
flipy = ~spriteram[offs + 1] & 0x80;
}
if (flipscreenx)
{
sx = 241 - sx; /* note: 241, not 240 */
flipx = !flipx;
}
if (flipscreeny)
{
sy = 240 - sy;
flipy = !flipy;
}
drawgfx(bitmap,Machine->gfx[1],
code,
colorbank | (spriteram[offs + 2] & 0x07),
flipx,flipy,
sx,sy,
flipscreenx ? &spritevisibleareaflipx : &spritevisiblearea,TRANSPARENCY_PEN,0);
}
}