jack.c

这个是延伸mame的在wince平台下的游戏模拟器的代码

/***************************************************************************

  vidhrdw/jack.c

  Functions to emulate the video hardware of the machine.

***************************************************************************/

#include "driver.h"
#include "vidhrdw/generic.h"


static int flipscreen = 0;

void jack_paletteram_w (int offset,int data)
{
	/* RGB output is inverted */
	paletteram_BBGGGRRR_w(offset,~data);
}


int jack_flipscreen_r(int offset)
{
	if (offset != flipscreen)
	{
		flipscreen = offset;
		memset(dirtybuffer,1,videoram_size);
	}

	return 0;
}

void jack_flipscreen_w(int offset, int data)
{
	jack_flipscreen_r(offset);
}


void jack_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 = videoram_size - 1;offs >= 0;offs--)
	{
		if (dirtybuffer[offs])
		{
			int sx,sy;


			dirtybuffer[offs] = 0;

			sx = offs / 32;
			sy = 31 - offs % 32;

			if (flipscreen)
			{
				sx = 31 - sx;
				sy = 31 - sy;
			}

			drawgfx(tmpbitmap,Machine->gfx[0],
					videoram[offs] + ((colorram[offs] & 0x18) << 5),
					colorram[offs] & 0x07,
					flipscreen,flipscreen,
					8*sx,8*sy,
					&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
		}
	}


	/* copy the temporary bitmap to the screen */
	copybitmap(bitmap,tmpbitmap,0,0,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);

	/* draw sprites */
	for (offs = 0;offs < spriteram_size;offs += 4)
	{
		int sx,sy;
		int num, color;

		sx    = spriteram[offs + 1];
		sy    = spriteram[offs];
		num   = spriteram[offs + 2] + ((spriteram[offs + 3] & 0x08) << 5);
		color = spriteram[offs + 3] & 0x07;

		if (flipscreen)
		{
			sx = 248 - sx;
			sy = 248 - sy;
		}

		drawgfx(bitmap,Machine->gfx[0],
				num,
				color,
				flipscreen,flipscreen,
				sx,sy,
				&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
	}
}