cclimber.c

这个是延伸mame的在wince平台下的游戏模拟器的代码

		bsdirtybuffer[offset] = 1;

		cclimber_bsvideoram[offset] = data;
	}
}



void swimmer_palettebank_w(int offset,int data)
{
	if (palettebank != (data & 1))
	{
		palettebank = data & 1;
		memset(dirtybuffer,1,videoram_size);
	}
}



void swimmer_sidepanel_enable_w(int offset,int data)
{
    if (data != sidepanel_enabled)
    {
		sidepanel_enabled = data;

		/* We only need to dirty the side panel, but this location is not */
		/* written to very often, so we just dirty the whole screen */
		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.

***************************************************************************/
static void drawbigsprite(struct osd_bitmap *bitmap)
{
	int sx,sy,flipx,flipy;


	sx = 136 - cclimber_bigspriteram[3];
	sy = 128 - cclimber_bigspriteram[2];
	flipx = cclimber_bigspriteram[1] & 0x10;
	flipy = cclimber_bigspriteram[1] & 0x20;
	if (flipscreen[1])      /* only the Y direction has to be flipped */
	{
		sy = 128 - sy;
		flipy = !flipy;
	}

	/* we have to draw if four times for wraparound */
	sx &= 0xff;
	sy &= 0xff;
	copybitmap(bitmap,bsbitmap,
			flipx,flipy,
			sx,sy,
			&Machine->drv->visible_area,TRANSPARENCY_COLOR,0);
	copybitmap(bitmap,bsbitmap,
			flipx,flipy,
			sx-256,sy,
			&Machine->drv->visible_area,TRANSPARENCY_COLOR,0);
	copybitmap(bitmap,bsbitmap,
			flipx,flipy,
			sx-256,sy-256,
			&Machine->drv->visible_area,TRANSPARENCY_COLOR,0);
	copybitmap(bitmap,bsbitmap,
			flipx,flipy,
			sx,sy-256,
			&Machine->drv->visible_area,TRANSPARENCY_COLOR,0);
}


void cclimber_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,flipx,flipy;


			dirtybuffer[offs] = 0;

			sx = offs % 32;
			sy = offs / 32;
			flipx = colorram[offs] & 0x40;
			flipy = colorram[offs] & 0x80;
			/* vertical flipping flips two adjacent characters */
			if (flipy) sy ^= 1;

			if (flipscreen[0])
			{
				sx = 31 - sx;
				flipx = !flipx;
			}
			if (flipscreen[1])
			{
				sy = 31 - sy;
				flipy = !flipy;
			}

			drawgfx(tmpbitmap,Machine->gfx[(colorram[offs] & 0x10) ? 1 : 0],
					videoram[offs] + 8 * (colorram[offs] & 0x20),
					colorram[offs] & 0x0f,
					flipx,flipy,
					8*sx,8*sy,
					0,TRANSPARENCY_NONE,0);
		}
	}


	/* copy the temporary bitmap to the screen */
	{
		int scroll[32];


		if (flipscreen[0])
		{
			for (offs = 0;offs < 32;offs++)
			{
				scroll[offs] = -cclimber_column_scroll[31 - offs];
				if (flipscreen[1]) scroll[offs] = -scroll[offs];
			}
		}
		else
		{
			for (offs = 0;offs < 32;offs++)
			{
				scroll[offs] = -cclimber_column_scroll[offs];
				if (flipscreen[1]) scroll[offs] = -scroll[offs];
			}
		}

		copyscrollbitmap(bitmap,tmpbitmap,0,0,32,scroll,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
	}


	/* update the "big sprite" */
	{
		int newcol;
		static int lastcol;


		newcol = cclimber_bigspriteram[1] & 0x07;

		for (offs = cclimber_bsvideoram_size - 1;offs >= 0;offs--)
		{
			int sx,sy;


			if (bsdirtybuffer[offs] || newcol != lastcol)
			{
				bsdirtybuffer[offs] = 0;

				sx = offs % 16;
				sy = offs / 16;

				drawgfx(bsbitmap,Machine->gfx[2],
						cclimber_bsvideoram[offs],newcol,
						0,0,
						8*sx,8*sy,
						0,TRANSPARENCY_NONE,0);
			}

		}

		lastcol = newcol;
	}


	if (cclimber_bigspriteram[0] & 1)
		/* draw the "big sprite" below sprites */
		drawbigsprite(bitmap);


	/* Draw the sprites. Note that it is important to draw them exactly in this */
	/* order, to have the correct priorities. */
	for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
	{
		int sx,sy,flipx,flipy;


		sx = spriteram[offs + 3];
		sy = 240 - spriteram[offs + 2];
		flipx = spriteram[offs] & 0x40;
		flipy = spriteram[offs] & 0x80;
		if (flipscreen[0])
		{
			sx = 240 - sx;
			flipx = !flipx;
		}
		if (flipscreen[1])
		{
			sy = 240 - sy;
			flipy = !flipy;
		}

		drawgfx(bitmap,Machine->gfx[spriteram[offs + 1] & 0x10 ? 4 : 3],
				(spriteram[offs] & 0x3f) + 2 * (spriteram[offs + 1] & 0x20),
				spriteram[offs + 1] & 0x0f,
				flipx,flipy,
				sx,sy,
				&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
	}


	if ((cclimber_bigspriteram[0] & 1) == 0)
		/* draw the "big sprite" over sprites */
		drawbigsprite(bitmap);
}



void swimmer_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,flipx,flipy,color;


			dirtybuffer[offs] = 0;

			sx = offs % 32;
			sy = offs / 32;
			flipx = colorram[offs] & 0x40;
			flipy = colorram[offs] & 0x80;
			/* vertical flipping flips two adjacent characters */
			if (flipy) sy ^= 1;

			if (flipscreen[0])
			{
				sx = 31 - sx;
				flipx = !flipx;
			}
			if (flipscreen[1])
			{
				sy = 31 - sy;
				flipy = !flipy;
			}

			color = (colorram[offs] & 0x0f) + 0x10 * palettebank;
			if (sx >= 24 && sidepanel_enabled)
			{
			    color += 32;
			}

			drawgfx(tmpbitmap,Machine->gfx[0],
					videoram[offs] + ((colorram[offs] & 0x10) << 4),
					color,
					flipx,flipy,
					8*sx,8*sy,
					0,TRANSPARENCY_NONE,0);
		}
	}


	/* copy the temporary bitmap to the screen */
	{
		int scroll[32];


		if (flipscreen[1])
		{
			for (offs = 0;offs < 32;offs++)
				scroll[offs] = cclimber_column_scroll[31 - offs];
		}
		else
		{
			for (offs = 0;offs < 32;offs++)
				scroll[offs] = -cclimber_column_scroll[offs];
		}

		copyscrollbitmap(bitmap,tmpbitmap,0,0,32,scroll,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
	}


	/* update the "big sprite" */
	{
		int newcol;
		static int lastcol;


		newcol = cclimber_bigspriteram[1] & 0x03;

		for (offs = cclimber_bsvideoram_size - 1;offs >= 0;offs--)
		{
			int sx,sy;


			if (bsdirtybuffer[offs] || newcol != lastcol)
			{
				bsdirtybuffer[offs] = 0;

				sx = offs % 16;
				sy = offs / 16;

				drawgfx(bsbitmap,Machine->gfx[2],
						cclimber_bsvideoram[offs] + ((cclimber_bigspriteram[1] & 0x08) << 5),
						newcol,
						0,0,
						8*sx,8*sy,
						0,TRANSPARENCY_NONE,0);
			}

		}

		lastcol = newcol;
	}


	if (cclimber_bigspriteram[0] & 1)
		/* draw the "big sprite" below sprites */
		drawbigsprite(bitmap);


	/* Draw the sprites. Note that it is important to draw them exactly in this */
	/* order, to have the correct priorities. */
	for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
	{
		int sx,sy,flipx,flipy;


		sx = spriteram[offs + 3];
		sy = 240 - spriteram[offs + 2];
		flipx = spriteram[offs] & 0x40;
		flipy = spriteram[offs] & 0x80;
		if (flipscreen[0])
		{
			sx = 240 - sx;
			flipx = !flipx;
		}
		if (flipscreen[1])
		{
			sy = 240 - sy;
			flipy = !flipy;
		}

		drawgfx(bitmap,Machine->gfx[1],
				(spriteram[offs] & 0x3f) | (spriteram[offs + 1] & 0x10) << 2,
				(spriteram[offs + 1] & 0x0f) + 0x10 * palettebank,
				flipx,flipy,
				sx,sy,
				&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
	}


	if ((cclimber_bigspriteram[0] & 1) == 0)
		/* draw the "big sprite" over sprites */
		drawbigsprite(bitmap);
}