blueprnt.c

这个是延伸mame的在wince平台下的游戏模拟器的代码

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

  vidhrdw.c

  Functions to emulate the video hardware of the machine.

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

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



static int flipscreen;



void blueprnt_flipscreen_w(int offset,int data)
{
	if (flipscreen != (~data & 2))
	{
		flipscreen = ~data & 2;
		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 blueprnt_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 = 31 - offs / 32;
			sy = offs % 32;
			if (flipscreen)
			{
				sx = 31 - sx;
				sy = 31 - sy;
			}

			drawgfx(tmpbitmap,Machine->gfx[0],
					videoram[offs],
					colorram[offs] & 0x7f,
					flipscreen,flipscreen,
					8*sx,8*sy,
					&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
		}
	}


	/* copy the character mapped graphics */
	copybitmap(bitmap,tmpbitmap,0,0,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);


	/* Draw the sprites */
	for (offs = 0;offs < spriteram_size;offs += 4)
	{
		int sx,sy,flipy;


		sx = spriteram[offs + 3];
		sy = 240 - spriteram[offs + 0];
		flipy = spriteram[offs + 2 - 4] & 0x80;	/* -4? Awkward, isn't it? */
		if (flipscreen)
		{
			sx = 248 - sx;
			sy = 240 - sy;
			flipy = !flipy;
		}

		drawgfx(bitmap,Machine->gfx[1],
				spriteram[offs + 1],
				0,
				flipscreen,flipy,
				2+sx,sy-1,	/* sprites are slightly misplaced, regardless of the screen flip */
				&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
	}


	/* redraw the characters which have priority over sprites */
	for (offs = videoram_size - 1;offs >= 0;offs--)
	{
		if (colorram[offs] & 0x80)
		{
			int sx,sy;


			sx = 31 - offs / 32;
			sy = offs % 32;
			if (flipscreen)
			{
				sx = 31 - sx;
				sy = 31 - sy;
			}

			drawgfx(bitmap,Machine->gfx[0],
					videoram[offs],
					colorram[offs] & 0x7f,
					flipscreen,flipscreen,
					8*sx,8*sy,
					&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
		}
	}
}