/*************************************************************************** vidhrdw.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "driver.h" #include "vidhrdw/generic.h" #define VIDEO_RAM_SIZE 0x1000 unsigned char *popeye_videoram,*popeye_colorram,*popeye_backgroundram; unsigned char *popeye_background_pos,*popeye_palette_bank; unsigned char *VideoChanged; struct osd_bitmap *ForeBitmap; /*************************************************************************** Convert the color PROMs into a more useable format. Popeye has four color PROMS: - 32x8 char palette - 32x8 background palette - two 256x4 sprite palette I don't know for sure how the PROMs are connected to the RGB output, but it's probably the usual: bit 7 -- 220 ohm resistor -- BLUE -- 470 ohm resistor -- BLUE -- 220 ohm resistor -- GREEN -- 470 ohm resistor -- GREEN -- 1 kohm resistor -- GREEN -- 220 ohm resistor -- RED -- 470 ohm resistor -- RED bit 0 -- 1 kohm resistor -- RED ***************************************************************************/ void popeye_vh_convert_color_prom(unsigned char *palette, unsigned char *colortable,const unsigned char *color_prom) { int i; for (i = 0;i < 256;i++) { int bits; bits = (i >> 0) & 0x07; palette[3*i] = (bits >> 1) | (bits << 2) | (bits << 5); bits = (i >> 3) & 0x07; palette[3*i + 1] = (bits >> 1) | (bits << 2) | (bits << 5); bits = (i >> 6) & 0x03; palette[3*i + 2] = bits | (bits >> 2) | (bits << 4) | (bits << 6); } for (i = 0;i < 32;i++) /* characters */ { colortable[2*i] = 0; colortable[2*i + 1] = color_prom[i]; } for (i = 0;i < 32;i++) /* background */ { colortable[i+32*2] = color_prom[i+32]; } for (i = 0;i < 64*4;i++) /* sprites */ { colortable[i+32*2+32] = (color_prom[i+64] & 0x0f) | ((color_prom[i+64+64*4] << 4) & 0xf0); } } void popeye_videoram_w(int offset,int data) { if ((popeye_videoram[offset] != data)) { popeye_videoram[offset] = data; VideoChanged[offset] = 1; } } void popeye_colorram_w(int offset,int data) { if ((popeye_colorram[offset] != data)) { popeye_colorram[offset] = data; VideoChanged[offset] = 1; } } void popeye_backgroundram_w(int offset,int data) { if (data & 0x80) /* write to the upper nibble */ { if ((popeye_backgroundram[offset] & 0xf0) != ((data << 4)&0xf0)) { dirtybuffer[offset] = 1; popeye_backgroundram[offset] = (popeye_backgroundram[offset] & 0x0f) | ((data << 4)&0xf0); } } else /* write to the lower nibble */ { if ((popeye_backgroundram[offset] & 0x0f) != (data & 0x0f)) { dirtybuffer[offset] = 1; popeye_backgroundram[offset] = (popeye_backgroundram[offset] & 0xf0) | (data & 0x0f); } } } void popeye_palettebank_w(int offset,int data) { if ((data & 0x08) != (*popeye_palette_bank & 0x08)) { int i; for (i = 0;i < VIDEO_RAM_SIZE;i++) dirtybuffer[i] = 1; } *popeye_palette_bank = data; } /*************************************************************************** Start the video hardware emulation. ***************************************************************************/ int popeye_vh_start(void) { int len; len = (Machine->drv->screen_width/8) * (Machine->drv->screen_height/8); /* round the length to the next 0x400 boundary. This is necessary to */ /* allocate a buffer large enough for Pac Man and other games using */ /* 224x288 and 288x224 video modes, but still a 32x32 video memory */ /* layout, and for Popeye, using a 512x480 screen but a 64x64 memory. */ len = (len + 0x3ff) & 0xfffffc00; if ((dirtybuffer = malloc(len)) == 0) return 1; memset(dirtybuffer,0,len); if ((VideoChanged = malloc(len)) == 0) return 1; memset(VideoChanged,0,len); if ((tmpbitmap = osd_create_bitmap(Machine->drv->screen_width,Machine->drv->screen_height)) == 0) { free(dirtybuffer); free(VideoChanged); return 1; } if ((ForeBitmap = osd_create_bitmap(Machine->drv->screen_width,Machine->drv->screen_height)) == 0) { free(dirtybuffer); free(VideoChanged); osd_free_bitmap(tmpbitmap); return 1; } return 0; } /*************************************************************************** Stop the video hardware emulation. ***************************************************************************/ void popeye_vh_stop(void) { free(dirtybuffer); free(VideoChanged); osd_free_bitmap(tmpbitmap); osd_free_bitmap(ForeBitmap); } /*************************************************************************** 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 popeye_vh_screenrefresh(struct osd_bitmap *bitmap) { int offs; int Update=0; /* Code split into two distinct sections, first section is for game */ /* where two video screens, and sprites are used. Second section is */ /* used for title, high score and credit screens, No background! */ if (popeye_background_pos[0] == 0) { /* Only update foreground if altered */ for (offs = 0;offs < 0x3FF;offs++) { if (VideoChanged[offs]) { int sx,sy; VideoChanged[offs] = 0; Update = 1; sx = 16 * (offs % 32); sy = 16 * (offs / 32) - 16; drawgfx(ForeBitmap,Machine->gfx[0], popeye_videoram[offs],popeye_colorram[offs], 0,0,sx,sy, &Machine->drv->visible_area,TRANSPARENCY_NONE,0); } } if (Update) copybitmap(bitmap,ForeBitmap,0,0,0,0, &Machine->drv->visible_area,TRANSPARENCY_NONE,0); /* Draw the sprites */ for (offs = 0;offs < 159*4;offs += 4) { if (spriteram[offs] != 0) drawgfx(bitmap,Machine->gfx[(spriteram[offs + 3] & 0x04) ? 1 : 2], 0xff - (spriteram[offs + 2] & 0x7f) - 8*(spriteram[offs + 3] & 0x10), (spriteram[offs + 3] & 0x07) + 8*(*popeye_palette_bank & 0x07), spriteram[offs + 2] & 0x80,spriteram[offs + 3] & 0x08, 2*(spriteram[offs])-7,2*(256-spriteram[offs + 1]) - 16, &Machine->drv->visible_area,TRANSPARENCY_PEN,0); } } else { for (offs = 128;offs < VIDEO_RAM_SIZE-128;offs++) { if (dirtybuffer[offs]) { int sx,sy,y,colour; dirtybuffer[offs] = 0; sx = 8 * (offs % 64); sy = 8 * (offs / 64) - 16; if (sx >= Machine->drv->visible_area.min_x && sx+7 <= Machine->drv->visible_area.max_x && sy >= Machine->drv->visible_area.min_y && sy+7 <= Machine->drv->visible_area.max_y) { colour = Machine->gfx[3]->colortable[(popeye_backgroundram[offs] & 0x0f) + 2*(*popeye_palette_bank & 0x08)]; for (y = 0;y < 4;y++) memset(&tmpbitmap->line[sy+y][sx],colour,8); colour = Machine->gfx[3]->colortable[(popeye_backgroundram[offs] >> 4) + 2*(*popeye_palette_bank & 0x08)]; for (y = 4;y < 8;y++) memset(&tmpbitmap->line[sy+y][sx],colour,8); } } } /* copy the background graphics */ copybitmap(bitmap,tmpbitmap,0,0, 400 - 2 * popeye_background_pos[0], 2 * (256 - popeye_background_pos[1]), &Machine->drv->visible_area,TRANSPARENCY_NONE,0); /* Draw the sprites. Note that it is important to draw them exactly in this */ /* order, to have the correct priorities. */ for (offs = 0;offs < 159*4;offs += 4) { /* * offs+3: * bit 7 ? * bit 6 ? * bit 5 ? * bit 4 MSB of sprite code * bit 3 vertical flip * bit 2 sprite bank * bit 1 \ color (with bit 2 as well) * bit 0 / */ if (spriteram[offs] != 0) drawgfx(bitmap,Machine->gfx[(spriteram[offs + 3] & 0x04) ? 1 : 2], 0xff - (spriteram[offs + 2] & 0x7f) - 8*(spriteram[offs + 3] & 0x10), (spriteram[offs + 3] & 0x07) + 8*(*popeye_palette_bank & 0x07), spriteram[offs + 2] & 0x80,spriteram[offs + 3] & 0x08, 2*(spriteram[offs])-7,2*(256-spriteram[offs + 1]) - 16, &Machine->drv->visible_area,TRANSPARENCY_PEN,0); } /* draw the frontmost playfield. They are characters, but draw them as sprites */ for (offs = 0;offs < 0x3FF;offs++) { int sx,sy; if (popeye_videoram[offs] != 0xff) /* don't draw spaces */ { sx = 16 * (offs % 32); sy = 16 * (offs / 32) - 16; drawgfx(bitmap,Machine->gfx[0], popeye_videoram[offs],popeye_colorram[offs], 0,0,sx,sy, &Machine->drv->visible_area,TRANSPARENCY_PEN,0); } } } }