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Diffstat (limited to 'src/mame/video/gundealr.c')
-rw-r--r--src/mame/video/gundealr.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/src/mame/video/gundealr.c b/src/mame/video/gundealr.c
new file mode 100644
index 00000000000..40916d82f9b
--- /dev/null
+++ b/src/mame/video/gundealr.c
@@ -0,0 +1,143 @@
+/***************************************************************************
+
+ video.c
+
+ Functions to emulate the video hardware of the machine.
+
+***************************************************************************/
+
+#include "driver.h"
+
+
+
+UINT8 *gundealr_bg_videoram,*gundealr_fg_videoram;
+
+static tilemap *bg_tilemap,*fg_tilemap;
+static int flipscreen;
+
+
+
+/***************************************************************************
+
+ Callbacks for the TileMap code
+
+***************************************************************************/
+
+static TILE_GET_INFO( get_bg_tile_info )
+{
+ UINT8 attr = gundealr_bg_videoram[2*tile_index+1];
+ SET_TILE_INFO(
+ 0,
+ gundealr_bg_videoram[2*tile_index] + ((attr & 0x07) << 8),
+ (attr & 0xf0) >> 4,
+ 0);
+}
+
+static TILEMAP_MAPPER( gundealr_scan )
+{
+ /* logical (col,row) -> memory offset */
+ return (row & 0x0f) + ((col & 0x3f) << 4) + ((row & 0x10) << 6);
+}
+
+static TILE_GET_INFO( get_fg_tile_info )
+{
+ UINT8 attr = gundealr_fg_videoram[2*tile_index+1];
+ SET_TILE_INFO(
+ 1,
+ gundealr_fg_videoram[2*tile_index] + ((attr & 0x03) << 8),
+ (attr & 0xf0) >> 4,
+ 0);
+}
+
+
+
+/***************************************************************************
+
+ Start the video hardware emulation.
+
+***************************************************************************/
+
+VIDEO_START( gundealr )
+{
+ bg_tilemap = tilemap_create(get_bg_tile_info,tilemap_scan_cols,TILEMAP_TYPE_PEN, 8, 8,32,32);
+ fg_tilemap = tilemap_create(get_fg_tile_info,gundealr_scan, TILEMAP_TYPE_PEN,16,16,64,32);
+
+ tilemap_set_transparent_pen(fg_tilemap,15);
+}
+
+
+
+/***************************************************************************
+
+ Memory handlers
+
+***************************************************************************/
+
+WRITE8_HANDLER( gundealr_bg_videoram_w )
+{
+ gundealr_bg_videoram[offset] = data;
+ tilemap_mark_tile_dirty(bg_tilemap,offset/2);
+}
+
+WRITE8_HANDLER( gundealr_fg_videoram_w )
+{
+ gundealr_fg_videoram[offset] = data;
+ tilemap_mark_tile_dirty(fg_tilemap,offset/2);
+}
+
+WRITE8_HANDLER( gundealr_paletteram_w )
+{
+ int r,g,b,val;
+
+
+ paletteram[offset] = data;
+
+ val = paletteram[offset & ~1];
+ r = (val >> 4) & 0x0f;
+ g = (val >> 0) & 0x0f;
+
+ val = paletteram[offset | 1];
+ b = (val >> 4) & 0x0f;
+ /* TODO: the bottom 4 bits are used as well, but I'm not sure about the meaning */
+
+ palette_set_color_rgb(Machine,offset / 2,pal4bit(r),pal4bit(g),pal4bit(b));
+}
+
+WRITE8_HANDLER( gundealr_fg_scroll_w )
+{
+ static UINT8 scroll[4];
+
+ scroll[offset] = data;
+ tilemap_set_scrollx(fg_tilemap,0,scroll[1] | ((scroll[0] & 0x03) << 8));
+ tilemap_set_scrolly(fg_tilemap,0,scroll[3] | ((scroll[2] & 0x03) << 8));
+}
+
+WRITE8_HANDLER( yamyam_fg_scroll_w )
+{
+ static UINT8 scroll[4];
+
+ scroll[offset] = data;
+ tilemap_set_scrollx(fg_tilemap,0,scroll[0] | ((scroll[1] & 0x03) << 8));
+ tilemap_set_scrolly(fg_tilemap,0,scroll[2] | ((scroll[3] & 0x03) << 8));
+}
+
+WRITE8_HANDLER( gundealr_flipscreen_w )
+{
+ flipscreen = data;
+ tilemap_set_flip(ALL_TILEMAPS,flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
+}
+
+
+
+/***************************************************************************
+
+ Display refresh
+
+***************************************************************************/
+
+VIDEO_UPDATE( gundealr )
+{
+ tilemap_draw(bitmap,cliprect,bg_tilemap,0,0);
+ tilemap_draw(bitmap,cliprect,fg_tilemap,0,0);
+ return 0;
+}