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Diffstat (limited to 'src/mame/video/battlex.c')
-rw-r--r--src/mame/video/battlex.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/src/mame/video/battlex.c b/src/mame/video/battlex.c
new file mode 100644
index 00000000000..a0b1a69a5a6
--- /dev/null
+++ b/src/mame/video/battlex.c
@@ -0,0 +1,120 @@
+#include "driver.h"
+
+static int battlex_scroll_lsb;
+static int battlex_scroll_msb;
+
+static tilemap *bg_tilemap;
+
+PALETTE_INIT( battlex )
+{
+ int i,col;
+
+ for (col = 0;col < 8;col++)
+ {
+ for (i = 0;i < 16;i++)
+ {
+ int data = i | col;
+ int g = pal1bit(data >> 0);
+ int b = pal1bit(data >> 1);
+ int r = pal1bit(data >> 2);
+
+#if 0
+ /* from Tim's shots, bit 3 seems to have no effect (see e.g. Laser Ship on title screen) */
+ if (i & 8)
+ {
+ r /= 2;
+ g /= 2;
+ b /= 2;
+ }
+#endif
+
+ palette_set_color(machine, i + 16 * col,MAKE_RGB(r,g,b));
+ }
+ }
+}
+
+WRITE8_HANDLER( battlex_palette_w )
+{
+ palette_set_color_rgb(Machine,16*8 + offset,pal1bit(data >> 2),pal1bit(data >> 0),pal1bit(data >> 1));
+}
+
+WRITE8_HANDLER( battlex_scroll_x_lsb_w )
+{
+ battlex_scroll_lsb = data;
+}
+
+WRITE8_HANDLER( battlex_scroll_x_msb_w )
+{
+ battlex_scroll_msb = data;
+}
+
+WRITE8_HANDLER( battlex_videoram_w )
+{
+ videoram[offset] = data;
+ tilemap_mark_tile_dirty(bg_tilemap, offset / 2);
+}
+
+WRITE8_HANDLER( battlex_flipscreen_w )
+{
+ /* bit 4 is used, but for what? */
+
+ /* bit 7 is flip screen */
+
+ if (flip_screen != (data & 0x80))
+ {
+ flip_screen_set(data & 0x80);
+ tilemap_mark_all_tiles_dirty(ALL_TILEMAPS);
+ }
+}
+
+static TILE_GET_INFO( get_bg_tile_info )
+{
+ int tile = videoram[tile_index*2] | (((videoram[tile_index*2+1] & 0x01)) << 8);
+ int color = (videoram[tile_index*2+1] & 0x0e) >> 1;
+
+ SET_TILE_INFO(0,tile,color,0);
+}
+
+VIDEO_START( battlex )
+{
+ bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows,
+ TILEMAP_TYPE_PEN, 8, 8, 64, 32);
+}
+
+static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect )
+{
+ const gfx_element *gfx = machine->gfx[1];
+ UINT8 *source = spriteram;
+ UINT8 *finish = spriteram + 0x200;
+
+ while( source<finish )
+ {
+ int sx = (source[0] & 0x7f) * 2 - (source[0] & 0x80) * 2;
+ int sy = source[3];
+ int tile = source[2] & 0x7f;
+ int color = source[1] & 0x07; /* bits 3,4,5 also used during explosions */
+ int flipy = source[1] & 0x80;
+ int flipx = source[1] & 0x40;
+
+ if (flip_screen)
+ {
+ sx = 240 - sx;
+ sy = 240 - sy;
+ flipx = !flipx;
+ flipy = !flipy;
+ }
+
+ drawgfx(bitmap,gfx,tile,color,flipx,flipy,sx,sy,cliprect,TRANSPARENCY_PEN,0);
+
+ source += 4;
+ }
+
+}
+
+VIDEO_UPDATE(battlex)
+{
+ tilemap_set_scrollx(bg_tilemap, 0, battlex_scroll_lsb | (battlex_scroll_msb << 8));
+ tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
+ draw_sprites(machine, bitmap, cliprect);
+ return 0;
+}