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Diffstat (limited to 'src/mame/video/gunsmoke.c')
-rw-r--r--src/mame/video/gunsmoke.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/src/mame/video/gunsmoke.c b/src/mame/video/gunsmoke.c
new file mode 100644
index 00000000000..79ec0530b2a
--- /dev/null
+++ b/src/mame/video/gunsmoke.c
@@ -0,0 +1,216 @@
+#include "driver.h"
+
+#define TOTAL_COLORS(gfxn) (machine->gfx[gfxn]->total_colors * machine->gfx[gfxn]->color_granularity)
+#define COLOR(gfxn,offs) (colortable[machine->drv->gfxdecodeinfo[gfxn].color_codes_start + offs])
+
+UINT8 *gunsmoke_scrollx;
+UINT8 *gunsmoke_scrolly;
+
+static UINT8 chon, objon, bgon;
+static UINT8 sprite3bank;
+
+static tilemap *bg_tilemap, *fg_tilemap;
+
+/***************************************************************************
+
+ Convert the color PROMs into a more useable format.
+
+ Gunsmoke has three 256x4 palette PROMs (one per gun) and a lot ;-) of
+ 256x4 lookup table PROMs.
+ The palette PROMs are connected to the RGB output this way:
+
+ bit 3 -- 220 ohm resistor -- RED/GREEN/BLUE
+ -- 470 ohm resistor -- RED/GREEN/BLUE
+ -- 1 kohm resistor -- RED/GREEN/BLUE
+ bit 0 -- 2.2kohm resistor -- RED/GREEN/BLUE
+
+***************************************************************************/
+PALETTE_INIT( gunsmoke )
+{
+ int i;
+
+ for (i = 0; i < machine->drv->total_colors; i++)
+ {
+ int bit0, bit1, bit2, bit3, r, g, b;
+
+ bit0 = (color_prom[0] >> 0) & 0x01;
+ bit1 = (color_prom[0] >> 1) & 0x01;
+ bit2 = (color_prom[0] >> 2) & 0x01;
+ bit3 = (color_prom[0] >> 3) & 0x01;
+
+ r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
+
+ bit0 = (color_prom[machine->drv->total_colors] >> 0) & 0x01;
+ bit1 = (color_prom[machine->drv->total_colors] >> 1) & 0x01;
+ bit2 = (color_prom[machine->drv->total_colors] >> 2) & 0x01;
+ bit3 = (color_prom[machine->drv->total_colors] >> 3) & 0x01;
+
+ g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
+
+ bit0 = (color_prom[2*machine->drv->total_colors] >> 0) & 0x01;
+ bit1 = (color_prom[2*machine->drv->total_colors] >> 1) & 0x01;
+ bit2 = (color_prom[2*machine->drv->total_colors] >> 2) & 0x01;
+ bit3 = (color_prom[2*machine->drv->total_colors] >> 3) & 0x01;
+
+ b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
+
+ palette_set_color(machine, i, MAKE_RGB(r, g, b));
+ color_prom++;
+ }
+
+ color_prom += 2 * machine->drv->total_colors;
+ /* color_prom now points to the beginning of the lookup table */
+
+ /* characters use colors 64-79 */
+ for (i = 0; i < TOTAL_COLORS(0); i++)
+ COLOR(0, i) = *(color_prom++) + 64;
+ color_prom += 128; /* skip the bottom half of the PROM - not used */
+
+ /* background tiles use colors 0-63 */
+ for (i = 0; i < TOTAL_COLORS(1); i++)
+ {
+ COLOR(1, i) = color_prom[0] + 16 * (color_prom[256] & 0x03);
+ color_prom++;
+ }
+ color_prom += TOTAL_COLORS(1);
+
+ /* sprites use colors 128-255 */
+ for (i = 0; i < TOTAL_COLORS(2); i++)
+ {
+ COLOR(2, i) = color_prom[0] + 16 * (color_prom[256] & 0x07) + 128;
+ color_prom++;
+ }
+ color_prom += TOTAL_COLORS(2);
+}
+
+WRITE8_HANDLER( gunsmoke_videoram_w )
+{
+ videoram[offset] = data;
+ tilemap_mark_tile_dirty(fg_tilemap, offset);
+}
+
+WRITE8_HANDLER( gunsmoke_colorram_w )
+{
+ colorram[offset] = data;
+ tilemap_mark_tile_dirty(fg_tilemap, offset);
+}
+
+WRITE8_HANDLER( gunsmoke_c804_w )
+{
+ /* bits 0 and 1 are for coin counters */
+ coin_counter_w(1, data & 0x01);
+ coin_counter_w(0, data & 0x02);
+
+ /* bits 2 and 3 select the ROM bank */
+ memory_set_bank(1, (data & 0x0c) >> 2);
+
+ /* bit 5 resets the sound CPU? - we ignore it */
+
+ /* bit 6 flips screen */
+ flip_screen_set(data & 0x40);
+
+ /* bit 7 enables characters? */
+ chon = data & 0x80;
+}
+
+WRITE8_HANDLER( gunsmoke_d806_w )
+{
+ /* bits 0-2 select the sprite 3 bank */
+ sprite3bank = data & 0x07;
+
+ /* bit 4 enables bg 1? */
+ bgon = data & 0x10;
+
+ /* bit 5 enables sprites? */
+ objon = data & 0x20;
+}
+
+static TILE_GET_INFO( get_bg_tile_info )
+{
+ UINT8 *tilerom = memory_region(REGION_GFX4);
+
+ int offs = tile_index * 2;
+ int attr = tilerom[offs + 1];
+ int code = tilerom[offs] + ((attr & 0x01) << 8);
+ int color = (attr & 0x3c) >> 2;
+ int flags = TILE_FLIPYX((attr & 0xc0) >> 6);
+
+ SET_TILE_INFO(1, code, color, flags);
+}
+
+static TILE_GET_INFO( get_fg_tile_info )
+{
+ int attr = colorram[tile_index];
+ int code = videoram[tile_index] + ((attr & 0xe0) << 2);
+ int color = attr & 0x1f;
+
+ SET_TILE_INFO(0, code, color, 0);
+}
+
+VIDEO_START( gunsmoke )
+{
+ /* configure ROM banking */
+ UINT8 *rombase = memory_region(REGION_CPU1);
+ memory_configure_bank(1, 0, 4, &rombase[0x10000], 0x4000);
+
+ /* create tilemaps */
+ bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_cols,
+ TILEMAP_TYPE_PEN, 32, 32, 2048, 8);
+
+ fg_tilemap = tilemap_create(get_fg_tile_info, tilemap_scan_rows,
+ TILEMAP_TYPE_COLORTABLE, 8, 8, 32, 32);
+
+ tilemap_set_transparent_pen(fg_tilemap, 0x4f);
+
+ /* register for saving */
+ state_save_register_global(chon);
+ state_save_register_global(objon);
+ state_save_register_global(bgon);
+ state_save_register_global(sprite3bank);
+}
+
+static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect)
+{
+ int offs;
+
+ for (offs = spriteram_size - 32; offs >= 0; offs -= 32)
+ {
+ int attr = spriteram[offs + 1];
+ int bank = (attr & 0xc0) >> 6;
+ int code = spriteram[offs];
+ int color = attr & 0x0f;
+ int flipx = 0;
+ int flipy = attr & 0x10;
+ int sx = spriteram[offs + 3] - ((attr & 0x20) << 3);
+ int sy = spriteram[offs + 2];
+
+ if (bank == 3) bank += sprite3bank;
+ code += 256 * bank;
+
+ if (flip_screen)
+ {
+ sx = 240 - sx;
+ sy = 240 - sy;
+ flipx = !flipx;
+ flipy = !flipy;
+ }
+
+ drawgfx(bitmap, machine->gfx[2], code, color, flipx, flipy,
+ sx, sy, cliprect, TRANSPARENCY_PEN, 0);
+ }
+}
+
+VIDEO_UPDATE( gunsmoke )
+{
+ tilemap_set_scrollx(bg_tilemap, 0, gunsmoke_scrollx[0] + 256 * gunsmoke_scrollx[1]);
+ tilemap_set_scrolly(bg_tilemap, 0, gunsmoke_scrolly[0]);
+
+ if (bgon)
+ tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
+ else
+ fillbitmap(bitmap, get_black_pen(machine), cliprect);
+
+ if (objon) draw_sprites(machine, bitmap, cliprect);
+ if (chon) tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0);
+ return 0;
+}