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-rw-r--r--src/mame/video/bankp.c205
1 files changed, 205 insertions, 0 deletions
diff --git a/src/mame/video/bankp.c b/src/mame/video/bankp.c
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+++ b/src/mame/video/bankp.c
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+/***************************************************************************
+
+ video.c
+
+ Functions to emulate the video hardware of the machine.
+
+***************************************************************************/
+
+#include "driver.h"
+
+UINT8 *bankp_videoram2;
+UINT8 *bankp_colorram2;
+
+static int scroll_x;
+static int priority;
+
+static tilemap *bg_tilemap, *fg_tilemap;
+static colortable *bankp_colortable;
+
+
+/***************************************************************************
+
+ Convert the color PROMs into a more useable format.
+
+ Bank Panic has a 32x8 palette PROM (I'm not sure whether the second 16
+ bytes are used - they contain the same colors as the first 16 with only
+ one different) and two 256x4 lookup table PROMs (one for charset #1, one
+ for charset #2 - only the first 128 nibbles seem to be used).
+
+ I don't know for sure how the palette PROM is 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
+
+***************************************************************************/
+PALETTE_INIT( bankp )
+{
+ int i;
+ #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])
+
+ /* allocate the colortable */
+ bankp_colortable = colortable_alloc(machine, 32);
+
+ for (i = 0;i < 32;i++)
+ {
+ int bit0,bit1,bit2,r,g,b;
+
+ /* red component */
+ bit0 = (*color_prom >> 0) & 0x01;
+ bit1 = (*color_prom >> 1) & 0x01;
+ bit2 = (*color_prom >> 2) & 0x01;
+ r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
+ /* green component */
+ bit0 = (*color_prom >> 3) & 0x01;
+ bit1 = (*color_prom >> 4) & 0x01;
+ bit2 = (*color_prom >> 5) & 0x01;
+ g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
+ /* blue component */
+ bit0 = 0;
+ bit1 = (*color_prom >> 6) & 0x01;
+ bit2 = (*color_prom >> 7) & 0x01;
+ b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
+
+ colortable_palette_set_color(bankp_colortable,i,MAKE_RGB(r,g,b));
+
+ color_prom++;
+ }
+
+ /* color_prom now points to the beginning of the lookup table */
+
+ /* charset #1 lookup table */
+ for (i = 0;i < machine->gfx[0]->total_colors * machine->gfx[0]->color_granularity;i++)
+ colortable_entry_set_value(bankp_colortable, machine->gfx[0]->color_base + i, *color_prom++ & 0x0f);
+
+ color_prom += 128; /* skip the bottom half of the PROM - seems to be not used */
+
+ /* charset #2 lookup table */
+ for (i = 0;i < machine->gfx[1]->total_colors * machine->gfx[1]->color_granularity;i++)
+ colortable_entry_set_value(bankp_colortable, machine->gfx[1]->color_base + i, *color_prom++ & 0x0f);
+
+ /* the bottom half of the PROM seems to be not used */
+}
+
+WRITE8_HANDLER( bankp_scroll_w )
+{
+ scroll_x = data;
+}
+
+WRITE8_HANDLER( bankp_videoram_w )
+{
+ videoram[offset] = data;
+ tilemap_mark_tile_dirty(fg_tilemap, offset);
+}
+
+WRITE8_HANDLER( bankp_colorram_w )
+{
+ colorram[offset] = data;
+ tilemap_mark_tile_dirty(fg_tilemap, offset);
+}
+
+WRITE8_HANDLER( bankp_videoram2_w )
+{
+ bankp_videoram2[offset] = data;
+ tilemap_mark_tile_dirty(bg_tilemap, offset);
+}
+
+WRITE8_HANDLER( bankp_colorram2_w )
+{
+ bankp_colorram2[offset] = data;
+ tilemap_mark_tile_dirty(bg_tilemap, offset);
+}
+
+WRITE8_HANDLER( bankp_out_w )
+{
+ /* bits 0-1 are playfield priority */
+ /* TODO: understand how this works */
+ priority = data & 0x03;
+
+ /* bits 2-3 unknown (2 is used) */
+
+ /* bit 4 controls NMI */
+ interrupt_enable_w(0,(data & 0x10)>>4);
+
+ /* bit 5 controls screen flip */
+ flip_screen_set(data & 0x20);
+
+ /* bits 6-7 unknown */
+}
+
+static TILE_GET_INFO( get_bg_tile_info )
+{
+ int code = bankp_videoram2[tile_index] + 256 * (bankp_colorram2[tile_index] & 0x07);
+ int color = bankp_colorram2[tile_index] >> 4;
+ int flags = (bankp_colorram2[tile_index] & 0x08) ? TILE_FLIPX : 0;
+
+ SET_TILE_INFO(1, code, color, flags);
+ tileinfo->group = color;
+}
+
+static TILE_GET_INFO( get_fg_tile_info )
+{
+ int code = videoram[tile_index] + 256 * ((colorram[tile_index] & 3) >> 0);
+ int color = colorram[tile_index] >> 3;
+ int flags = (colorram[tile_index] & 0x04) ? TILE_FLIPX : 0;
+
+ SET_TILE_INFO(0, code, color, flags);
+ tileinfo->group = color;
+}
+
+VIDEO_START( bankp )
+{
+ bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows,
+ TILEMAP_TYPE_PEN, 8, 8, 32, 32);
+
+ fg_tilemap = tilemap_create(get_fg_tile_info, tilemap_scan_rows,
+ TILEMAP_TYPE_PEN, 8, 8, 32, 32);
+
+ colortable_configure_tilemap_groups(bankp_colortable, bg_tilemap, machine->gfx[1], 0);
+ colortable_configure_tilemap_groups(bankp_colortable, fg_tilemap, machine->gfx[0], 0);
+}
+
+VIDEO_UPDATE( bankp )
+{
+ if (flip_screen)
+ {
+ tilemap_set_scrollx(fg_tilemap, 0, -scroll_x);
+ tilemap_set_scrollx(bg_tilemap, 0, 0);
+ }
+ else
+ {
+ tilemap_set_scrollx(fg_tilemap, 0, scroll_x);
+ tilemap_set_scrollx(bg_tilemap, 0, 0);
+ }
+
+
+ // only one bit matters?
+ switch (priority)
+ {
+ case 0: // combat hawk uses this
+ tilemap_draw(bitmap, cliprect, bg_tilemap, TILEMAP_DRAW_OPAQUE, 0);
+ tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0);
+ break;
+ case 1:
+ tilemap_draw(bitmap, cliprect, bg_tilemap, TILEMAP_DRAW_OPAQUE, 0);
+ tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0);
+ break;
+ case 2:
+ tilemap_draw(bitmap, cliprect, fg_tilemap, TILEMAP_DRAW_OPAQUE, 0);
+ tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
+ break;
+ case 3:
+ tilemap_draw(bitmap, cliprect, fg_tilemap, TILEMAP_DRAW_OPAQUE, 0); // just a guess
+ tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
+ break;
+ }
+ return 0;
+}