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Diffstat (limited to 'src/mame/video/videopin.c')
-rw-r--r--src/mame/video/videopin.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/src/mame/video/videopin.c b/src/mame/video/videopin.c
new file mode 100644
index 00000000000..a4992fc45c4
--- /dev/null
+++ b/src/mame/video/videopin.c
@@ -0,0 +1,116 @@
+/*************************************************************************
+
+ Atari Video Pinball video emulation
+
+*************************************************************************/
+
+#include "driver.h"
+#include "includes/videopin.h"
+
+UINT8* videopin_video_ram;
+
+static int ball_x;
+static int ball_y;
+
+static tilemap* bg_tilemap;
+
+
+static TILEMAP_MAPPER( get_memory_offset )
+{
+ return num_rows * ((col + 16) % 48) + row;
+}
+
+
+static TILE_GET_INFO( get_tile_info )
+{
+ UINT8 code = videopin_video_ram[tile_index];
+
+ SET_TILE_INFO(0, code, 0, (code & 0x40) ? TILE_FLIPY : 0);
+}
+
+
+VIDEO_START( videopin )
+{
+ bg_tilemap = tilemap_create(get_tile_info, get_memory_offset, TILEMAP_TYPE_PEN, 8, 8, 48, 32);
+}
+
+
+VIDEO_UPDATE( videopin )
+{
+ int col;
+ int row;
+
+ tilemap_set_scrollx(bg_tilemap, 0, -8); /* account for delayed loading of shift reg C6 */
+
+ tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0);
+
+ for (row = 0; row < 32; row++)
+ {
+ for (col = 0; col < 48; col++)
+ {
+ UINT32 offset = get_memory_offset(col, row, 48, 32);
+
+ if (videopin_video_ram[offset] & 0x80) /* ball bit found */
+ {
+ rectangle rect;
+
+ int x = 8 * col;
+ int y = 8 * row;
+
+ int i;
+ int j;
+
+ x += 4; /* account for delayed loading of flip-flop C4 */
+
+ rect.min_x = x;
+ rect.min_y = y;
+ rect.max_x = x + 15;
+ rect.max_y = y + 15;
+
+ if (rect.min_x < cliprect->min_x)
+ rect.min_x = cliprect->min_x;
+ if (rect.min_y < cliprect->min_y)
+ rect.min_y = cliprect->min_y;
+ if (rect.max_x > cliprect->max_x)
+ rect.max_x = cliprect->max_x;
+ if (rect.max_y > cliprect->max_y)
+ rect.max_y = cliprect->max_y;
+
+ x -= ball_x;
+ y -= ball_y;
+
+ /* ball placement is still 0.5 pixels off but don't tell anyone */
+
+ for (i = 0; i < 2; i++)
+ {
+ for (j = 0; j < 2; j++)
+ {
+ drawgfx(bitmap, machine->gfx[1],
+ 0, 0,
+ 0, 0,
+ x + 16 * i,
+ y + 16 * j,
+ &rect, TRANSPARENCY_PEN, 0);
+ }
+ }
+
+ return 0; /* keep things simple and ignore the rest */
+ }
+ }
+ }
+ return 0;
+}
+
+
+WRITE8_HANDLER( videopin_ball_w )
+{
+ ball_x = data & 15;
+ ball_y = data >> 4;
+}
+
+
+WRITE8_HANDLER( videopin_video_ram_w )
+{
+ videopin_video_ram[offset] = data;
+ tilemap_mark_tile_dirty(bg_tilemap, offset);
+}