diff options
| -rw-r--r-- | vdp.c | 16 |
1 files changed, 15 insertions, 1 deletions
@@ -2706,13 +2706,14 @@ static void check_switch_inactive(vdp_context *context, uint8_t is_h40) static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t is_h40, uint8_t mode_5) { - uint8_t buf_clear_slot, index_reset_slot, bg_end_slot, vint_slot, line_change, jump_start, jump_dest; + uint8_t buf_clear_slot, index_reset_slot, bg_end_slot, vint_slot, line_change, jump_start, jump_dest, latch_slot; uint8_t index_reset_value, max_draws, max_sprites; uint16_t vint_line, active_line; uint32_t bg_color; if (mode_5) { if (is_h40) { + latch_slot = 165; buf_clear_slot = 163; index_reset_slot = 167; bg_end_slot = BG_START_SLOT + LINEBUF_SIZE/2; @@ -2734,10 +2735,15 @@ static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t i line_change = LINE_CHANGE_H32; jump_start = 147; jump_dest = 233; + latch_slot = 243; } vint_line = context->inactive_start; active_line = 0x1FF; + if (context->regs[REG_MODE_3] & BIT_VSCROLL) { + latch_slot = 220; + } } else { + latch_slot = 220; bg_end_slot = BG_START_SLOT + (256+HORIZ_BORDER)/2; max_draws = MAX_DRAWS_H32_MODE4; max_sprites = 8; @@ -2821,6 +2827,14 @@ static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t i } else if (context->hslot == index_reset_slot) { context->sprite_index = index_reset_value; context->slot_counter = mode_5 ? 0 : max_sprites; + } else if (context->hslot == latch_slot) { + //it seems unlikely to me that vscroll actually gets latched when the display is off + //but it's the only straightforward way to reconcile what I'm seeing between Skitchin + //(which seems to expect vscroll to be latched early) and the intro of Gunstar Heroes + //(which disables the display and ends up with garbage if vscroll is latched during that period) + //without it. Some more tests are definitely needed + context->vscroll_latch[0] = context->vsram[0]; + context->vscroll_latch[1] = context->vsram[1]; } else if (context->vcounter == vint_line && context->hslot == vint_slot) { context->flags2 |= FLAG2_VINT_PENDING; context->pending_vint_start = context->cycles; |