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comparison vdp.c @ 1454:a664bade4b29

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Fix minor graphical regression in Gunstar Heroes
author Michael Pavone <pavone@retrodev.com>
date Tue, 29 Aug 2017 23:49:57 -0700
parents da72344af3ff
children 3c1661305219
comparison
equal deleted inserted replaced
1453:cd6e566eb6b9 1454:a664bade4b29
2704 } 2704 }
2705 } 2705 }
2706 2706
2707 static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t is_h40, uint8_t mode_5) 2707 static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t is_h40, uint8_t mode_5)
2708 { 2708 {
2709 uint8_t buf_clear_slot, index_reset_slot, bg_end_slot, vint_slot, line_change, jump_start, jump_dest; 2709 uint8_t buf_clear_slot, index_reset_slot, bg_end_slot, vint_slot, line_change, jump_start, jump_dest, latch_slot;
2710 uint8_t index_reset_value, max_draws, max_sprites; 2710 uint8_t index_reset_value, max_draws, max_sprites;
2711 uint16_t vint_line, active_line; 2711 uint16_t vint_line, active_line;
2712 uint32_t bg_color; 2712 uint32_t bg_color;
2713 2713
2714 if (mode_5) { 2714 if (mode_5) {
2715 if (is_h40) { 2715 if (is_h40) {
2716 latch_slot = 165;
2716 buf_clear_slot = 163; 2717 buf_clear_slot = 163;
2717 index_reset_slot = 167; 2718 index_reset_slot = 167;
2718 bg_end_slot = BG_START_SLOT + LINEBUF_SIZE/2; 2719 bg_end_slot = BG_START_SLOT + LINEBUF_SIZE/2;
2719 max_draws = MAX_DRAWS-1; 2720 max_draws = MAX_DRAWS-1;
2720 max_sprites = MAX_SPRITES_LINE; 2721 max_sprites = MAX_SPRITES_LINE;
2732 index_reset_value = 0x80; 2733 index_reset_value = 0x80;
2733 vint_slot = VINT_SLOT_H32; 2734 vint_slot = VINT_SLOT_H32;
2734 line_change = LINE_CHANGE_H32; 2735 line_change = LINE_CHANGE_H32;
2735 jump_start = 147; 2736 jump_start = 147;
2736 jump_dest = 233; 2737 jump_dest = 233;
2738 latch_slot = 243;
2737 } 2739 }
2738 vint_line = context->inactive_start; 2740 vint_line = context->inactive_start;
2739 active_line = 0x1FF; 2741 active_line = 0x1FF;
2742 if (context->regs[REG_MODE_3] & BIT_VSCROLL) {
2743 latch_slot = 220;
2744 }
2740 } else { 2745 } else {
2746 latch_slot = 220;
2741 bg_end_slot = BG_START_SLOT + (256+HORIZ_BORDER)/2; 2747 bg_end_slot = BG_START_SLOT + (256+HORIZ_BORDER)/2;
2742 max_draws = MAX_DRAWS_H32_MODE4; 2748 max_draws = MAX_DRAWS_H32_MODE4;
2743 max_sprites = 8; 2749 max_sprites = 8;
2744 buf_clear_slot = 136; 2750 buf_clear_slot = 136;
2745 index_reset_slot = 253; 2751 index_reset_slot = 253;
2819 } 2825 }
2820 memset(context->linebuf, 0, LINEBUF_SIZE); 2826 memset(context->linebuf, 0, LINEBUF_SIZE);
2821 } else if (context->hslot == index_reset_slot) { 2827 } else if (context->hslot == index_reset_slot) {
2822 context->sprite_index = index_reset_value; 2828 context->sprite_index = index_reset_value;
2823 context->slot_counter = mode_5 ? 0 : max_sprites; 2829 context->slot_counter = mode_5 ? 0 : max_sprites;
2830 } else if (context->hslot == latch_slot) {
2831 //it seems unlikely to me that vscroll actually gets latched when the display is off
2832 //but it's the only straightforward way to reconcile what I'm seeing between Skitchin
2833 //(which seems to expect vscroll to be latched early) and the intro of Gunstar Heroes
2834 //(which disables the display and ends up with garbage if vscroll is latched during that period)
2835 //without it. Some more tests are definitely needed
2836 context->vscroll_latch[0] = context->vsram[0];
2837 context->vscroll_latch[1] = context->vsram[1];
2824 } else if (context->vcounter == vint_line && context->hslot == vint_slot) { 2838 } else if (context->vcounter == vint_line && context->hslot == vint_slot) {
2825 context->flags2 |= FLAG2_VINT_PENDING; 2839 context->flags2 |= FLAG2_VINT_PENDING;
2826 context->pending_vint_start = context->cycles; 2840 context->pending_vint_start = context->cycles;
2827 } else if (context->vcounter == context->inactive_start && context->hslot == 1 && (context->regs[REG_MODE_4] & BIT_INTERLACE)) { 2841 } else if (context->vcounter == context->inactive_start && context->hslot == 1 && (context->regs[REG_MODE_4] & BIT_INTERLACE)) {
2828 context->flags2 ^= FLAG2_EVEN_FIELD; 2842 context->flags2 ^= FLAG2_EVEN_FIELD;