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Diffstat (limited to 'vdp.c')
-rw-r--r--vdp.c83
1 files changed, 48 insertions, 35 deletions
diff --git a/vdp.c b/vdp.c
index 8663d9e..6cbcf20 100644
--- a/vdp.c
+++ b/vdp.c
@@ -98,6 +98,13 @@ static void update_video_params(vdp_context *context)
context->border_bot = BORDER_TOP_V28;
}
}
+ if (context->regs[REG_MODE_4] & BIT_H40) {
+ context->max_sprites_frame = MAX_SPRITES_FRAME;
+ context->max_sprites_line = MAX_SPRITES_LINE;
+ } else {
+ context->max_sprites_frame = MAX_SPRITES_FRAME_H32;
+ context->max_sprites_line = MAX_SPRITES_LINE_H32;
+ }
if (context->state == INACTIVE) {
//Undo forced INACTIVE state due to neither Mode 4 nor Mode 5 being active
if (context->vcounter < context->inactive_start) {
@@ -544,7 +551,7 @@ static uint8_t is_active(vdp_context *context)
static void scan_sprite_table(uint32_t line, vdp_context * context)
{
- if (context->sprite_index && context->slot_counter) {
+ if (context->sprite_index && ((uint8_t)context->slot_counter) < context->max_sprites_line) {
line += 1;
line &= 0xFF;
uint16_t ymask, ymin;
@@ -563,12 +570,8 @@ static void scan_sprite_table(uint32_t line, vdp_context * context)
height_mult = 8;
}
context->sprite_index &= 0x7F;
- if (context->regs[REG_MODE_4] & BIT_H40) {
- if (context->sprite_index >= MAX_SPRITES_FRAME) {
- context->sprite_index = 0;
- return;
- }
- } else if(context->sprite_index >= MAX_SPRITES_FRAME_H32) {
+ //TODO: Implement squirelly behavior documented by Kabuto
+ if (context->sprite_index >= context->max_sprites_frame) {
context->sprite_index = 0;
return;
}
@@ -579,19 +582,15 @@ static void scan_sprite_table(uint32_t line, vdp_context * context)
//printf("Sprite %d | y: %d, height: %d\n", context->sprite_index, y, height);
if (y <= line && line < (y + height)) {
//printf("Sprite %d at y: %d with height %d is on line %d\n", context->sprite_index, y, height, line);
- context->sprite_info_list[--(context->slot_counter)].size = context->sat_cache[address+2];
+ context->sprite_info_list[context->slot_counter].size = context->sat_cache[address+2];
context->sprite_info_list[context->slot_counter].index = context->sprite_index;
- context->sprite_info_list[context->slot_counter].y = y-ymin;
+ context->sprite_info_list[context->slot_counter++].y = y-ymin;
}
context->sprite_index = context->sat_cache[address+3] & 0x7F;
- if (context->sprite_index && context->slot_counter)
+ if (context->sprite_index && ((uint8_t)context->slot_counter) < context->max_sprites_line)
{
- if (context->regs[REG_MODE_4] & BIT_H40) {
- if (context->sprite_index >= MAX_SPRITES_FRAME) {
- context->sprite_index = 0;
- return;
- }
- } else if(context->sprite_index >= MAX_SPRITES_FRAME_H32) {
+ //TODO: Implement squirelly behavior documented by Kabuto
+ if (context->sprite_index >= context->max_sprites_frame) {
context->sprite_index = 0;
return;
}
@@ -601,13 +600,14 @@ static void scan_sprite_table(uint32_t line, vdp_context * context)
//printf("Sprite %d | y: %d, height: %d\n", context->sprite_index, y, height);
if (y <= line && line < (y + height)) {
//printf("Sprite %d at y: %d with height %d is on line %d\n", context->sprite_index, y, height, line);
- context->sprite_info_list[--(context->slot_counter)].size = context->sat_cache[address+2];
+ context->sprite_info_list[context->slot_counter].size = context->sat_cache[address+2];
context->sprite_info_list[context->slot_counter].index = context->sprite_index;
- context->sprite_info_list[context->slot_counter].y = y-ymin;
+ context->sprite_info_list[context->slot_counter++].y = y-ymin;
}
context->sprite_index = context->sat_cache[address+3] & 0x7F;
}
}
+ //TODO: Seems like the overflow flag should be set here if we run out of sprite info slots without hitting the end of the list
}
static void scan_sprite_table_mode4(vdp_context * context)
@@ -632,7 +632,6 @@ static void scan_sprite_table_mode4(vdp_context * context)
}
context->sprite_info_list[--(context->slot_counter)].size = size;
context->sprite_info_list[context->slot_counter].index = context->sprite_index;
- context->sprite_info_list[context->slot_counter].y = y;
}
context->sprite_index++;
}
@@ -651,7 +650,6 @@ static void scan_sprite_table_mode4(vdp_context * context)
}
context->sprite_info_list[--(context->slot_counter)].size = size;
context->sprite_info_list[context->slot_counter].index = context->sprite_index;
- context->sprite_info_list[context->slot_counter].y = y;
}
context->sprite_index++;
}
@@ -662,7 +660,10 @@ static void scan_sprite_table_mode4(vdp_context * context)
static void read_sprite_x(uint32_t line, vdp_context * context)
{
- if (context->cur_slot >= context->slot_counter) {
+ if (context->cur_slot == context->max_sprites_line) {
+ context->cur_slot = 0;
+ }
+ if (context->cur_slot < context->slot_counter) {
if (context->sprite_draws) {
line += 1;
line &= 0xFF;
@@ -677,15 +678,26 @@ static void read_sprite_x(uint32_t line, vdp_context * context)
}
height *= 2;
}
+ uint16_t ymask, ymin;
+ if (context->double_res) {
+ ymask = 0x3FF;
+ ymin = 256;
+ } else {
+ ymask = 0x1FF;
+ ymin = 128;
+ }
uint16_t att_addr = mode5_sat_address(context) + context->sprite_info_list[context->cur_slot].index * 8 + 4;
uint16_t tileinfo = (context->vdpmem[att_addr] << 8) | context->vdpmem[att_addr+1];
uint8_t pal_priority = (tileinfo >> 9) & 0x70;
uint8_t row;
+ uint16_t cache_addr = context->sprite_info_list[context->cur_slot].index * 4;
+ int16_t y = ((context->sat_cache[cache_addr] << 8 | context->sat_cache[cache_addr+1]) & ymask) - ymin;
if (tileinfo & MAP_BIT_V_FLIP) {
- row = (context->sprite_info_list[context->cur_slot].y + height - 1) - line;
+ row = (y + height - 1) - line;
} else {
- row = line-context->sprite_info_list[context->cur_slot].y;
+ row = line-y;
}
+ row &= ymask >> 4;
uint16_t address;
if (context->double_res) {
address = ((tileinfo & 0x3FF) << 6) + row * 4;
@@ -730,11 +742,11 @@ static void read_sprite_x(uint32_t line, vdp_context * context)
if (!context->sprite_draws) {
context->flags |= FLAG_DOT_OFLOW;
}
- context->cur_slot--;
} else {
context->flags |= FLAG_DOT_OFLOW;
}
}
+ context->cur_slot++;
}
static void read_sprite_x_mode4(vdp_context * context)
@@ -1899,7 +1911,7 @@ static void vdp_h40(vdp_context * context, uint32_t target_cycles)
}
}
context->sprite_index = 0x80;
- context->slot_counter = MAX_SPRITES_LINE;
+ context->slot_counter = 0;
render_sprite_cells( context);
scan_sprite_table(context->vcounter, context);
CHECK_LIMIT
@@ -1981,10 +1993,11 @@ static void vdp_h40(vdp_context * context, uint32_t target_cycles)
case 0:
render_map_output(context->vcounter, 0, context);
scan_sprite_table(context->vcounter, context);//Just a guess
- //reverse context slot counter so it counts the number of sprite slots
- //filled rather than the number of available slots
- //context->slot_counter = MAX_SPRITES_LINE - context->slot_counter;
- context->cur_slot = MAX_SPRITES_LINE-1;
+ //seems like the sprite table scan fills a shift register
+ //values are FIFO, but unused slots precede used slots
+ //so we set cur_slot to slot_counter and let it wrap around to
+ //the beginning of the list
+ context->cur_slot = context->slot_counter;
context->sprite_draws = MAX_DRAWS;
context->flags &= (~FLAG_CAN_MASK & ~FLAG_MASKED);
CHECK_LIMIT
@@ -2106,7 +2119,7 @@ static void vdp_h32(vdp_context * context, uint32_t target_cycles)
}
}
context->sprite_index = 0x80;
- context->slot_counter = MAX_SPRITES_LINE_H32;
+ context->slot_counter = 0;
render_sprite_cells( context);
scan_sprite_table(context->vcounter, context);
CHECK_LIMIT
@@ -2186,7 +2199,7 @@ static void vdp_h32(vdp_context * context, uint32_t target_cycles)
//reverse context slot counter so it counts the number of sprite slots
//filled rather than the number of available slots
//context->slot_counter = MAX_SPRITES_LINE - context->slot_counter;
- context->cur_slot = MAX_SPRITES_LINE_H32-1;
+ context->cur_slot = context->slot_counter;
context->sprite_draws = MAX_DRAWS_H32;
context->flags &= (~FLAG_CAN_MASK & ~FLAG_MASKED);
CHECK_LIMIT
@@ -2376,8 +2389,8 @@ static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t i
if (mode_5) {
if (is_h40) {
- buf_clear_slot = 161;
- index_reset_slot = 165;
+ buf_clear_slot = 163;
+ index_reset_slot = 167;
bg_end_slot = BG_START_SLOT + LINEBUF_SIZE/2;
max_draws = MAX_DRAWS-1;
max_sprites = MAX_SPRITES_LINE;
@@ -2450,7 +2463,7 @@ static void vdp_inactive(vdp_context *context, uint32_t target_cycles, uint8_t i
memset(context->linebuf, 0, LINEBUF_SIZE);
} else if (context->hslot == index_reset_slot) {
context->sprite_index = index_reset_value;
- context->slot_counter = max_sprites;
+ context->slot_counter = mode_5 ? 0 : max_sprites;
} else if (context->vcounter == vint_line && context->hslot == vint_slot) {
context->flags2 |= FLAG2_VINT_PENDING;
context->pending_vint_start = context->cycles;
@@ -2662,7 +2675,7 @@ int vdp_control_port_write(vdp_context * context, uint16_t value)
context->flags2 &= ~FLAG2_EVEN_FIELD;
}
}
- if (reg == REG_MODE_2) {
+ if (reg == REG_MODE_1 || reg == REG_MODE_2 || reg == REG_MODE_4) {
update_video_params(context);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-19 19:33:40 +0000