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[Core/VDP] improved Mode 5 sprite parsing accuracy (verified on real hardware)

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EkeEke 2014-07-06 21:04:33 +02:00
parent 331ec8b7cb
commit 8c91bdc05e
1 changed files with 35 additions and 29 deletions
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64
core/vdp_render.c
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@ -3812,44 +3812,50 @@ void parse_satb_m5(int line)
do do
{ {
/* Read Y position & size from internal SAT */ /* Read Y position from internal SAT cache */
ypos = (q[link] >> im2_flag) & 0x1FF; ypos = (q[link] >> im2_flag) & 0x1FF;
size = q[link + 1] >> 8;
/* Sprite height */ /* Check if sprite Y position has been reached */
height = 8 + ((size & 3) << 3); if (line >= ypos)
/* Y range */
ypos = line - ypos;
/* Sprite is visble on this line ? */
if ((ypos >= 0) && (ypos < height))
{ {
/* Sprite overflow */ /* Read sprite size from internal SAT cache */
if (count == max) size = q[link + 1] >> 8;
/* Sprite height */
height = 8 + ((size & 3) << 3);
/* Y range */
ypos = line - ypos;
/* Check if sprite is visible on current line */
if (ypos < height)
{ {
status |= 0x40; /* Sprite overflow */
break; if (count == max)
{
status |= 0x40;
break;
}
/* Update sprite list (only name, attribute & xpos are parsed from VRAM) */
object_info->attr = p[link + 2];
object_info->xpos = p[link + 3] & 0x1ff;
object_info->ypos = ypos;
object_info->size = size & 0x0f;
/* Increment Sprite count */
++count;
/* Next sprite entry */
object_info++;
} }
/* Update sprite list (only name, attribute & xpos are parsed from VRAM) */
object_info->attr = p[link + 2];
object_info->xpos = p[link + 3] & 0x1ff;
object_info->ypos = ypos;
object_info->size = size & 0x0f;
/* Increment Sprite count */
++count;
/* Next sprite entry */
object_info++;
} }
/* Read link data from internal SAT */ /* Read link data from internal SAT cache */
link = (q[link + 1] & 0x7F) << 2; link = (q[link + 1] & 0x7F) << 2;
/* Last sprite */ /* Stop parsing if link data points to first entry (#0) or after the last entry (#64 in H32 mode, #80 in H40 mode) */
if (link == 0) break; if ((link == 0) || (link >= bitmap.viewport.w)) break;
} }
while (--total); while (--total);