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MGA flicker fixes.

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It's time to end the flickers once and for all by making the start address correctly emulated in vblank_start when in power graphics mode.
This commit is contained in:
TC1995
2023-12-23 15:02:15 +01:00
parent 28775d2583
commit 012527fc4e
1 changed files with 32 additions and 49 deletions
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81
src/video/vid_mga.c
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@@ -722,27 +722,6 @@ mystique_out(uint16_t addr, uint8_t val, void *priv)
if (mystique->crtcext_idx < 6)
mystique->crtcext_regs[mystique->crtcext_idx] = val;
if (mystique->crtcext_idx == 0 && (mystique->crtcext_regs[3] & CRTCX_R3_MGAMODE))
{
svga->rowoffset = svga->crtc[0x13] | ((mystique->crtcext_regs[0] & CRTCX_R0_OFFSET_MASK) << 4);
svga->rowoffset <<= 1;
svga->ma_latch = ((mystique->crtcext_regs[0] & CRTCX_R0_STARTADD_MASK) << 16) | (svga->crtc[0xc] << 8) | svga->crtc[0xd];
if (mystique->pci_regs[0x41] & (OPTION_INTERLEAVE >> 8)) {
svga->rowoffset <<= 1;
svga->ma_latch <<= 1;
}
if (mystique->type >= MGA_1064SG) {
svga->ma_latch <<= 1;
if (svga->ma_latch != mystique->ma_latch_old) {
if (svga->interlace && svga->oddeven)
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2) + (svga->rowoffset << 1);
else
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2);
mystique->ma_latch_old = svga->ma_latch;
}
}
}
if (mystique->crtcext_idx == 4) {
if (svga->gdcreg[6] & 0xc) {
/*64k banks*/
@@ -829,6 +808,33 @@ mystique_line_compare(svga_t *svga)
return 0;
}
static void
mystique_vblank_start(svga_t *svga)
{
mystique_t *mystique = (mystique_t *) svga->priv;
if (mystique->crtcext_regs[3] & CRTCX_R3_MGAMODE) {
svga->ma_latch = ((mystique->crtcext_regs[0] & CRTCX_R0_STARTADD_MASK) << 16) | (svga->crtc[0xc] << 8) | svga->crtc[0xd];
if (mystique->pci_regs[0x41] & (OPTION_INTERLEAVE >> 8))
svga->ma_latch <<= 1;
if (mystique->type >= MGA_1064SG) {
/*Mystique, unlike most SVGA cards, allows display start to take
effect mid-screen*/
svga->ma_latch <<= 1;
/* Only change maback so the new display start will take effect on the next
horizontal retrace. */
if (svga->ma_latch != mystique->ma_latch_old) {
if (svga->interlace && svga->oddeven)
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2) + (svga->rowoffset << 1);
else
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2);
mystique->ma_latch_old = svga->ma_latch;
}
}
}
}
static void
mystique_vsync_callback(svga_t *svga)
{
@@ -896,39 +902,14 @@ mystique_recalctimings(svga_t *svga)
if (mystique->crtcext_regs[3] & CRTCX_R3_MGAMODE) {
svga->lowres = 0;
svga->char_width = 8;
svga->hdisp = (svga->crtc[1] + 1) * 8;
svga->hdisp = (svga->crtc[1] + 1) << 3;
svga->hdisp_time = svga->hdisp;
svga->rowoffset = svga->crtc[0x13] | ((mystique->crtcext_regs[0] & CRTCX_R0_OFFSET_MASK) << 4);
svga->ma_latch = ((mystique->crtcext_regs[0] & CRTCX_R0_STARTADD_MASK) << 16) | (svga->crtc[0xc] << 8) | svga->crtc[0xd];
if (mystique->pci_regs[0x41] & (OPTION_INTERLEAVE >> 8)) {
if (mystique->pci_regs[0x41] & (OPTION_INTERLEAVE >> 8))
svga->rowoffset <<= 1;
svga->ma_latch <<= 1;
}
if (mystique->type >= MGA_1064SG) {
/*Mystique, unlike most SVGA cards, allows display start to take
effect mid-screen*/
svga->ma_latch <<= 1;
#ifdef CHANGE_MA
if (svga->ma_latch != mystique->ma_latch_old) {
if (svga->interlace && svga->oddeven)
svga->ma = svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2) + (svga->rowoffset << 1);
else
svga->ma = svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2);
mystique->ma_latch_old = svga->ma_latch;
}
#else
/* Only change maback so the new display start will take effect on the next
horizontal retrace. */
if (svga->ma_latch != mystique->ma_latch_old) {
if (svga->interlace && svga->oddeven)
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2) + (svga->rowoffset << 1);
else
svga->maback = (svga->maback - (mystique->ma_latch_old << 2)) + (svga->ma_latch << 2);
mystique->ma_latch_old = svga->ma_latch;
}
#endif
svga->rowoffset <<= 1;
switch (mystique->xmulctrl & XMULCTRL_DEPTH_MASK) {
case XMULCTRL_DEPTH_8:
@@ -979,9 +960,11 @@ mystique_recalctimings(svga_t *svga)
}
svga->packed_chain4 = 1;
svga->line_compare = mystique_line_compare;
svga->vblank_start = mystique_vblank_start;
} else {
svga->packed_chain4 = 0;
svga->line_compare = NULL;
svga->vblank_start = NULL;
if (mystique->type >= MGA_1064SG)
svga->bpp = 8;
}