From 3061afa4b181b9723b1945aba3765a35bd714546 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Sun, 19 Jan 2025 17:08:37 -0500
Subject: [PATCH] Fix Prestel double-height bottom clearing issue
Any change to any double-height bit anywhere on the screen can
potentially change the display of every character after it on the
screen. If the bit changes, force a full redraw from vmem
(Luckily there's no graphics in Prestel mode).
Fixes ticket 181
Ugh.
---
src/conio/bitmap_con.c | 48 +++++++++++++++++++++++++++++++++---------
1 file changed, 38 insertions(+), 10 deletions(-)
diff --git a/src/conio/bitmap_con.c b/src/conio/bitmap_con.c
index 627eded961..2993e6b05c 100644
--- a/src/conio/bitmap_con.c
+++ b/src/conio/bitmap_con.c
@@ -278,6 +278,7 @@ bitmap_vmem_puttext_locked(int sx, int sy, int ex, int ey, struct vmem_cell *fil
int x,y;
struct vmem_cell *vc;
struct vmem_cell *fi = fill;
+ bool fullredraw = false;
if(!bitmap_initialized)
return(0);
@@ -297,16 +298,27 @@ bitmap_vmem_puttext_locked(int sx, int sy, int ex, int ey, struct vmem_cell *fil
for(y=sy-1;y<ey;y++) {
vc = vmem_cell_ptr(vstat.vmem, sx - 1, y);
for(x=sx-1;x<ex;x++) {
+ if (vstat.mode == PRESTEL_40X24 && ((vc->bg & 0x02000000) || (fi->bg & 0x02000000))) {
+ if ((vc->bg & 0x01000000) != (fi->bg & 0x01000000)) {
+ // *ANY* change to double-height potentially changes
+ // *EVERY* character on the screen
+ fullredraw = true;
+ }
+ }
*vc = *(fi++);
- if (vstat.mode == PRESTEL_40X24 && (vc->bg & 0x02000000) && (vc->legacy_attr & 0x08)) {
- if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
- vc->fg |= 0x01000000;
- else
- vc->fg &= ~0x01000000;
+ if (vstat.mode == PRESTEL_40X24 && (vc->bg & 0x02000000)) {
+ if (vc->legacy_attr & 0x08) {
+ if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
+ vc->fg |= 0x01000000;
+ else
+ vc->fg &= ~0x01000000;
+ }
}
vc = vmem_next_ptr(vstat.vmem, vc);
}
}
+ if (fullredraw)
+ request_redraw_locked();
return(1);
}
@@ -334,11 +346,26 @@ set_vmem_cell(size_t x, size_t y, uint16_t cell, uint32_t fg, uint32_t bg)
vc->legacy_attr = cell >> 8;
vc->ch = cell & 0xff;
vc->fg = fg;
- if (vstat.mode == PRESTEL_40X24 && (vc->bg & 0x02000000) && (vc->legacy_attr & 0x08)) {
- if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
- vc->fg |= 0x01000000;
- else
- vc->fg &= ~0x01000000;
+ if (vstat.mode == PRESTEL_40X24 && ((vc->bg & 0x02000000) || (bg & 0x02000000))) {
+ if (vc->legacy_attr & 0x08) {
+ if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
+ vc->fg |= 0x01000000;
+ else
+ vc->fg &= ~0x01000000;
+ }
+ if ((vc->bg & 0x01000000) != (bg & 0x01000000)) {
+ // *ANY* change to double-height potentially changes
+ // *EVERY* character on the screen
+ request_redraw_locked();
+ }
+ }
+ if (vstat.mode == PRESTEL_40X24 && (vc->bg & 0x02000000)) {
+ if (vc->legacy_attr & 0x08) {
+ if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
+ vc->fg |= 0x01000000;
+ else
+ vc->fg &= ~0x01000000;
+ }
}
vc->bg = bg;
vc->font = font;
@@ -1080,6 +1107,7 @@ same_cell(struct vmem_cell *bitmap_cell, struct vmem_cell *c2)
return false;
if (bitmap_cell->bg != c2->bg)
return false;
+ // Handles reveal/unreveal updates, modifies vmem
if (vstat.mode == PRESTEL_40X24 && (c2->bg & 0x02000000)) {
if (c2->legacy_attr & 0x08) {
if (cio_api.options & CONIO_OPT_PRESTEL_REVEAL)
--
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