[SeaBIOS] [PATCH] vgabios: Simplify scroll logic
Kevin O'Connor
kevin at koconnor.net
Thu Jul 21 17:01:10 CEST 2016
Introduce a new function vgafb_scroll() to scroll a window on the
screen and update vgabios.c to use only that function for scrolling.
This makes the low-level vgafb_move_chars() and vgafb_clear_chars()
local to vgafb.c, and it simplifies the callers.
Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
---
vgasrc/vgabios.c | 57 ++++++++++++---------------------------------
vgasrc/vgabios.h | 6 ++---
vgasrc/vgafb.c | 70 ++++++++++++++++++++++++++++++++++++++------------------
3 files changed, 64 insertions(+), 69 deletions(-)
diff --git a/vgasrc/vgabios.c b/vgasrc/vgabios.c
index cfb6ba2..2c8cc79 100644
--- a/vgasrc/vgabios.c
+++ b/vgasrc/vgabios.c
@@ -198,15 +198,10 @@ write_teletype(struct cursorpos *pcp, struct carattr ca)
if (pcp->y > nbrows) {
pcp->y--;
- struct cursorpos dest = {0, 0, pcp->page};
- struct cursorpos src = {0, 1, pcp->page};
- struct cursorpos size = {GET_BDA(video_cols), nbrows};
- vgafb_move_chars(dest, src, size);
-
- struct cursorpos clr = {0, nbrows, pcp->page};
+ struct cursorpos win = {0, 0, pcp->page};
+ struct cursorpos winsize = {GET_BDA(video_cols), nbrows+1};
struct carattr attr = {' ', 0, 0};
- struct cursorpos clrsize = {GET_BDA(video_cols), 1};
- vgafb_clear_chars(clr, attr, clrsize);
+ vgafb_scroll(win, winsize, 1, attr);
}
}
@@ -400,6 +395,7 @@ handle_1005(struct bregs *regs)
static void
verify_scroll(struct bregs *regs, int dir)
{
+ // Verify parameters
u8 ulx = regs->cl, uly = regs->ch, lrx = regs->dl, lry = regs->dh;
u16 nbrows = GET_BDA(video_rows) + 1;
if (lry >= nbrows)
@@ -410,41 +406,16 @@ verify_scroll(struct bregs *regs, int dir)
int wincols = lrx - ulx + 1, winrows = lry - uly + 1;
if (wincols <= 0 || winrows <= 0)
return;
-
- u8 page = GET_BDA(video_page);
- int clearlines = regs->al, movelines = winrows - clearlines;
- if (!clearlines || movelines <= 0) {
- // Clear whole area.
- struct cursorpos clr = {ulx, uly, page};
- struct carattr attr = {' ', regs->bh, 1};
- struct cursorpos clrsize = {wincols, winrows};
- vgafb_clear_chars(clr, attr, clrsize);
- return;
- }
-
- if (dir > 0) {
- // Normal scroll
- struct cursorpos dest = {ulx, uly, page};
- struct cursorpos src = {ulx, uly + clearlines, page};
- struct cursorpos size = {wincols, movelines};
- vgafb_move_chars(dest, src, size);
-
- struct cursorpos clr = {ulx, uly + movelines, page};
- struct carattr attr = {' ', regs->bh, 1};
- struct cursorpos clrsize = {wincols, clearlines};
- vgafb_clear_chars(clr, attr, clrsize);
- } else {
- // Scroll down
- struct cursorpos dest = {ulx, uly + clearlines, page};
- struct cursorpos src = {ulx, uly, page};
- struct cursorpos size = {wincols, movelines};
- vgafb_move_chars(dest, src, size);
-
- struct cursorpos clr = {ulx, uly, page};
- struct carattr attr = {' ', regs->bh, 1};
- struct cursorpos clrsize = {wincols, clearlines};
- vgafb_clear_chars(clr, attr, clrsize);
- }
+ int lines = regs->al;
+ if (lines >= winrows)
+ lines = 0;
+ lines *= dir;
+
+ // Scroll (or clear) window
+ struct cursorpos win = {ulx, uly, GET_BDA(video_page)};
+ struct cursorpos winsize = {wincols, winrows};
+ struct carattr attr = {' ', regs->bh, 1};
+ vgafb_scroll(win, winsize, lines, attr);
}
static void
diff --git a/vgasrc/vgabios.h b/vgasrc/vgabios.h
index 831f694..9fbfb14 100644
--- a/vgasrc/vgabios.h
+++ b/vgasrc/vgabios.h
@@ -126,10 +126,8 @@ extern struct video_func_static static_functionality;
void init_gfx_op(struct gfx_op *op, struct vgamode_s *vmode_g);
void handle_gfx_op(struct gfx_op *op);
void *text_address(struct cursorpos cp);
-void vgafb_move_chars(struct cursorpos dest
- , struct cursorpos src, struct cursorpos movesize);
-void vgafb_clear_chars(struct cursorpos dest
- , struct carattr ca, struct cursorpos movesize);
+void vgafb_scroll(struct cursorpos win, struct cursorpos winsize
+ , int lines, struct carattr ca);
void vgafb_write_char(struct cursorpos cp, struct carattr ca);
struct carattr vgafb_read_char(struct cursorpos cp);
void vgafb_write_pixel(u8 color, u16 x, u16 y);
diff --git a/vgasrc/vgafb.c b/vgasrc/vgafb.c
index 58c60ad..bd1c8dd 100644
--- a/vgasrc/vgafb.c
+++ b/vgasrc/vgafb.c
@@ -346,7 +346,7 @@ handle_gfx_op(struct gfx_op *op)
// Move characters when in graphics mode.
static void
gfx_move_chars(struct vgamode_s *vmode_g, struct cursorpos dest
- , struct cursorpos src, struct cursorpos movesize)
+ , struct cursorpos movesize, int lines)
{
struct gfx_op op;
init_gfx_op(&op, vmode_g);
@@ -355,23 +355,23 @@ gfx_move_chars(struct vgamode_s *vmode_g, struct cursorpos dest
int cheight = GET_BDA(char_height);
op.y = dest.y * cheight;
op.ylen = movesize.y * cheight;
- op.srcy = src.y * cheight;
+ op.srcy = op.y + lines * cheight;
op.op = GO_MEMMOVE;
handle_gfx_op(&op);
}
// Clear area of screen in graphics mode.
static void
-gfx_clear_chars(struct vgamode_s *vmode_g, struct cursorpos dest
- , struct carattr ca, struct cursorpos clearsize)
+gfx_clear_chars(struct vgamode_s *vmode_g, struct cursorpos win
+ , struct cursorpos winsize, struct carattr ca)
{
struct gfx_op op;
init_gfx_op(&op, vmode_g);
- op.x = dest.x * 8;
- op.xlen = clearsize.x * 8;
+ op.x = win.x * 8;
+ op.xlen = winsize.x * 8;
int cheight = GET_BDA(char_height);
- op.y = dest.y * cheight;
- op.ylen = clearsize.y * cheight;
+ op.y = win.y * cheight;
+ op.ylen = winsize.y * cheight;
op.pixels[0] = ca.attr;
if (vga_emulate_text())
op.pixels[0] = ca.attr >> 4;
@@ -580,45 +580,71 @@ text_address(struct cursorpos cp)
}
// Move characters on screen.
-void
-vgafb_move_chars(struct cursorpos dest
- , struct cursorpos src, struct cursorpos movesize)
+static void
+vgafb_move_chars(struct cursorpos dest, struct cursorpos movesize, int lines)
{
struct vgamode_s *vmode_g = get_current_mode();
if (!vmode_g)
return;
- vgafb_set_swcursor(0);
if (GET_GLOBAL(vmode_g->memmodel) != MM_TEXT) {
- gfx_move_chars(vmode_g, dest, src, movesize);
+ gfx_move_chars(vmode_g, dest, movesize, lines);
return;
}
int stride = GET_BDA(video_cols) * 2;
- memmove_stride(GET_GLOBAL(vmode_g->sstart)
- , text_address(dest), text_address(src)
+ void *dest_addr = text_address(dest), *src_addr = dest_addr + lines * stride;
+ memmove_stride(GET_GLOBAL(vmode_g->sstart), dest_addr, src_addr
, movesize.x * 2, stride, movesize.y);
}
// Clear area of screen.
-void
-vgafb_clear_chars(struct cursorpos dest
- , struct carattr ca, struct cursorpos clearsize)
+static void
+vgafb_clear_chars(struct cursorpos win, struct cursorpos winsize
+ , struct carattr ca)
{
struct vgamode_s *vmode_g = get_current_mode();
if (!vmode_g)
return;
- vgafb_set_swcursor(0);
if (GET_GLOBAL(vmode_g->memmodel) != MM_TEXT) {
- gfx_clear_chars(vmode_g, dest, ca, clearsize);
+ gfx_clear_chars(vmode_g, win, winsize, ca);
return;
}
int stride = GET_BDA(video_cols) * 2;
u16 attr = ((ca.use_attr ? ca.attr : 0x07) << 8) | ca.car;
- memset16_stride(GET_GLOBAL(vmode_g->sstart), text_address(dest), attr
- , clearsize.x * 2, stride, clearsize.y);
+ memset16_stride(GET_GLOBAL(vmode_g->sstart), text_address(win), attr
+ , winsize.x * 2, stride, winsize.y);
+}
+
+// Scroll characters within a window on the screen
+void
+vgafb_scroll(struct cursorpos win, struct cursorpos winsize
+ , int lines, struct carattr ca)
+{
+ vgafb_set_swcursor(0);
+ if (!lines) {
+ // Clear window
+ vgafb_clear_chars(win, winsize, ca);
+ } else if (lines > 0) {
+ // Scroll the window up (eg, from page down key)
+ winsize.y -= lines;
+ vgafb_move_chars(win, winsize, lines);
+
+ win.y += winsize.y;
+ winsize.y = lines;
+ vgafb_clear_chars(win, winsize, ca);
+ } else {
+ // Scroll the window down (eg, from page up key)
+ win.y -= lines;
+ winsize.y += lines;
+ vgafb_move_chars(win, winsize, lines);
+
+ win.y += lines;
+ winsize.y = -lines;
+ vgafb_clear_chars(win, winsize, ca);
+ }
}
// Write a character to the screen.
--
2.5.5
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