# If a screen is too wide, split it up into a fixed size of pages.
# We take control of drawing and moving the cursor, and delegate everything else.
# Never scroll; use the 'done-drawing?' method instead.
#
# Example usage:
# initialize-paginated-screen
# on each frame
# start-drawing
# while !done-drawing
# add-grapheme ...
type paginated-screen {
screen: (handle screen)
nrows: int # const
ncols: int # const
page-width: int
toprow: int
botrow: int
leftcol: int
rightcol: int
row: int
col: int
}
fn initialize-paginated-screen _self: (addr paginated-screen), page-width: int {
# hardcoded parameters:
# top-margin
# page-margin
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var _screen-addr/eax: (addr screen) <- lookup *screen-ah
var screen-addr/edi: (addr screen) <- copy _screen-addr
var nrows/eax: int <- copy 0
var ncols/ecx: int <- copy 0
nrows, ncols <- screen-size screen-addr
var dest/edx: (addr int) <- copy 0
# self->nrows = nrows
dest <- get self, nrows
copy-to *dest, nrows
# self->ncols = ncols
dest <- get self, ncols
copy-to *dest, ncols
# self->page-width = page-width
{
var pg/eax: int <- copy page-width
dest <- get self, page-width
copy-to *dest, pg
}
# self->toprow = top-margin
dest <- get self, toprow
copy-to *dest, 2 # top-margin
# self->botrow = nrows
dest <- get self, botrow
copy-to *dest, nrows
#
start-drawing self
}
fn start-drawing _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
clear-paginated-screen self
var tmp/eax: (addr int) <- copy 0
var tmp2/ecx: int <- copy 0
# self->leftcol = page-margin
tmp <- get self, leftcol
copy-to *tmp, 5 # left-margin
# self->rightcol = self->leftcol + page-width
tmp <- get self, rightcol
#? copy-to *tmp, 0x1f # ncols - 1
copy-to *tmp, 0x45 # left-margin + page-width
# self->row = self->toprow
tmp <- get self, toprow
tmp2 <- copy *tmp
tmp <- get self, row
copy-to *tmp, tmp2
# self->col = self->leftcol
tmp <- get self, leftcol
tmp2 <- copy *tmp
tmp <- get self, col
copy-to *tmp, tmp2
#
reposition-cursor self
}
fn done-drawing? _self: (addr paginated-screen) -> result/eax: boolean {
$done-drawing?:body: {
# return self->rightcol >= self->ncols
var self/esi: (addr paginated-screen) <- copy _self
var max/ecx: (addr int) <- get self, ncols
var tmp/eax: (addr int) <- get self, rightcol
var right/eax: int <- copy *tmp
compare right, *max
{
break-if->=
result <- copy 0 # false
break $done-drawing?:body
}
{
break-if-<
result <- copy 1 # true
}
}
}
fn add-grapheme _self: (addr paginated-screen), c: grapheme {
$add-grapheme:body: {
var self/esi: (addr paginated-screen) <- copy _self
{
compare c, 0xa # newline
break-if-!=
next-line self
reposition-cursor self
break $add-grapheme:body
}
# print c
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
print-grapheme screen-addr, c
# self->col++
var tmp/eax: (addr int) <- get self, col
increment *tmp
# if (self->col > self->rightcol) next-line(self)
var tmp2/ecx: int <- copy *tmp
tmp <- get self, rightcol
compare tmp2, *tmp
{
break-if-<=
next-line self
reposition-cursor self
}
}
}
## tests
fn initialize-fake-paginated-screen _self: (addr paginated-screen), nrows: int, ncols: int, page-width: int {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
allocate screen-ah
var screen-addr/eax: (addr screen) <- lookup *screen-ah
initialize-screen screen-addr, nrows, ncols
initialize-paginated-screen self, page-width
}
## simple delegates
fn reposition-cursor _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var r/ecx: (addr int) <- get self, row
var c/edx: (addr int) <- get self, col
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
move-cursor screen-addr, *r *c
}
fn clear-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
clear-screen screen-addr
}
fn start-color-on-paginated-screen _self: (addr paginated-screen), fg: int, bg: int {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
start-color screen-addr, fg, bg
}
fn start-bold-on-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
start-bold screen-addr
}
fn start-underline-on-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
start-underline screen-addr
}
fn start-reverse-video-on-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
start-reverse-video screen-addr
}
fn start-blinking-on-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
start-blinking screen-addr
}
fn reset-formatting-on-paginated-screen _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var screen-ah/eax: (addr handle screen) <- get self, screen
var screen-addr/eax: (addr screen) <- lookup *screen-ah
reset-formatting screen-addr
}
## helpers
fn next-line _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var tmp/eax: (addr int) <- copy 0
var tmp2/ecx: int <- copy 0
# self->col = self->leftcol
tmp <- get self, leftcol
tmp2 <- copy *tmp
tmp <- get self, col
copy-to *tmp, tmp2
# self->row++
tmp <- get self, row
increment *tmp
# if (self->row > self->botrow) next-page(self)
tmp2 <- copy *tmp
tmp <- get self, botrow
compare tmp2, *tmp
{
break-if-<=
next-page self
}
}
fn next-page _self: (addr paginated-screen) {
var self/esi: (addr paginated-screen) <- copy _self
var pg/edi: (addr int) <- get self, page-width
var tmp/eax: (addr int) <- copy 0
var tmp2/ecx: int <- copy 0
#? # temporary: stop
#? tmp <- get self, ncols
#? tmp2 <- copy *tmp
#? tmp <- get self, rightcol
#? copy-to *tmp, tmp2
# real: multiple pages
# self->leftcol = self->rightcol + page-margin
tmp <- get self, rightcol
tmp2 <- copy *tmp
tmp2 <- add 5 # page-margin
tmp <- get self, leftcol
copy-to *tmp, tmp2
# self->rightcol = self->leftcol + page-width
tmp2 <- copy *tmp
tmp2 <- add *pg
tmp <- get self, rightcol
copy-to *tmp, tmp2
# self->row = self->toprow
tmp <- get self, toprow
tmp2 <- copy *tmp
tmp <- get self, row
copy-to *tmp, tmp2
# self->col = self->leftcol
tmp <- get self, leftcol
tmp2 <- copy *tmp
tmp <- get self, col
copy-to *tmp, tmp2
}