start double-buffering

Amazing how much difference it makes even when the implementation is so
naive and slow.
This commit is contained in:
Kartik K. Agaram 2021-05-18 10:23:54 -07:00
parent 2952a29960
commit fd57c48c60
3 changed files with 48 additions and 8 deletions

View File

@ -33,9 +33,7 @@ __check-mu-array-bounds: # index: int, elem-size: int, arr-size: int, function-
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 " is too large for array '" 3 0) # 3=cyan
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x18) 3 0) # 3=cyan
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "'" 3 0) # 3=cyan
{
eb/jump loop/disp8
}
(abort "")
# never gets here
$__check-mu-array-bounds:end:
# . restore registers
@ -53,9 +51,7 @@ __check-mu-array-bounds:overflow:
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 ": offset to array '" 3 0) # 3=cyan
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x18) 3 0) # 3=cyan
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "' overflowed 32 bits" 3 0) # 3=cyan
{
eb/jump loop/disp8
}
(abort "")
# never gets here
__mu-abort-null-index-base-address:

View File

@ -516,3 +516,42 @@ fn pixel-index _screen: (addr screen), x: int, y: int -> _/ecx: int {
result <- add x
return result
}
# double-buffering primitive
# 'screen' must be a fake screen. 'target-screen' is usually real.
# Both screens must have the same size.
fn copy-pixels _screen: (addr screen), target-screen: (addr screen) {
var screen/esi: (addr screen) <- copy _screen
var pixels-ah/eax: (addr handle array byte) <- get screen, pixels
var _pixels/eax: (addr array byte) <- lookup *pixels-ah
var pixels/edi: (addr array byte) <- copy _pixels
var width-a/edx: (addr int) <- get screen, width
var width/edx: int <- copy *width-a
width <- shift-left 3/log2-font-width
var height-a/ebx: (addr int) <- get screen, height
var height/ebx: int <- copy *height-a
height <- shift-left 4/log2-font-height
var i/esi: int <- copy 0
var y/ecx: int <- copy 0
{
# screen top left pixels x y width height
compare y, height
break-if->=
var x/eax: int <- copy 0
{
compare x, width
break-if->=
{
var color-addr/ebx: (addr byte) <- index pixels, i
var color/ebx: byte <- copy-byte *color-addr
var color2/ebx: int <- copy color
pixel target-screen, x, y, color2
}
x <- increment
i <- increment
loop
}
y <- increment
loop
}
}

View File

@ -16,7 +16,11 @@ fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk)
var env-storage: environment
var env/esi: (addr environment) <- address env-storage
initialize-environment env
render screen, env
var second-buffer: screen
var second-screen/edi: (addr screen) <- address second-buffer
initialize-screen second-screen, 0x80, 0x30, 1/include-pixels
render second-screen, env
copy-pixels second-screen, screen
{
edit keyboard, env
var play?/eax: (addr boolean) <- get env, play?
@ -24,7 +28,8 @@ fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk)
{
break-if-=
step env
render screen, env
render second-screen, env
copy-pixels second-screen, screen
}
linger env
loop