ReC98/th04/tiles_redraw.asm

61 lines
1.2 KiB
NASM

; void tiles_redraw_invalidated();
public tiles_redraw_invalidated
tiles_redraw_invalidated proc near
push si
push di
call egc_start_copy_inlined_noframe
mov ax, GRAM_400
mov es, ax
assume es:nothing
mov bx, offset _halftiles_dirty[TILES_MEMORY_X * (TILE_FLAGS_Y - 1)]
mov di, ((RES_Y - TILE_FLAG_H) * ROW_SIZE) + PLAYFIELD_VRAM_X
mov dh, TILE_FLAGS_Y
mov si, TILES_MEMORY_X * (TILES_Y - 1) * 2
@@start_row:
mov dl, TILES_X
@@dirty?:
cmp byte ptr [bx], 0
jz short @@next_tile_in_row
push si
mov byte ptr [bx], 0
mov si, _tile_ring[si]
test dh, 1
jnz short @@redraw
add si, TILE_FLAG_H * ROW_SIZE
@@redraw:
mov cx, TILE_FLAG_H
@@blit_tile_redraw_lines:
mov ax, es:[si]
mov es:[di], ax
add si, ROW_SIZE
add di, ROW_SIZE
loop @@blit_tile_redraw_lines
sub di, TILE_FLAG_H * ROW_SIZE
pop si
@@next_tile_in_row:
add di, 2
add si, 2
inc bx
dec dl
jnz short @@dirty?
test dh, 1
jnz short @@previous_row
add si, (TILES_MEMORY_X * 2)
@@previous_row:
sub si, (TILES_MEMORY_X * 2) + (TILES_X * 2)
dec dh
sub bx, TILES_X + TILES_MEMORY_X
sub di, (TILES_X * 2) + (TILE_FLAG_H * ROW_SIZE)
jge short @@start_row
call egc_off
pop di
pop si
retn
tiles_redraw_invalidated endp