omos-tcnj2024/sys/drv/vga/video.c

42 lines
765 B
C

#include <types.h>
#include <video.h>
void
vga_write(s8 *sequence, s16 size, s8 flags)
{
if (size > VGA_TEXT_SIZE) {
s16 using_size = size - VGA_TEXT_SIZE;
for (s16 i = 0; i <= VGA_SIZE; i++) {
vga_vidmem[i] = sequence[using_size + i];
vga_vidmem[++i] = flags;
}
unused = 4001;
return;
}
s16 needed_space = size + unused - VGA_TEXT_SIZE;
if (needed_space >= 0) {
for (s16 i = 0; i <= VGA_SIZE - needed_space; i++) {
vga_vidmem[i] = vga_vidmem[i + needed_space];
}
unused = VGA_SIZE - needed_space;
}
while (*sequence != '\0') {
vga_vidmem[unused++] = *sequence;
*sequence++;
vga_vidmem[unused++] = flags;
}
}
void
vga_clearscreen(void)
{
for (s16 i = 0; i <= VGA_SIZE; i++) {
vga_vidmem[i] = 0;
}
}