bringelle/src/drivers/framebuffer.c
2021-04-12 10:28:04 +02:00

58 lines
949 B
C

#include "framebuffer.h"
#define MAX_COL 80
#define MAX_LINE 25
VIDEO_STATE VS={
(u8 *)0xB8000,
0,
0,
BLACK,
GRAY,
};
void putchar(char c){
// Handle newline here
if(c=='\n'){
VS.col=0;
VS.line+=1;
if(VS.line>=MAX_LINE){
VS.line=MAX_LINE-1;
scrollup();
}
return;
}
// Print char
VS.mem[VS.col*2+MAX_COL*VS.line*2]=c;
VS.mem[VS.col*2+MAX_COL*VS.line*2+1]=VS.fg|VS.bg<<4;
// Refresh location
VS.col+=1;
if(VS.col>= MAX_COL){
VS.col=0;
VS.line+=1;
if(VS.line>=MAX_LINE){
VS.line=MAX_LINE-1;
scrollup();
}
}
}
void clear(){
for(char i=0;i<MAX_LINE;i++){
scrollup();
}
}
void scrollup(){
// Move VS.line up
for(char i=1;i<=MAX_LINE;i++){
for(char j=0;j<=MAX_COL;j++)
VS.mem[j*2+MAX_COL*(i-1)*2]=VS.mem[j*2+MAX_COL*i*2];
}
// Clear last VS.line
for(char i=0;i<=MAX_COL;i++){
VS.mem[i*2+MAX_COL*(MAX_LINE-1)*2]='\0';
}
}