RockOS/kernel/lib/console.c

#include <lib/console.h>
#include <lib/font.h>

#include <drivers/vga/vga.h>

static psf_font_t* font;

static uint32_t console_row;
static uint32_t console_col;
static uint32_t console_text_color;
static uint32_t console_backgrnd_color;

static void write_vga_char(char c) {
    uint32_t vga_pitch = vga_get_pitch();
    uint8_t* glyph = (uint8_t*)font->glyphs + (c * font->hdr->charsz);

    uint32_t pixel_y_start = console_row * font->hdr->charsz;
    uint32_t pixel_x_start = console_col * 8;

    for (uint32_t y = 0; y < font->hdr->charsz; y++) {
        uint8_t bits = glyph[y];
        uint8_t* row_bytes = (uint8_t*)VGA_FRAMEBUFFER + ((pixel_y_start + y) * vga_pitch);
        uint32_t* pixel_row = (uint32_t*)row_bytes;

        for (int x = 0; x < 8; x++) {
            if (bits & (0b10000000 >> x)) {
                pixel_row[pixel_x_start + x] = console_text_color;
            } else {
                pixel_row[pixel_x_start + x] = console_backgrnd_color;
            }
        }
    }
}

int set_console_font(const char* path) {
    font = load_font(path);
    return font != NULL;
}

void set_console_fg(uint32_t color) {
    console_text_color = color;
}

void set_console_bg(uint32_t color) {
    console_backgrnd_color = color;
}

void console_init() {
    console_row = 0;
    console_col = 0;
    set_console_fg(0xFFFFFFFF);
    vga_clear_scrn(0x000000FF);
}

void console_putchar(char c) {
    write_vga_char(c);
}