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#include <types.h>
#include <graphics.h>
#include <multiboot2.h>
#include <font.h>
#include <libk/string.h>
#include <libk/math.h>
fb_t main_fb;
uint32_t* pixel_offset(fb_t fb, uint32_t x, uint32_t y)
{
return (uint32_t*)((char*)fb.addr + y * fb.pitch + x * fb.bpp / 8);
}
void fb_draw_pixel(fb_t fb, int32_t x, int32_t y, uint32_t col)
{
if (x < 0 || y < 0) return;
if (x >= (int32_t)fb.width || y >= (int32_t)fb.height) return;
uint32_t* fb_offset = pixel_offset(fb, (uint32_t)x, (uint32_t)y);
*fb_offset = col;
}
/* https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm */
void fb_draw_line_low(fb_t fb, int32_t x0, int32_t y0, int32_t x1, int32_t y1, uint32_t col)
{
int32_t dx = x1 - x0;
int32_t dy = y1 - y0;
int32_t yi = 1;
if (dy < 0) {
yi = -1;
dy = -dy;
}
int32_t D = (2 * dy) - dx;
int32_t y = y0;
for (int32_t x = x0; x <= x1; x++) {
fb_draw_pixel(fb, x, y, col);
if (D > 0) {
y = y + yi;
D = D + (2 * (dy - dx));
} else {
D = D + 2 * dy;
}
}
}
void fb_draw_line_high(fb_t fb, int32_t x0, int32_t y0, int32_t x1, int32_t y1, uint32_t col)
{
int32_t dx = x1 - x0;
int32_t dy = y1 - y0;
int32_t xi = 1;
if (dx < 0) {
xi = -1;
dx = -dx;
}
int32_t D = (2 * dx) - dy;
int32_t x = x0;
for (int32_t y = y0; y <= y1; y++) {
fb_draw_pixel(fb, x, y, col);
if (D > 0) {
x = x + xi;
D = D + (2 * (dx - dy));
} else {
D = D + 2 * dx;
}
}
}
void fb_draw_line(fb_t fb, int32_t x0, int32_t y0, int32_t x1, int32_t y1, uint32_t col)
{
if (abs(y1 - y0) < abs(x1 - x0)) {
if (x0 > x1)
fb_draw_line_low(fb, x1, y1, x0, y0, col);
else
fb_draw_line_low(fb, x0, y0, x1, y1, col);
} else {
if (y0 > y1)
fb_draw_line_high(fb, x1, y1, x0, y0, col);
else
fb_draw_line_high(fb, x0, y0, x1, y1, col);
}
}
void fb_draw_character(fb_t fb, char c, int32_t x, int32_t y, uint32_t char_col, uint32_t bg_col)
{
if (c < 0) return;
int32_t offset = 32 + c * 16;
for (int32_t i = 0 ; i < 16; i++)
{
for (int32_t j = 0 ; j < 8; j++)
{
if (font[offset + i] & (1 << (7 - j))) {
fb_draw_pixel(fb, x + j, y + i, char_col);
} else {
fb_draw_pixel(fb, x + j, y + i, bg_col);
}
}
}
}
void fb_draw_string(fb_t fb, const char* s, int32_t x, int32_t y, uint32_t char_col, uint32_t bg_col)
{
for (size_t i = 0; i < strlen(s); i++) {
fb_draw_character(fb, s[i], (x + (int32_t)i * 8), y, char_col, bg_col);
}
}
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