2023-01-23 16:39:02 +08:00

53 lines
1.7 KiB
C

#include <stdint.h>
#include "monoimg.h"
#define max(a,b) ((a) >= (b) ? (a) : (b))
#define min(a,b) ((a) <= (b) ? (a) : (b))
uint8_t mimg_get_pixel_unsafe(const uint8_t *img, uint8_t x, uint8_t y) {
// MVLSB format
uint8_t width = img[0] + 1;
uint16_t index = (y >> 3) * width + x + 2;
uint8_t offset = y & 0x07;
uint8_t value = (img[index] >> offset) & 0x01;
return value; // return 1 or 0
}
uint8_t mimg_get_pixel(const uint8_t *img, uint16_t x, uint16_t y) {
// MVLSB format
uint8_t width = img[0] + 1;
uint8_t height = img[1] + 1;
if (x >= width || y >= height) {
return 0;
}
return mimg_get_pixel_unsafe(img, (uint8_t)x, (uint8_t)y);
}
void mimg_draw(mimg_FunctionSetPixel set_pixel, uint16_t x, uint16_t y, uint16_t color, const uint8_t *img, mimg_Area area) {
uint8_t width_s1 = img[0]; // width - 1
uint8_t height_s1 = img[1]; // height - 1
uint8_t ix = min(area.x, width_s1);
uint8_t iy = min(area.y, height_s1);
uint8_t iw = min(area.w, width_s1 - ix + 1);
uint8_t ih = min(area.h, height_s1 - iy + 1);
uint8_t off_x, off_y;
for (off_y = 0; off_y < ih; off_y ++) {
for (off_x = 0; off_x < iw; off_x ++) {
if (mimg_get_pixel_unsafe(img, ix + off_x, iy + off_y)) {
set_pixel(x + off_x, y + off_y, color);
}
}
}
}
mimg_Area mimg_get_tile_area(const uint8_t *img, uint8_t cols, uint8_t rows, uint8_t index) {
uint8_t width = img[0] + 1;
uint8_t height = img[1] + 1;
mimg_Area area;
area.w = width / cols;
area.h = height / rows;
area.y = (index / cols) * area.h;
area.x = (index % cols) * area.w;
return area;
}