Read and write pixels for Flipper zero

flipper_pixels.c

typedef enum {
    Black,
    White,
    Inverse
} DrawMode;

unsigned flipBit(uint8_t x, uint8_t bit) {
    return x ^ (1 << bit);
}

unsigned setBit(uint8_t x, uint8_t bit) {
    return x | (1 << bit);
}

unsigned unsetBit(uint8_t x, uint8_t bit) {
    return x & ~(1 << bit);
}

bool in_screen(int16_t x, int16_t y) {
    return x >= 0 && x < SCREEN_WIDTH && y >= 0 && y < SCREEN_HEIGHT;
}

bool test_pixel(uint8_t *data, uint8_t x, uint8_t y, uint8_t width) {
    uint8_t current_bit = (y % 8);
    uint8_t current_row = ((y - current_bit) / 8);
    uint8_t current_value = data[current_row * width + x];
    return current_value & (1 << current_bit);
}

bool read_pixel(Canvas *const canvas, int16_t x, int16_t y) {
    if (in_screen(x, y)) {
        return test_pixel(canvas->fb.tile_buf_ptr, x, y, SCREEN_WIDTH);
    }
    return false;
}

void set_pixel(Canvas *const canvas, int16_t x, int16_t y, DrawMode draw_mode) {
    if (in_screen(x, y)) {
        uint8_t current_bit = (y % 8);
        uint8_t current_row = ((y - current_bit) / 8);
        uint32_t i = current_row * SCREEN_WIDTH + x;

        uint8_t current_value = canvas->fb.tile_buf_ptr[i];
        if (draw_mode == Inverse) {
            canvas->fb.tile_buf_ptr[i] = flipBit(current_value, current_bit);
        } else {
            if (draw_mode == White) {
                canvas->fb.tile_buf_ptr[i] = unsetBit(current_value, current_bit);
            } else {
                canvas->fb.tile_buf_ptr[i] = setBit(current_value, current_bit);
            }
        }
    }
}