正确移动未签名变量给出了奇怪的结果-C / GBDK

Question

我正在GBDK中开发游戏男孩游戏，但是我在右键（8bit）无符号变量方面有问题。代码看起来像这样。

#include <gb/gb.h>
#include <stdio.h>

#define GAME_OBJ_MAX_WIDTH 10
#define GAME_OBJ_MAX_HEIGHT 8

struct game_obj
{
    UBYTE matrix[GAME_OBJ_MAX_WIDTH];
    UBYTE width, height;
};

void draw_game_obj(struct game_obj *object)
{
    for (unsigned char i = 0; i < object->width && i < GAME_OBJ_MAX_WIDTH; i++)
   {
       printf("BASE->%d\n", object->matrix[i]);
       for (unsigned char j = 0; j < object->height && j < GAME_OBJ_MAX_HEIGHT; j++)
           printf("Shift by %d->%u\n", j, object->matrix[i] >> j);
   }
}

void main() {
    struct game_obj racer;
    racer.height = 4;
    racer.width = 3;
    racer.matrix[0] = 10;
    racer.matrix[1] = 7;
    racer.matrix[2] = 10;
    draw_game_obj(&racer);
}

output 是：

BASE->10
Shift by 0->235
Shift by 1->117
Shift by 2->58
Shift by 3->29
BASE->7
Shift by 0->235
Shift by 1->117
Shift by 2->58
Shift by 3->29
BASE->10
Shift by 0->235
Shift by 1->117
Shift by 2->58
Shift by 3->29

基本上任何未签名的值右移动（即使由0）更改为> > 235，117，58等...我试图理解为什么是这样。

解决方案

通过分配对象 - ＆gt; matrix [i]将问题解决的问题。

void draw_game_obj(struct game_obj *object)
{
    for (unsigned char i = 0; i < object->width && i < GAME_OBJ_MAX_WIDTH; i++)
   {
       printf("BASE->%d\n", object->matrix[i]);
       UBYTE u = object->matrix[i];
       for (unsigned char j = 0; j < object->height && j < GAME_OBJ_MAX_HEIGHT; j++)
           printf("Shift by %d->%u\n", j, u >> j);
   }
}