【ESK32-360测评】+LCD库函数BUG测评反馈
本帖最后由 szkei 于 2020-8-14 22:41 编辑<p><strong>一，上篇使用了LCD库函数显示奥运五色环及合泰测评的图片。<a href="https://bbs.eeworld.com.cn/thread-1136336-1-1.html" target="_blank">帖子链接。</a></strong></p>
<p><strong>二，函数坐标顺序位置对调。</strong></p>
<p> 继续使用后发现上个测评所用到以下的函数的坐标顺序是对调，出来效果是X，Y坐标对调。 </p>
<p> 1，void LCD_CircleDraw (u32 X_Location, u32 Y_Location, u32 Radius) ； //画半径参数的圆<br />
2，void LCD_LineDraw (u32 X_Location, u32 Y_Location, u32 Length, u32 Direction) ；//画线</p>
<p> 3，void LCD_PicDraw (u8 X_Location, u16 Y_Location, u8 Height, u16 Width, uc8 *Pptr) ；//显示图片<br />
4， void LCD_RectDraw (u32 X_Location, u32 Y_Location, u32 Height, u32 Width) //画方框</p>
<p><strong>三，各个函数输入不同坐标显示。</strong></p>
<p><strong> </strong>1，void LCD_CircleDraw (u32 X_Location, u32 Y_Location, u32 Radius) ； //画半径参数的圆</p>
<p> LCD_CircleDraw (50，50，50);</p>
<p> </p>
<p> LCD_CircleDraw (100，50，50);</p>
<p> </p>
<p> LCD_CircleDraw (50，100，50);</p>
<p></p>
<p>以上三个输入坐标，只有第一个不察觉到，第二及第三的从标是Y，X的方向显示了。</p>
<p> 2，void LCD_LineDraw (u32 X_Location, u32 Y_Location, u32 Length, u32 Direction) ；//画线</p>
<p>LCD_LineDraw(0,0,100,0);</p>
<p></p>
<p>LCD_LineDraw(100,0,100,0);</p>
<p></p>
<p>LCD_LineDraw(0,100,100,0);</p>
<p></p>
<p> </p>
<p>3，void LCD_PicDraw (u8 X_Location, u16 Y_Location, u8 Height, u16 Width, uc8 *Pptr) ；//显示图片<br />
4， void LCD_RectDraw (u32 X_Location, u32 Y_Location, u32 Height, u32 Width) //画方框</p>
<p>这二个同样显示显示效果坐标同上二个一样，在此省略。</p>
<p><strong>四，void LCD_CircleDraw (u32 X_Location, u32 Y_Location, u32 Radius) ，存在严重的BUG。</strong></p>
<p><strong> </strong>1，当Radius输入为0时，存在以下二种情况。</p>
<p> 2，不在while等循环体内，无法正常显示。屏幕没有显示，白色底图一张。</p>
<p>3，当在循环体内，显示杂乱，成一条条直线，直至布满整个屏幕。</p>
<p></p>
<p>4，进入LCD_CircleDraw函数内，代码如下：</p>
<pre>
<code>/*********************************************************************************************************//**
* <a href="home.php?mod=space&uid=159083" target="_blank">@brief</a>Display a circle.
* @paramX_Location: specify the X position.
* @paramY_Location: specify the Y position.
* @paramRadius: radius of the circle.
* @retval None
***********************************************************************************************************/
void LCD_CircleDraw(u32 X_Location, u32 Y_Location, u32 Radius)
{
s32DV;// Decision Variable
u32X_Value; // Current X Value
u32Y_Value; // Current Y Value
DV = 3 - (Radius << 1);
X_Value = 0;
Y_Value = Radius;
while (X_Value <= Y_Value)
{
LCD_StarterSet(X_Location + X_Value, Y_Location + Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + X_Value, Y_Location - Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - X_Value, Y_Location + Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - X_Value, Y_Location - Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + Y_Value, Y_Location + X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + Y_Value, Y_Location - X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - Y_Value, Y_Location + X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - Y_Value, Y_Location - X_Value);
LCD_WriteRAMWord(Color_Text);
if (DV < 0)
{
DV += (X_Value << 2) + 6;
}
else
{
DV += ((X_Value - Y_Value) << 2) + 10;
Y_Value--;
}
X_Value++;
}
}</code></pre>
<p>5，查看分析，发现是Y_Value--，没有先判断为是否为0。如果是0，执行后Y_Value的值等于 2^32 - 1 = 4294967295,一直不断循环执行下去。只要先判断不为0时，才能执行Y_Value--，这样才不会一直循环执行下去。修改代码如下：</p>
<pre>
<code>/*********************************************************************************************************//**
* @briefDisplay a circle.
* @paramX_Location: specify the X position.
* @paramY_Location: specify the Y position.
* @paramRadius: radius of the circle.
* @retval None
***********************************************************************************************************/
void LCD_CircleDraw(u32 X_Location, u32 Y_Location, u32 Radius)
{
s32DV;// Decision Variable
u32X_Value; // Current X Value
u32Y_Value; // Current Y Value
DV = 3 - (Radius << 1);
X_Value = 0;
Y_Value = Radius;
while (X_Value <= Y_Value)
{
LCD_StarterSet(X_Location + X_Value, Y_Location + Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + X_Value, Y_Location - Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - X_Value, Y_Location + Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - X_Value, Y_Location - Y_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + Y_Value, Y_Location + X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location + Y_Value, Y_Location - X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - Y_Value, Y_Location + X_Value);
LCD_WriteRAMWord(Color_Text);
LCD_StarterSet(X_Location - Y_Value, Y_Location - X_Value);
LCD_WriteRAMWord(Color_Text);
if (DV < 0)
{
DV += (X_Value << 2) + 6;
}
else
{
DV += ((X_Value - Y_Value) << 2) + 10;
if(Y_Value > 0){ //增加Y_Value非0判断
Y_Value--;
}
}
X_Value++;
}
}</code></pre>
<p>6，修正代码后运行正常，如下图。</p>
<p></p>
<p><strong>五，建议逻辑正确性。</strong></p>
<p><strong> </strong> 在进行加减法操作时，一定要加上判断及执行结果界限值，否则容易人为错误引入BUG。</p>
<p>分析的很好</p>
<p> </p>
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