嗨,我正在使用arm控制器lm3s8962 im无法理解下面的代码,因为我的理解是它检查字符是否来自数组,或者不是,使用ascii字符创建的字符{即in while循环:而(!* pcStr = 0)}, 我不能够得到什么,他是线“建设,并显示字符缓冲区”后做的代码PLZ谁能解释这arm cortex m3 display
void
RIT128x96x4StringDraw(const char *pcStr, unsigned long ulX,
unsigned long ulY, unsigned char ucLevel)
{
unsigned long ulIdx1, ulIdx2;
unsigned char ucTemp;
//
// Check the arguments.
//
ASSERT(ulX < 128);
ASSERT((ulX & 1) == 0);
ASSERT(ulY < 96);
ASSERT(ucLevel < 16);
//
// Setup a window starting at the specified column and row, ending
// at the right edge of the display and 8 rows down (single character row).
//
g_pucBuffer[0] = 0x15;
g_pucBuffer[1] = ulX/2;
g_pucBuffer[2] = 63;
RITWriteCommand(g_pucBuffer, 3);
g_pucBuffer[0] = 0x75;
g_pucBuffer[1] = ulY;
g_pucBuffer[2] = ulY + 7;
RITWriteCommand(g_pucBuffer, 3);
RITWriteCommand(g_pucRIT128x96x4VerticalInc,
sizeof(g_pucRIT128x96x4VerticalInc));
//
// Loop while there are more characters in the string.
//
while(*pcStr != 0)
{
//
// Get a working copy of the current character and convert to an
// index into the character bit-map array.
//
ucTemp = *pcStr++ & 0x7f;
if(ucTemp < ' ')
{
ucTemp = 0;
}
else
{
ucTemp -= ' ';
}
//
// Build and display the character buffer.
//
for(ulIdx1 = 0; ulIdx1 < 6; ulIdx1 += 2)
{
//
// Convert two columns of 1-bit font data into a single data
// byte column of 4-bit font data.
//
for(ulIdx2 = 0; ulIdx2 < 8; ulIdx2++)
{
g_pucBuffer[ulIdx2] = 0;
if(g_pucFont[ucTemp][ulIdx1] & (1 << ulIdx2))
{
g_pucBuffer[ulIdx2] = (ucLevel << 4) & 0xf0;
}
if((ulIdx1 < 4) &&
(g_pucFont[ucTemp][ulIdx1 + 1] & (1 << ulIdx2)))
{
g_pucBuffer[ulIdx2] |= (ucLevel << 0) & 0x0f;
}
}
//
// Send this byte column to the display.
//
RITWriteData(g_pucBuffer, 8);
ulX += 2;
//
// Return if the right side of the display has been reached.
//
if(ulX == 128)
{
return;
}
}
}
}
如果你想要的答案,请重新组织你的问题,也请阅读常见问题 – stdcall 2013-03-13 05:48:47
嗨Mellowcandle我编辑了我的帖子,看看你是否能够理解我的问题实际上我无法找到他如何建设buffercan u plz明确这对我来说谢谢你的回复 – user2159417 2013-03-13 06:27:10