rekahsoft/avr-lcd-lib
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Fix off-by-one errors in lcdLib cursor functions

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Signed-off-by: Collin J. Doering <collin.doering@rekahsoft.ca>
This commit is contained in:
Collin J. Doering 2015-10-22 00:27:54 -04:00
parent 2f8eafd8de
commit 38ce0ce37f
1 changed files with 8 additions and 4 deletions
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12
lcdLib.c
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@ -411,7 +411,7 @@ void moveCursorUp(uint8_t n) {
}
void moveCursorDown(uint8_t n) {
if (n + currentLineNum < LCD_NUMBER_OF_LINES + 1) {
if (n + currentLineNum < LCD_NUMBER_OF_LINES) {
currentLineNum += n;
} else {
currentLineNum = LCD_NUMBER_OF_LINES - 1;
@ -421,7 +421,7 @@ void moveCursorDown(uint8_t n) {
}
void moveCursorForward(uint8_t n) {
if (n + currentLineChars < LCD_CHARACTERS_PER_LINE + 1) {
if (n + currentLineChars < LCD_CHARACTERS_PER_LINE) {
currentLineChars += n;
} else {
currentLineChars = LCD_CHARACTERS_PER_LINE - 1;
@ -441,7 +441,9 @@ void moveCursorBackward(uint8_t n) {
}
void moveCursorNextLine(uint8_t n) {
if (n + currentLineNum > LCD_NUMBER_OF_LINES - 1) {
currentLineChars = 0;
if (n + currentLineNum < LCD_NUMBER_OF_LINES) {
currentLineNum += n;
} else {
currentLineNum = LCD_NUMBER_OF_LINES - 1;
@ -451,6 +453,8 @@ void moveCursorNextLine(uint8_t n) {
}
void moveCursorPreviousLine(uint8_t n) {
currentLineChars = 0;
if (n < currentLineNum + 1) {
currentLineNum -= n;
} else {
@ -461,7 +465,7 @@ void moveCursorPreviousLine(uint8_t n) {
}
void moveCursorToColumn(uint8_t n) {
if (n < LCD_CHARACTERS_PER_LINE) {
if (n <= LCD_CHARACTERS_PER_LINE) {
currentLineChars = n ? n - 1 : 0;
writeLCDInstr(INSTR_DDRAM_ADDR | (lineBeginnings[currentLineNum] + currentLineChars));
} // else index out of range (off screen column)