From eeb5f3d50ce3831e2a12262984657b1b9a4ae7fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gu=C3=B0ni=20M=C3=A1r=20Gilbert?= <gudni.m.g@gmail.com>
Date: Sat, 14 Jan 2023 14:58:04 +0000
Subject: [PATCH] optimisation:  refactor menu_draw_P()

Add a way to only change the LCD column

Change in memory:
Flash: -90 bytes
SRAM: 0 bytes
---
 Firmware/lcd.cpp  | 28 +++++++++++++++++++++++-----
 Firmware/lcd.h    |  4 ++++
 Firmware/menu.cpp | 22 +++++++++++++++-------
 3 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/Firmware/lcd.cpp b/Firmware/lcd.cpp
index a726c6db2..8677ea0c4 100644
--- a/Firmware/lcd.cpp
+++ b/Firmware/lcd.cpp
@@ -329,13 +329,31 @@ void lcd_no_autoscroll(void)
 }
 #endif
 
-void lcd_set_cursor(uint8_t col, uint8_t row)
+/// @brief set the current LCD row
+/// @param row LCD row number, ranges from 0 to LCD_HEIGHT - 1
+static void FORCE_INLINE lcd_set_current_row(uint8_t row)
+{
+	lcd_currline = min(row, LCD_HEIGHT - 1);
+}
+
+/// @brief Calculate the LCD row offset
+/// @param row LCD row number, ranges from 0 to LCD_HEIGHT - 1
+/// @return row offset which the LCD register understands
+static uint8_t __attribute__((noinline)) lcd_get_row_offset(uint8_t row)
 {
 	uint8_t row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
-	if (row >= LCD_HEIGHT)
-		row = LCD_HEIGHT - 1;    // we count rows starting w/0
-	lcd_currline = row;  
-	lcd_command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
+	return row_offsets[min(row, LCD_HEIGHT - 1)];
+}
+
+void lcd_set_cursor(uint8_t col, uint8_t row)
+{
+	lcd_set_current_row(row);
+	lcd_command(LCD_SETDDRAMADDR | (col + lcd_get_row_offset(lcd_currline)));
+}
+
+void lcd_set_cursor_column(uint8_t col)
+{
+	lcd_command(LCD_SETDDRAMADDR | (col + lcd_get_row_offset(lcd_currline)));
 }
 
 // Allows us to fill the first 8 CGRAM locations
diff --git a/Firmware/lcd.h b/Firmware/lcd.h
index 9949683cb..08c48a615 100644
--- a/Firmware/lcd.h
+++ b/Firmware/lcd.h
@@ -37,6 +37,10 @@ extern void lcd_no_autoscroll(void);*/
 
 extern void lcd_set_cursor(uint8_t col, uint8_t row);
 
+/// @brief Change the cursor column position while preserving the current row position
+/// @param col column number, ranges from 0 to LCD_WIDTH - 1
+void lcd_set_cursor_column(uint8_t col);
+
 extern void lcd_createChar_P(uint8_t, const uint8_t*);
 
 
diff --git a/Firmware/menu.cpp b/Firmware/menu.cpp
index e4e2259c1..56e729639 100755
--- a/Firmware/menu.cpp
+++ b/Firmware/menu.cpp
@@ -435,13 +435,21 @@ static void menu_draw_P(char chr, const char* str, int16_t val);
 template<>
 void menu_draw_P<int16_t*>(char chr, const char* str, int16_t val)
 {
-	int text_len = strlen_P(str);
-	if (text_len > 15) text_len = 15;
-	char spaces[LCD_WIDTH + 1] = {0};
-    memset(spaces,' ', LCD_WIDTH);
-	if (val <= -100) spaces[15 - text_len - 1] = 0;
-	else spaces[15 - text_len] = 0;
-	lcd_printf_P(menu_fmt_int3, chr, str, spaces, val);
+	// The LCD row position is controlled externally. We may only modify the column here
+	lcd_putc(chr);
+	uint8_t len = lcd_print_pad_P(str, LCD_WIDTH - 1);
+	lcd_set_cursor_column((LCD_WIDTH - 1) - len + 1);
+	lcd_putc(':');
+
+	// The value is right adjusted, set the cursor then render the value
+	if (val < 10) { // 1 digit
+		lcd_set_cursor_column(LCD_WIDTH - 1);
+	} else if (val < 100) { // 2 digits
+		lcd_set_cursor_column(LCD_WIDTH - 2);
+	} else { // 3 digits
+		lcd_set_cursor_column(LCD_WIDTH - 3);
+	}
+	lcd_print(val);
 }
 
 template<>