Buffer based OLED panning, write byte to buffer at arbitrary index (#8055)

* Add buffer based single line pan, arbitrary byte write to buffer

* Change dirty mask to inverse of OLED_BLOCK_TYPE for future proofing larger buffer sizes

* Updating docs to include new functions

* Updating to clarify scroll vs pan

docs/feature_oled_driver.md

@@ -221,6 +221,12 @@ void oled_write(const char *data, bool invert);
 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
 void oled_write_ln(const char *data, bool invert);
 
+// Pans the buffer to the right (or left by passing true) by moving contents of the buffer
+// Useful for moving the screen in preparation for new drawing 
+// oled_scroll_left or oled_scroll_right should be preferred for all cases of moving a static
+// image such as a logo or to avoid burn-in as it's much, much less cpu intensive
+void oled_pan(bool left);
+
 // Writes a PROGMEM string to the buffer at current cursor position
 // Advances the cursor while writing, inverts the pixels if true
 // Remapped to call 'void oled_write(const char *data, bool invert);' on ARM
@@ -235,6 +241,9 @@ void oled_write_ln_P(const char *data, bool invert);
 // Writes a string to the buffer at current cursor position
 void oled_write_raw(const char *data, uint16_t size);
 
+// Writes a single byte into the buffer at the specified index
+void oled_write_raw_byte(const char data, uint16_t index);
+
 // Writes a PROGMEM string to the buffer at current cursor position
 void oled_write_raw_P(const char *data, uint16_t size);
 

drivers/oled/oled_driver.c

@@ -428,6 +428,31 @@ void oled_write_ln(const char *data, bool invert) {
     oled_advance_page(true);
 }
 
+void oled_pan(bool left) {
+    uint16_t i = 0;
+    for (uint16_t y = 0; y < OLED_DISPLAY_HEIGHT/8; y++) {
+        if(left) {
+            for (uint16_t x = 0; x < OLED_DISPLAY_WIDTH - 1; x++) {
+                i = y * OLED_DISPLAY_WIDTH + x;
+                oled_buffer[i] = oled_buffer[i+1];
+            }
+        } else {
+            for (uint16_t x = OLED_DISPLAY_WIDTH -1; x > 0; x--) {
+                i = y * OLED_DISPLAY_WIDTH + x;
+                oled_buffer[i] = oled_buffer[i-1];
+            }
+        }
+    }
+    oled_dirty = ~((OLED_BLOCK_TYPE)0);
+}
+
+void oled_write_raw_byte(const char data, uint16_t index) {
+    if (index > OLED_MATRIX_SIZE) index = OLED_MATRIX_SIZE;
+    if (oled_buffer[index] == data) return;
+    oled_buffer[index] = data;
+    oled_dirty |= (1 << (index / OLED_BLOCK_SIZE));
+}
+
 void oled_write_raw(const char *data, uint16_t size) {
     if (size > OLED_MATRIX_SIZE) size = OLED_MATRIX_SIZE;
     for (uint16_t i = 0; i < size; i++) {

drivers/oled/oled_driver.h

@@ -200,7 +200,11 @@ void oled_write(const char *data, bool invert);
 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
 void oled_write_ln(const char *data, bool invert);
 
+// Pans the buffer to the right (or left by passing true) by moving contents of the buffer
+void oled_pan(bool left);
+
 void oled_write_raw(const char *data, uint16_t size);
+void oled_write_raw_byte(const char data, uint16_t index);
 
 #if defined(__AVR__)
 // Writes a PROGMEM string to the buffer at current cursor position