legacy: don't add more pixels than needed in oledSCA

(cherry picked from commit 6720690452)

legacy/firmware/layout2.c

@@ -546,7 +546,9 @@ void layoutResetWord(const char *word, int pass, int word_pos, bool last) {
                  FONT_STANDARD);
   oledDrawStringCenter(OLED_WIDTH / 2, 4 * 9 - 3, word,
                        FONT_FIXED | FONT_DOUBLE);
-  oledSCA(4 * 9 - 3 - 2, 4 * 9 - 3 + 15 + 2, OLED_WIDTH / 2);
+  // 30 is the maximum pixels used for a pixel row in the BIP39 word "abstract"
+  oledSCA(4 * 9 - 3 - 2, 4 * 9 - 3 + 15 + 2, 30);
+  oledInvert(0, 4 * 9 - 3 - 2, OLED_WIDTH - 1, 4 * 9 - 3 + 15 + 2);
   layoutButtonYes(btnYes);
   oledRefresh();
 }

legacy/firmware/pinmatrix.c

@@ -46,8 +46,8 @@ void pinmatrix_draw(const char *text) {
     }
   }
   for (int i = 0; i < 3; i++) {
-    oledSCA(12 + i * (h + pad), 12 + i * (h + pad) + h - 1, OLED_WIDTH / 2);
-    oledInvert(0, 12 + i * (h + pad), OLED_WIDTH - 1, 12 + i * (h + pad) + h - 1);
+    // 36 is the maximum pixels used for a pin matrix pixel row
+    oledSCA(12 + i * (h + pad), 12 + i * (h + pad) + h - 1, 36);
   }
   oledRefresh();
 }

legacy/gen/bitmaps.c

@@ -6,7 +6,7 @@ const uint8_t bmp_digit1_data[] = { 0xff, 0xff, 0xfc, 0x3f, 0xf8, 0x3f, 0xf0, 0x
 const uint8_t bmp_digit2_data[] = { 0xff, 0xff, 0xe0, 0x1f, 0xe0, 0x0f, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xf8, 0x0f, 0xf0, 0x1f, 0xe1, 0xff, 0xe1, 0xff, 0xe1, 0xff, 0xe1, 0xff, 0xe0, 0x07, 0xe0, 0x07, 0xff, 0xff, };
 const uint8_t bmp_digit3_data[] = { 0xff, 0xff, 0xe0, 0x1f, 0xe0, 0x0f, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xf8, 0x0f, 0xf8, 0x0f, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xe0, 0x0f, 0xe0, 0x1f, 0xff, 0xff, };
 const uint8_t bmp_digit4_data[] = { 0xff, 0xff, 0xff, 0x0f, 0xfe, 0x0f, 0xfc, 0x0f, 0xf8, 0x0f, 0xf1, 0x0f, 0xe3, 0x0f, 0xc7, 0x0f, 0xcf, 0x0f, 0xc0, 0x0f, 0xc0, 0x0f, 0xff, 0x0f, 0xff, 0x0f, 0xff, 0x0f, 0xff, 0x0f, 0xff, 0xff, };
-const uint8_t bmp_digit5_data[] = { 0xff, 0xff, 0xe0, 0x1f, 0xe0, 0x1f, 0xe7, 0xff, 0xe7, 0xff, 0xe0, 0x1f, 0xe0, 0x0f, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xe0, 0x0f, 0xe0, 0x1f, 0xff, 0xff, };
+const uint8_t bmp_digit5_data[] = { 0xff, 0xff, 0xe0, 0x0f, 0xe0, 0x0f, 0xe1, 0xff, 0xe1, 0xff, 0xe0, 0x1f, 0xe0, 0x0f, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xff, 0x87, 0xe0, 0x0f, 0xe0, 0x1f, 0xff, 0xff, };
 const uint8_t bmp_digit6_data[] = { 0xff, 0xff, 0xf8, 0x1f, 0xf0, 0x1f, 0xe1, 0xff, 0xe1, 0xff, 0xe0, 0x1f, 0xe0, 0x0f, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xf0, 0x0f, 0xf8, 0x1f, 0xff, 0xff, };
 const uint8_t bmp_digit7_data[] = { 0xff, 0xff, 0xe0, 0x07, 0xe0, 0x07, 0xff, 0x87, 0xff, 0x87, 0xff, 0x0f, 0xfe, 0x1f, 0xfc, 0x1f, 0xfc, 0x3f, 0xf8, 0x7f, 0xf8, 0x7f, 0xf8, 0x7f, 0xf8, 0x7f, 0xf8, 0x7f, 0xf8, 0x7f, 0xff, 0xff, };
 const uint8_t bmp_digit8_data[] = { 0xff, 0xff, 0xf8, 0x1f, 0xf0, 0x0f, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xf0, 0x0f, 0xf0, 0x0f, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xe1, 0x87, 0xf0, 0x0f, 0xf8, 0x1f, 0xff, 0xff, };

legacy/oled.c

@@ -422,7 +422,7 @@ void oledSwipeRight(void) {
 }
 
 /*
- * Mitigate SCA on lines y1-y2 by setting exactly width pixels black
+ * Mitigate SCA on lines y1-y2 by setting at least width pixels white
  */
 void oledSCA(int y1, int y2, int width) {
   y1 = MAX(y1, 0);
@@ -432,9 +432,14 @@ void oledSCA(int y1, int y2, int width) {
     for (int x = 0; x < OLED_WIDTH; x++) {
       pix += oledGetPixel(x, y);
     }
-    pix = MAX(width - pix, 0);
-    for (int x = 0 + (pix / 2); x < OLED_WIDTH - ((pix + 1) / 2); x++) {
-      oledInvertPixel(x, y);
+    if (width > pix) {
+      pix = width - pix;
+      for (int x = 0; x < pix / 2; x++) {
+        oledDrawPixel(x, y);
+      }
+      for (int x = OLED_WIDTH - ((pix + 1) / 2); x < OLED_WIDTH; x++) {
+        oledDrawPixel(x, y);
+      }
     }
   }
 }