Informational 15 Bitcoin Committed May 1, 2026 · 10:32 UTC

fonts: simplify font setting

d42f01da View source ↗

Public commit record

What the developer wrote

Authored by Jon Griffiths

58/100 · Thin

fonts: simplify font setting

Note that data such as the maximum character width, computed when each font
is set could be computed at compile time, or cached when first set.

✓ Descriptive subject✓ Provides detailed explanatory context

The short version

What changed, and why it matters

This commit is a small internal cleanup of how fonts are selected on the device's screen. It removes an unused second argument from the font-setting function and adds a minor caching shortcut so the same font isn't re-initialized repeatedly. There is no visible security change.

Recommended action

No security action required. Treat as a normal code-quality refactor.

Security signals we found

No strong security signals were identified.

Technical analysis

Evidence from the diff

The patch refactors display_set_font() from taking (uint8_t font, const char* font_file) to taking only (uint8_t font). The font_file parameter was always passed as NULL and never used. The function now uses a local font_data pointer and, after selection, checks if the chosen font is already the current one and cfont.max_x_size is already set; if so, it returns early. Otherwise it populates cfont fields as before. Callers in display.c and gui.c are updated to drop the NULL argument. No bounds checks, memory allocations, or trust boundaries change.

Changed components

main/display.cmain/display.hmain/gui.c

Inspect captured patch +34 / −30

diff --git a/main/display.c b/main/display.c
index 07682f0..c087533 100644
--- a/main/display.c
+++ b/main/display.c
@@ -279,7 +279,7 @@ void display_init(TaskHandle_t* gui_h)
         .x2 = TOUCH_BUTTON_WIDTH + CONFIG_DISPLAY_OFFSET_X,
         .y2 = (CONFIG_DISPLAY_HEIGHT + (TOUCH_BUTTON_AREA - TOUCH_BUTTON_MARGIN)) + CONFIG_DISPLAY_OFFSET_Y };
 
-    display_set_font(JADE_SYMBOLS_16x16_FONT, NULL);
+    display_set_font(JADE_SYMBOLS_16x16_FONT);
     display_print_in_area("H", CENTER, CENTER, disp_win_virtual_buttons, 0);
     disp_win_virtual_buttons.x1 = ((CONFIG_DISPLAY_WIDTH / 2) + CONFIG_DISPLAY_OFFSET_X) - (TOUCH_BUTTON_WIDTH / 2);
     disp_win_virtual_buttons.x2 = ((CONFIG_DISPLAY_WIDTH / 2) + CONFIG_DISPLAY_OFFSET_X) + (TOUCH_BUTTON_WIDTH / 2);
@@ -288,7 +288,7 @@ void display_init(TaskHandle_t* gui_h)
         = ((CONFIG_DISPLAY_WIDTH - TOUCH_BUTTON_MARGIN) + CONFIG_DISPLAY_OFFSET_X) - TOUCH_BUTTON_WIDTH;
     disp_win_virtual_buttons.x2 = (CONFIG_DISPLAY_WIDTH - TOUCH_BUTTON_MARGIN) + CONFIG_DISPLAY_OFFSET_X;
     display_print_in_area("I", CENTER, CENTER, disp_win_virtual_buttons, 0);
-    display_set_font(DEFAULT_FONT, NULL);
+    display_set_font(DEFAULT_FONT);
 
     vTaskDelay(50 / portTICK_PERIOD_MS);
 #endif
@@ -747,56 +747,60 @@ static void get_max_width_height(void)
     cfont.size = tempPtr;
 }
 
-void display_set_font(uint8_t font, const char* font_file)
+void display_set_font(const uint8_t font)
 {
-    cfont.font = NULL;
+    const uint8_t* font_data;
 
     if (font == DEJAVU18_FONT) {
-        cfont.font = tft_Dejavu18;
+        font_data = tft_Dejavu18;
     } else if (font == DEJAVU24_FONT) {
-        cfont.font = tft_Dejavu24;
+        font_data = tft_Dejavu24;
     } else if (font == UBUNTU16_FONT) {
-        cfont.font = tft_Ubuntu16;
+        font_data = tft_Ubuntu16;
     } else if (font == COMIC24_FONT) {
-        cfont.font = tft_Comic24;
+        font_data = tft_Comic24;
     } else if (font == MINYA24_FONT) {
-        cfont.font = tft_minya24;
+        font_data = tft_minya24;
     } else if (font == TOONEY32_FONT) {
-        cfont.font = tft_tooney32;
+        font_data = tft_tooney32;
     } else if (font == SMALL_FONT) {
-        cfont.font = tft_SmallFont;
+        font_data = tft_SmallFont;
     } else if (font == DEF_SMALL_FONT) {
-        cfont.font = tft_def_small;
+        font_data = tft_def_small;
     } else if (font == BIG_FONT) {
-        cfont.font = tft_BigFont;
+        font_data = tft_BigFont;
     } else if (font == SINCLAIR_M) {
-        cfont.font = tft_Sinclair_M;
+        font_data = tft_Sinclair_M;
     } else if (font == SINCLAIR_S) {
-        cfont.font = tft_Sinclair_S;
+        font_data = tft_Sinclair_S;
     } else if (font == RETRO_8X16) {
-        cfont.font = tft_Retro8x16;
+        font_data = tft_Retro8x16;
     } else if (font == VARIOUS_SYMBOLS_FONT) {
-        cfont.font = tft_various_symbols;
+        font_data = tft_various_symbols;
     } else if (font == VARIOUS_SYMBOLS_32_FONT) {
-        cfont.font = tft_Various_Symbols_32x32;
+        font_data = tft_Various_Symbols_32x32;
     } else if (font == BATTERY_FONT) {
-        cfont.font = tft_Battery_24x48;
+        font_data = tft_Battery_24x48;
     } else if (font == JADE_SYMBOLS_16x16_FONT) {
-        cfont.font = jade_symbols_16x16;
+        font_data = jade_symbols_16x16;
     } else if (font == JADE_SYMBOLS_16x32_FONT) {
-        cfont.font = jade_symbols_16x32;
+        font_data = jade_symbols_16x32;
     } else if (font == JADE_SYMBOLS_24x24_FONT) {
-        cfont.font = jade_symbols_24x24;
+        font_data = jade_symbols_24x24;
     } else {
-        cfont.font = tft_DefaultFont;
+        font_data = tft_DefaultFont;
     }
 
+    if (font_data == cfont.font && cfont.max_x_size) {
+        return;
+    }
+    cfont.font = font_data;
     cfont.bitmap = 1;
-    cfont.x_size = cfont.font[0];
-    cfont.y_size = cfont.font[1];
+    cfont.x_size = font_data[0];
+    cfont.y_size = font_data[1];
     if (cfont.x_size > 0) {
-        cfont.offset = cfont.font[2];
-        cfont.numchars = cfont.font[3];
+        cfont.offset = font_data[2];
+        cfont.numchars = font_data[3];
         cfont.size = cfont.x_size * cfont.y_size * cfont.numchars;
     } else {
         cfont.offset = 4;
diff --git a/main/display.h b/main/display.h
index ba6350d..a625da4 100644
--- a/main/display.h
+++ b/main/display.h
@@ -98,7 +98,7 @@ void display_fill_rect(int x, int y, int w, int h, color_t color);
 void display_icon(const Icon* imgbuf, int x, int y, color_t color, dispWin_t area, const color_t* bg_color);
 void display_print_in_area(const char* st, int x, int y, dispWin_t areaWin, bool wrap);
 int display_get_string_width(const char* str);
-void display_set_font(uint8_t font, const char* font_file);
+void display_set_font(uint8_t font);
 int display_get_font_height(void);
 void display_flush(void);
 #endif /* DISPLAY_H_ */
diff --git a/main/gui.c b/main/gui.c
index 4fd5582..b44afa5 100644
--- a/main/gui.c
+++ b/main/gui.c
@@ -1482,7 +1482,7 @@ static inline bool can_text_fit(const char* text, uint32_t font, dispWin_t cs)
 {
     JADE_ASSERT(text);
 
-    display_set_font(font, NULL); // measure relative to this font
+    display_set_font(font); // measure relative to this font
     return display_get_string_width(text) <= cs.x2 - cs.x1;
 }
 
@@ -1967,7 +1967,7 @@ static void render_text(gui_view_node_t* node, dispWin_t cs)
     JADE_ASSERT(node);
     JADE_ASSERT(node->kind == TEXT);
 
-    display_set_font(node->text->font, NULL);
+    display_set_font(node->text->font);
 
     if (node->text->scroll) {
         // this text has the scroll enable, so disable wrap

Risk score

Why this scored 15/100

Our methodology →

Potential impact 0/30

Exploitability 0/25

Stealth signal 0/15

Affected reach 0/15

Confidence 10/10

Evidence quality 5/5

Human-validated context

Community notes

Notes can correct, qualify, or add evidence to the AI analysis. Every note shown here has been validated by a human moderator.

No validated notes yet.

The AI analysis stands alone for now. Submit a note if you can add evidence or important context.

What the developer wrote

What changed, and why it matters

Security signals we found

Evidence from the diff

Changed components

Why this scored 15/100

Community notes

Related watches

fmt: fix and prevent future use of unsupported format spec "zu"

otp: release md context on failure and clean temporary buffers

identity: clean temporary hash buffer