updated version

include/String.h

@@ -1,4 +1,4 @@
-#define CUSTOM_STRING_MAX_LEN 64
+#define CUSTOM_STRING_MAX_LEN 256
 
 typedef struct {
     char buffer[CUSTOM_STRING_MAX_LEN];

include/font_pack.h

@@ -3,21 +3,25 @@
 #define FONT_PACK_H
 #include <stdint.h>
 
-#define FONT_WIDTH  16
+#define FONT_WIDTH 16
 #define FONT_HEIGHT 16
-#define FONT_BITMAP_SIZE ((FONT_WIDTH * FONT_HEIGHT) / 8) // 32 bytes per character
+#define FONT_BITMAP_SIZE                                                       \
+  ((FONT_WIDTH * FONT_HEIGHT) / 8) // 32 bytes per character
 static const uint8_t empty_char_16x16[32] = {0};
 
 typedef struct {
-    const uint8_t *bitmaps[26]; // Pointers to each 16x16 bitmap
+  const uint8_t *bitmaps[26]; // Pointers to each 16x16 bitmap
 } FontPack;
 
 extern const FontPack basic_font_pack;
 
-static inline const uint8_t *font_get_char_bitmap(const FontPack *pack, char c) {
-    if (c >= 'A' && c <= 'Z')
-        return pack->bitmaps[c - 'A'];
-    return empty_char_16x16; // Or point to empty_char_16x16
+static inline const uint8_t *font_get_char_bitmap(const FontPack *pack,
+                                                  char c) {
+  if (c >= 'a' && c <= 'z') // convert to uppercase
+    c = c - 'a' + 'A';
+  if (c >= 'A' && c <= 'Z')
+    return pack->bitmaps[c - 'A'];
+  return empty_char_16x16; // fallback for other characters
 }
 
 #endif // FONT_PACK_H

include/io.h

@@ -53,6 +53,14 @@ static void uart_print_int(unsigned int value)
         uart_putc(buffer[i]);
 }
 
+static char uart_getc_nonblocking(void)
+{
+    if (UART0_FR & (1 << 4)) // RXFE = receive FIFO empty
+        return 0; // indicate no data
+    return (char)(UART0_DR & 0xFF);
+}
+
+
 // UART_IO instance with function pointers assigned
 static const UART_IO uart_io = {
     .putc = uart_putc,

include/renderer.h

@@ -4,6 +4,8 @@
 #include <stddef.h>
 #include <stdbool.h>
 #include "font_pack.h"
+#include <math.h>  // For sqrt, round
+
 
 typedef struct RenderObject {
     unsigned int x, y;
@@ -27,6 +29,11 @@ typedef struct Renderer {
     void (*draw_rect)(struct Renderer *renderer, RenderObject *obj);
     void (*draw_text)(struct Renderer *renderer, RenderText *text);
     void (*draw_objects)(struct Renderer *renderer, RenderObject *objs[], unsigned int count);
+    void (*draw_line)(struct Renderer *renderer, int x0, int y0, int x1, int y1, unsigned int color);
+    void (*draw_circle)(struct Renderer *renderer, int cx, int cy, int radius, unsigned int color);
+    void (*fill_circle)(struct Renderer *renderer, int cx, int cy, int radius, unsigned int color);
+    void (*draw_triangle)(struct Renderer *renderer, int x0, int y0, int x1, int y1, int x2, int y2, unsigned int color);
+    void (*fill_triangle)(struct Renderer *renderer, int x0, int y0, int x1, int y1, int x2, int y2, unsigned int color);
 } Renderer;
 
 // ===== Window definition =====