Handle codepoints outside the BMP

Author: Wires77

engine/common/common.cpp

@@ -479,7 +479,7 @@ IndexedUTF32String IndexUTF8ToUTF32(std::string_view input)
 			auto p0 = (uint32_t)b[0] & 0b111;
 			auto p1 = (uint32_t)b[1] & 0b11'1111;
 			auto p2 = (uint32_t)b[2] & 0b11'1111;
-			auto p3 = (uint32_t)b[2] & 0b11'1111;
+			auto p3 = (uint32_t)b[3] & 0b11'1111;
 			codepoint = p0 << 18 | p1 << 12 | p2 << 6 | p3;
 			byteIdx += 4;
 		}

engine/system/win/sys_console.cpp

@@ -281,7 +281,13 @@ void sys_console_c::Print(std::u32string_view string_view_text)
 			// Skip colour escapes
 			b+= escLen - 1;
 		} else {
-			len++;
+			if (text[b] > UINT16_MAX) {
+				// Higher codepoints will be separated into surrogate pairs
+				len += 2;
+			}
+			else {
+				len++;
+			}
 		}
 	}
 
@@ -298,7 +304,16 @@ void sys_console_c::Print(std::u32string_view string_view_text)
 			b+= escLen - 1;
 		} else {
 			// Add character
-			*(p++) = (char16_t)text[b];
+			if (text[b] > UINT16_MAX) { // Outside the BMP
+				char16_t high_surrogate = ((text[b] - 0x10000) / 0x400) + 0xD800;
+				char16_t low_surrogate = ((text[b] - 0x10000) % 0x400) + 0xDC00;
+				*(p++) = high_surrogate;
+				*(p++) = low_surrogate;
+			}
+			else {
+				*(p++) = (char16_t)text[b];
+			}
+			
 		}
 	}
 	winText[len] = 0;