From c201da97363a9a022502931a6bfc7c4c2667e577 Mon Sep 17 00:00:00 2001
From: Garritt McCune <glmccune@gmail.com>
Date: Sun, 10 Jul 2022 15:17:18 -0500
Subject: [PATCH] Updated the interface for the TStringGetStringRange function.
 It will now fill a buffer, leaving a null byte at the end, with as many
 characters as it can depending on the supplied buffer's size.

---
 src/main.c    | 16 +++++++---------
 src/tstring.c | 36 +++++++++++++++---------------------
 src/tstring.h |  2 +-
 3 files changed, 23 insertions(+), 31 deletions(-)

diff --git a/src/main.c b/src/main.c
index 0d51c43..53dd14c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -7,6 +7,7 @@
 int main(int argc, char** argv) {
     char input[1024] = { 0 };
     char glyph[8] = { 0 };
+    char buffer[11] = { 0 };
     char* file;
     size_t bytesRead;
 
@@ -90,11 +91,12 @@ int main(int argc, char** argv) {
 
                 int count = strtol(input, NULL, 10);
 
-                char* text = TStringGetStringRange(num, count, string);
+                //char* text = TStringGetStringRange(num, count, string);
+                TStringGetStringRange(string, num, count, sizeof buffer, buffer);
 
-                printf("Returned String:\n'%s'\n", text);
-
-                free(text);
+                printf("Returned String:\n'%s'\n", buffer);
+                for (int i = 0; i < sizeof buffer; i++) printf("%02X ", buffer[i] & 0xFF);
+                printf("\n");
 
                 continue;
             }
@@ -102,10 +104,6 @@ int main(int argc, char** argv) {
 
         TStringAppendText(input, string);
     }
-    //fgets(glyph, 10, stdin);
-
-    //glyph[strlen(glyph) - 1] = 0;
-
-    //printf("Width %d byte(s).\n", GetGlyphByteWidth(glyph));
+    
     TStringFree(string);
 }
\ No newline at end of file
diff --git a/src/tstring.c b/src/tstring.c
index 8f61502..cd8a482 100644
--- a/src/tstring.c
+++ b/src/tstring.c
@@ -202,35 +202,29 @@ char* TStringGetString(const TString* string) {
     return text;
 }
 
-char* TStringGetStringRange(int startIndex, int count, const TString* string) {
-    if (!string) return NULL;
-    if (startIndex < 0 || startIndex >= string->Length) return NULL;
-    if (count > string->Length) return NULL;
+void TStringGetStringRange(const TString* string, unsigned int startIndex, unsigned int count, unsigned int bufferSize, char buffer[]) {
+    if (!string || !buffer) return;
+    if (count > string->Length) return;
 
-    char* text = calloc(string->ByteCount + 1, sizeof(char));
-
-    if (!text) {
-        fprintf(stderr, "Failed to calloc memory for TString text. %s.\n", strerror(errno));
-
-        return NULL;
-    }
-
-    unsigned int startByte = 0;
-    unsigned int glyphCount = 0;
-
-    while(glyphCount != startIndex) {
+    unsigned int glyphCount = 0, startByte = 0;
+    
+    while (glyphCount != startIndex) {
         startByte += GetGlyphByteWidth(string->Characters[startByte]);
-
+        
         glyphCount++;
     }
 
     unsigned int endByte = startByte;
 
-    for (glyphCount = 0; glyphCount < count && endByte <= string->ByteCount; glyphCount++) endByte += GetGlyphByteWidth(string->Characters[endByte]);
-    
-    memcpy(text, &string->Characters[startByte], endByte - startByte);
+    for(glyphCount = 0; glyphCount < count && endByte <= string->ByteCount && endByte - startByte < bufferSize; glyphCount++) {
+        int width = GetGlyphByteWidth(string->Characters[endByte]);
 
-    return text;
+        if (width + endByte - startByte < bufferSize) endByte += width;
+        else break;
+    }
+
+    memset(buffer, 0, bufferSize);
+    memcpy(buffer, &string->Characters[startByte], endByte - startByte);
 }
 
 void TStringGetGlyph(int index, char buffer[8], const TString* string) {
diff --git a/src/tstring.h b/src/tstring.h
index 665798e..25bcbcb 100644
--- a/src/tstring.h
+++ b/src/tstring.h
@@ -15,8 +15,8 @@ void TStringPrintDetails(const TString* string, int statsOnly);
 void TStringInsertText(const char* text, int index, TString* string);
 void TStringPop(char buffer[8], TString* string);
 void TStringRemoveRange(int startIndex, int count, TString* string);
+void TStringGetStringRange(const TString* string, unsigned int startIndex, unsigned int count, unsigned int bufferSize, char buffer[]);
 char* TStringGetString(const TString* string);
-char* TStringGetStringRange(int startIndex, int count, const TString* string);
 int TStringLength(const TString* string);