utils/str: Supplements functions.

Added strDirname(), which returns the directory path name from the given string.
Added str2int(), which converts from the string to the integer.

These functions are used to supplement the existing string manipulation functions in the utils/str module.

src/loaders/lottie/tvgLottieLoader.cpp

@@ -39,16 +39,6 @@ static bool _checkDotLottie(const char *str)
 }
 
 
-static int _str2int(const char* str, int len)
-{
-    int ret = 0;
-    for(int i = 0; i < len; ++i) {
-        ret = ret * 10 + (str[i] - '0');
-    }
-    return ret;
-}
-
-
 static int _str2float(const char* str, int len)
 {
     auto tmp = strDuplicate(str, len);
@@ -149,7 +139,7 @@ bool LottieLoader::header()
             p += 4;
             auto e = strstr(p, ",");
             if (!e) e = strstr(p, "}");
-            w = static_cast<float>(_str2int(p, e - p));
+            w = static_cast<float>(str2int(p, e - p));
             p = e;
             continue;
         }
@@ -158,7 +148,7 @@ bool LottieLoader::header()
             p += 4;
             auto e = strstr(p, ",");
             if (!e) e = strstr(p, "}");
-            h = static_cast<float>(_str2int(p, e - p));
+            h = static_cast<float>(str2int(p, e - p));
             p = e;
             continue;
         }

src/utils/tvgStr.cpp

@@ -205,6 +205,15 @@ error:
 }
 
 
+int str2int(const char* str, size_t n)
+{
+    int ret = 0;
+    for(size_t i = 0; i < n; ++i) {
+        ret = ret * 10 + (str[i] - '0');
+    }
+    return ret;
+}
+
 char* strDuplicate(const char *str, size_t n)
 {
     auto len = strlen(str);
@@ -217,4 +226,14 @@ char* strDuplicate(const char *str, size_t n)
     return (char *) memcpy(ret, str, n);
 }
 
+char* strDirname(const char* path)
+{
+    const char *ptr = strrchr(path, '/');
+#ifdef _WIN32
+    if (ptr) ptr = strrchr(ptr + 1, '\\');
+#endif
+    int len = int(ptr + 1 - path);  // +1 to include '/'
+    return strDuplicate(path, len);
+}
+
 }

src/utils/tvgStr.h

@@ -23,11 +23,15 @@
 #ifndef _TVG_STR_H_
 #define _TVG_STR_H_
 
+#include <cstddef>
+
 namespace tvg
 {
 
-float strToFloat(const char *nPtr, char **endPtr);
-char* strDuplicate(const char *str, size_t n);
+float strToFloat(const char *nPtr, char **endPtr);  //convert to float
+int str2int(const char* str, size_t n);             //convert to integer
+char* strDuplicate(const char *str, size_t n);      //copy the string
+char* strDirname(const char* path);                 //return the full directory name
 
 }
 #endif //_TVG_STR_H_