diff --git a/CMakeLists.txt b/CMakeLists.txt
index dd229a2..86f5923 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,3 +2,4 @@ project(SpriteExtractor)
 
 set(SOURCES main.c)
 add_executable(sprite_extractor ${SOURCES})
+target_link_libraries(sprite_extractor m)
diff --git a/main.c b/main.c
index 6548913..942785f 100644
--- a/main.c
+++ b/main.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <math.h>
+#include <limits.h>
 
 #define MAX_FRAMES 65536
 #define MAX_POINTS 100000
@@ -48,6 +49,7 @@ typedef struct
     int maxDistFromEdge;
 	int minW, minH;
     bool pot;
+    bool ground;
     int dw;
     int packW, packH;
 	bool label;
@@ -162,8 +164,10 @@ static void PrintUsage(const char* app)
 	fprintf(stderr, "\t--label\n\t\tPrints the rectangle indices into the top-left corner of the frames.\n");
 	fprintf(stderr, "\t--metadata\n\t\tIf specified, the rectangles are output to a text file in the format mentioned below.\n");
     fprintf(stderr, "\t--pack PACKED_IMAGE_WIDTH PACKED_IMAGE_HEIGHT\n\t\tIf this is supplied, then the frames are tightly packed and metadata is generated for each frame.\n\t\tThe metadata is simply a text file with the number of frames followed by 4 integers\n\t\tfor each frame: x y w h\n");
+    fprintf(stderr, "\t--ground\n\t\tIf this is supplied, then the frames are grounded on the floor instead of centered\n");
 }
 
+
 static bool ParseArgs(Args* args, int argc, char** argv)
 {
     if(argc < 2) {
@@ -206,6 +210,8 @@ static bool ParseArgs(Args* args, int argc, char** argv)
             i += 2;
         } else if(strcmp(argv[i], "--pot") == 0) {
             args->pot = true;
+		} else if(strcmp(argv[i], "--ground") == 0) {
+            args->ground = true;
 		} else if (strcmp(argv[i], "--label") == 0) {
 			args->label = true;
 		} else if (strcmp(argv[i], "--row-thresh") == 0) {
@@ -452,7 +458,7 @@ int main(int argc, char** argv)
     }
 
     if(args.isDir) {
-		tfTraverse(args.inputImage, TraverseImages, &args);
+		tfTraverseAlphabetically(args.inputImage, TraverseImages, &args);
     } else {
         ExtractFrames(args.inputImage, &args);
     }
@@ -569,7 +575,11 @@ int main(int argc, char** argv)
 			int columns = dw / fw;
 
             dx = (i % columns) * fw + fw / 2 - r.w / 2;
-            dy = (i / columns) * fh + fh / 2 - r.h / 2;
+            if(args.ground) {
+                dy = (i / columns) * fh + fh - r.h;
+            } else {    
+                dy = (i / columns) * fh + fh / 2 - r.h / 2;
+            }
         } else {
             dx = rects[i].x;
             dy = rects[i].y;
diff --git a/tinyfiles.h b/tinyfiles.h
index 01a1b79..26d6576 100644
--- a/tinyfiles.h
+++ b/tinyfiles.h
@@ -54,6 +54,7 @@
 #endif
 
 #include <string.h> // strerror, strncpy
+#include <stdlib.h> // qsort
 
 // change to 0 to compile out any debug checks
 #define TF_DEBUG_CHECKS 1
@@ -258,6 +259,51 @@ void tfTraverse( const char* path, tfCallback cb, void* udata )
 	tfDirClose( &dir );
 }
 
+static int compareFiles(const void* a, const void* b) {
+    tfFILE* fileA = (tfFILE*)a;
+    tfFILE* fileB = (tfFILE*)b;
+    return strcmp(fileA->name, fileB->name);
+}
+
+void tfTraverseAlphabetically(const char* path, tfCallback cb, void* udata) {
+    tfDIR dir;
+    tfFILE files[1024];
+    int fileCount = 0;
+
+    if (!tfDirOpen(&dir, path)) {
+        return;
+    }
+
+    while (dir.has_next) {
+        tfFILE file;
+        if (tfReadFile(&dir, &file)) {
+            files[fileCount++] = file;
+        }
+        tfDirNext(&dir);
+    }
+
+    tfDirClose(&dir);
+
+    qsort(files, fileCount, sizeof(tfFILE), compareFiles);
+
+    for (int i = 0; i < fileCount; ++i) {
+        tfFILE* file = &files[i];
+        
+        if (file->is_dir && file->name[0] != '.') {
+            char path2[TF_MAX_PATH];
+            int n = tfSafeStrCpy(path2, path, 0, TF_MAX_PATH);
+            n = tfSafeStrCpy(path2, "/", n - 1, TF_MAX_PATH);
+            tfSafeStrCpy(path2, file->name, n - 1, TF_MAX_PATH);
+            tfTraverse(path2, cb, udata);
+        }
+
+        if (file->is_reg) {
+            cb(file, udata);
+        }
+    }
+}
+
+
 int tfMatchExt( tfFILE* file, const char* ext )
 {
 	if (*ext == '.') ++ext;