diff --git a/.gitignore b/.gitignore
index 9bd7521..e728f92 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,5 @@ rayjs.app/
 rayjs.exe
 include/generated/
 .DS_Store
+controls_test
+controls_test.exe
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c620ba7..898f128 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,4 +38,8 @@ add_executable(${CMAKE_PROJECT_NAME} ${files})
 target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE include)
 target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE src)
 target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE thirdparty/raygui/src)
-target_link_libraries(${CMAKE_PROJECT_NAME} quickjs raylib)
\ No newline at end of file
+target_link_libraries(${CMAKE_PROJECT_NAME} quickjs raylib)
+
+add_executable(controls_test thirdparty/raygui/examples/controls_test_suite/controls_test_suite.c)
+target_include_directories(controls_test PRIVATE thirdparty/raygui/src)
+target_link_libraries(controls_test raylib)
\ No newline at end of file
diff --git a/bindings/src/index.ts b/bindings/src/index.ts
index e4cca19..6c9cb4b 100644
--- a/bindings/src/index.ts
+++ b/bindings/src/index.ts
@@ -504,6 +504,8 @@ function main(){
             customConverter: gen => {
                 gen.declare(param.name+"_out", param.type.replace(" *",""))
                 gen.declare(param.name, param.type, false, "&"+param.name+"_out")
+                gen.call("JS_GetPropertyStr", ["ctx","argv["+index+"]", '"'+param.name+'"'], { name: param.name+"_js", type: "JSValue" })
+                gen.call("JS_ToInt32", ["ctx",param.name,param.name+"_js"])
             },
             customCleanup: gen => {
                 gen.call("JS_SetPropertyStr", ["ctx", "argv["+index+"]", `"${param.name}"`, "JS_NewInt32(ctx,"+param.name+"_out)"])
diff --git a/bindings/src/quickjs.ts b/bindings/src/quickjs.ts
index 36c9687..5b492a5 100644
--- a/bindings/src/quickjs.ts
+++ b/bindings/src/quickjs.ts
@@ -93,8 +93,8 @@ export abstract class GenericQuickJsGenerator<T extends QuickJsGenerator> extend
             // String
             case "const char *":
             //case "char *":
-                if(!supressDeclaration) this.statement(`${type} ${name} = (${type})JS_ToCString(ctx, ${src})`)
-                else this.statement(`${name} = (${type})JS_ToCString(ctx, ${src})`)
+                if(!supressDeclaration) this.statement(`${type} ${name} = JS_IsNull(${src}) ? NULL : (${type})JS_ToCString(ctx, ${src})`)
+                else this.statement(`${name} = JS_IsNull(${src}) ? NULL : (${type})JS_ToCString(ctx, ${src})`)
                 break;
             case "double":
                 if(!supressDeclaration) this.statement(`${type} ${name}`)
diff --git a/examples/raygui/controls_test_suite.js b/examples/raygui/controls_test_suite.js
index f15a0d9..1db39d0 100644
--- a/examples/raygui/controls_test_suite.js
+++ b/examples/raygui/controls_test_suite.js
@@ -140,8 +140,8 @@ while (!exitWindow)    // Detect window close button or ESC key
         guiPanel(new Rectangle(320, 25, 225, 140), "Panel Info");
         colorPickerValue = guiColorPicker(new Rectangle(320, 185, 196, 192), null, colorPickerValue);
 
-        sliderValue = guiSlider(new Rectangle(355, 400, 165, 20), "TEST", sliderValue.toString(), sliderValue, -50, 100);
-        sliderBarValue = guiSliderBar(new Rectangle(320, 430, 200, 20), null, sliderBarValue.toString(), sliderBarValue, 0, 100);
+        sliderValue = guiSlider(new Rectangle(355, 400, 165, 20), "TEST", Math.floor(sliderValue), sliderValue, -50, 100);
+        sliderBarValue = guiSliderBar(new Rectangle(320, 430, 200, 20), null, Math.floor(sliderBarValue), sliderBarValue, 0, 100);
         progressValue = guiProgressBar(new Rectangle(320, 460, 200, 20), null, null, progressValue, 0, 1);
 
         // NOTE: View rectangle could be used to perform some scissor test
diff --git a/generate-bindings.js b/generate-bindings.js
index 6b4ed21..93807ad 100644
--- a/generate-bindings.js
+++ b/generate-bindings.js
@@ -422,9 +422,9 @@ class GenericQuickJsGenerator extends generation_1.GenericCodeGenerator {
             case "const char *":
                 //case "char *":
                 if (!supressDeclaration)
-                    this.statement(`${type} ${name} = (${type})JS_ToCString(ctx, ${src})`);
+                    this.statement(`${type} ${name} = JS_IsNull(${src}) ? NULL : (${type})JS_ToCString(ctx, ${src})`);
                 else
-                    this.statement(`${name} = (${type})JS_ToCString(ctx, ${src})`);
+                    this.statement(`${name} = JS_IsNull(${src}) ? NULL : (${type})JS_ToCString(ctx, ${src})`);
                 break;
             case "double":
                 if (!supressDeclaration)
@@ -1389,6 +1389,8 @@ function main() {
             customConverter: gen => {
                 gen.declare(param.name + "_out", param.type.replace(" *", ""));
                 gen.declare(param.name, param.type, false, "&" + param.name + "_out");
+                gen.call("JS_GetPropertyStr", ["ctx", "argv[" + index + "]", '"' + param.name + '"'], { name: param.name + "_js", type: "JSValue" });
+                gen.call("JS_ToInt32", ["ctx", param.name, param.name + "_js"]);
             },
             customCleanup: gen => {
                 gen.call("JS_SetPropertyStr", ["ctx", "argv[" + index + "]", `"${param.name}"`, "JS_NewInt32(ctx," + param.name + "_out)"]);
diff --git a/src/bindings/js_raylib_core.h b/src/bindings/js_raylib_core.h
index 08386d4..8c8618c 100644
--- a/src/bindings/js_raylib_core.h
+++ b/src/bindings/js_raylib_core.h
@@ -2036,7 +2036,7 @@ static JSValue js_initWindow(JSContext * ctx, JSValueConst this_val, int argc, J
     JS_ToInt32(ctx, &width, argv[0]);
     int height;
     JS_ToInt32(ctx, &height, argv[1]);
-    const char * title = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * title = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     InitWindow(width, height, title);
     JS_FreeCString(ctx, title);
     return JS_UNDEFINED;
@@ -2146,7 +2146,7 @@ static JSValue js_setWindowIcon(JSContext * ctx, JSValueConst this_val, int argc
 }
 
 static JSValue js_setWindowTitle(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * title = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * title = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     SetWindowTitle(title);
     JS_FreeCString(ctx, title);
     return JS_UNDEFINED;
@@ -2308,7 +2308,7 @@ static JSValue js_getMonitorName(JSContext * ctx, JSValueConst this_val, int arg
 }
 
 static JSValue js_setClipboardText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * text = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * text = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     SetClipboardText(text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -2463,8 +2463,8 @@ static JSValue js_endScissorMode(JSContext * ctx, JSValueConst this_val, int arg
 }
 
 static JSValue js_loadShader(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * vsFileName = (const char *)JS_ToCString(ctx, argv[0]);
-    const char * fsFileName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * vsFileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fsFileName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Shader returnVal = LoadShader(vsFileName, fsFileName);
     JS_FreeCString(ctx, vsFileName);
     JS_FreeCString(ctx, fsFileName);
@@ -2476,8 +2476,8 @@ static JSValue js_loadShader(JSContext * ctx, JSValueConst this_val, int argc, J
 }
 
 static JSValue js_loadShaderFromMemory(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * vsCode = (const char *)JS_ToCString(ctx, argv[0]);
-    const char * fsCode = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * vsCode = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fsCode = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Shader returnVal = LoadShaderFromMemory(vsCode, fsCode);
     JS_FreeCString(ctx, vsCode);
     JS_FreeCString(ctx, fsCode);
@@ -2501,7 +2501,7 @@ static JSValue js_getShaderLocation(JSContext * ctx, JSValueConst this_val, int
     Shader* shader_ptr = (Shader*)JS_GetOpaque2(ctx, argv[0], js_Shader_class_id);
     if(shader_ptr == NULL) return JS_EXCEPTION;
     Shader shader = *shader_ptr;
-    const char * uniformName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * uniformName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int returnVal = GetShaderLocation(shader, uniformName);
     JS_FreeCString(ctx, uniformName);
     JSValue ret = JS_NewInt32(ctx, returnVal);
@@ -2512,7 +2512,7 @@ static JSValue js_getShaderLocationAttrib(JSContext * ctx, JSValueConst this_val
     Shader* shader_ptr = (Shader*)JS_GetOpaque2(ctx, argv[0], js_Shader_class_id);
     if(shader_ptr == NULL) return JS_EXCEPTION;
     Shader shader = *shader_ptr;
-    const char * attribName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * attribName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int returnVal = GetShaderLocationAttrib(shader, attribName);
     JS_FreeCString(ctx, attribName);
     JSValue ret = JS_NewInt32(ctx, returnVal);
@@ -2756,7 +2756,7 @@ static JSValue js_setRandomSeed(JSContext * ctx, JSValueConst this_val, int argc
 }
 
 static JSValue js_takeScreenshot(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     TakeScreenshot(fileName);
     JS_FreeCString(ctx, fileName);
     return JS_UNDEFINED;
@@ -2772,7 +2772,7 @@ static JSValue js_setConfigFlags(JSContext * ctx, JSValueConst this_val, int arg
 static JSValue js_traceLog(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
     int logLevel;
     JS_ToInt32(ctx, &logLevel, argv[0]);
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     TraceLog(logLevel, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -2786,14 +2786,14 @@ static JSValue js_setTraceLogLevel(JSContext * ctx, JSValueConst this_val, int a
 }
 
 static JSValue js_openURL(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * url = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * url = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     OpenURL(url);
     JS_FreeCString(ctx, url);
     return JS_UNDEFINED;
 }
 
 static JSValue js_loadFileData(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     unsigned int bytesRead;
     unsigned char * retVal = LoadFileData(fileName, &bytesRead);
     JSValue buffer = JS_NewArrayBufferCopy(ctx, (const uint8_t*)retVal, bytesRead);
@@ -2802,7 +2802,7 @@ static JSValue js_loadFileData(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_saveFileData(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     size_t data_size;
     void * data_js = (void *)JS_GetArrayBuffer(ctx, &data_size, argv[1]);
     if(data_js == NULL) {
@@ -2820,7 +2820,7 @@ static JSValue js_saveFileData(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_loadFileText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     char * returnVal = LoadFileText(fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2829,8 +2829,8 @@ static JSValue js_loadFileText(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_saveFileText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
-    char * text = (char *)JS_ToCString(ctx, argv[1]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
+    char * text = JS_IsNull(argv[1]) ? NULL : (char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = SaveFileText(fileName, text);
     JS_FreeCString(ctx, fileName);
     JS_FreeCString(ctx, text);
@@ -2839,7 +2839,7 @@ static JSValue js_saveFileText(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_fileExists(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     bool returnVal = FileExists(fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -2847,7 +2847,7 @@ static JSValue js_fileExists(JSContext * ctx, JSValueConst this_val, int argc, J
 }
 
 static JSValue js_directoryExists(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * dirPath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * dirPath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     bool returnVal = DirectoryExists(dirPath);
     JS_FreeCString(ctx, dirPath);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -2855,8 +2855,8 @@ static JSValue js_directoryExists(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_isFileExtension(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
-    const char * ext = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
+    const char * ext = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = IsFileExtension(fileName, ext);
     JS_FreeCString(ctx, fileName);
     JS_FreeCString(ctx, ext);
@@ -2865,7 +2865,7 @@ static JSValue js_isFileExtension(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_getFileLength(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int returnVal = GetFileLength(fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewInt32(ctx, returnVal);
@@ -2873,7 +2873,7 @@ static JSValue js_getFileLength(JSContext * ctx, JSValueConst this_val, int argc
 }
 
 static JSValue js_getFileExtension(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     const char * returnVal = GetFileExtension(fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2881,7 +2881,7 @@ static JSValue js_getFileExtension(JSContext * ctx, JSValueConst this_val, int a
 }
 
 static JSValue js_getFileName(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * filePath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * filePath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     const char * returnVal = GetFileName(filePath);
     JS_FreeCString(ctx, filePath);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2889,7 +2889,7 @@ static JSValue js_getFileName(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_getFileNameWithoutExt(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * filePath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * filePath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     const char * returnVal = GetFileNameWithoutExt(filePath);
     JS_FreeCString(ctx, filePath);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2897,7 +2897,7 @@ static JSValue js_getFileNameWithoutExt(JSContext * ctx, JSValueConst this_val,
 }
 
 static JSValue js_getDirectoryPath(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * filePath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * filePath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     const char * returnVal = GetDirectoryPath(filePath);
     JS_FreeCString(ctx, filePath);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2905,7 +2905,7 @@ static JSValue js_getDirectoryPath(JSContext * ctx, JSValueConst this_val, int a
 }
 
 static JSValue js_getPrevDirectoryPath(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * dirPath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * dirPath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     const char * returnVal = GetPrevDirectoryPath(dirPath);
     JS_FreeCString(ctx, dirPath);
     JSValue ret = JS_NewString(ctx, returnVal);
@@ -2925,7 +2925,7 @@ static JSValue js_getApplicationDirectory(JSContext * ctx, JSValueConst this_val
 }
 
 static JSValue js_changeDirectory(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * dir = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * dir = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     bool returnVal = ChangeDirectory(dir);
     JS_FreeCString(ctx, dir);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -2933,7 +2933,7 @@ static JSValue js_changeDirectory(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_isPathFile(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * path = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * path = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     bool returnVal = IsPathFile(path);
     JS_FreeCString(ctx, path);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -2941,7 +2941,7 @@ static JSValue js_isPathFile(JSContext * ctx, JSValueConst this_val, int argc, J
 }
 
 static JSValue js_loadDirectoryFiles(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * dirPath = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * dirPath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     FilePathList files = LoadDirectoryFiles(dirPath);
     JSValue ret = JS_NewArray(ctx);
     for(int i; i < files.count; i++){
@@ -2953,8 +2953,8 @@ static JSValue js_loadDirectoryFiles(JSContext * ctx, JSValueConst this_val, int
 }
 
 static JSValue js_loadDirectoryFilesEx(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * basePath = (const char *)JS_ToCString(ctx, argv[0]);
-    const char * filter = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * basePath = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
+    const char * filter = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool scanSubdirs = JS_ToBool(ctx, argv[2]);
     FilePathList files = LoadDirectoryFilesEx(basePath, filter, scanSubdirs);
     JSValue ret = JS_NewArray(ctx);
@@ -2984,7 +2984,7 @@ static JSValue js_loadDroppedFiles(JSContext * ctx, JSValueConst this_val, int a
 }
 
 static JSValue js_getFileModTime(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     long returnVal = GetFileModTime(fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewInt32(ctx, returnVal);
@@ -3123,7 +3123,7 @@ static JSValue js_getGamepadAxisMovement(JSContext * ctx, JSValueConst this_val,
 }
 
 static JSValue js_setGamepadMappings(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * mappings = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * mappings = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int returnVal = SetGamepadMappings(mappings);
     JS_FreeCString(ctx, mappings);
     JSValue ret = JS_NewInt32(ctx, returnVal);
@@ -4093,7 +4093,7 @@ static JSValue js_getCollisionRec(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_loadImage(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Image returnVal = LoadImage(fileName);
     JS_FreeCString(ctx, fileName);
     Image* ret_ptr = (Image*)js_malloc(ctx, sizeof(Image));
@@ -4104,7 +4104,7 @@ static JSValue js_loadImage(JSContext * ctx, JSValueConst this_val, int argc, JS
 }
 
 static JSValue js_loadImageRaw(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int width;
     JS_ToInt32(ctx, &width, argv[1]);
     int height;
@@ -4123,7 +4123,7 @@ static JSValue js_loadImageRaw(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_loadImageFromMemory(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileType = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileType = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     size_t fileData_size;
     void * fileData_js = (void *)JS_GetArrayBuffer(ctx, &fileData_size, argv[1]);
     if(fileData_js == NULL) {
@@ -4185,7 +4185,7 @@ static JSValue js_exportImage(JSContext * ctx, JSValueConst this_val, int argc,
     Image* image_ptr = (Image*)JS_GetOpaque2(ctx, argv[0], js_Image_class_id);
     if(image_ptr == NULL) return JS_EXCEPTION;
     Image image = *image_ptr;
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * fileName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = ExportImage(image, fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -4347,7 +4347,7 @@ static JSValue js_genImageText(JSContext * ctx, JSValueConst this_val, int argc,
     JS_ToInt32(ctx, &width, argv[0]);
     int height;
     JS_ToInt32(ctx, &height, argv[1]);
-    const char * text = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * text = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     Image returnVal = GenImageText(width, height, text);
     JS_FreeCString(ctx, text);
     Image* ret_ptr = (Image*)js_malloc(ctx, sizeof(Image));
@@ -4385,7 +4385,7 @@ static JSValue js_imageFromImage(JSContext * ctx, JSValueConst this_val, int arg
 }
 
 static JSValue js_imageText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * text = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * text = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int fontSize;
     JS_ToInt32(ctx, &fontSize, argv[1]);
     Color* color_ptr = (Color*)JS_GetOpaque2(ctx, argv[2], js_Color_class_id);
@@ -4404,7 +4404,7 @@ static JSValue js_imageTextEx(JSContext * ctx, JSValueConst this_val, int argc,
     Font* font_ptr = (Font*)JS_GetOpaque2(ctx, argv[0], js_Font_class_id);
     if(font_ptr == NULL) return JS_EXCEPTION;
     Font font = *font_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     double _double_fontSize;
     JS_ToFloat64(ctx, &_double_fontSize, argv[2]);
     float fontSize = (float)_double_fontSize;
@@ -4905,7 +4905,7 @@ static JSValue js_imageDraw(JSContext * ctx, JSValueConst this_val, int argc, JS
 static JSValue js_imageDrawText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
     Image* dst = (Image*)JS_GetOpaque2(ctx, argv[0], js_Image_class_id);
     if(dst == NULL) return JS_EXCEPTION;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int posX;
     JS_ToInt32(ctx, &posX, argv[2]);
     int posY;
@@ -4926,7 +4926,7 @@ static JSValue js_imageDrawTextEx(JSContext * ctx, JSValueConst this_val, int ar
     Font* font_ptr = (Font*)JS_GetOpaque2(ctx, argv[1], js_Font_class_id);
     if(font_ptr == NULL) return JS_EXCEPTION;
     Font font = *font_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * text = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     Vector2* position_ptr = (Vector2*)JS_GetOpaque2(ctx, argv[3], js_Vector2_class_id);
     if(position_ptr == NULL) return JS_EXCEPTION;
     Vector2 position = *position_ptr;
@@ -4945,7 +4945,7 @@ static JSValue js_imageDrawTextEx(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_loadTexture(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Texture2D returnVal = LoadTexture(fileName);
     JS_FreeCString(ctx, fileName);
     Texture2D* ret_ptr = (Texture2D*)js_malloc(ctx, sizeof(Texture2D));
@@ -5391,7 +5391,7 @@ static JSValue js_getFontDefault(JSContext * ctx, JSValueConst this_val, int arg
 }
 
 static JSValue js_loadFont(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Font returnVal = LoadFont(fileName);
     JS_FreeCString(ctx, fileName);
     Font* ret_ptr = (Font*)js_malloc(ctx, sizeof(Font));
@@ -5402,7 +5402,7 @@ static JSValue js_loadFont(JSContext * ctx, JSValueConst this_val, int argc, JSV
 }
 
 static JSValue js_loadFontEx(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int fontSize;
     JS_ToInt32(ctx, &fontSize, argv[1]);
     Font returnVal = LoadFontEx(fileName, fontSize, NULL, 0);
@@ -5458,7 +5458,7 @@ static JSValue js_drawFPS(JSContext * ctx, JSValueConst this_val, int argc, JSVa
 }
 
 static JSValue js_drawText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * text = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * text = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int posX;
     JS_ToInt32(ctx, &posX, argv[1]);
     int posY;
@@ -5477,7 +5477,7 @@ static JSValue js_drawTextEx(JSContext * ctx, JSValueConst this_val, int argc, J
     Font* font_ptr = (Font*)JS_GetOpaque2(ctx, argv[0], js_Font_class_id);
     if(font_ptr == NULL) return JS_EXCEPTION;
     Font font = *font_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Vector2* position_ptr = (Vector2*)JS_GetOpaque2(ctx, argv[2], js_Vector2_class_id);
     if(position_ptr == NULL) return JS_EXCEPTION;
     Vector2 position = *position_ptr;
@@ -5499,7 +5499,7 @@ static JSValue js_drawTextPro(JSContext * ctx, JSValueConst this_val, int argc,
     Font* font_ptr = (Font*)JS_GetOpaque2(ctx, argv[0], js_Font_class_id);
     if(font_ptr == NULL) return JS_EXCEPTION;
     Font font = *font_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Vector2* position_ptr = (Vector2*)JS_GetOpaque2(ctx, argv[2], js_Vector2_class_id);
     if(position_ptr == NULL) return JS_EXCEPTION;
     Vector2 position = *position_ptr;
@@ -5543,7 +5543,7 @@ static JSValue js_drawTextCodepoint(JSContext * ctx, JSValueConst this_val, int
 }
 
 static JSValue js_measureText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * text = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * text = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     int fontSize;
     JS_ToInt32(ctx, &fontSize, argv[1]);
     int returnVal = MeasureText(text, fontSize);
@@ -5556,7 +5556,7 @@ static JSValue js_measureTextEx(JSContext * ctx, JSValueConst this_val, int argc
     Font* font_ptr = (Font*)JS_GetOpaque2(ctx, argv[0], js_Font_class_id);
     if(font_ptr == NULL) return JS_EXCEPTION;
     Font font = *font_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     double _double_fontSize;
     JS_ToFloat64(ctx, &_double_fontSize, argv[2]);
     float fontSize = (float)_double_fontSize;
@@ -5943,7 +5943,7 @@ static JSValue js_drawGrid(JSContext * ctx, JSValueConst this_val, int argc, JSV
 }
 
 static JSValue js_loadModel(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Model returnVal = LoadModel(fileName);
     JS_FreeCString(ctx, fileName);
     Model* ret_ptr = (Model*)js_malloc(ctx, sizeof(Model));
@@ -6231,7 +6231,7 @@ static JSValue js_exportMesh(JSContext * ctx, JSValueConst this_val, int argc, J
     Mesh* mesh_ptr = (Mesh*)JS_GetOpaque2(ctx, argv[0], js_Mesh_class_id);
     if(mesh_ptr == NULL) return JS_EXCEPTION;
     Mesh mesh = *mesh_ptr;
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * fileName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = ExportMesh(mesh, fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -6657,7 +6657,7 @@ static JSValue js_setMasterVolume(JSContext * ctx, JSValueConst this_val, int ar
 }
 
 static JSValue js_loadWave(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Wave returnVal = LoadWave(fileName);
     JS_FreeCString(ctx, fileName);
     Wave* ret_ptr = (Wave*)js_malloc(ctx, sizeof(Wave));
@@ -6668,7 +6668,7 @@ static JSValue js_loadWave(JSContext * ctx, JSValueConst this_val, int argc, JSV
 }
 
 static JSValue js_loadWaveFromMemory(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileType = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileType = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     size_t fileData_size;
     void * fileData_js = (void *)JS_GetArrayBuffer(ctx, &fileData_size, argv[1]);
     if(fileData_js == NULL) {
@@ -6698,7 +6698,7 @@ static JSValue js_isWaveReady(JSContext * ctx, JSValueConst this_val, int argc,
 }
 
 static JSValue js_loadSound(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Sound returnVal = LoadSound(fileName);
     JS_FreeCString(ctx, fileName);
     Sound* ret_ptr = (Sound*)js_malloc(ctx, sizeof(Sound));
@@ -6767,7 +6767,7 @@ static JSValue js_exportWave(JSContext * ctx, JSValueConst this_val, int argc, J
     Wave* wave_ptr = (Wave*)JS_GetOpaque2(ctx, argv[0], js_Wave_class_id);
     if(wave_ptr == NULL) return JS_EXCEPTION;
     Wave wave = *wave_ptr;
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * fileName = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = ExportWave(wave, fileName);
     JS_FreeCString(ctx, fileName);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -6885,7 +6885,7 @@ static JSValue js_waveFormat(JSContext * ctx, JSValueConst this_val, int argc, J
 }
 
 static JSValue js_loadMusicStream(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     Music returnVal = LoadMusicStream(fileName);
     JS_FreeCString(ctx, fileName);
     Music* ret_ptr = (Music*)js_malloc(ctx, sizeof(Music));
@@ -8769,7 +8769,7 @@ static JSValue js_guiWindowBox(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * title = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * title = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = GuiWindowBox(bounds, title);
     JS_FreeCString(ctx, title);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -8780,7 +8780,7 @@ static JSValue js_guiGroupBox(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiGroupBox(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -8790,7 +8790,7 @@ static JSValue js_guiLine(JSContext * ctx, JSValueConst this_val, int argc, JSVa
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiLine(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -8800,7 +8800,7 @@ static JSValue js_guiPanel(JSContext * ctx, JSValueConst this_val, int argc, JSV
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiPanel(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -8810,7 +8810,7 @@ static JSValue js_guiScrollPanel(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Rectangle* content_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[2], js_Rectangle_class_id);
     if(content_ptr == NULL) return JS_EXCEPTION;
     Rectangle content = *content_ptr;
@@ -8829,7 +8829,7 @@ static JSValue js_guiLabel(JSContext * ctx, JSValueConst this_val, int argc, JSV
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiLabel(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -8839,7 +8839,7 @@ static JSValue js_guiButton(JSContext * ctx, JSValueConst this_val, int argc, JS
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = GuiButton(bounds, text);
     JS_FreeCString(ctx, text);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -8850,7 +8850,7 @@ static JSValue js_guiLabelButton(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool returnVal = GuiLabelButton(bounds, text);
     JS_FreeCString(ctx, text);
     JSValue ret = JS_NewBool(ctx, returnVal);
@@ -8861,7 +8861,7 @@ static JSValue js_guiToggle(JSContext * ctx, JSValueConst this_val, int argc, JS
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool active = JS_ToBool(ctx, argv[2]);
     bool returnVal = GuiToggle(bounds, text, active);
     JS_FreeCString(ctx, text);
@@ -8873,7 +8873,7 @@ static JSValue js_guiToggleGroup(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int active;
     JS_ToInt32(ctx, &active, argv[2]);
     int returnVal = GuiToggleGroup(bounds, text, active);
@@ -8886,7 +8886,7 @@ static JSValue js_guiCheckBox(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     bool checked = JS_ToBool(ctx, argv[2]);
     bool returnVal = GuiCheckBox(bounds, text, checked);
     JS_FreeCString(ctx, text);
@@ -8898,7 +8898,7 @@ static JSValue js_guiComboBox(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int active;
     JS_ToInt32(ctx, &active, argv[2]);
     int returnVal = GuiComboBox(bounds, text, active);
@@ -8911,9 +8911,11 @@ static JSValue js_guiDropdownBox(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int active_out;
     int * active = &active_out;
+    JSValue active_js = JS_GetPropertyStr(ctx, argv[2], "active");
+    JS_ToInt32(ctx, active, active_js);
     bool editMode = JS_ToBool(ctx, argv[3]);
     bool returnVal = GuiDropdownBox(bounds, text, active, editMode);
     JS_FreeCString(ctx, text);
@@ -8926,9 +8928,11 @@ static JSValue js_guiSpinner(JSContext * ctx, JSValueConst this_val, int argc, J
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int value_out;
     int * value = &value_out;
+    JSValue value_js = JS_GetPropertyStr(ctx, argv[2], "value");
+    JS_ToInt32(ctx, value, value_js);
     int minValue;
     JS_ToInt32(ctx, &minValue, argv[3]);
     int maxValue;
@@ -8945,9 +8949,11 @@ static JSValue js_guiValueBox(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int value_out;
     int * value = &value_out;
+    JSValue value_js = JS_GetPropertyStr(ctx, argv[2], "value");
+    JS_ToInt32(ctx, value, value_js);
     int minValue;
     JS_ToInt32(ctx, &minValue, argv[3]);
     int maxValue;
@@ -8964,8 +8970,8 @@ static JSValue js_guiSlider(JSContext * ctx, JSValueConst this_val, int argc, JS
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * textLeft = (const char *)JS_ToCString(ctx, argv[1]);
-    const char * textRight = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * textLeft = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
+    const char * textRight = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     double _double_value;
     JS_ToFloat64(ctx, &_double_value, argv[3]);
     float value = (float)_double_value;
@@ -8986,8 +8992,8 @@ static JSValue js_guiSliderBar(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * textLeft = (const char *)JS_ToCString(ctx, argv[1]);
-    const char * textRight = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * textLeft = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
+    const char * textRight = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     double _double_value;
     JS_ToFloat64(ctx, &_double_value, argv[3]);
     float value = (float)_double_value;
@@ -9008,8 +9014,8 @@ static JSValue js_guiProgressBar(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * textLeft = (const char *)JS_ToCString(ctx, argv[1]);
-    const char * textRight = (const char *)JS_ToCString(ctx, argv[2]);
+    const char * textLeft = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
+    const char * textRight = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
     double _double_value;
     JS_ToFloat64(ctx, &_double_value, argv[3]);
     float value = (float)_double_value;
@@ -9030,7 +9036,7 @@ static JSValue js_guiStatusBar(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiStatusBar(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -9040,7 +9046,7 @@ static JSValue js_guiDummyRec(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     GuiDummyRec(bounds, text);
     JS_FreeCString(ctx, text);
     return JS_UNDEFINED;
@@ -9050,7 +9056,7 @@ static JSValue js_guiGrid(JSContext * ctx, JSValueConst this_val, int argc, JSVa
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     double _double_spacing;
     JS_ToFloat64(ctx, &_double_spacing, argv[2]);
     float spacing = (float)_double_spacing;
@@ -9069,9 +9075,11 @@ static JSValue js_guiListView(JSContext * ctx, JSValueConst this_val, int argc,
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     int scrollIndex_out;
     int * scrollIndex = &scrollIndex_out;
+    JSValue scrollIndex_js = JS_GetPropertyStr(ctx, argv[2], "scrollIndex");
+    JS_ToInt32(ctx, scrollIndex, scrollIndex_js);
     int active;
     JS_ToInt32(ctx, &active, argv[3]);
     int returnVal = GuiListView(bounds, text, scrollIndex, active);
@@ -9085,9 +9093,9 @@ static JSValue js_guiMessageBox(JSContext * ctx, JSValueConst this_val, int argc
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * title = (const char *)JS_ToCString(ctx, argv[1]);
-    const char * message = (const char *)JS_ToCString(ctx, argv[2]);
-    const char * buttons = (const char *)JS_ToCString(ctx, argv[3]);
+    const char * title = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
+    const char * message = JS_IsNull(argv[2]) ? NULL : (const char *)JS_ToCString(ctx, argv[2]);
+    const char * buttons = JS_IsNull(argv[3]) ? NULL : (const char *)JS_ToCString(ctx, argv[3]);
     int returnVal = GuiMessageBox(bounds, title, message, buttons);
     JS_FreeCString(ctx, title);
     JS_FreeCString(ctx, message);
@@ -9100,7 +9108,7 @@ static JSValue js_guiColorPicker(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Color* color_ptr = (Color*)JS_GetOpaque2(ctx, argv[2], js_Color_class_id);
     if(color_ptr == NULL) return JS_EXCEPTION;
     Color color = *color_ptr;
@@ -9117,7 +9125,7 @@ static JSValue js_guiColorPanel(JSContext * ctx, JSValueConst this_val, int argc
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     Color* color_ptr = (Color*)JS_GetOpaque2(ctx, argv[2], js_Color_class_id);
     if(color_ptr == NULL) return JS_EXCEPTION;
     Color color = *color_ptr;
@@ -9134,7 +9142,7 @@ static JSValue js_guiColorBarAlpha(JSContext * ctx, JSValueConst this_val, int a
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     double _double_alpha;
     JS_ToFloat64(ctx, &_double_alpha, argv[2]);
     float alpha = (float)_double_alpha;
@@ -9148,7 +9156,7 @@ static JSValue js_guiColorBarHue(JSContext * ctx, JSValueConst this_val, int arg
     Rectangle* bounds_ptr = (Rectangle*)JS_GetOpaque2(ctx, argv[0], js_Rectangle_class_id);
     if(bounds_ptr == NULL) return JS_EXCEPTION;
     Rectangle bounds = *bounds_ptr;
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     double _double_value;
     JS_ToFloat64(ctx, &_double_value, argv[2]);
     float value = (float)_double_value;
@@ -9159,7 +9167,7 @@ static JSValue js_guiColorBarHue(JSContext * ctx, JSValueConst this_val, int arg
 }
 
 static JSValue js_guiLoadStyle(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * fileName = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * fileName = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     GuiLoadStyle(fileName);
     JS_FreeCString(ctx, fileName);
     return JS_UNDEFINED;
@@ -9181,7 +9189,7 @@ static JSValue js_guiDisableTooltip(JSContext * ctx, JSValueConst this_val, int
 }
 
 static JSValue js_guiSetTooltip(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
-    const char * tooltip = (const char *)JS_ToCString(ctx, argv[0]);
+    const char * tooltip = JS_IsNull(argv[0]) ? NULL : (const char *)JS_ToCString(ctx, argv[0]);
     GuiSetTooltip(tooltip);
     JS_FreeCString(ctx, tooltip);
     return JS_UNDEFINED;
@@ -9190,7 +9198,7 @@ static JSValue js_guiSetTooltip(JSContext * ctx, JSValueConst this_val, int argc
 static JSValue js_guiIconText(JSContext * ctx, JSValueConst this_val, int argc, JSValueConst * argv) {
     int iconId;
     JS_ToInt32(ctx, &iconId, argv[0]);
-    const char * text = (const char *)JS_ToCString(ctx, argv[1]);
+    const char * text = JS_IsNull(argv[1]) ? NULL : (const char *)JS_ToCString(ctx, argv[1]);
     const char * returnVal = GuiIconText(iconId, text);
     JS_FreeCString(ctx, text);
     JSValue ret = JS_NewString(ctx, returnVal);