From 6d256761457d21aa68f9cd1406178d0da122b2a9 Mon Sep 17 00:00:00 2001
From: NickHardeman <nickhardeman@gmail.com>
Date: Fri, 20 Mar 2026 11:21:28 -0400
Subject: [PATCH] urlFileLoader progress function

---
 libs/openFrameworks/utils/ofURLFileLoader.cpp | 22 +++++++++++++++++++
 libs/openFrameworks/utils/ofURLFileLoader.h   |  1 +
 2 files changed, 23 insertions(+)

diff --git a/libs/openFrameworks/utils/ofURLFileLoader.cpp b/libs/openFrameworks/utils/ofURLFileLoader.cpp
index 81fce02e52e..c6ce82c8380 100644
--- a/libs/openFrameworks/utils/ofURLFileLoader.cpp
+++ b/libs/openFrameworks/utils/ofURLFileLoader.cpp
@@ -299,6 +299,21 @@ size_t readBody_cb(void * ptr, size_t size, size_t nmemb, void * userdata) {
 	}
 	return 0; /* no more data left to deliver */
 }
+int progress_cb(void* ptr, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow) {
+	auto & request = *static_cast<ofHttpRequest*>(ptr);
+	if (request.progressCallback) {
+		float progress = 0.0f;
+		if (request.method == ofHttpRequest::GET && dltotal > 0) {
+			progress = (float)dlnow / (float)dltotal;
+			// note: we may want to support upload and download for POST
+		} else if ((request.method == ofHttpRequest::PUT || request.method == ofHttpRequest::POST) && ultotal > 0) {
+			progress = (float)ulnow / (float)ultotal;
+		}
+		
+		request.progressCallback(request, progress);
+	}
+	return 0;
+}
 }
 
 ofHttpResponse ofURLFileLoaderImpl::handleRequest(const ofHttpRequest & request) {
@@ -412,6 +427,13 @@ ofHttpResponse ofURLFileLoaderImpl::handleRequest(const ofHttpRequest & request)
 	// start request and receive response
 	ofHttpResponse response(request, 0, "");
 	CURLcode err = CURLE_OK;
+	
+	if (request.progressCallback) {
+		curl_easy_setopt(curl.get(), CURLOPT_XFERINFOFUNCTION, progress_cb);
+		curl_easy_setopt(curl.get(), CURLOPT_XFERINFODATA, &request);
+		curl_easy_setopt(curl.get(), CURLOPT_NOPROGRESS, 0L);
+	}
+	
 	if (request.saveTo) {
 		ofFile saveTo(request.name, ofFile::WriteOnly, true);
 		curl_easy_setopt(curl.get(), CURLOPT_WRITEDATA, &saveTo);
diff --git a/libs/openFrameworks/utils/ofURLFileLoader.h b/libs/openFrameworks/utils/ofURLFileLoader.h
index 1d73cb878cb..1e33f162cbd 100644
--- a/libs/openFrameworks/utils/ofURLFileLoader.h
+++ b/libs/openFrameworks/utils/ofURLFileLoader.h
@@ -23,6 +23,7 @@ class ofHttpRequest {
 	std::string body; ///< POST body data
 	std::string contentType; ///< POST data mime type
 	std::function<void(const ofHttpResponse &)> done;
+	std::function<void(const ofHttpRequest &, float)> progressCallback = nullptr; ///< pass a function for progress of download
 	size_t timeoutSeconds = 0;
 	bool headerOnly = false;