chainImageSet and threadedChainImageLoader

1 files changed, 99 insertions, 0 deletions

diff --git a/gui/src/threadedChainImageLoader.cpp b/gui/src/threadedChainImageLoader.cpp
new file mode 100644
index 0000000..ba3dd26
--- /dev/null
+++ b/gui/src/threadedChainImageLoader.cpp
@@ -0,0 +1,99 @@
+#include "threadedChainImageLoader.h"
+#include <sstream>
+
+threadedChainImageLoader::threadedChainImageLoader(){
+	nextID = 0;
+    ofAddListener(ofEvents().update, this, &threadedChainImageLoader::update);
+	ofAddListener(ofURLResponseEvent(),this,&threadedChainImageLoader::urlResponse);
+    
+    startThread();
+    lastUpdate = 0;
+}
+
+threadedChainImageLoader::~threadedChainImageLoader(){
+	images_to_load_from_disk.close();
+	images_to_update.close();
+	waitForThread(true);
+    ofRemoveListener(ofEvents().update, this, &threadedChainImageLoader::update);
+	ofRemoveListener(ofURLResponseEvent(),this,&threadedChainImageLoader::urlResponse);
+}
+
+// Load an image from disk.
+//--------------------------------------------------------------
+void threadedChainImageLoader::loadFromDisk(chainImage& image, string filename) {
+	nextID++;
+	chainImageLoaderEntry entry(image);
+	entry.filename = filename;
+	entry.image->setUseTexture(false);
+	entry.name = filename;
+    
+	images_to_load_from_disk.send(entry);
+}
+
+
+// Load an url asynchronously from an url.
+//--------------------------------------------------------------
+void threadedChainImageLoader::loadFromURL(chainImage& image, string url) {
+	nextID++;
+	chainImageLoaderEntry entry(image);
+	entry.url = url;
+	entry.image->setUseTexture(false);	
+	entry.name = "image" + ofToString(nextID);
+	images_async_loading[entry.name] = entry;
+	ofLoadURLAsync(entry.url, entry.name);
+}
+
+
+// Reads from the queue and loads new images.
+//--------------------------------------------------------------
+void threadedChainImageLoader::threadedFunction() {
+	setThreadName("threadedChainImageLoader " + ofToString(thread.get_id()));
+	chainImageLoaderEntry entry;
+	while( images_to_load_from_disk.receive(entry) ) {
+		if(entry.image->load(entry.filename) )  {
+			images_to_update.send(entry);
+		}else{
+			ofLogError("threadedChainImageLoader") << "couldn't load file: \"" << entry.filename << "\"";
+		}
+	}
+	ofLogVerbose("threadedChainImageLoader") << "finishing thread on closed queue";
+}
+
+
+// When we receive an url response this method is called; 
+// The loaded image is removed from the async_queue and added to the
+// update queue. The update queue is used to update the texture.
+//--------------------------------------------------------------
+void threadedChainImageLoader::urlResponse(ofHttpResponse & response) {
+	// this happens in the update thread so no need to lock to access
+	// images_async_loading
+	entry_iterator it = images_async_loading.find(response.request.name);
+	if(response.status == 200) {
+		if(it != images_async_loading.end()) {
+			it->second.image->load(response.data);
+			images_to_update.send(it->second);
+		}
+	}else{
+		// log error.
+		ofLogError("threadedChainImageLoader") << "couldn't load url, response status: " << response.status;
+		ofRemoveURLRequest(response.request.getID());
+	}
+
+	// remove the entry from the queue
+	if(it != images_async_loading.end()) {
+		images_async_loading.erase(it);
+	}
+}
+
+
+// Check the update queue and update the texture
+//--------------------------------------------------------------
+void threadedChainImageLoader::update(ofEventArgs & a){
+    // Load 1 image per update so we don't block the gl thread for too long
+	chainImageLoaderEntry entry;
+	if (images_to_update.tryReceive(entry)) {
+		entry.image->setUseTexture(true);
+		entry.image->update();
+	}
+}
+