some more optimizing!

now runs much better with lower power systems as we refactored code to firstly rule out double invokelaters, and we optimized the capture loop iteslf!

and we introduced a ShowError class which will be refactored and used quite thoroughly!

Signed-off-by: rattatwinko <seppmutterman@gmail.com>

src/main/java/io/swtc/proccessing/WebcamCaptureLoop.java

@@ -2,76 +2,84 @@ package io.swtc.proccessing;
 
 import com.github.sarxos.webcam.Webcam;
 import com.github.sarxos.webcam.WebcamException;
+import com.github.sarxos.webcam.WebcamResolution;
 
 import java.awt.Dimension;
 import java.awt.image.BufferedImage;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.LockSupport;
 import java.util.function.Consumer;
 import javax.swing.*;
 
+import io.swtc.proccessing.ui.ShowError;
+
 public class WebcamCaptureLoop {
     private final Webcam webcam;
     private final Consumer<BufferedImage> onFrameCaptured;
     private volatile boolean running = false;
     private final AtomicBoolean cleanedUp = new AtomicBoolean(false);
+    private final int targetframes = 20;
 
     public WebcamCaptureLoop(Webcam webcam, Consumer<BufferedImage> onFrameCaptured) {
         this.webcam = webcam;
         this.onFrameCaptured = onFrameCaptured;
 
-        // this is some of the most stupid shit ive seen in years, this is needed for opening the stream.
-        // the webcam package may not know the res before its opened and well this is before we open it. that is below in the thread.
-        // so this freaks out and doesnt want to cooperate.
-        if (!webcam.getName().toLowerCase().contains("ipcam")) {
-            Dimension[] sizes = webcam.getViewSizes();
-            webcam.setViewSize(sizes[sizes.length - 1]);
+        Dimension vga = WebcamResolution.VGA.getSize();
+        if (isSizeSupported(webcam, vga)) { // we dont do stupid shit anymore! cause we are smarter than before...
+            webcam.setViewSize(vga);
+        } else {
+            Dimension[] dimensions = webcam.getViewSizes();
+            webcam.setViewSize(dimensions[dimensions.length - 1]);
         }
     }
 
+    private boolean isSizeSupported(Webcam webcam, Dimension vga) {
+        for (Dimension d: webcam.getViewSizes()) {
+            if (
+                    d.width == vga.width && d.height == vga.height
+            ) return true; // this should return 640x480 :)
+        }
+        return false;
+    }
+
     public void start() {
         if (running) return;
         running = true;
 
         Thread captureThread = new Thread(() -> {
-            // this is where we open it. if the res isnt known then it fucks up.
             try {
-                webcam.open();
-            } catch (WebcamException e) {
-                JOptionPane.showMessageDialog(
-                        null,
-                        "WebcamException" + e.getMessage(),
-                        "WebcamException",
-                        JOptionPane.ERROR_MESSAGE
-                );
-            }
+                if (!webcam.isOpen()) webcam.open(); // open if not
 
-            while (running) {
-                BufferedImage img = webcam.getImage();
-                if (img != null) {
-                    //System.err.println(img);
-                    onFrameCaptured.accept(img);
+                long frameDurationLimitns = 1_000_000_000L / targetframes; // we use NanoSeconds cause its more accurate
+
+                while (running) {
+                    long startTime = System.nanoTime();
+
+                    BufferedImage img = webcam.getImage();
+                    if (img != null)
+                        // there is no need for a invoke later swing wise!
+                        onFrameCaptured.accept(img);
+
+                    long timespent = System.nanoTime() - startTime;
+                    long sleeptime = frameDurationLimitns - timespent;
+
+                    if (sleeptime > 0) {
+                        LockSupport.parkNanos(sleeptime);
+                    } else {
+                        // do a yield to prevent ui freezes
+                        Thread.yield();
+                    }
                 }
-
-                try {
-                    Thread.sleep(15);
-                } catch (InterruptedException e) {
-                    break;
-                }
-            }
-            try {
-                webcam.close();
-
-            } catch (IllegalStateException e) {
-                // show a error message from javax.swing.awt.JOptionPane
-                JOptionPane.showMessageDialog(
+            } catch (Exception e) {
+                ShowError.warning(
                         null,
-                        "IllegalStateException@"+e,
-                        "IllegalStateException",
-                        JOptionPane.ERROR_MESSAGE
+                        "Exception" + e,
+                        "Exception"
                 );
+            } finally {
+                cleanup();
             }
-        });
-        captureThread.setName("cam_cap_thread");
+        }, "cam_cap_thread");
         captureThread.start();
     }
 
@@ -111,6 +119,5 @@ public class WebcamCaptureLoop {
      */
     public void stop() {
         running = false;
-        cleanup();
     }
 }