[orx-panel] Fix creation of 0x0 render target on window minimization

orx-panel/src/main/kotlin/org/openrndr/panel/ControlManager.kt

@@ -361,8 +361,9 @@ class ControlManager : Extension {
         this.width = width
         this.height = height
 
+        // check if user did not minimize window
+        if (width > 0 && height > 0) {
             body?.draw?.dirty = true
-
             if (renderTarget.colorAttachments.isNotEmpty()) {
                 renderTarget.colorBuffer(0).destroy()
                 renderTarget.depthBuffer?.destroy()
@@ -385,6 +386,7 @@ class ControlManager : Extension {
             renderTargetCache.forEach { (_, u) -> u.destroy() }
             renderTargetCache.clear()
         }
+    }
 
     private fun drawElement(element: Element, drawer: Drawer, zIndex: Int, zComp: Int) {
         val newZComp =