Qt: Initial shader editor support

include/renderer.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <array>
 #include <span>
+#include <string>
 #include <optional>
 
 #include "PICA/pica_vertex.hpp"
@@ -66,6 +67,13 @@ class Renderer {
 	// This function does things like write back or cache necessary state before we delete our context
 	virtual void deinitGraphicsContext() = 0;
 
+	// Functions for hooking up the renderer core to the frontend's shader editor for editing ubershaders in real time
+	// SupportsShaderReload: Indicates whether the backend offers ubershader reload support or not
+	// GetUbershader/SetUbershader: Gets or sets the renderer's current ubershader
+	virtual bool supportsShaderReload() { return false; }
+	virtual std::string getUbershader() { return ""; }
+	virtual void setUbershader(const std::string& shader) {}
+
 	// Functions for initializing the graphics context for the Qt frontend, where we don't have the convenience of SDL_Window
 #ifdef PANDA3DS_FRONTEND_QT
 	virtual void initGraphicsContext(GL::Context* context) { Helpers::panic("Tried to initialize incompatible renderer with GL context"); }