Add callbacks to override render state for flat renderer.

renderer/flat_renderer.cpp

@@ -88,6 +88,16 @@ void FlatRenderer::begin()
 	queue.set_shader_suites(suite);
 }
 
+void FlatRenderer::set_opaque_state_callback(std::function<void (Vulkan::CommandBuffer &)> cb)
+{
+	opaque_state_cb = std::move(cb);
+}
+
+void FlatRenderer::set_transparent_state_callback(std::function<void (Vulkan::CommandBuffer &)> cb)
+{
+	transparent_state_cb = std::move(cb);
+}
+
 void FlatRenderer::flush(Vulkan::CommandBuffer &cmd, const vec3 &camera_pos, const vec3 &camera_size)
 {
 	struct GlobalData
@@ -108,13 +118,21 @@ void FlatRenderer::flush(Vulkan::CommandBuffer &cmd, const vec3 &camera_pos, con
 
 	queue.sort();
 
-	cmd.set_opaque_sprite_state();
+	if (opaque_state_cb)
+		opaque_state_cb(cmd);
+	else
+		cmd.set_opaque_sprite_state();
+
 	CommandBufferSavedState state = {};
 	cmd.save_state(COMMAND_BUFFER_SAVED_SCISSOR_BIT | COMMAND_BUFFER_SAVED_VIEWPORT_BIT | COMMAND_BUFFER_SAVED_RENDER_STATE_BIT, state);
 	queue.dispatch(Queue::Opaque, cmd, &state);
 	queue.dispatch(Queue::OpaqueEmissive, cmd, &state);
 
-	cmd.set_transparent_sprite_state();
+	if (transparent_state_cb)
+		transparent_state_cb(cmd);
+	else
+		cmd.set_transparent_sprite_state();
+
 	cmd.save_state(COMMAND_BUFFER_SAVED_SCISSOR_BIT | COMMAND_BUFFER_SAVED_VIEWPORT_BIT | COMMAND_BUFFER_SAVED_RENDER_STATE_BIT, state);
 	queue.dispatch(Queue::Transparent, cmd, &state);
 }

renderer/flat_renderer.hpp

@@ -26,6 +26,7 @@
 #include "renderer.hpp"
 #include "sprite.hpp"
 #include <vector>
+#include <functional>
 
 namespace Granite
 {
@@ -99,6 +100,9 @@ class FlatRenderer : public EventHandler
 	void push_scissor(const vec2 &offset, const vec2 &size);
 	void pop_scissor();
 
+	void set_opaque_state_callback(std::function<void (Vulkan::CommandBuffer &)> cb);
+	void set_transparent_state_callback(std::function<void (Vulkan::CommandBuffer &)> cb);
+
 	Vulkan::Device &get_device();
 
 private:
@@ -109,6 +113,9 @@ class FlatRenderer : public EventHandler
 	RenderQueue queue;
 	ShaderSuite suite[Util::ecast(RenderableType::Count)];
 
+	std::function<void (Vulkan::CommandBuffer &)> opaque_state_cb;
+	std::function<void (Vulkan::CommandBuffer &)> transparent_state_cb;
+
 	struct Scissor
 	{
 		vec2 offset;

ui/ui_manager.hpp

@@ -62,6 +62,11 @@ class UIManager final : public EventHandler, public UIManagerInterface
 	void reset_children();
 	void remove_child(Widget *widget);
 
+	inline FlatRenderer &get_flat_renderer()
+	{
+		return renderer;
+	}
+
 private:
 	FlatRenderer renderer;
 	std::vector<WidgetHandle> widgets;