From b95aa29809038b39e6729f4e53af0dfb545bfcdc Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 12 Nov 2021 21:36:05 +0200
Subject: [PATCH] Move a few bits of Renderer into a backend class

This allows the upcoming Vulkan backend to take care of submitting
command buffers.
---
 source/backends/opengl/renderer_backend.cpp | 13 ++++++++++++
 source/backends/opengl/renderer_backend.h   | 23 +++++++++++++++++++++
 source/render/renderer.cpp                  |  7 +++++--
 source/render/renderer.h                    |  7 ++++---
 4 files changed, 45 insertions(+), 5 deletions(-)
 create mode 100644 source/backends/opengl/renderer_backend.cpp
 create mode 100644 source/backends/opengl/renderer_backend.h

diff --git a/source/backends/opengl/renderer_backend.cpp b/source/backends/opengl/renderer_backend.cpp
new file mode 100644
index 00000000..e49f6ce6
--- /dev/null
+++ b/source/backends/opengl/renderer_backend.cpp
@@ -0,0 +1,13 @@
+#include "renderer.h"
+#include "renderer_backend.h"
+
+namespace Msp {
+namespace GL {
+
+void OpenGLRenderer::end()
+{
+	static_cast<Renderer *>(this)->commands.use_pipeline(0);
+}
+
+} // namespace GL
+} // namespace Msp
diff --git a/source/backends/opengl/renderer_backend.h b/source/backends/opengl/renderer_backend.h
new file mode 100644
index 00000000..f6f7334b
--- /dev/null
+++ b/source/backends/opengl/renderer_backend.h
@@ -0,0 +1,23 @@
+#ifndef MSP_GL_RENDERER_BACKEND_H_
+#define MSP_GL_RENDERER_BACKEND_H_
+
+#include "pipelinestate.h"
+
+namespace Msp {
+namespace GL {
+
+class OpenGLRenderer
+{
+protected:
+	PipelineState pipeline_state;
+
+	void begin() { }
+	void end();
+};
+
+using RendererBackend = OpenGLRenderer;
+
+} // namespace GL
+} // namespace Msp
+
+#endif
diff --git a/source/render/renderer.cpp b/source/render/renderer.cpp
index 999ff1a2..6c8f1b67 100644
--- a/source/render/renderer.cpp
+++ b/source/render/renderer.cpp
@@ -38,6 +38,9 @@ void Renderer::begin()
 
 	state_stack.push_back(State());
 	current_state = &state_stack.back();
+
+	RendererBackend::begin();
+
 	add_shader_data(standard_shdata);
 }
 
@@ -46,12 +49,12 @@ void Renderer::end()
 	if(!current_state || state_stack.size()>1)
 		throw invalid_operation("Renderer::end");
 
+	RendererBackend::end();
+
 	current_state = 0;
 	state_stack.clear();
 	texture_stack.clear();
 	shdata_stack.clear();
-
-	commands.use_pipeline(0);
 }
 
 void Renderer::push_state()
diff --git a/source/render/renderer.h b/source/render/renderer.h
index 575dbe67..a0b4e75f 100644
--- a/source/render/renderer.h
+++ b/source/render/renderer.h
@@ -5,8 +5,8 @@
 #include <vector>
 #include "commands.h"
 #include "matrix.h"
-#include "pipelinestate.h"
 #include "programdata.h"
+#include "renderer_backend.h"
 #include "tag.h"
 
 namespace Msp {
@@ -39,8 +39,10 @@ Renderables can save the state by pushing it on the stack before beginning
 their work, and pop it afterwards to restore it without disturbing state set
 by outer scopes.
 */
-class Renderer
+class Renderer: public RendererBackend
 {
+	friend RendererBackend;
+
 public:
 	/**
 	RAII helper class for pushing state on the stack.
@@ -104,7 +106,6 @@ private:
 	ProgramData standard_shdata;
 	std::vector<BoundProgramData> shdata_stack;
 	std::vector<BoundTexture> texture_stack;
-	PipelineState pipeline_state;
 	Commands commands;
 
 public:
-- 
2.43.0