Add ability to configure which renderers are used by love.graphics.

- Add t.renderers and t.excluderenderers love.conf fields. They can be an array of renderer names.
- Add --renderers a,list,of,renderernames and --excluderenderers more,renderers argument options.

src/modules/graphics/Graphics.cpp

@@ -110,7 +110,30 @@ namespace opengl { extern love::graphics::Graphics *createInstance(); }
 namespace metal { extern love::graphics::Graphics *createInstance(); }
 #endif
 
-Graphics *Graphics::createInstance(const std::vector<Renderer> &renderers)
+static std::vector<Renderer> defaultRenderers =
+{
+	RENDERER_METAL,
+	RENDERER_OPENGL,
+};
+
+static std::vector<Renderer> _renderers = defaultRenderers;
+
+const std::vector<Renderer> &getDefaultRenderers()
+{
+	return defaultRenderers;
+}
+
+const std::vector<Renderer> &getRenderers()
+{
+	return _renderers;
+}
+
+void setRenderers(const std::vector<Renderer> &renderers)
+{
+	_renderers = renderers;
+}
+
+Graphics *Graphics::createInstance()
 {
 	Graphics *instance = Module::getInstance<Graphics>(M_GRAPHICS);
 
@@ -118,7 +141,7 @@ Graphics *Graphics::createInstance(const std::vector<Renderer> &renderers)
 		instance->retain();
 	else
 	{
-		for (auto renderer : renderers)
+		for (auto renderer : _renderers)
 		{
 			if (renderer == RENDERER_OPENGL)
 				instance = opengl::createInstance();
@@ -2147,5 +2170,12 @@ STRINGMAP_CLASS_BEGIN(Graphics, Graphics::StackType, Graphics::STACK_MAX_ENUM, s
 }
 STRINGMAP_CLASS_END(Graphics, Graphics::StackType, Graphics::STACK_MAX_ENUM, stackType)
 
+STRINGMAP_BEGIN(Renderer, RENDERER_MAX_ENUM, renderer)
+{
+	{ "opengl", RENDERER_OPENGL },
+	{ "metal",  RENDERER_METAL  },
+}
+STRINGMAP_END(Renderer, RENDERER_MAX_ENUM, renderer)
+
 } // graphics
 } // love

src/modules/graphics/Graphics.h

@@ -65,6 +65,14 @@ typedef Optional<ColorD> OptionalColorD;
 
 const int MAX_COLOR_RENDER_TARGETS = 8;
 
+enum Renderer
+{
+	RENDERER_NONE,
+	RENDERER_OPENGL,
+	RENDERER_METAL,
+	RENDERER_MAX_ENUM
+};
+
 /**
  * Globally sets whether gamma correction is enabled. Ideally this should be set
  * prior to using any Graphics module function.
@@ -95,6 +103,10 @@ Colorf unGammaCorrectColor(const Colorf &c);
 
 bool isDebugEnabled();
 
+const std::vector<Renderer> &getDefaultRenderers();
+const std::vector<Renderer> &getRenderers();
+void setRenderers(const std::vector<Renderer> &renderers);
+
 class Graphics : public Module
 {
 public:
@@ -151,14 +163,6 @@ public:
 		FEATURE_MAX_ENUM
 	};
 
-	enum Renderer
-	{
-		RENDERER_NONE,
-		RENDERER_OPENGL,
-		RENDERER_METAL,
-		RENDERER_MAX_ENUM
-	};
-
 	enum SystemLimit
 	{
 		LIMIT_POINT_SIZE,
@@ -860,7 +864,7 @@ public:
 		return (T *) scratchBuffer.data();
 	}
 
-	static Graphics *createInstance(const std::vector<Renderer> &renderers);
+	static Graphics *createInstance();
 
 	STRINGMAP_CLASS_DECLARE(DrawMode);
 	STRINGMAP_CLASS_DECLARE(ArcMode);
@@ -1016,6 +1020,8 @@ private:
 
 }; // Graphics
 
+STRINGMAP_DECLARE(Renderer);
+
 } // graphics
 } // love
 

src/modules/graphics/metal/Graphics.mm

@@ -2016,7 +2016,7 @@ bool Graphics::isPixelFormatSupported(PixelFormat format, PixelFormatUsageFlags
 	return (usage & flags) == usage;
 }
 
-Graphics::Renderer Graphics::getRenderer() const
+Renderer Graphics::getRenderer() const
 {
 	return RENDERER_METAL;
 }

src/modules/graphics/opengl/Graphics.cpp

@@ -1599,7 +1599,7 @@ void Graphics::releaseBufferMapMemory(void *mem)
 		free(mem);
 }
 
-Graphics::Renderer Graphics::getRenderer() const
+Renderer Graphics::getRenderer() const
 {
 	return RENDERER_OPENGL;
 }

src/modules/graphics/wrap_Graphics.cpp

@@ -3697,16 +3697,7 @@ static const lua_CFunction types[] =
 
 extern "C" int luaopen_love_graphics(lua_State *L)
 {
-	Graphics *instance = nullptr;
-
-	{
-		std::vector<Graphics::Renderer> renderers;
-#if defined(LOVE_MACOS) || defined(LOVE_IOS)
-		renderers.push_back(Graphics::RENDERER_METAL);
-#endif
-		renderers.push_back(Graphics::RENDERER_OPENGL);
-		instance = Graphics::createInstance(renderers);
-	}
+	Graphics *instance = Graphics::createInstance();
 
 	if (instance == nullptr)
 	{