Multi-canvas rendering (love.graphics.setCanvas with multiple canvases) now allows canvases with different formats, if the system supports it. Added 'multicanvasformats' to the table returned by love.graphics.getSupported.

--HG--
branch : minor

src/modules/graphics/opengl/Canvas.cpp

@@ -416,19 +416,21 @@ void Canvas::startGrab(const std::vector<Canvas *> &canvases)
 			throw love::Exception("Multi-canvas rendering is not supported on this system.");
 
 		if ((int) canvases.size() + 1 > gl.getMaxRenderTargets())
-			throw love::Exception("This system can't simultaniously render to %d canvases.", canvases.size()+1);
+			throw love::Exception("This system can't simultaneously render to %d canvases.", canvases.size()+1);
 
 		if (actual_samples != 0)
 			throw love::Exception("Multi-canvas rendering is not supported with MSAA.");
 	}
 
+	bool multiformatsupported = isMultiFormatMultiCanvasSupported();
+
 	for (size_t i = 0; i < canvases.size(); i++)
 	{
 		if (canvases[i]->getWidth() != width || canvases[i]->getHeight() != height)
-			throw love::Exception("All canvas arguments must have the same dimensions.");
+			throw love::Exception("All canvases must have the same dimensions.");
 
-		if (canvases[i]->getTextureFormat() != format)
-			throw love::Exception("All canvas arguments must have the same texture format.");
+		if (canvases[i]->getTextureFormat() != format && !multiformatsupported)
+			throw love::Exception("This system doesn't support multi-canvas rendering with different canvas formats.");
 
 		if (canvases[i]->getMSAA() != 0)
 			throw love::Exception("Multi-canvas rendering is not supported with MSAA.");
@@ -785,6 +787,11 @@ bool Canvas::isMultiCanvasSupported()
 	return gl.getMaxRenderTargets() >= 4;
 }
 
+bool Canvas::isMultiFormatMultiCanvasSupported()
+{
+	return isMultiCanvasSupported() && (GLAD_ES_VERSION_3_0 || GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object);
+}
+
 bool Canvas::supportedFormats[] = {false};
 bool Canvas::checkedFormats[] = {false};
 

src/modules/graphics/opengl/Canvas.h

@@ -119,6 +119,7 @@ public:
 
 	static bool isSupported();
 	static bool isMultiCanvasSupported();
+	static bool isMultiFormatMultiCanvasSupported();
 	static bool isFormatSupported(Format format);
 
 	static Canvas *current;

src/modules/graphics/opengl/Graphics.cpp

@@ -1336,6 +1336,8 @@ bool Graphics::isSupported(Support feature) const
 	{
 	case SUPPORT_MULTI_CANVAS:
 		return Canvas::isMultiCanvasSupported();
+	case SUPPORT_MULTI_CANVAS_FORMATS:
+		return Canvas::isMultiFormatMultiCanvasSupported();
 	case SUPPORT_SRGB:
 		// sRGB support for the screen is guaranteed if it's supported as a
 		// Canvas format.