Added love.touch.getPressure(touchid). Not useful on most touch-capable devices, but I do expect Apple's Force Touch to make it into iPhones in the near future.

src/modules/touch/sdl/Touch.cpp

@@ -51,6 +51,15 @@ void Touch::getPosition(int64 id, double &x, double &y) const
 	y = it->second.y;
 }
 
+double Touch::getPressure(int64 id) const
+{
+	const auto it = touches.find(id);
+	if (it == touches.end())
+		throw love::Exception("Invalid active touch ID: %d", id);
+
+	return it->second.pressure;
+}
+
 const char *Touch::getName() const
 {
 	return "love.touch.sdl";

src/modules/touch/sdl/Touch.h

@@ -43,11 +43,12 @@ public:
 
 	virtual ~Touch() {}
 
-	virtual std::vector<int64> getIDs() const;
-	virtual void getPosition(int64 id, double &x, double &y) const;
+	std::vector<int64> getIDs() const override;
+	void getPosition(int64 id, double &x, double &y) const override;
+	double getPressure(int64 id) const override;
 
 	// Implements Module.
-	virtual const char *getName() const;
+	const char *getName() const override;
 
 	// SDL has functions to query the state of touch presses, but unfortunately
 	// they are updated on a different thread in some backends, which causes