Initial commit

input/gesture_detector.cpp

@@ -0,0 +1,68 @@
+// Unfinished.
+// TODO:
+// Zoom gesture a la http://www.zdnet.com/blog/burnette/how-to-use-multi-touch-in-android-2-part-6-implementing-the-pinch-zoom-gesture/1847
+
+#include "input/gesture_detector.h"
+
+namespace GestureDetector {
+
+struct Finger {
+	bool down;
+	float X;
+	float Y;
+	float lastX;
+	float lastY;
+	float downX;
+	float downY;
+	float deltaX;
+	float deltaY;
+	float smoothDeltaX;
+	float smoothDeltaY;
+};
+
+// State
+#define MAX_FINGERS 4
+
+static Finger fingers[MAX_FINGERS];
+
+void update(const InputState &state) {
+	// Mouse / 1-finger-touch control.
+	if (state.mouse_buttons_down & 1) {
+		fingers[0].down = true;
+		fingers[0].downX = state.mouse_x;
+		fingers[0].downY = state.mouse_y;
+	} else {
+		fingers[0].down = false;
+	}
+
+	fingers[0].lastX = fingers[0].X;
+	fingers[0].lastY = fingers[0].Y;
+
+	// TODO: real multitouch
+}
+
+bool down(int i, float *xdelta, float *ydelta) {
+	if (!fingers[i].down) {
+		return false;
+	}
+	*xdelta = fingers[i].downX;
+	*ydelta = fingers[i].downY;
+}
+
+bool dragDistance(int i, float *xdelta, float *ydelta) {
+	if (!fingers[i].down)
+		return false;
+
+	*xdelta = fingers[i].X - fingers[i].downX;
+	*ydelta = fingers[i].Y - fingers[i].downY;
+}
+
+bool dragDelta(int i, float *xdelta, float *ydelta) {
+	if (!fingers[i].down)
+		return false;
+
+	*xdelta = fingers[i].X - fingers[i].lastX;
+	*ydelta = fingers[i].Y - fingers[i].lastY;
+}
+
+}