var delta_horizontal_angle = 0;
var delta_vertical_angle = 0;
var delta_position = [0,0,0];


//  Use to rotate selected points about a vector line
var selection_rotation_axis = null;
var rotation_center = [0,0,0];
var zoom_center = origin.slice(0);

var selected_points_start_loc = [];

// right click
addKeyListener(1002, function(e, s, lasts){
	if(s == 0){
		delta_horizontal_angle = 0;
		delta_vertical_angle = 0; }
		
	//else if(getKeyState(16)){  // use default as rotation center
		//rotation_center = origin.slice(0); }
		
	else if(highlight_object > 0){  // use highlighted points for rotation center.
		if(highlight_object < points.length){
			rotation_center = points[highlight_object].slice(0); }
			
		else{
			var line = lines[highlight_object];
			var pointa = points[line[0]];
			var pointb = points[line[1]];
			rotation_center = vector_midpoint(pointa, pointb);
			selection_rotation_axis = vector_minus(pointa, pointb);
			if(vector_dot(selection_rotation_axis, view_transform[2]) < 0){
				vector_scale(-1, selection_rotation_axis, selection_rotation_axis); }}}  // axis should be pointing vertical, horizontal motions along the screen will dictate motion angle.
	
	else if(selected_points.length){  //find average of selected points for rotation center
		rotation_center = [0,0,0];
	    for(var i = 0; i < selected_points.length; ++i){
			vector_add(rotation_center, points[selected_points[i]], rotation_center); }
		var l = selected_points.length;
		rotation_center = [rotation_center[0]/l, rotation_center[1]/l, rotation_center[2]/l];
        // alert("Rotation center: " + rotation_center);

		}});


function writeMsg(canvas, msg){
	var lines = msg.split("\n");
	var ctx = canvas.getContext("2d");
	ctx.font = "9pt sans-serif"

    // camera centric uses the camera axes to perform the rotation instead of the space axes.   
    if(cameracentric) norm = matrix_mult(view_transform, [norm])[0];
    var rotation = vector_rotation(norm, theta);
    
    view_transform = matrix_mult(rotation, view_transform); }
	
	



    
    
function rotateHorizontal(theta){
    rotateView([0, 1, 0], theta, false); }
    
function rotateVertical(theta){
    if(vertical_camera_rotation + theta > Math.PI/2)

				var pt = points[selected_points[i]];
				vector_add(pt, delta_position, pt); }}
		
		else{
			moveCamera(delta_position, false); }
			
			
		if(!selected_points.length || getKeyState(16)){
			if(delta_horizontal_angle) rotateHorizontal(delta_horizontal_angle);
			if(delta_vertical_angle) rotateVertical(delta_vertical_angle); }
			
		else{ // rotate selected points
            var rotation_transform;
            if(selection_rotation_axis){  // 
                rotation_transform = vector_rotation(selection_rotation_axis, delta_horizontal_angle); }
            else{
                rotation_transform = vector_rotation([0, 1, 0], delta_horizontal_angle);
                rotation_transform = matrix_mult(vector_rotation([0, 0, 1], -delta_vertical_angle), rotation_transform); }

            for(var i = 0; i < selected_points.length; ++i){
                var index = selected_points[i];
                var pt = points[index];

                vector_minus(pt, rotation_center, pt);
                pt = matrix_mult(rotation_transform, [pt])[0];
                vector_add(pt, rotation_center, pt);
                points[index] = pt; }}
        
       
        //  overwrite point projections
        //  TODO this may not be perfect if points are deleted etc.        
        point_projections.length = 0;
        for(var i = 0; i < points.length; ++i){
            point_projections[i] = project(canvas, points[i], view_transform, origin); }