What is Doodleback?

A lot of drawing apps let you construct a circle but usually in only one way. They let you copy an object but in only one way or erase but in only one way. But what if you wanted to erase with a star or copy something by rotation? Doodleback’s philosophy is that how you’re able to construct things is almost as important as what you can construct. Being able to precisely place objects at the moment of their creation simplifies many drawings that would otherwise be difficult or almost impossible. You can get it here on Google Play.

Point Along Line

The Point Along Line tool lets you position a point along a line defined by two points. Your initial touch defines the first point of the line. You use the Mark Button

to define the second point. You can also use the Drag Constraint button
to position the point horizontally or vertically relative to the initial point. Here’s an example:

points 

Point by Angle

The Point by Angle tool allows you to create a point which is positioned based on an angle that you define. Your initial touch defines the vertex of the angle. You then drag and use the Mark Button to define the two endpoints of the angle. This is different from how angles are usually defined in Doodleback (it’s usually endpoint-vertex-endpoint), but the reason is that the two endpoints actually define the line on which the point will lie so really what you’re defining is a vertex and then a guide segment. [Read More]
points 

Point by Intersection

The Point by Intersection tool allows you to construct a Point at the intersection of two lines. The initial touch defines one point of the first line. While keeping your finger on the screen, drag it to another location and tap the Mark Button to define the other end point for the first line. After the first line is defined, keep your finger on the Paper, drag it to another location, and tap the mark button to define the first point on the second line. [Read More]
points 

Point on Each Vertex

The Point on Each Vertex tool creates a collection of Points matching the vertices of a selected polygon. There’s also an option to include the center of the polygon in the collection and a construction option to Bind the Points together at the time of creation. These Points are completely independent of the original polygon. Here’s an example:

points 

Point Trace Polygon

The Point Trace Polygon tool allows you to trace out a polygon using Points laid out on the canvas. First layout the corners of some shape with the Point tool, and then simply trace the shape with your finger. You can easily remove the points after construction by using the Delete Path Collection tool. The only construction options available are the number of Bezier Points and whether or not the first vertex and last vertex are connected. [Read More]
points 

Parallelogram

The Parallelogram tool allows you to create a parallelogram by defining one side and then either its next side or its diagonal. You can use the Drag Constraints button to control the horizontal or vertical orientation of the sides or to define a vector to guide the drawing of the side. Here’s an example. Also, as with the other polygon tools, the Bezier Points button lets you specify the number of bezier points on each side. [Read More]

Rectangle

The Rectangle tool offers several different ways to construct a rectangle. Corner to opposite corner Center to corner Corner to center Define one side with Mark Button and then drag to define other side Define dividing center line with Mark Button and then drag to define other side Define dividing center line from center with Mark Button and then drag to define other side You can use Drag Constraints for the last three options to restrict the sides horizontally, vertically, or freely (no constraints). [Read More]

Regular Polygon

A Regular Polygon is a polygon where all its sides and angles are equal. There are four Regular Polygon tools, one for 3-12 sides, one for 13-32 sides, one for 33-64 sides, and one for 65-128 sides. This is simply for convenience to reduce the number of options during construction. The four tools work exactly the same. You can construct a regular polygon in the following ways. Center to side Side to center Center to vertex Vertex to center Mark side Mark half side (vertex then midpoint) Mark half side (midpoint then vertex) Vertex to opposite side or opposite vertex (depending on if the polygon has an even or odd number number of sides) Side to opposite vertex or oppsoite side (depending on if the polygon has an even or odd number number of sides) You can use the Drag Contraints button to control the horizontal and vertical orientation of the polygon. [Read More]

Rhombus

The Rhombus tool lets you create a rhombus (a parallelogram with four equal sides) in three different ways Drag from one vertex to an opposite vertex, Mark it, drag to define the other sides Drag from the center to a vertex, Mark it, drag to define the other sides Drag from a vertex to the center, Mark it, drag to define the other sides You can use the Drag Constraints button to control the horizontal or vertical orientation of the sides. [Read More]

Square

The Square tool allows you to create a square in several different ways. Corner to corner Center to corner Corner to center Center to midpoint of side Midpoint of side to center Midpoint of side to midpoint of opposite side Mark Side and drag to define which side the square falls on Corner to midpoint of side, mark, and then drag to define which side the square falls on Midpoint of side to corner, mark, and then drag to define which side the square falls on The construction mode button graphically shows each of these methods. [Read More]