Drawing arbitrary shapes with the mouse

In this recipe, we will learn how to draw arbitrary shapes using the mouse.

We will begin a new contour every time the user presses the mouse button, and draw when the user drags the mouse.

The shape will be drawn using fill and stroke.

Getting ready

Include the necessary files to draw and create a ci::Shape2d object.

Add the following code snippet at the top of your source file:

#include "cinder/gl/gl.h"
#include "cinder/shape2d.h"

How to do it…

We will create a ci::Shape2d object and create vertices using mouse coordinates. Perform the following steps to do so:

1. Declare a ci::Shape2d object to define our shape and two ci::Color objects to define the fill and stroke colors.

   Shape2d mShape;
   Color fillColor, strokeColor;

2. Initialize the colors in the setup method.

   We'll be using black for stroke and yellow for fill.

   mFillColor = Color( 1.0f, 1.0f, 0.0f );
   mStrokeColor = Color( 0.0f, 0.0f, 0.0f );

3. Since the drawing will be made with the mouse, it is necessary to use...