# Interaction Umeå Wiki

### Site Tools

courses:intro.prototyping.fall.2014.sep30

# Differences

This shows you the differences between two versions of the page.

 — courses:intro.prototyping.fall.2014.sep30 [2014/09/30 02:28] (current)rickard created 2014/09/30 02:28 rickard created 2014/09/30 02:28 rickard created Line 1: Line 1: + === Intro to processing === + + Processing is an open source programming environment and community that can be found at[[http://​www.processing.org/​|processing.org]] ​ + + Homework until next time: Using 2D-shapes, draw some graphics, and have hem change somehow. For example change the value of color, size, position, movement. + + We learned to draw 2D stuff with code like this: + + + void setup()// This is where we prepare stuff + { + size(640, 480);//size of canvas + background(0);//​color of background + fill(200);//​color filled areas + stroke(255, 0, 0);//color of lines + } + + void draw()//​This is where the magic happens + { + rect(70, 70, 100, 100);//draw a rectangle + } + + ​ + + To keep track of the X-coordinate while moving a rectangle we used a variable: + + int Joe; //Naming the variable, and stating it's a number + + void setup()// This is where we prepare stuff + { + size(320, 240); + Joe = 10;//​setting inital value + } + + void draw()//​This is where the magic happens + { + background(0);//​redraw background + Joe=Joe+1; //​increasing the variable by one + rect(Joe, 70, 100, 100);//​drawing the rectangle using the variable as x-coordinate + } + ​ + + We got introduced to IF-statements to make changes when circumstances are met: + + + if(Joe > 320) //If variable is more than 320 + { + Joe = 0;  //we set variable back to 0 + } + ​ + + + ​ + + System variables we talked about: + width: contains the width of your sketch as a number + height: contains the height of your sketch as a number + mouseX: contains the X-coordinate of the pointer as a number + mouseY: contains the Y-coordinate of the pointer as a number + ​ + Commands we used: + point();//​draw point + line();//​draw line + rect(); //draw rectangle + ellipse();//​draw ellipse or circle + + noCursor();//​hides the mousepointer + background();//​draws background with specified color + fill();//​sets color for shape areas + stroke();//​sets color of lines and frames + ​ + ​ + For the full info of the use of these commands I encourage you to look up the commands in the[[http://​www.processing.org/​reference|reference]] part of the processing site. + 