For Project 3, you will create a simple drawing application where 4 buttons allow you to choose which pattern to draw. One additional button will clear the drawing canvas. 3 Sliders will be used to change the hue, saturation, brightness of the pattern that's drawn.
The code on this page, and the image below shows a first iteration for this project
Overall Project Logic - Including Slider Logic
Setup: Initialize Global Variables
ButtonGroup, ClearButton, Sliders, Patterns, Background Color
In Setup, create an array btnArray of 4 Buttons that function as a ButtonGroup to control which pattern is drawn.
Initialize each Button: btnArray[ i ] by calling the Button or PImageButton constructor.
Pass the array of buttons into the ButtonGroup constructor.
In draw: add logic to displayButtons( ) , each frame.
Add logic in mouseClicked( ) to have btnGroup.clicked( mouseX, mouseY) execucted
Within mouseClicked, if the activeButton has changed, execute changePattern( ), custom method.
In the main tab: you will define a function: ChangePattern( ) that will connect the active button with a corresponding simple Pattern (PShapes) that can be drawn at the mouse position, the active pattern can be changed by selecting one of 4 pattern buttons.
Individual Button to Clear Canvas
Create an additional 5th Button that will clear the canvas, but is not part of the ButtonGroup buttons.
Pattern Objects to draw patterns
Create 2 Global Pattern Object variables, Initialize in Setup:
Pattern eraserPattern; //initialize in setup with PShape eraser, fillColor is backgroundColor
Pattern currentPattern; // will point to current active pattern - set to eraserPattern to initialize in setup
draw( ): Animation Logic
Checks if Sliders have changed value, if using a scale slider, then the patterns must also be changed to reflect the new value of len.
Checks if Mouse is pressed. If so, then display current active pattern, also requires translation of origin to mouse position, patterns are drawn at origin.
CheckSliders( ) must occur before ChangePattern( )
CheckSlider( ) method, checks each slider to see if it's value has changed. Also includes logic for color dependency between sliders:
satSlider's hue is set by the hueSlider's sliderVal;
brightSlider's hue is set by the hueSlider's sliderVal;
brightSlider's sat is set by the satSlider's sliderVal;
ChangePatternColor( )
Sliders modify Color for Patterns in ChangePatternColor( )
Before displaying the currentPattern, we'll use custom sliders to set the hue, saturation, brightness of the globalColor variable that's used when displaying patterns. This logic must be executed before displaying the currentPattern. See code details below below:
Simple method that changes the values for the global pattern color using the Slider's sliderVal.
Defines hue, sat, bright values:
Uses those values to set the global patternFillColor
float hue = hueSlider.sliderVal;
float sat = 100; //..initialize using satSlider
float bright= 100; //..initialize using brightSlider
patternFillColor = color( hue, sat, bright );//set from slider values
ChangePattern( ) Switch-case Control Structure
Switch-case structure allows one pattern to be set as active by using the activeBtnIndex of the ButtonGroup, to set an active pattern to be drawn on the canvas. If using a Length slider, then use a len variable that's modified by the lengthSlider, then used when creating each PShape.
DisplayPattern( )
Sets the pattern color depending if it's the eraser or not, then calls curPattern.display()
ClearCanvas( )
A function to draw a rectangle of canvas-size, and backgroundColor, hides all previous patterns, called from mouseClicked when the clearButton is clicked. After the clearButton is clicked, this method is executed, then the clearButton must be reset( ).
Main Tab Logic:
Use Functions to organize main-tab Logic
Use Classes to structure project logic.
Detailed Project Logic:
Declare Global Variables in Main Tab
//Global Variables
//Main Tab
//Make objects, objects call methods
//Global Variables
ButtonGroup btnGroup; //will hold 4 pattern buttons
Button clearButton;//declare the variable as global - btn is null
color backgroundColor;
Pattern currentPattern; //pointer variable keeps track of active Pattern
Pattern eraserPattern; //has a PShape circle and background fillColor
Slider hueSlider, satSlider, brightSlider;
Logic In Main Tab:
Logic to Initialize Objects in setup( )
Set Canvas Size: min: 800 x 600
Set colorMode - HSB
Initialize objects by calling constructors:
declare an Array of Buttons
Button[] btnArray;
initialize Array of Buttons
btnArray = new Button[4];
initialize each Array element by calling Button , PImageButton ConstructorsYou need to figure out Button constructor parameter values so that buttons are positioned in a vertical stack.
Button[] btnArray = new Button[4]; //declare and initialize button array
btnArray[0] = new Button( 10, 10, 100, 100, "Eraser");
PImage img1 = loadImage( "pattern1Btn.png"); //file name with extension
btnArray[1] = new PImageButton( ... parameters ...);
btnArray[2] = new PImageButton( ... parameters ...);
btnArray[3] = new PImageButton( ... parameters ...);
//Initialize ButtonGroup
btnGroup = new ButtonGroup( btnArray );
initialize btnGroup by calling ButtonGroup Constructor and pass buttonArray as a parameter
btnGroup = new ButtonGroup( btnArray);
initialize clearButton by calling Button Constructor - use either Button or PImageButton
clearButton = new Button( ...parameters... );
initialize eraserPattern, currentPattern Objects
Create 1 PShape, pass one to Pattern Constructor
Example initialization for 2 Patterns shown below
2 pattern objects required
eraserPattern initialized with PShape
currentPattern initialized by pointing to eraserPattern's object data in heap: sets to same memory address
PShape EraserPShape = createShape( ELLIPSE, 0,0,30,30);
eraserPattern = new Pattern( EraserPShape);
//keeps track of current pattern
currentPattern = eraserPattern;
Initialize Sliders Initialize Sliders by calling constructors with proper input parameters to determine position, size, min, max range
hueSlider = new HueSlider( 40, height-100, 200, 50, 0, 360 );
satSlider = new SatSlider( parameters );
brightSlider = new BrightSlider( parameters );
Logic In draw( ):
if mousePressed
checkSliders( ); //check before drawPattern, when mousePressed
changePattern( ); //if using scale slider and checkSliders returns true
sets len for currentPattern if using a length slider's sliderVal
eraserPattern color is not changed by sliders, should have fillColor, strokeColor set to global backgroundColor;
use switch-case structure
switch: check which buttonGroup button is active
void changePattern( ){
Pattern currentPatttern = eraserPattern;
float len = 100;
//Add Logic to modify len if using a scale slider
//len = lengthSlider.sliderVal;
switch(buttonGroup.activeBtnIndex){
case 0:
currentPatttern = eraserPattern;
break;
case 1:
PShape shape1 = createShape( RECT, 0,0,len, len);
currentPatttern = new Pattern( shape1 );
break;
case 2:
//call your custom vertex function - remove color parameter
//PShape shape2 = createShape( RECT, 0,0,len*0.8, len* 1.2);
PShape shape2 = vertexShape2( len );
currentPatttern = new Pattern( shape2);
break;
case 3:
//call your custom vertex function - remove color parameter
//PShape shape3 = createShape( ELLIPSE, 0,0,len*0.6, len* 1.2);
PShape shape3 = vertexShape3( len );
currentPatttern = new Pattern( shape3);
break;
default:
println("no match");
}//end switch-case
} // end checkPattern();
Logic in displayPattern( )
void displayPattern(){
if( currentPattern == eraserPattern){
currentPattern.fillColor = eraserPattern.fillColor;
currentPattern.strokeColor = backgroundColor;
}
currentPattern.fillColor = patternFillColor; // in check sliders
currentPattern.strokeColor = color(0);//reset to black
currentPattern.display(); //sliders will set colors for other patterns
}
Logic in drawButtonMenu( ):
Draw 5 buttons: 4 buttons in buttonGroup, 1 clearButton
draw a menu-background (rectangle)
buttonGroup.display();
clearButton.display();
Logic In MouseClicked( ):
btnGroup.clicked( parameters )
if
clearButton.click( parameters )
if clearButton is selected
clearCanvas( ) - draw rectangle over the canvas surface
reset the clearButton
Detailed Logic for Adding Sliders to Drawing Application
void mouseClicked( ) {
//see if the activeButtonIndex has changed to indicate a new button is active
boolean isChanged = btnGroup.clicked( mouseX, mouseY);
if( isChanged){
changePattern();
}
clearButton.clicked( mouseX, mouseY);
if( clearButton.selected ){
clearCanvas(); //call custom method to clear canvas
clearButton.reset(); //turn clearButton off
}
} //end mouseClicked
In this project, sliders will be used to control Hue, Saturation, Brightness of the patterns drawn.
The sliders must be checked each time the draw-loop executes if the mousePressed, to see if the sliderVal has changed.
Sliders must always be checked for changes in sliderVal before drawing any patterns.
checkSliders( ) is a custom function in the main tab, that contains logic for checking each slider.
Declare global variables:
Slider hueSlider, satSlider, brightSlider;
Initialize 3 Sliders in setup( ) by calling child class constructors: example
Incorporate Sliders into project using custom functions:
void checkSliders( );
void setPatternColor( );
void drawSliders ( );
in displayPattern( ) - set currentPattern fillColor using patternFillColor right before currentPattern is displayed: currentPattern.display()
see drawPattern above for integration of this example code:
if( currentPattern != eraserPattern){
//set color using sliders sliderVal if not the eraserPattern
//set
currentPattern.fillColor = patternFillColor;
}
Logic in DisplaySliders( )
This code is similar to DrawButtons, we simply want to draw a rectangle behind the sliders, and then have each slider display itself by calling the over-ridden display( ) method.
In CheckSliders, we must check to see if each slider has been pressed. We need to set the hue value for the satSlider using the current sliderVal of the hueSlider since the display of satSlider should change when the hueSlider is changed. Similarly for the brightSlider, it must have it's hue and sat reset to reflect current hueSlider and satSlider values.
The clearButton is a regular button that is used to clear the canvas. The clearButton must be declared as a global object-reference variable. The clearButton behaves like a door-bell, meaning it never displays that it is in the selected state. When the clearButton is clicked, it clears the canvas, then the reset( ) method is called to turn the button off.
//global variable
Button clearButton;
Initialize in setup() The clearButton is not part of the buttonGroup buttons, but it's parameters should be defined so that the button is displayed below the other buttons that are part of the buttonGroup. `
//in setup()
clearButton = new Button( parameters );
Add code in displayButtons( ), to display the clearButton
Add code in mouseClicked( ) Add code to check if the clearButton has been clicked. Then, check to see if the clearButton is currently selected, if it is, then call custom function: clearCanvas( ), then turn-off the clearButton by calling the reset( ) method.
void mouseClicked(){
btnGroup.clicked( mouseX, mouseY);
clearButton.clicked( mouseX, mouseY); //check to see if it's been clicked
if( clearButton.selected){
//do something
clearCanvas();
clearButton.reset(); //turn the button off
}
}
Logic in clearCanvas( ):
called when clearButton has been clicked and has on==true
set fill to global background color: backgroundColor
draw a rectangle, the size of the entire canvas, to clear the canvas. rect( 0, 0, width, height)
void clearCanvas(){
//TODO add code to draw a rectangle over the full canvas using background color
fill( backgroundColor);
}//end clearCanvas
Main Tab Final Structure
//Main Tab
//Make objects, objects call methods
//Global Variables
ButtonGroup btnGroup; //will hold 4 pattern buttons
Button clearButton;//declare the variable as global - btn is null
color backgroundColor;
color patternFillColor; //global
color patternStrokeColor; //global
Pattern currentPattern; //pointer variable keeps track of active Pattern
Pattern eraserPattern; //has a PShape circle and background fillColor
//SLIDERS
Slider lengthSlider, hueSlider;
void setup() {
size( 800, 800);
colorMode(HSB, 360, 100, 100, 100);
backgroundColor = color( 300); //light gray
background( backgroundColor);
// Button( float x, float y, float w, float h, String label )
clearButton = new Button( 10, 450, 100, 100, "Clear"); //initialize - move to bottom
Button[] btnArray = new Button[4]; //declare and initialize button array
btnArray[0] = new Button( 10, 10, 100, 100, "Eraser");
PImage img1 = loadImage( "pattern1Btn.png"); //file name with extension
btnArray[1] = new PImageButton( 10, 120, 100, 100, img1);
//initailize other buttons
//btnArray[2]
/// btnArray[3]
btnGroup = new ButtonGroup( btnArray );
//Logic for patterns
PShape s0 = createShape( ELLIPSE, 0,0, 50, 50);
eraserPattern = new Pattern( s0 );
eraserPattern.fillColor = color(backgroundColor);//start with Purple
eraserPattern.strokeColor = color(backgroundColor);
currentPattern = eraserPattern;
//Slider(float x, float y, float w, float h, float min, float max, String label ){
lengthSlider = new Slider( 40,height - 40, 200, 30, 10, 200, "Length");
hueSlider = new Slider( 280, height - 40, 200, 30, 0, 360, "Hue");
//initialize other
//checkSliders at beginning to initialize sliders
checkSliders();
setPatternColor(); //initialize patternFillColor
} // end setup
void draw( ) {
if( mousePressed){
checkSliders( )
translate( mouseX, mouseY );
displayPattern( ); //draw currentPattern
resetMatrix();
}
displayButtons(); //do after drawing patterns
displaySliders();
} //end draw
void mouseClicked( ) {
boolean isChanged = btnGroup.clicked( mouseX, mouseY);
if( isChanged){
changePattern();
}
clearButton.clicked( mouseX, mouseY);
if( clearButton.selected ){
clearCanvas();
clearButton.reset();
}
} //end mouseClicked
void displaySliders(){
lengthSlider.display();
hueSlider.display();
}//end displaySliders
boolean checkSliders(){
boolean isChanged = false;
if( hueSlider.checkPressed( mouseX, mouseY)){
//add logic for dependencies between sliders
//satSlider.hue = hueSlider.sliderVal
//brightSlider.hue = hueSlider.sliderVal
isChanged = true;
}
//if any hue, sat, bright slider has changed, then changePatternColor
if( isChanged == true){
setPatternColor( ); //always changePatternColor if a slider has changed
}
if( lengthSlider.checkPressed( mouseX, mouseY)){
changePattern( ) //length must be used to change Pattern
isChanged = true;
}
return isChanged;
} //end checkSliders
void setPatternColor( ){
float hue = hueSlider.sliderVal;
float sat = 100;
float bright = 100;
patternFillColor = color(hue, sat, bright);
}
void changePattern(){
//TODO add logic to connect buttons to patterns
//activeBtnIndex will let us determine which pattern should be the currentPattern
//Switch Case Statement
float len = 100; //scale slider will set / modify this value
len = lengthSlider.sliderVal;
switch( btnGroup.activeBtnIndex){
case 0:
currentPattern = eraserPattern;
break;
case 1:
PShape s1 = createShape( RECT, 0,0,len *.8 , len);
currentPattern = new Pattern( s1);
break;
case 2:
PShape s2 = createShape( RECT, 0,0,len , len);
currentPattern = new Pattern( s2);
break;
case 3:
PShape s3 = vertexShape1( len );
currentPattern = new Pattern( s3 );
break;
default:
println("No match on switch case");
break;
} //end switch-case statement
} //end changePattern
void displayPattern(){
if( currentPattern != eraserPattern){
//patternFillColor = color( 280, 100, 100, 50);
//set in the Sliders
patternStrokeColor = color( 0, 50);
currentPattern.fillColor = patternFillColor;
currentPattern.strokeColor = patternStrokeColor;
}
currentPattern.display(); //sliders will set colors for other patterns
} //end displayPattern
void clearCanvas(){
//TODO add code to draw a rectangle over the full canvas using background color
}//end clearCanvas
void displayButtons(){
fill(0); //black
rect( 0,0, 120, height);//background of menu
btnGroup.display();
clearButton.display();
} //end displayButtons
