API.md

L5 Reference

Processing is not a single programming language, but an arts-centric system for learning, teaching, and making visual form with code. --Processing.py reference

STRUCTURE

• {} (curly braces - defines a table for arrays, classes, objects, dictionaries, data and more)
• [] (access items from an ordered table aka "array")
• -- (comment)
• --[[ (multi-line comment) ]]--
• = (assign global variable)
• local (assign local variable)
• ==
• nil
• true
• false
• setup()
• draw()
• for i=1,5 do end
• loop
• noLoop()
• isLooping() -- equals true or false
• exit() (quits/stops/exits the program)
• redraw() (executes draw one time)
• windowTitle()
• function (used to define a new user-defined function)

Control

Conditionals

• break (finish a loop that contains it)
• if
• then
• end
• elseif

Relational Operators

• == (equality)
• ~= (inequality)

Iteration

• for (runs a set number of times)
• while do (runs while true, checks before executing)
• repeat until (loops but checks condition at end. executes at least once)

Logical Operators

• and
• or
• not

Environment

• size()
• print()
• deltaTime
• describe() --implementing as text to console, takes string input, should be in setup
• displayDensity()
• pixelDensity()
• displayHeight
• displayWidth
• focused --boolean var
• frameCount
• frameRate()
• fullscreen() --returns true if in fullscreen, false otherwise. if passed true, turns on fullscreen, or turns off if passed false. equivalent to p5.js implementation
• width -- width of canvas in pixels
• height -- height of canvas in pixels
• resizeWindow() -- changes width and height of window
• windowResized() -- function that runs when window is resized

I/O

Input

• loadJSON() --Not included currently. A simple parser could be written, or a robust library used.
• loadStrings() --takes filename as arg, returns table
• loadTable() --takes 1 or 2 arguments: filename, optional "header" string if header in csv or tsv present. Detects suffix (csv, tsv or lua) and processes accordingly. Saves to a table.
• loadXML() --Not included currently.

Output

• saveJSON() --Not included currently.
• saveStrings() --takes table and output filename as arguments
• saveTable() --takes table and filename as arguments, and optional format "csv","tsv" or "lua". Auto-selects output based on filename suffix if third argument empty.

Time and Date

• millis() - returns time since start of program in milliseconds
• day() - returns day 1 - 31
• month() - returns month 1 - 12
• year() - returns year YYYY
• hour() - returns hour 0 - 23
• minute() - returns minute 0-59
• second() - returns seconds 0-59

Events

Keyboard

• key
• keyCode --not needed as key can detect all
• keyIsDown() --not in Processing
• keyIsPressed --boolean, called keyPressed in Processing
• keyPressed()
• keyReleased()
• keyTyped()

Mouse

• mouseButton --A variable that returns which mouse button was last pressed: LEFT, RIGHT or CENTER
• mouseClicked() --called once after a mouse button pressed and released
• mouseDragged() -- called while mouse moves and a mouse button is pressed
• mouseIsPressed --boolean, called mousePressed in Processing
• mouseMoved() --called when mouse moved, no button pressed
• mousePressed() --called once after mouse button pressed
• mouseReleased() --called once when a mouse button released
• mouseWheel() --runs once while wheel is moving if passed x,y then can return change of -1 or 1 for x (left or right), -1 or 1 for y (up or down)
• mouseX --horizontal coordinate of mouse
• mouseY --vertical coordinate of mouse
• movedX --mouseX-pmouseX, not in Processing
• movedY --mouseY-pmouseY, not in Processing
• pmouseX --mouseX in previous frame
• pmouseY --mouseY in previous frame

Touch -- Not under development. Could be added later if interest.

SHAPE

2D Primitives

• arc()
• circle()
• ellipse()
• line()
• point()
• rect()
• square()
• triangle()

Attributes

• ellipseMode()
• rectMode()
• strokeWeight()
• noSmooth()
• smooth()
• strokeJoin() --MITER, BEVEL, NONE. No ROUND. MITER is default. Also affected by strokeCap (because of Love2d's internals)

Curves

• curve()

Vertex

• beginContour()
• beginShape() -- resets table of vertices for a custom shape
• bezier()
• curveVertex()
• endContour()
• endShape() -- draws a polygon with the table of vertices for a custom shape
• quadraticVertex()
• texture() -- draw texture mesh to polygon
• textureMode() -- change coodinate system for uv coordinates of drawing textures. default is IMAGE mode, or NORMAL (0-1) mode.
• textureWrap() -- define if textures CLAMP or REPEAT on texture mesh. default: CLAMP
• vertex() -- adds a x,y pair to table of vertices for a custom shape, or x, y, u, v for wrapping texture

Creating & Reading

• alpha() (gets alpha aka 4th value of a color)
• blue() (gets blue aka 3rd value of a color)
• red() (gets red value of a color)
• brightness() (extracts HSB brightness value of a color)
• color() (creates a color object) --G, G,A R,G,B R,G,B,A or html color name. affected by colormode.
• green() (gets the green value of a color)
• hue() (gets the hue value of a color)
• lerpColor()
• lightness()
• paletteLerp()
• saturation()

Setting

• background() --G, G,A R,G,B R,G,B,A or html color name. affected by colorMode.
• clear()
• HSB --mode, a constant
• HSL --mode, a constant
• colorMode() --default: RGB. alternately: HSB, HSL. optional second val sets max color values.
• fill() - G, G,A R,G,B R,G,B,A or html color name. affected by colorMode.
• noFill()
• noStroke()
• stroke() --G, G,A R,G,B R,G,B,A or html color name. affected by colorMode.

Rendering

• createGraphics -- creates an offscreen buffer to draw to, with beginDraw() and endDraw() methods

Transform

• push() (saves previous drawing style settings)
• pop() (restores previous drawing style settings)
• translate()
• rotate()
• scale()
• applyMatrix()

Constants

• HALF_PI (1.57079...)
• PI (3.14159...)
• QUARTER_PI (0.78539...)
• TAU (6.28318...)
• TWO_PI (6.28318...)

Math

• random() --takes 1 or 2 arguments. if a table name is given, returns a random value from the table
• randomSeed()
• randomGaussian()
• noise() --1, 2 or 3 dimensional Simplex noise generation
• lerp()
• abs() --absolute value
• ceil() --round up
• floor() --round down
• fract()
• log()
• norm()
• pow()
• exp()
• sq()
• sqrt()
• round() --round up or down
• int() --convert to integer
• constrain() --limit range of variable
• map() --remap variable from one range to another
• dist() -- return distance in pixels between 2 sets of x,y coordinates
• max() --return max of 2 values
• min() --return min of 2 values

DATA

Conversion

• boolean() --convert to boolean
• byte() --convert to signed byte
• char() --convert number to letter char
• float() --convert to number
• hex() --convert to hexadecimal, with optional padding
• str() --convert number to string
• unchar() --convert char to number

Trigonometry

• angleMode()
• degrees()
• radians()
• sin()
• cos()
• tan()
• asin()
• acos()
• atan()
• atan2()

Typography

• loadFont() --create new font
• text() --display text, at x,y, optional max width for wrapping
• textFont() --change to loaded font
• textWidth() --returns width of text
• textHeight() -- returns height of text
• textMode() --not currently planning on implementing this
• textAlign() --first parameter sets horizontal alignment LEFT (default), CENTER, or RIGHT. Optional second parameter sets TOP, CENTER or BOTTOM vertical alignment.
• textWrap()
• textSize()

Loading and Displaying

• image()
• imageMode()
• loadImage()
• noTint()
• tint()
• save()
• cursor() (see https://www.love2d.org/wiki/love.mouse.setCursor )
• noCursor()

Pixels

• blend() -- copies a region of pixels from one image to another
• copy() -- copies pixels from a source image to a region of the canvas
• filter() --implemented basic implementation with shaders
• PixelDensity() - get or set pixel density for normal or high pixel density displays. Default is 1.
• loadPixels() - loads current canvas into pixel array
• pixels - global variable holding pixel array of colors for each pixel on screen
• updatePixels() - draws the pixel array to screen as series of RGBA values
• get() - get value of a pixel or a region of the window
• set() - set color of a pixel or draw an image to canvas