Paint from scratch

• What?
  • Example 1: Hedgehog eats a horse
  • Example 2: Load image from file
  • Example 3: Blur the image
• Demos
  • Demo 1: Paint
  • Demo 2: Apply filters
• Roadmap
  • ver 0.1: simple button
  • ver 0.2: simple canvas
  • ver 0.3: connect canvas-buttons
  • ver 0.3.5: step-to-filters
  • ver 0.4: filters [@currently here]
  • ver 0.5: Drop-down menu
  • ver 0.6: More tools
  • ver ??: serialization
  • ver ??: raytracer
  • features:

What?

I develop GUI library from scratch (use only SFML drawing primitives - e.g. rectangles). This project is mostly about developing complex OOP system. At this stage I've already used several OOP patterns like:

• Compositor for Widget system.
• Strategy for canvas drawing tools.
• Decorator for texted and textured buttons.

Example 1: Hedgehog eats a horse

Example 2: Load image from file

Example 3: Blur the image

Demos

Demo 1: Paint

Demo 2: Apply filters

Roadmap

ver 0.1: simple button

[Button]

state = PRESS | UNPRESS
position
size
color

	funcs:

process_click()
press()
unpress()
is_in_area()

results:

• button changes state (and color) with click
• mutex button manager (only one button can be pressed)

ver 0.2: simple canvas

results:

• point is drawn when click on button

ver 0.3: connect canvas-buttons

results:

• draw on canvas with active color
• draw on canvas with active instrument

Buttons:

• red, green, blue - set canvas active color
• brush, eraser [const white brush], pouring [check pouring algo] - set canvas active instrument

Parameterize canvas with instrument (make class from instrument).

[Instrument]

properties: size...

	funcs:

apply(position)

ver 0.3.5: step-to-filters

results:

• textured widget
• text on widget
• load picture -> text input box (button that on click gets keyboard input)

Use decorator pattern to implement decorations.

ver 0.4: filters [@currently here]

results:

• Apply filter to every pixel when click on concrete filter

Filters:

• B&W [R=G=B = average(R,G,B)]
• inverse [R=255-R ...]
• Blur (check B2B1 video about convolution)

ver 0.5: Drop-down menu

results:

• Drop-down menu when click on filter button

ver 0.6: More tools

results:

• New tools (that need layering)

Tools:

• Line
• Rectangle
• Triangle
• Polyline

ver ??: serialization

Tree traverse and dump Restore from dump (check factory pattern)

ver ??: raytracer

2 mods:

• canvas works as screen for raytracer
• paint

Objects can be added to the scene on air with special menu. Also spheres can be dragged directly by touching image.

(for spheres managing MVC may be applied)

features:

• undo opearation (history of operations? queue of instruments applied? and should be considered - how to reverse them)
• save picture (guess smth with sfml)
• load picture (guess smth with sfml and OS interaction)
• help panel
• plugins
• instruments to toolbox: line, rectangle (!!)
• set properties for instruments (size for brush)
• filters with curves
• user can add new layers, choose one to draw on it