Safe Haskell | None |
---|

A `Monoid`

models figures in the plane.
Then, figures are displayed or animated using
a Processing script.

For example, this expression represents a circle of radius 10 centered at the origin:

Circle (0,0) 10

The origin will be represented at the center of
the screen. As opposed to the other modules,
*y*-coordinates increase to the top, while *x*-coordinates
still increase to the right.

This is a red rectangle with top-left corner at the origin, 10 points height and 10 points width:

FillColor (Color 255 0 0 255) $ Rectangle (0,0) 10 10

To display several figures together, use the `Monoid`

instance:

Circle (0,0) 10 <> Circle (0,20) 10

If you just want to display this figure in the target canvas,
use `displayFigure`

. If you want to animate it, use `animateFigure`

.
Animations depend on the number of frames since the beginning of
the execution, instead of in the time spent.

Once you have created a processing script (a value of type
`ProcScript`

), use `renderFile`

to write it to a file. See
also the Graphics.Web.Processing.Html module.

The default filling color and line color are white and black
respectively. Use `FillColor`

and `LineColor`

to change these
colors. `Color`

s are in RGBA format, meaning that they may be
transparent (with an alpha value of 0), opaque (with an alpha
value of 255) or something in between. Use a fully transparent
color to indicate that a Figure should not be filled.

You can apply transformations like translation, rotation and
scaling. If `p`

is a point and `f`

a figure, `Translate p f`

will draw `f`

with `p`

as the origin of coordinates. Rotations
and scalings are always done in respect to the origin, but note
that you can modify where the origin is using `Translate`

.

- module Graphics.Web.Processing.Core.Types
- data Color = Color {}
- type Proc_Point = (Proc_Float, Proc_Float)
- type Path = [Proc_Point]
- data Figure
- = Line Path
- | Polygon Path
- | Ellipse Proc_Point Proc_Float Proc_Float
- | Circle Proc_Point Proc_Float
- | Arc Proc_Point Proc_Float Proc_Float Proc_Float Proc_Float
- | Rectangle Proc_Point Proc_Float Proc_Float
- | Bezier Proc_Point Proc_Point Proc_Point Proc_Point
- | Text Proc_Point Proc_Text
- | LineColor Color Figure
- | FillColor Color Figure
- | Translate Proc_Point Figure
- | Rotate Proc_Float Figure
- | Scale Proc_Float Proc_Float Figure
- | Figures [Figure]

- module Data.Monoid
- displayFigure :: Maybe Int -> Maybe Int -> Color -> Figure -> ProcScript
- animateFigure :: Maybe Int -> Maybe Int -> Int -> Color -> (Proc_Int -> Figure) -> ProcScript
- interactiveFigure :: CustomValue w => Maybe Int -> Maybe Int -> Int -> w -> (w -> Figure) -> (w -> Color) -> (Proc_Int -> w -> w) -> (Proc_Point -> w -> w) -> [(Key, w -> w)] -> ProcScript
- data Key
- data ArrowKey
- data KeyModifier
- data SpecialKey
- module Graphics.Web.Processing.Mid.CustomVar

# Types

RGBA colors. Values must be between 0 and 255, including in the alpha channel.

type Proc_Point = (Proc_Float, Proc_Float)Source

A point as a pair of floating point numbers.

type Path = [Proc_Point]Source

A path is just a list of points.

# Figure type

The monoid of plane figures.

Line Path | Line joining a list of points. |

Polygon Path | Polygon given a list of vertex. |

Ellipse Proc_Point Proc_Float Proc_Float | Ellipse centered at the given point, with width and height also specified. |

Circle Proc_Point Proc_Float | Circle centered at the given point and with the specified radius. |

Arc Proc_Point Proc_Float Proc_Float Proc_Float Proc_Float | Arc. The arc is drawn following the line of an ellipse between two angles. The first argument is the center of the ellipse. The next two arguments are the width and height of the ellipse. The last two arguments are the initial and end angles of the arc. |

Rectangle Proc_Point Proc_Float Proc_Float | Rectangle such that the top-left corner is at the specified point, and its width and height are specified by the other two arguments. |

Bezier Proc_Point Proc_Point Proc_Point Proc_Point | Bezier curve. First and last arguments are the initial and end points of the curve. The other points are control points. |

Text Proc_Point Proc_Text | Text. |

LineColor Color Figure | Set the line color of a figure. |

FillColor Color Figure | Set the filling color of a figure. |

Translate Proc_Point Figure | Translate a figure in the direction of a vector. |

Rotate Proc_Float Figure | Rotate a figure by the given angle in radians. |

Scale Proc_Float Proc_Float Figure | Scale a figure by the given x and y factors. |

Figures [Figure] | List of figures. |

# Monoids

A re-export of the Data.Monoid module is provided.
You may be using it to join different `Figure`

s into one.

module Data.Monoid

# Script

:: Maybe Int | Width (if none, takes as much as is available). |

-> Maybe Int | Height (if none, takes as much as is available). |

-> Color | Background color. |

-> Figure | Figure to display. |

-> ProcScript |

Display a figure using a Processing script.

:: Maybe Int | Width (if none, takes as much as is available). |

-> Maybe Int | Height (if none, takes as much as is available). |

-> Int | Frame rate. |

-> Color | Background color. |

-> (Proc_Int -> Figure) | Function to produce the next frame of animation, given the current frame number. |

-> ProcScript |

Create a Processing animation from a `Figure`

-valued function.

## Interactive

:: CustomValue w | |

=> Maybe Int | Width (if none, takes as much as is available). |

-> Maybe Int | Height (if none, takes as much as is available). |

-> Int | Frame rate. |

-> w | Initial state. |

-> (w -> Figure) | How to print the state. |

-> (w -> Color) | Background color, depending on the current state. |

-> (Proc_Int -> w -> w) | Function to step the world one iteration. It is passed the number of frames from the beginning. |

-> (Proc_Point -> w -> w) | Function called each time the mouse is clicked. |

-> [(Key, w -> w)] | Key events. List of pairs, where the first component is
a |

-> ProcScript |

Framework to create interactive scripts.

Note that is required for the state to be an instance of `CustomValue`

.
More info on how to instantiate a type in the `CustomValue`

class in the
Graphics.Web.Processing.Mid.CustomVar module.

### Keyboard

Keyboard keys recognized by Processing.

### Custom values

Module re-export for convenience.