Chapter 6. Vector Graphics

Chapter 6. Vector Graphics
←		→

Chapter 6. Vector Graphics

Table of Contents

Introduction

Graphic Palettes

Tk Canvas
TkPath
TkZinc 3.3.4

Creating Graphical Objects

Introduction
Creating an Graphical Object
Interactive Object Creation
Using Splines

Abridged Chapter

Importing Scalable Vector Graphics

Requirements
Import
Limitations

Introduction

From its early days onward Tcl/Tk contained a vector graphics window: »canvas«. This canvas window provides interactive graphical objects. Graphical objects behave quite similar to ordinary windows. Even animations are available since Tcl/Tk 8.3.

Canvas Item Support in Jeszra

All properties, including state and animation properties.
Interactive operations like scale and move.
Embeding windows, limited for canvas child windows only!
Event handling. The -tags property of a graphical object are referenced event handler sets. Bindings for each event handler set are monitored and included in the code generation.
The »Event« page, inside the Inspector provides direct access to the first tag, listed in the tags property of a graphical object.
Alternative use the »Shell« from the »Extra« menu to define events for a specific canvas tag.

The canvas vector graphics abilities are far to limited for visualization purposes. There are however 3rd party visualization systems such as the following:

Visualization Systems

TkZinc 3.3.4 is a full fledged visualization system, used in European aviation control. TkZinc 3.3.4 has very sophisticated capabilities for tracking movements.
The zinc window uses OpenGL® for rendering.
TkZinc 3.3.4 is open source and licensed under the GNU Public License.
TkPath, Jeszra supports both current versions 0.2 and 0.3. The 0.2 version should be at least: 0.2.7. Earlier TkPath versions will cause Jeszra to crash.

In addition there are also 3D visualization packages available for Tcl/Tk, but these are not yet supported by Jeszra.

Jeszra extensively supports vector graphics. Jeszra provides a wide range of direct manipulations for vector graphic objects.

Graphics Manipulation

Via the Inspector properties can be set.

Via the Inspector coordinates can be set.

Via the Inspector event handlers are registered for tags.

Via the hierarchy view the item Z-order can be changed –by using Drag'n'Drop.

Item coordinates are direct definable –interactive creation.

Most item coordinates are direct edit able –not yet possible for »curve«.

Interactive definable coordinate types for »path« objects.

Interactive removing of coordinates.

Interactive conversion from line to bézier spline segments.

Tk canvas, TkPath and TkZinc 3.3.4 may serve as geometry managers.
Direct move operations in a Tk canvas.
Direct scale operations in a Tk canvas.
With TkPath and TkZinc 3.3.4, direct translate or move operations.
With TkPath and TkZinc 3.3.4, direct rotate operations.
With TkPath and TkZinc 3.3.4 direct skew operations.
With TkPath and TkZinc 3.3.4 direct zoom or scale operations.
Via the hierarchy view,TkPath 0.3 and TkZinc 3.3.4 items can be regrouped –uses Drag'n'Drop.
Via the Inspector, TkZinc 3.3.4 and TkPath gradients can be modified.
Direct manipulation of TkPath gradients.

As listed in Graphics Manipulation, Jeszra’s vector graphics features are already extensive.

Abridged Chapter

This chapter is abridged. The full text is available in printed form or as a PDF from: www.lulu.com.

←		→
Inside Documentation	↑	Graphic Palettes

Copyright © 2009–2010 Arndt Roger Schneider