SWFLIB - a free Flash authoring library

• Download demo project - 27.7 Kb
• Download source - 33.4 Kb
• SWFLIB Programmers Reference [PDF] - 56.8 Kb
• Download sample movies - 7.17 Kb

Introduction

This article is about a small SWF authoring library written in C++. It can be used from any desktop application to generate Flash animations at run-time. In this release, the library can generate SWF version 3 movies, without sounds and text. This release has extended SWF tag support to cover buttons, actions, and sprites. Since this is an a experimental project, the future releases will be extended with additional functionality. For now, you are able to generate any kind of animation from the C++ source code and test it in any browser that supports Flash. The goal here is not to chase the latest SWF file format specification, but to enable developers to test this tool in their projects.

Background

Similar SWF authoring tools could be found on the Internet but with different support for generating Flash animations.

Using the code

You can use this library by downloading the SWFLIB project file and recompiling it. The project you use the library in must include the library header files and link to the swflib.lib file. The possible problem would be default project linking to the LIBCD.LIB library in the Project->Settings... and then the Link tab. The solution would be to select Input from the Category combo-box and to write the library name (LIBCD.LIB) in the Ignore section. It has worked for me in the TestProject that can be found in the download section on this page.

Generating a simple Flash movie would look like this:

#include "SWFMovie.h"

SIZE_F movieSize = {400, 400};
int frameRate = 12;
CSWFMovie swfMovie;

// Open new .SWF file
swfMovie.OpenSWFFile("Sample.swf", movieSize, frameRate);

// Define a simple shape
USHORT nID = 1;
USHORT depth = 1;
RECT_F shapeRect = {0, 0, 200, 200};
CSWFShape shape(nID, shapeRect, depth);
int lineWidth = 2;
SWF_RGBA lineColor = {255, 0, 0, 255};
shape.AddLineStyle(lineWidth, lineColor);
SWF_RGBA fillColor = {0, 0, 255, 255};
shape.AddSolidFillStyle(fillColor);
shape.AddLineSegment(100, 0);
shape.AddLineSegment(0, 100);
shape.AddLineSegment(-100, 0);
shape.AddLineSegment(0, -100);
swfMovie.AddShape(&shape, shape.m_Depth, true);
swfMovie.ShowFrame();

// Close .SWF file
swfMovie.CloseSWFFile();

Please understand that it is not possible to describe the whole functionality of the SWFLIB library using a single web page. You can find the SWFLIB Programmers Reference document in the download section, with the complete SWFLIB library specification.

Very important note

This library is just a thin wrapper around SWF tags, so don't expect final solutions. You'll have to build them using your mathematical skills and imagination. The animations are all about mathematical transformations, so you need 2D math tricks in order to get interesting effects. But don't be sad, with some practice, you'll make it for sure.

Points of interest

Working on this project was very exciting, and the future releases will increase the functionality of this library. So far, there are no noticed memory leaks, but if you detect one, please report it.

History

SWFLIB.LIB v1.1, release date - July 4, 2006

• Buttons
• SWF 3 Actions
• Sprites

SWFLIB.LIB v1.0, release date - June 26, 2006

• Custom shapes
• Morphing shapes
• JPEG file support
• Line and fill style definition
• Geometrical transformations
• Color transformations