matrix4_transform 1.0.2

Helper math class for easily creating Matrix4 transformations, that you can use in Container's transform parameter and elsewhere.

matrix4_transform

Helper class for easily creating Matrix4 transformations, that you can use in Container's transform parameter, and elsewhere.

Example:

// Rotates the Container 45 degrees and then
// translates 25 pixels to the right. 
Container(
   transform:
     Matrix4Transform()
       .rotateDegrees(45, origin: Offset(25, 25))
       .translate(x: 25)
       .matrix4,
   child: ...
);

To see it in action, run the example in the example tab.

How to use it

Matrix4Transform is immutable (in contrast, Matrix4 is mutable).

First create a Matrix4Transform:

Matrix4Transform();

Then call the methods to transform it. For example:

Matrix4Transform()
   .scale(1.5)
   .upRight(35)
   .rotate(pi/2);

In the end, call matrix4:

Matrix4 myMatrix 
   = Matrix4Transform()
     .scale(1.5)
     .upRight(35)
     .rotate(pi/2)
     .matrix4;                        

Note: The transformations will be applied in order, and their order may change the end result.

If you already have a matrix4 and want to further transform it, you can use the from constructor:

Matrix4 myMatrix = ...;

var myTransform = Matrix4Transform.from(myMatrix);

Methods you can use

• rotate(double angleRadians, {Offset origin})
• rotateDegrees(double angleDegrees, {Offset origin})
• rotateByCenterDegrees(double angleDegrees, Size size)
• rotateByCenter(_toRadians(angleDegrees), size)
• translate({double x = 0, double y = 0})
• translateOriginalCoordinates({double x = 0, double y = 0})
• scale(double factor, {Offset origin})
• scaleBy({double x = 1, double y = 1, Offset origin})
• scaleHorizontally(double factor)
• scaleVertically(double factor)
• translateOffset(Offset offset)
• up(double distance)
• down(double distance)
• right(double distance)
• left(double distance)
• direction(double directionRadians, double distance)
• directionDegrees(double directionDegrees, double distance)
• upRight(double distance)
• upLeft(double distance)
• downRight(double distance)
• downLeft(double distance)

And, of course:

• Matrix4 toMatrix4

Animate it

You can put the Matrix4Transform in a Container's transform parameter, and then animate the Matrix4Transform parameters.

Then, you can use AlignPositioned or Stack+Positioned to move the Container around in relation to the screen or some parent widget.

Matrix4Transform can also be used in AnimatedContainer's transform parameter. However, since Matrix4Tween will not animate linearly as you'd expect, it's possible that the intermediary transformations will be "strange", although the start and end should be correct.

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Special thanks to Martin Kamleithner and Simon Lightfoot.

The Flutter packages I've authored:

• async_redux
• align_positioned
• network_to_file_image
• align_positioned
• back_button_interceptor
• indexed_list_view
• animated_size_and_fade

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https://github.com/marcglasberg
https://twitter.com/glasbergmarcelo
https://stackoverflow.com/users/3411681/marcg
https://medium.com/@marcglasberg