## Question(s) about transformation matrix

General topics related to Rainmeter.

### Question(s) about transformation matrix

Hello everyone.
I'm working with transformation matrix, but I do not understand how to make a skew of a polygon (the green square in the following images).

I use a couple of images to explain:
I have this image:
and my goal is this

where the blue point is the origin i.e. the top-left corner of the entire skin.

Now, the first question: how I calculate the new origin point for the square (you can see that the blue point, after the transformation, is at a new value of X) ?
the second question: if I wanted to change the origin point of the transformation, what should I insert in the matrix ?

An example code:

Code: Select all

`[Rainmeter]Update=-1AccurateText=1DynamicWindowSize=1[Variables]Angle=-60X_prime=150Y_prime=150[MeasureScaleX]Measure=CalcFormula=1[MeasureSkewY]Measure=CalcFormula=0DynamicVariables=1[MeasureSkewX]Measure=CalcFormula=TAN(Rad(#Angle#))DynamicVariables=1[MeasureScaleY]Measure=CalcFormula=1[MeasureMoveX]Measure=CalcFormula=(#X_prime# - [MeterSquare:X] * [MeasureScaleX:] - [MeterSquare:Y] * [MeasureSkewX:])DynamicVariables=1[MeasureMoveY]Measure=CalcFormula=(#Y_prime# - [MeterSquare:X] * [MeasureSkewY:] - [MeterSquare:Y] * [MeasureScaleY:])DynamicVariables=1[MeterBackground]Meter=ImageX=0Y=0W=400H=400SolidColor=200,200,200,125[MeterSquare]Meter=ImageX=150Y=150W=100H=100SolidColor=255,0,0,255SolidColor2=0,255,0,255GradientAngle=270AntiAlias=1TransformationMatrix=([MeasureScaleX:]);([MeasureSkewY:]);([MeasureSkewX:]);([MeasureScaleY:]);([MeasureMoveX:]);([MeasureMoveY:])DynamicVariables=1`

Easy...

### Re: Question(s) about transformation matrix

FreeRaider wrote:Now, the first question: how I calculate the new origin point for the square (you can see that the blue point, after the transformation, is at a new value of X) ?
the second question: if I wanted to change the origin point of the transformation, what should I insert in the matrix ?

The last two parameters of the TransformationMatrix option are used to move the "transformed" meter horizontally, respectively vertically (obviously the fifth moves it horizontally, while the sixth vertically). So you should have to alter the fifth parameter. In your initial code it is `([MeasureMoveX:])`. I'd modify the Formula option of the [MeasureMoveX] measure, to `Formula=(2 * #X_prime# - [MeterSquare:X] * [MeasureScaleX:] - [MeterSquare:Y] * [MeasureSkewX:])` (I marked red what I've changed). Not sure this will entirely match your needs, but if it doesn't, you can add a constant value: `Formula=(2 * #X_prime# - [MeterSquare:X] * [MeasureScaleX:] - [MeterSquare:Y] * [MeasureSkewX:] + 23)`. I think you have to make a few tries to find the best value to add, 23 is just a first approach.
I hope this answers both questions. If it doesn't please let me know.

### Re: Question(s) about transformation matrix

balala wrote:used to move the "transformed" meter
this sentence has opened my mind.

Precisely, the measure must be

Code: Select all

`[MeasureMoveX]Measure=CalcFormula=(#X_prime# - [MeterSquare:X] * [MeasureScaleX:] - [MeterSquare:Y] * [MeasureSkewX:] - [MeterSquare:H] * [MeasureSkewX:])DynamicVariables=1`

The updated code

Code: Select all

`[Rainmeter]Update=-1AccurateText=1DynamicWindowSize=1[Variables]Angle=(0-30)X_prime=150Y_prime=150[MeasureScaleX]Measure=CalcFormula=1[MeasureSkewY]Measure=CalcFormula=0DynamicVariables=1[MeasureSkewX]Measure=CalcFormula=TAN(Rad(#Angle#))DynamicVariables=1[MeasureScaleY]Measure=CalcFormula=1[MeasureMoveX]Measure=CalcFormula=(#X_prime# - [MeterSquare:X] * [MeasureScaleX:] - [MeterSquare:Y] * [MeasureSkewX:] - [MeterSquare:H] * [MeasureSkewX:])DynamicVariables=1[MeasureMoveY]Measure=CalcFormula=(#Y_prime# - [MeterSquare:X] * [MeasureSkewY:] - [MeterSquare:Y] * [MeasureScaleY:])DynamicVariables=1[MeterBackground]Meter=ImageX=0Y=0W=400H=400SolidColor=200,200,200,125[MeterSquare]Meter=ImageX=150Y=150W=100H=100SolidColor=255,0,0,255SolidColor2=0,255,0,255GradientAngle=270AntiAlias=1TransformationMatrix=([MeasureScaleX:]);([MeasureSkewY:]);([MeasureSkewX:]);([MeasureScaleY:]);([MeasureMoveX:]);([MeasureMoveY:])DynamicVariables=1[MeterVertical]Meter=ImageX=150Y=0W=1H=400SolidColor=0,0,0,255[MeterHorizontal]Meter=ImageX=0Y=150W=400H=1SolidColor=0,0,0,255`