LOVR-OOP-Graphics-Engine

Transform Class

Description

A transform object represents a position, rotation, and scale.
transform objects are automatically applied to node, light, model, and body objects.
Transformations can be rather confusing, but so much is possible using them. If you’re unfamiliar with transformation matrices, I suggest taking a look at this explanation.

Properties of a Transform object

matrix mat4: A transformation matrix.
position vector3: The position applied to the matrix.
scale vector3: The scale applied to the matrix.
rotation vector4: The rotation applied to the matrix. Though this is a vector4, the x, y, z, w components map to a quaternion’s angle, ax, ay, az components.
prevMatrix mat4: Used when detecting if the transform has been changed.
changed bool: Whether the transform has been changed since the last Transform:updatePrevMatrix() call.

Creating a Transform object

Passing in an optional array with a mat4, pos, rot, and/or scale will automatically set the transform object to include these values.

-- Create a new transform object at position (1, 1, 1)
LGE.Transform({
  pos = lovr.math.vec3(1, 1, 1)
})
-- Create a transform object with all values set to (0, 0, 0)
LGE.Transform()

General Methods

Create a new transformation matrix with the values of the matrix of the current transform object.
```
Transform:cloneMatrix()
```

Change any value(s) of the transform object.

Transform:setMatrix(info [array])
-- Example:
Transform:setMatrix({
  rot = lovr.math.vec4(math.rad(25), 1, 0, 0)
})

Update prevMatrix and changed a change in the position, rotation, scale, or matrix of the transform object.
```
Transform:updatePevMatrix()
```

Helper Functions

Extract position components x, y, z from a transformation matrix.
```
LGE.Transform.getPositionFromMat4(mat4 [mat4])
```
Extract rotation components angle, ax, ay, az from a transformation matrix.
```
LGE.Transform.getRotationFromMat4(mat4 [mat4])
```
Extract scale components x, y, z from a transformation matrix.
```
LGE.Transform.getScaleFromMat4(mat4 [mat4])
```
Extract position and rotation components x, y, z, angle, ax, ay, az from a transformation matrix.
```
LGE.Transform.getPose(mat4 [mat4])
```

Convert a matrix to a transformation matrix.

LGE.Transform.getTransformMatFromMat4(mat4 [mat4])

Extract a string from a matrix.

LGE.Transform.getStringFromMat4(mat4 [mat4])