How should we handle transformations in OpenGL?

Blessing number 1, look at MV.js from the Common folder.
- Note vec2, ... vec4 are declared.
- Note mat2 ... mat4 are declared
- Plus equal, add, subtract and mult are declared for vectors and matrix combinations
- Plus dot, negate, cross, length and normalize for vectors
- Some matrix operations we will not use.
Blessing number 2
- translate, rotate, scalem
  - What do these take?
  - What do they produce?
- And a few I don't understand
  - lookat
  - project
  - ortho
  - perspective
Remember our coordinate systems for modeling objects in Mr Smiley's Scroll
- A coordinate system for each basic object.
- A coordinate system for compound objects.
- A world coordinate system.
I used the following algorithm

Apply World Transformation
For each Object
    Apply Static Transformation
    Draw All Static Parts // Including sub-objects
    For each Moving Part
        Apply Motion Transformation
	Draw All Parts of this piece in Motion // including sub-objects
	Remove Motion Transformation
    Remove Static Transformation

How can we accomplish this given the Widget object?
- A Widget is a buffer and a drawing routine.
- It does not handle any transformations.
- Assume it is a primitive that you have created.
Should a Widget contain color information?
Should a Widget contain transformations?
Say we want four cubes on the screen,
- Should we have four cube widget instances?
Let's design a higher object.
- It should have a set of setable transformations (translate, scale, rotate)
  - What order?
  - Changable?
- It should contain a pointer to a Widget (or more)
- If it has movable parts, it should have setable transformations for each of these
  - Or possibly settable by calls to functions like Animate(), or Next()
- Where will each of these transformation matrices be stored?
What will the supporting vertex shader look like?
- ```
// guess 1
gl_Position = uProject * uWTOC * uTransform * vPosition
```
  // or gl_Position = uProject * uWTOC * uT1 * uT2 * vPosition
Let's think of two godzillas on a sea-saw