Bouwsel

# tempono/cube-building

A building of cubes drawn in 3D from its plan. The pupil counts the cubes,
colours the front, side or top view, writes the plan with numbers, or works
out how many cubes make it a full block. Graded per task.

## Config

| Field | Type | Notes |
| --- | --- | --- |
| heights | rows of 0-4 | The plan seen from above: the back row first, the front row last; each number is a stack. At most 4 by 4. |
| plan | boolean | Print the plan with numbers next to the building (easier: the hidden cubes show). Default false. |
| ask | 1-3 of count, front, side, top, plan, full | count: how many cubes; front / side / top: colour the view (side = from the right, front on the left); plan: write the numbers; full: cubes to add for a solid block of width × depth × tallest stack. |
| tone | accent, blue, green, orange, purple, red, brown | Colour of the cubes. Default accent. |

The drawing looks from the front, a little from the right and from above:
the front of the building is its lower left side ("voor"), the right side
its lower right side ("rechts"). On the plan and the top view the front is
at the bottom.

## Example

```yaml
- type: task
  id: q1
  prompt: Tel de kubussen en kleur het vooraanzicht.
  answer:
    type: tempono/cube-building@1.0.0
    heights:
    - [3, 2, 1]
    - [2, 1, 0]
    ask: [count, front]
```

## Grading

One point per item in `ask`. A view counts only when every cell is right;
the plan only when every square is (an empty square may be left blank).
Typed answers: one part per item, separated by `;`, e.g. `9; 3 2 1`
(a view as the column heights, the top view as 1 and 0 per square, the plan
as all its numbers, back row first).

## Checks

- Rows of equal length, at least one cube, no empty outer row or column.
- Without `plan: true`, the top of every stack must be visible in the
  drawing (a stack k squares nearer along the line of sight and k or more
  higher hides it). This tests the middle of each top, so a top that is
  half hidden passes: look at the render.
- `plan` can't be both printed and asked.