Run-time Optimisation
The thread.stackFrames array is accessed all the time to retrieve the
'parent' stack frame. This is done using as index of [this.stack.length
- 1]. However, a lot of the time this evaluated to [-1]. Although this
results in null, which is fine, to get to this javascript actually
defers from a numeric array lookup to an object lookup using the string
"-1". This is roughly 100 times slower to compute and so a simple catch
for negative indexes is well worth the extra check.
Had to update the test scripts to handle the alpha channel, also I note
that all the hex tests are using CSS notation, not scratch notation
(which is 0x not #)
Changes include:
- Added missing JSDoc for items in `scratch3_pen.js` and `target.js`.
- Moved constants used by `Scratch3PenBlocks` into the class.
- Created a constant for minimum and maximum pen size.
- Added `util/clone.js` to host cloning functionality.
- Pen blocks now check for the renderer before trying to use it.
- The pen integration test covers all blocks, though `clear`, `stamp`,
and `pen down` will skip some of their functionality when there is no
renderer.
Also, fix a math error in `Color.rgbToHsv`.
Newly covered functions:
- `toRbgColorObject` from `util/cast.js`
- `hsvToRgb` from `util/colors.js`
- `rgbToHsv` from `util/colors.js`
- `mixRgb` from `util/colors.js`
These blocks implement pen features as found in Scratch 2.0
Supporting changes include:
- `Target` is now an event emitter
- `RenderedTarget` now emits an event when it moves
- `Target` can now store arbitrary "extra" data, called "custom state"
in the code, using a `Target`'s `setCustomState` and `getCustomState`
methods. This is used to store per-target pen state without requiring
`Target` or `RenderedTarget` to know anything about the pen.
- `Cast` can now cast to an RGB color object.
- `Color` now has functions to convert between RGB and HSV, constants
for for black & white, and a `mixRgb` function to lerp between two
colors.
* Move Node output: /dist.js => /dist/node/scratch-vm.js
* Move web output: /vm{.js,.min.js} => /dist/web/scratch-vm{.js,.min.js}
* Update build output references in package.json and the playground's index.html
* Move the VirtualMachine class out of index.js into its own file, referenced by index.js. The VirtualMachine class is otherwise unchanged.
* Add .gitattributes rules for new file types which were added to this repository without specifying their text/binary attributes
* Turn on source maps in webpack and add corresponding .gitignore rule
This prevents sending `NaN`s to the renderer as the rotation center, which prevents the initial render of the costume/backdrop.
Towards LLK/scratch-gui#18
Previously it assumed every costume to have a `bitmapResolution` property which doesn't apply to vector costumes. This caused the renderer to not render added SVG costumes when they were added with setCostume.
