-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
8 changed files
with
83 additions
and
8 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,11 @@ | ||
Copyright 2024 Jon Mease | ||
|
||
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: | ||
|
||
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. | ||
|
||
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. | ||
|
||
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. | ||
|
||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,11 @@ | ||
Copyright 2024 Jon Mease | ||
|
||
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: | ||
|
||
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. | ||
|
||
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. | ||
|
||
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. | ||
|
||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,49 @@ | ||
# Avenger: A visualization engine and renderer | ||
Avenger is an early stage prototype of a new foundational rendering library for information visualization (InfoVis) systems. Avenger defines a 2D scenegraph representation tailored to the needs of InfoVis systems. To start with, the initial application of Avenger is to serve as an alternative, GPU accelerated, rendering backend for Vega visualizations. | ||
|
||
# Try it out in Python with Vega-Altair | ||
The `avenger` Python package provides a [custom Altair renderer](https://altair-viz.github.io/user_guide/custom_renderers.html) named `avenger-png`. This renderer relies on vl-convert to extract the vega scenegraph corresponding to a chart and then uses Avenger to render the chart to a static PNG image. | ||
|
||
First, install altair, vega-datasets, avenger, and vl-convert-python | ||
``` | ||
pip install -U altair vega_datasets avenger "vl-convert-python>=1.2.3" | ||
``` | ||
|
||
Then import Altair and activate the `avenger-png` renderer | ||
|
||
```python | ||
import altair as alt | ||
alt.renderers.enable('avenger-png', scale=1) | ||
``` | ||
|
||
Then create and display an Altair chart as usual: | ||
|
||
```python | ||
import altair as alt | ||
from vega_datasets import data | ||
|
||
source = data.cars() | ||
|
||
chart = alt.Chart(source).mark_circle(size=60).encode( | ||
x='Horsepower', | ||
y='Miles_per_Gallon', | ||
color='Origin', | ||
) | ||
chart | ||
``` | ||
![cars_scatter](https://github.com/jonmmease/avenger/assets/15064365/d661e142-c7c5-4816-a375-49a73985bb6d) | ||
|
||
Or, convert the chart to a PNG rendered by Avenger: | ||
|
||
```python | ||
import avenger | ||
png = avenger.altair_utils.chart_to_png(chart, scale=1) | ||
with open("scatter.png", "wb") as f: | ||
f.write(png) | ||
``` | ||
## Comparison to vl-convert | ||
There aren't currently many advantages to using Avenger to render Altar charts to PNG as compared with vl-convert, which performs rendering using [resvg](https://github.com/RazrFalcon/resvg). Performance is generally comparable, though Avenger can be a bit faster for charts with a large number of symbol instances. | ||
|
||
One advantage is that Avenger's text rendering support is based on [COSMIC Text](https://github.com/pop-os/cosmic-text), which supports emoji (unlike resvg's text handling). For example, here is the result of rendering the emoji example from https://altair-viz.github.io/gallery/isotype_emoji.html using Avenger: | ||
|
||
![isotype_emoji](https://github.com/jonmmease/avenger/assets/15064365/91a1db89-9bdd-46f3-b540-c7d7bcaac3c2) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters