49 lines
2 KiB
Markdown
49 lines
2 KiB
Markdown
#  Documentation
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Background and more in depth information about the rendring techniques can be found in [this technical report](media/sdf-2d.pdf).
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## Links
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- [Repository](https://github.com/schmelczerandras/sdf-2d)
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- [Demo](https://sdf2d.schmelczer.dev/)
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- [Minimal example](https://github.com/schmelczerandras/sdf-2d-minimal-example)
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- [More complex example](https://github.com/schmelczerandras/sdf-2d-minimal-example)
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## Important to know
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### Coordinates
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Anywhere, where positions need to specified, the `y` values grow upwards, so are the `x` values. That means, when specifying the view area, the origin is at the bottom left corner of the display.
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### Tile-based rendering
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For optimising the evaluation of the distance field, the display is divided up into a grid of tiles. The shader for each tile is compiled to support a fix maximum number of objects on it. When using the built-in drawables, it is possible that after a certain number of on-screen objects, new ones won't be visible.
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Mitigating this issue is quite easy. Instead of the following code:
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```js
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this.renderer = await compile(canvas, [Circle.descriptor, CircleLight.descriptor]);
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```
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Modify it to something similar:
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```js
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this.renderer = await compile(canvas, [
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{
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...Circle.descriptor,
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shaderCombinationSteps: [0, 1, 2, 24, 64],
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},
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{
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...CircleLight.descriptor,
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shaderCombinationSteps: [0, 1, 2, 4],
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},
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]);
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```
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The usage of too large numbers is not advised for compatibility and performance reasons alike.
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> Steps are very useful for tile-based rendering, because it is possible for one tile (at a given moment) to be empty or contain just a few objects, while others have a large cluster of objects. The compiled shaders only take into account the necesseary number of objects on each tiles.
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## Usage
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To start using cutting-edge 2D graphics, first you have get a renderer instance. This is possible by calling the [compile function](globals.html#compile).
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