add example renderers to concepts page

pull/1/head
Evan Hemsley 2019-06-13 10:43:08 -07:00
parent cadb230de6
commit 8fe24b8174
1 changed files with 38 additions and 1 deletions

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@ -14,6 +14,43 @@ There are two kinds of renderers: GeneralRenderers and EntityRenderers.
A GeneralRenderer is a Renderer which reads the game state in order to draw elements to the screen. It also requires a layer, which represents the order in which it will draw to the screen.
If you were using the LOVE engine, a GeneralRenderer might look like this:
```ts
import { GeneralRenderer } from "encompass-ecs";
import { ScoreComponent } from "game/components/score";
export class ScoreRenderer extends GeneralRenderer {
public layer = 4;
public render() {
const score_component = this.read_component(ScoreComponent);
love.graphics.print(score_component.score, 20, 20);
}
}
```
An EntityRenderer provides a structure for the common pattern of drawing an Entity which has a particular collection of Components and a specific type of DrawComponent. They also have the ability to draw DrawComponents at their specific layer.
For 2D games, you will need to be specific about the order in which things draw. For a 3D game you will probably end up delegating rendering to some kind of scene/camera system.
If you were using the LOVE engine, a GeneralRenderer might look like this:
```ts
import { EntityRenderer } from "encompass-ecs";
import { PointComponent } from "game/components/point";
import { PositionComponent } from "game/components/position";
@Renders(PointComponent, PositionComponent)
export class PointRenderer extends EntityRenderer {
public render(entity: Entity) {
const point_component = entity.get_component(PointComponent);
const position_component = entity.get_component(PositionComponent);
const color = point_component.color;
love.graphics.setColor(color.r, color.g, color.b, color.a);
love.graphics.point(position_component.x, position_component.y);
}
}
```
For 2D games, you will need to be use layers to be specific about the order in which entities draw. For a 3D game you will probably end up delegating rendering to some kind of scene/camera system.