liquidfun's GetPositionBuffer() doesn't return a list #77

8Observer8 · 2024-06-14T22:56:53Z

I try to use liquid fun. GetPositionBuffer doesn't return a list:

    const positions = particleSystem.GetPositionBuffer();
    console.log(positions[0]);

I prints undefined.

But it must return a list because C++ works like this:

    b2Vec2 *pos = m_particleSystem->GetPositionBuffer();
    qDebug() << pos[0].x  << pos[0].y;

Full example that includes the liquid fun lib library: get-position-buffer-box2dwasm-js.zip

index.js

import { box2d, initBox2D } from "./init-box2d.js";

async function init() {
    await initBox2D();

    const {
        b2CircleShape,
        b2ParticleGroupDef,
        b2ParticleSystemDef,
        b2Vec2,
        b2World
    } = box2d;

    const world = new b2World();
    const pixelsPerMeter = 50;

    const particleSystemDef = new b2ParticleSystemDef();
    particleSystemDef.radius = 5 / pixelsPerMeter;
    const particleSystem = world.CreateParticleSystem(particleSystemDef);
    const spawnArea = new b2CircleShape();
    spawnArea.m_radius = 20 / pixelsPerMeter;
    spawnArea.m_p.x = 100 / pixelsPerMeter;
    spawnArea.m_p.y = 30 / pixelsPerMeter;
    const particleGroupDefinition = new b2ParticleGroupDef();
    particleGroupDefinition.shape = spawnArea;
    particleSystem.CreateParticleGroup(particleGroupDefinition);

    const positions = particleSystem.GetPositionBuffer();
    console.log(positions[0].x);
}

init();

index.html

<!DOCTYPE html>

<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Liquid fun</title>
</head>

<body>
    <script type="importmap">
        {
            "imports": {
                "box2d-wasm": "/libs/[email protected]/es/entry.js"
            }
        }
    </script>

    <script type="module" src="./js/index.js"></script>
</body>

</html>

The text was updated successfully, but these errors were encountered:

8Observer8 · 2024-06-15T00:02:12Z

And I have this messages: wasm streaming and falling back to ArrayBuffer when I run the example above:

flygOn-LiTe · 2024-06-16T00:39:59Z

I am having the same issue. The GetPositionBuffer method is returning a single object with x and y properties instead of a buffer. I can confirm all particles are there when debugging but cannot render the particles due to GetPositionBuffer not working as expected.

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

liquidfun's GetPositionBuffer() doesn't return a list #77

liquidfun's GetPositionBuffer() doesn't return a list #77

8Observer8 commented Jun 14, 2024 •

edited

Loading

8Observer8 commented Jun 15, 2024

flygOn-LiTe commented Jun 16, 2024

liquidfun's GetPositionBuffer() doesn't return a list #77

liquidfun's GetPositionBuffer() doesn't return a list #77

Comments

8Observer8 commented Jun 14, 2024 • edited Loading

8Observer8 commented Jun 15, 2024

flygOn-LiTe commented Jun 16, 2024

8Observer8 commented Jun 14, 2024 •

edited

Loading