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// Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
import Qt3D.Core 2.0
import Qt3D.Render 2.0
import Qt3D.Extras 2.0
Entity {
property alias particleStep: computeMaterial.particleStep
property alias finalCollisionFactor: computeMaterial.finalCollisionFactor
readonly property int _SPHERE: 0
readonly property int _CUBE: 1
readonly property int _CYLINDER: 2
readonly property int _TORUS: 3
property int particlesShape: _SPHERE
signal reset()
components: [
RenderSettings {
ComputeFrameGraph {
camera: sceneCamera
}
// explicitly set RenderingPolicy to AlwaysRender, as changes in the
// scene won't be reflected in actual Qt scene-graph changes (due to
// GPU compute calls)
renderPolicy: RenderSettings.Always
}
]
FirstPersonCameraController { camera: sceneCamera }
Camera {
id: sceneCamera
projectionType: CameraLens.PerspectiveProjection
viewCenter: Qt.vector3d(0, 0, 0)
position: Qt.vector3d(0, 0, -800)
nearPlane: 0.1
farPlane: 1000
fieldOfView: 25
aspectRatio: 1.33
}
property int particlesCount: 50 * 1024
readonly property int floatSize: 4
function buildParticlesBuffer() {
var byteSizeOfParticleData = 12;
var bufferData = new Float32Array(particlesCount * byteSizeOfParticleData);
var factor = 500.0;
for (var i = 0; i < particlesCount; ++i) {
var positionIdx = i * byteSizeOfParticleData;
var velocityIdx = i * byteSizeOfParticleData + 4;
var colorIdx = i * byteSizeOfParticleData + 8;
for (var j = 0; j < 3; ++j) {
bufferData[positionIdx + j] = (Math.random() - 0.5) * factor;
bufferData[velocityIdx + j] = Math.random() * 2.0;
bufferData[colorIdx + j] = 0.75 + Math.sin(((i / 1024.0) + j * 0.333) * 6.0) * 0.25;
}
bufferData[positionIdx + 3] = 1.0;
bufferData[velocityIdx + 3] = 0.0;
bufferData[colorIdx + 3] = 1.0;
}
return bufferData
}
Buffer {
id: particleBuffer
// struct ParticleData
// {
// vec3 position; // Aligned to 4 floats
// vec3 velocity; // Aligned to 4 floats
// vec3 color; // Aligned to 4 floats
// };
data: buildParticlesBuffer()
}
onReset : {
particleBuffer.data = buildParticlesBuffer()
}
Attribute {
id: particlePositionDataAttribute
name: "particlePosition"
attributeType: Attribute.VertexAttribute
vertexBaseType: Attribute.Float
vertexSize: 3
divisor: 1
byteStride: 12 * floatSize
buffer: particleBuffer
}
Attribute {
id: particleColorDataAttribute
name: "particleColor"
attributeType: Attribute.VertexAttribute
vertexBaseType: Attribute.Float
vertexSize: 3
divisor: 1
byteOffset: 8 * floatSize
byteStride: 12 * floatSize
buffer: particleBuffer
}
ComputeMaterial {
id: computeMaterial
dataBuffer: particleBuffer
}
Entity {
id: particleComputeEntity
readonly property ComputeCommand particlesComputeJob: ComputeCommand {}
components: [
particlesComputeJob,
computeMaterial
]
}
SphereGeometry {
id: sphereGeometry
rings: 10
slices: 10
radius: 1
// Additional Attributes
attributes: [
particlePositionDataAttribute,
particleColorDataAttribute
]
}
CuboidGeometry {
id: cubeGeometry
yzMeshResolution: Qt.size(2, 2)
xzMeshResolution: Qt.size(2, 2)
xyMeshResolution: Qt.size(2, 2)
// Additional Attributes
attributes: [
particlePositionDataAttribute,
particleColorDataAttribute
]
}
CylinderGeometry {
id: cylinderGeometry
rings: 10
slices: 10
radius: 1
length: 1.5
// Additional Attributes
attributes: [
particlePositionDataAttribute,
particleColorDataAttribute
]
}
TorusGeometry {
id: torusGeometry
rings: 10
slices: 10
radius: 1
minorRadius: 0.5
// Additional Attributes
attributes: [
particlePositionDataAttribute,
particleColorDataAttribute
]
}
Entity {
id: particleRenderEntity
readonly property GeometryRenderer particlesRenderer: GeometryRenderer {
instanceCount: particlesCount
indexOffset: 0
firstInstance: 0
primitiveType: GeometryRenderer.Triangles
geometry: {
switch (particlesShape) {
case _SPHERE:
return sphereGeometry;
case _CUBE:
return cubeGeometry;
case _CYLINDER:
return cylinderGeometry;
case _TORUS:
return torusGeometry;
}
}
}
components: [
particlesRenderer,
computeMaterial
]
}
}
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