three-stdlib
Version:
stand-alone library of threejs examples
234 lines (223 loc) • 9.05 kB
JavaScript
var __defProp = Object.defineProperty;
var __defNormalProp = (obj, key, value) => key in obj ? __defProp(obj, key, { enumerable: true, configurable: true, writable: true, value }) : obj[key] = value;
var __publicField = (obj, key, value) => {
__defNormalProp(obj, typeof key !== "symbol" ? key + "" : key, value);
return value;
};
import { DataTexture, RGBAFormat, FloatType, RepeatWrapping, NearestFilter, Mesh, InstancedMesh, DynamicDrawUsage, Matrix4 } from "three";
const CHANNELS = 4;
const TEXTURE_WIDTH = 1024;
const TEXTURE_HEIGHT = 4;
const initSplineTexture = (numberOfCurves = 1) => {
const dataArray = new Float32Array(TEXTURE_WIDTH * TEXTURE_HEIGHT * numberOfCurves * CHANNELS);
const dataTexture = new DataTexture(dataArray, TEXTURE_WIDTH, TEXTURE_HEIGHT * numberOfCurves, RGBAFormat, FloatType);
dataTexture.wrapS = RepeatWrapping;
dataTexture.wrapT = RepeatWrapping;
dataTexture.magFilter = NearestFilter;
dataTexture.needsUpdate = true;
return dataTexture;
};
const updateSplineTexture = (texture, splineCurve, offset = 0) => {
const numberOfPoints = Math.floor(TEXTURE_WIDTH * (TEXTURE_HEIGHT / 4));
splineCurve.arcLengthDivisions = numberOfPoints / 2;
splineCurve.updateArcLengths();
const points = splineCurve.getSpacedPoints(numberOfPoints);
const frenetFrames = splineCurve.computeFrenetFrames(numberOfPoints, true);
for (let i = 0; i < numberOfPoints; i++) {
const rowOffset = Math.floor(i / TEXTURE_WIDTH);
const rowIndex = i % TEXTURE_WIDTH;
let pt = points[i];
setTextureValue(texture, rowIndex, pt.x, pt.y, pt.z, 0 + rowOffset + TEXTURE_HEIGHT * offset);
pt = frenetFrames.tangents[i];
setTextureValue(texture, rowIndex, pt.x, pt.y, pt.z, 1 + rowOffset + TEXTURE_HEIGHT * offset);
pt = frenetFrames.normals[i];
setTextureValue(texture, rowIndex, pt.x, pt.y, pt.z, 2 + rowOffset + TEXTURE_HEIGHT * offset);
pt = frenetFrames.binormals[i];
setTextureValue(texture, rowIndex, pt.x, pt.y, pt.z, 3 + rowOffset + TEXTURE_HEIGHT * offset);
}
texture.needsUpdate = true;
};
const setTextureValue = (texture, index, x, y, z, o) => {
const image = texture.image;
const { data } = image;
const i = CHANNELS * TEXTURE_WIDTH * o;
data[index * CHANNELS + i + 0] = x;
data[index * CHANNELS + i + 1] = y;
data[index * CHANNELS + i + 2] = z;
data[index * CHANNELS + i + 3] = 1;
};
const getUniforms = (splineTexture) => ({
spineTexture: { value: splineTexture },
pathOffset: { type: "f", value: 0 },
// time of path curve
pathSegment: { type: "f", value: 1 },
// fractional length of path
spineOffset: { type: "f", value: 161 },
spineLength: { type: "f", value: 400 },
flow: { type: "i", value: 1 }
});
function modifyShader(material, uniforms, numberOfCurves = 1) {
if (material.__ok)
return;
material.__ok = true;
material.onBeforeCompile = (shader) => {
if (shader.__modified)
return;
shader.__modified = true;
Object.assign(shader.uniforms, uniforms);
const vertexShader = (
/* glsl */
`
uniform sampler2D spineTexture;
uniform float pathOffset;
uniform float pathSegment;
uniform float spineOffset;
uniform float spineLength;
uniform int flow;
float textureLayers = ${TEXTURE_HEIGHT * numberOfCurves}.;
float textureStacks = ${TEXTURE_HEIGHT / 4}.;
${shader.vertexShader}
`.replace("#include <beginnormal_vertex>", "").replace("#include <defaultnormal_vertex>", "").replace("#include <begin_vertex>", "").replace(
/void\s*main\s*\(\)\s*\{/,
/* glsl */
`
void main() {
#include <beginnormal_vertex>
vec4 worldPos = modelMatrix * vec4(position, 1.);
bool bend = flow > 0;
float xWeight = bend ? 0. : 1.;
#ifdef USE_INSTANCING
float pathOffsetFromInstanceMatrix = instanceMatrix[3][2];
float spineLengthFromInstanceMatrix = instanceMatrix[3][0];
float spinePortion = bend ? (worldPos.x + spineOffset) / spineLengthFromInstanceMatrix : 0.;
float mt = (spinePortion * pathSegment + pathOffset + pathOffsetFromInstanceMatrix)*textureStacks;
#else
float spinePortion = bend ? (worldPos.x + spineOffset) / spineLength : 0.;
float mt = (spinePortion * pathSegment + pathOffset)*textureStacks;
#endif
mt = mod(mt, textureStacks);
float rowOffset = floor(mt);
#ifdef USE_INSTANCING
rowOffset += instanceMatrix[3][1] * ${TEXTURE_HEIGHT}.;
#endif
vec3 spinePos = texture2D(spineTexture, vec2(mt, (0. + rowOffset + 0.5) / textureLayers)).xyz;
vec3 a = texture2D(spineTexture, vec2(mt, (1. + rowOffset + 0.5) / textureLayers)).xyz;
vec3 b = texture2D(spineTexture, vec2(mt, (2. + rowOffset + 0.5) / textureLayers)).xyz;
vec3 c = texture2D(spineTexture, vec2(mt, (3. + rowOffset + 0.5) / textureLayers)).xyz;
mat3 basis = mat3(a, b, c);
vec3 transformed = basis
* vec3(worldPos.x * xWeight, worldPos.y * 1., worldPos.z * 1.)
+ spinePos;
vec3 transformedNormal = normalMatrix * (basis * objectNormal);
`
).replace(
"#include <project_vertex>",
/* glsl */
`vec4 mvPosition = modelViewMatrix * vec4( transformed, 1.0 );
gl_Position = projectionMatrix * mvPosition;`
)
);
shader.vertexShader = vertexShader;
};
}
class Flow {
/**
* @param {Mesh} mesh The mesh to clone and modify to bend around the curve
* @param {number} numberOfCurves The amount of space that should preallocated for additional curves
*/
constructor(mesh, numberOfCurves = 1) {
__publicField(this, "curveArray");
__publicField(this, "curveLengthArray");
__publicField(this, "object3D");
__publicField(this, "splineTexure");
__publicField(this, "uniforms");
const obj3D = mesh.clone();
const splineTexure = initSplineTexture(numberOfCurves);
const uniforms = getUniforms(splineTexure);
obj3D.traverse((child) => {
if (child instanceof Mesh || child instanceof InstancedMesh) {
child.material = child.material.clone();
modifyShader(child.material, uniforms, numberOfCurves);
}
});
this.curveArray = new Array(numberOfCurves);
this.curveLengthArray = new Array(numberOfCurves);
this.object3D = obj3D;
this.splineTexure = splineTexure;
this.uniforms = uniforms;
}
updateCurve(index, curve) {
if (index >= this.curveArray.length)
throw Error("Index out of range for Flow");
const curveLength = curve.getLength();
this.uniforms.spineLength.value = curveLength;
this.curveLengthArray[index] = curveLength;
this.curveArray[index] = curve;
updateSplineTexture(this.splineTexure, curve, index);
}
moveAlongCurve(amount) {
this.uniforms.pathOffset.value += amount;
}
}
const matrix = /* @__PURE__ */ new Matrix4();
class InstancedFlow extends Flow {
/**
*
* @param {number} count The number of instanced elements
* @param {number} curveCount The number of curves to preallocate for
* @param {Geometry} geometry The geometry to use for the instanced mesh
* @param {Material} material The material to use for the instanced mesh
*/
constructor(count, curveCount, geometry, material) {
const mesh = new InstancedMesh(geometry, material, count);
mesh.instanceMatrix.setUsage(DynamicDrawUsage);
mesh.frustumCulled = false;
super(mesh, curveCount);
__publicField(this, "offsets");
__publicField(this, "whichCurve");
this.offsets = new Array(count).fill(0);
this.whichCurve = new Array(count).fill(0);
}
/**
* The extra information about which curve and curve position is stored in the translation components of the matrix for the instanced objects
* This writes that information to the matrix and marks it as needing update.
*
* @param {number} index of the instanced element to update
*/
writeChanges(index) {
matrix.makeTranslation(this.curveLengthArray[this.whichCurve[index]], this.whichCurve[index], this.offsets[index]);
this.object3D.setMatrixAt(index, matrix);
this.object3D.instanceMatrix.needsUpdate = true;
}
/**
* Move an individual element along the curve by a specific amount
*
* @param {number} index Which element to update
* @param {number} offset Move by how much
*/
moveIndividualAlongCurve(index, offset) {
this.offsets[index] += offset;
this.writeChanges(index);
}
/**
* Select which curve to use for an element
*
* @param {number} index the index of the instanced element to update
* @param {number} curveNo the index of the curve it should use
*/
setCurve(index, curveNo) {
if (isNaN(curveNo))
throw Error("curve index being set is Not a Number (NaN)");
this.whichCurve[index] = curveNo;
this.writeChanges(index);
}
}
export {
Flow,
InstancedFlow,
getUniforms,
initSplineTexture,
modifyShader,
updateSplineTexture
};
//# sourceMappingURL=CurveModifier.js.map