@polygonjs/polygonjs/dist/src/core/geometry/operation/AttribFromTexture.js

node-based WebGL 3D engine https://polygonjs.com

"use strict";
import { BufferAttribute } from "three";
import { CoreImage } from "../../Image";
import { CoreAttribute } from "../../geometry/Attribute";
import { clamp } from "../../math/_Module";
import { corePointClassFactory } from "../CoreObjectFactory";
export class AttribFromTexture {
  // currently assumes we read the red channel and create a 1-dimension (float) attribute
  setAttribute(params) {
    const { object, texture, uvAttribName, targetAttribName, targetAttribSize, add, mult } = params;
    const corePointClass = corePointClassFactory(object);
    if (targetAttribSize < 1 || targetAttribSize > 4) {
      return;
    }
    const texture_data = this._dataFromTexture(texture);
    if (!texture_data) {
      return;
    }
    const { data, resx, resy } = texture_data;
    const texture_component_size = data.length / (resx * resy);
    const uv_attrib = corePointClass.attribute(object, uvAttribName);
    if (!uv_attrib) {
      return;
    }
    const uvs = uv_attrib.array;
    const points_count = uvs.length / 2;
    const values = new Array(points_count * targetAttribSize);
    let uv_stride, uvx, uvy, x, y, i, j, val, c;
    for (i = 0; i < points_count; i++) {
      uv_stride = i * 2;
      uvx = clamp(uvs[uv_stride], 0, 1);
      uvy = clamp(uvs[uv_stride + 1], 0, 1);
      x = Math.floor((resx - 1) * uvx);
      y = Math.floor((resy - 1) * (1 - uvy));
      j = y * resx + x;
      for (c = 0; c < targetAttribSize; c++) {
        val = data[texture_component_size * j + c];
        values[i * targetAttribSize + c] = mult * val + add;
      }
    }
    const attribName = CoreAttribute.remapName(targetAttribName);
    const array = new Float32Array(values);
    corePointClass.addAttribute(object, attribName, new BufferAttribute(array, targetAttribSize));
  }
  _dataFromTexture(texture) {
    if (texture.image) {
      if (texture.image.data) {
        return this._dataFromDataTexture(texture);
      }
      return this._dataFromDefaultTexture(texture);
    }
  }
  _dataFromDefaultTexture(texture) {
    const resx = texture.image.width;
    const resy = texture.image.height;
    const image_data = CoreImage.data_from_image(texture.image);
    const data = image_data.data;
    return {
      data,
      resx,
      resy
    };
  }
  _dataFromDataTexture(texture) {
    const data = texture.image.data;
    const resx = texture.image.width;
    const resy = texture.image.height;
    return {
      data,
      resx,
      resy
    };
  }
}