mdx-m3-viewer/src/viewer/handlers/tga/texture.js

A browser WebGL model viewer. Mainly focused on models of the games Warcraft 3 and Starcraft 2.

import {scaleNPOT} from '../../../common/canvas';
import Texture from '../../texture';

/**
 * A TGA texture handler.
 */
export default class TgaTexture extends Texture {
  /**
   * @param {ArrayBuffer} src
   */
  load(src) {
    let gl = this.viewer.gl;
    let dataView = new DataView(src);
    let imageType = dataView.getUint8(2);

    if (imageType !== 2) {
      throw new Error('Unsupported image type');
    }

    let width = dataView.getUint16(12, true);
    let height = dataView.getUint16(14, true);
    let pixelDepth = dataView.getUint8(16);

    if (pixelDepth !== 32) {
      throw new Error('Unsupported bits per pixel');
    }

    // Upscale to POT if the size is NPOT.
    let imageData = scaleNPOT(new ImageData(new Uint8ClampedArray(src, 18, width * height * 4), width, height));

    let id = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, id);
    this.viewer.webgl.setTextureMode(gl.REPEAT, gl.REPEAT, gl.LINEAR, gl.LINEAR_MIPMAP_LINEAR);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, imageData);
    gl.generateMipmap(gl.TEXTURE_2D);

    this.imageData = imageData;
    this.width = imageData.width; // Note: might not be the same as 'width' and 'height' due to NPOT upscaling.
    this.height = imageData.height;
    this.webglResource = id;
  }
}