@woosh/meep-engine/src/engine/graphics/geometry/MikkT/GenerateInitialVerticesIndexList.js

Pure JavaScript game engine. Fully featured and production ready.

import { m_getNumFaces } from "./m_getNumFaces.js";
import { MakeIndex } from "./MakeIndex.js";
import { assert } from "../../../../core/assert.js";

/**
 *
 * @param {STriInfo[]} pTriInfos
 * @param {number[]|Int32Array} piTriList_out
 * @param {SMikkTSpaceContext } pContext
 * @param {number} iNrTrianglesIn
 * @return {number}
 */
export function GenerateInitialVerticesIndexList(pTriInfos, piTriList_out, pContext, iNrTrianglesIn) {
    let iTSpacesOffs = 0;
    let iDstTriIndex = 0;

    const face_count = m_getNumFaces(pContext);

    for (let f = 0; f < face_count; f++) {

        const tri_info = pTriInfos[iDstTriIndex];

        tri_info.iOrgFaceNumber = f;
        tri_info.iTSpacesOffs = iTSpacesOffs;

        const pVerts = tri_info.vert_num;

        pVerts[0] = 0;
        pVerts[1] = 1;
        pVerts[2] = 2;

        piTriList_out[iDstTriIndex * 3 ] = MakeIndex(f, 0);
        piTriList_out[iDstTriIndex * 3 + 1] = MakeIndex(f, 1);
        piTriList_out[iDstTriIndex * 3 + 2] = MakeIndex(f, 2);

        ++iDstTriIndex;	// next

        iTSpacesOffs += 3;
        assert.lessThanOrEqual(iDstTriIndex, iNrTrianglesIn);
    }

    for (let t = 0; t < iNrTrianglesIn; t++) {
        pTriInfos[t].iFlag = 0;
    }

    // return total amount of tspaces
    return iTSpacesOffs;
}