aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/ClientStack/Linden/Caps/BunchOfCaps/MeshCost.cs
blob: f6a950f581ea29aae44f15ec34605d2346258aef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Text;

using OpenMetaverse;
using OpenMetaverse.StructuredData;

using OpenSim.Framework;
using OpenSim.Region.Framework;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Framework.Capabilities;

using ComponentAce.Compression.Libs.zlib;

using OSDArray = OpenMetaverse.StructuredData.OSDArray;
using OSDMap = OpenMetaverse.StructuredData.OSDMap;

namespace OpenSim.Region.ClientStack.Linden
{
    public struct ModelPrimLimits
    {
        
    }

    public class ModelCost
    {

        // upload fee defaults
        // fees are normalized to 1.0
        // this parameters scale them to basic cost ( so 1.0 translates to 10 )

        public float ModelMeshCostFactor = 0.0f; // scale total cost relative to basic (excluding textures)
        public float ModelTextureCostFactor = 1.0f; // scale textures fee to basic.
        public float ModelMinCostFactor = 0.0f; // 0.5f; // minimum total model free excluding textures

        // itens costs in normalized values
        // ie will be multiplied by basicCost and factors above
        public float primCreationCost = 0.002f;  // extra cost for each prim creation overhead
        // weigthed size to normalized cost
        public float bytecost = 1e-5f;

        // mesh upload fees based on compressed data sizes
        // several data sections are counted more that once
        // to promote user optimization
        // following parameters control how many extra times they are added
        // to global size.
        // LOD meshs
        const float medSizeWth = 1f; // 2x
        const float lowSizeWth = 1.5f; // 2.5x
        const float lowestSizeWth = 2f; // 3x
        // favor potencially physical optimized meshs versus automatic decomposition
        const float physMeshSizeWth = 6f; // counts  7x
        const float physHullSizeWth = 8f; // counts  9x      

        // stream cost area factors 
        // more or less like SL
        const float highLodFactor = 17.36f;
        const float midLodFactor = 277.78f;
        const float lowLodFactor = 1111.11f;

        // physics cost is below, identical to SL, assuming shape type convex
        // server cost is below identical to SL assuming non scripted non physical object

        // internal
        const int bytesPerCoord = 6; // 3 coords, 2 bytes per each

        // control prims dimensions
        public float PrimScaleMin = 0.001f;
        public float NonPhysicalPrimScaleMax = 256f;
        public float PhysicalPrimScaleMax = 10f;
        public int ObjectLinkedPartsMax = 512;

        // storage for a single mesh asset cost parameters       
        private class ameshCostParam
        {
            // LOD sizes for size dependent streaming cost
            public int highLODSize;
            public int medLODSize;
            public int lowLODSize;
            public int lowestLODSize;
            // normalized fee based on compressed data sizes
            public float costFee;
            // physics cost
            public float physicsCost;
        }

        // calculates a mesh model costs
        // returns false on error, with a reason on parameter error
        // resources input LLSD request
        // basicCost input region assets upload cost
        // totalcost returns model total upload fee
        // meshcostdata returns detailed costs for viewer 
        // avatarSkeleton if mesh includes a avatar skeleton
        // useAvatarCollider if we should use physics mesh for avatar
        public bool MeshModelCost(LLSDAssetResource resources, int basicCost, out int totalcost,
            LLSDAssetUploadResponseData meshcostdata, out string error, ref string warning)
        {
            totalcost = 0;
            error = string.Empty;

            bool avatarSkeleton = false;
            
            if (resources == null ||
                resources.instance_list == null ||
                resources.instance_list.Array.Count == 0)
            {
                error = "missing model information.";
                return false;
            }

            int numberInstances = resources.instance_list.Array.Count;

            if( numberInstances > ObjectLinkedPartsMax )
            {
                error = "Model whould have more than " + ObjectLinkedPartsMax.ToString() + " linked prims";
                return false;
            }

            meshcostdata.model_streaming_cost = 0.0;
            meshcostdata.simulation_cost = 0.0;
            meshcostdata.physics_cost = 0.0;
            meshcostdata.resource_cost = 0.0;

            meshcostdata.upload_price_breakdown.mesh_instance = 0;
            meshcostdata.upload_price_breakdown.mesh_physics = 0;
            meshcostdata.upload_price_breakdown.mesh_streaming = 0;
            meshcostdata.upload_price_breakdown.model = 0;

            int itmp;

            // textures cost
            if (resources.texture_list != null && resources.texture_list.Array.Count > 0)
            {
                float textures_cost = (float)(resources.texture_list.Array.Count * basicCost);
                textures_cost *= ModelTextureCostFactor;

                itmp = (int)(textures_cost + 0.5f); // round
                meshcostdata.upload_price_breakdown.texture = itmp;
                totalcost += itmp;
            }

            // meshs assets cost
            float meshsfee = 0;
            int numberMeshs = 0;
            bool haveMeshs = false;

            bool curskeleton;
            bool curAvatarPhys;

            List<ameshCostParam> meshsCosts = new List<ameshCostParam>();

            if (resources.mesh_list != null && resources.mesh_list.Array.Count > 0)
            {
                numberMeshs = resources.mesh_list.Array.Count;
                
                for (int i = 0; i < numberMeshs; i++)
                {
                    ameshCostParam curCost = new ameshCostParam();
                    byte[] data = (byte[])resources.mesh_list.Array[i];

                    if (!MeshCost(data, curCost,out curskeleton, out curAvatarPhys, out error))
                    {
                        return false;
                    }

                    if (curskeleton)
                    {
                        if (avatarSkeleton)
                        {
                            error = "model can only contain a avatar skeleton";
                            return false;
                        }
                        avatarSkeleton = true;
                    }
                    meshsCosts.Add(curCost);
                    meshsfee += curCost.costFee;
                }
                haveMeshs = true;
            }

            // instances (prims) cost
            

            int mesh;
            int skipedSmall = 0;
            for (int i = 0; i < numberInstances; i++)
            {
                Hashtable inst = (Hashtable)resources.instance_list.Array[i];

                ArrayList ascale = (ArrayList)inst["scale"];
                Vector3 scale;
                double tmp;
                tmp = (double)ascale[0];
                scale.X = (float)tmp;
                tmp = (double)ascale[1];
                scale.Y = (float)tmp;
                tmp = (double)ascale[2];
                scale.Z = (float)tmp;

                if (scale.X < PrimScaleMin || scale.Y < PrimScaleMin || scale.Z < PrimScaleMin)
                {
                    skipedSmall++;
                    continue;
                }

                if (scale.X > NonPhysicalPrimScaleMax || scale.Y > NonPhysicalPrimScaleMax || scale.Z > NonPhysicalPrimScaleMax)
                {
                    error = "Model contains parts with sides larger than " + NonPhysicalPrimScaleMax.ToString() + "m. Please ajust scale";
                    return false;
                }

                if (haveMeshs && inst.ContainsKey("mesh"))
                {
                    mesh = (int)inst["mesh"];

                    if (mesh >= numberMeshs)
                    {
                        error = "Incoerent model information.";
                        return false;
                    }

                    // streamming cost

                    float sqdiam = scale.LengthSquared();

                    ameshCostParam curCost = meshsCosts[mesh];
                    float mesh_streaming = streamingCost(curCost, sqdiam);

                    meshcostdata.model_streaming_cost += mesh_streaming;
                    meshcostdata.physics_cost += curCost.physicsCost;
                }
                else // instance as no mesh ??
                {
                    // to do later if needed
                    meshcostdata.model_streaming_cost += 0.5f;
                    meshcostdata.physics_cost += 1.0f;
                }

                // assume unscripted and static prim server cost
                meshcostdata.simulation_cost += 0.5f;
                // charge for prims creation
                meshsfee += primCreationCost;
            }

            if (skipedSmall > 0)
            {
                if (skipedSmall > numberInstances / 2)
                {
                    error = "Model contains too many prims smaller than " + PrimScaleMin.ToString() +
                        "m minimum allowed size. Please check scalling";
                    return false;
                }
                else
                    warning += skipedSmall.ToString() + " of the requested " +numberInstances.ToString() +
                        " model prims will not upload because they are smaller than " + PrimScaleMin.ToString() +
                        "m minimum allowed size. Please check scalling ";
            }

            if (meshcostdata.physics_cost <= meshcostdata.model_streaming_cost)
                meshcostdata.resource_cost = meshcostdata.model_streaming_cost;
            else
                meshcostdata.resource_cost = meshcostdata.physics_cost;

            if (meshcostdata.resource_cost < meshcostdata.simulation_cost)
                meshcostdata.resource_cost = meshcostdata.simulation_cost;

            // scale cost
            // at this point a cost of 1.0 whould mean basic cost
            meshsfee *= ModelMeshCostFactor;

            if (meshsfee < ModelMinCostFactor)
                meshsfee = ModelMinCostFactor;

            // actually scale it to basic cost
            meshsfee *= (float)basicCost;

            meshsfee += 0.5f; // rounding

            totalcost += (int)meshsfee;

            // breakdown prices
            // don't seem to be in use so removed code for now
            
            return true;
        }

        // single mesh asset cost
        private bool MeshCost(byte[] data, ameshCostParam cost,out bool skeleton, out bool avatarPhys, out string error)
        {
            cost.highLODSize = 0;
            cost.medLODSize = 0;
            cost.lowLODSize = 0;
            cost.lowestLODSize = 0;
            cost.physicsCost = 0.0f;
            cost.costFee = 0.0f;

            error = string.Empty;

            skeleton = false;
            avatarPhys = false;

            if (data == null || data.Length == 0)
            {
                error = "Missing model information.";
                return false;
            }

            OSD meshOsd = null;
            int start = 0;

            error = "Invalid model data";

            using (MemoryStream ms = new MemoryStream(data))
            {
                try
                {
                    OSD osd = OSDParser.DeserializeLLSDBinary(ms);
                    if (osd is OSDMap)
                        meshOsd = (OSDMap)osd;
                    else
                        return false;
                }
                catch (Exception e)
                {
                    return false;
                }
                start = (int)ms.Position;
            }

            OSDMap map = (OSDMap)meshOsd;
            OSDMap tmpmap;

            int highlod_size = 0;
            int medlod_size = 0;
            int lowlod_size = 0;
            int lowestlod_size = 0;
            int skin_size = 0;

            int hulls_size = 0;
            int phys_nhulls;
            int phys_hullsvertices = 0;

            int physmesh_size = 0;
            int phys_ntriangles = 0;

            int submesh_offset = -1;

            if (map.ContainsKey("skeleton"))
            {
                tmpmap = (OSDMap)map["skeleton"];
                if (tmpmap.ContainsKey("offset") && tmpmap.ContainsKey("size"))
                {
                    int sksize = tmpmap["size"].AsInteger();
                    if(sksize > 0)
                        skeleton = true;
                }               
            }

            if (map.ContainsKey("physics_convex"))
            {
                tmpmap = (OSDMap)map["physics_convex"];
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    hulls_size = tmpmap["size"].AsInteger();
            }

            if (submesh_offset < 0 || hulls_size == 0)
            {
                error = "Missing physics_convex block";
                return false;
            }

            if (!hulls(data, submesh_offset, hulls_size, out phys_hullsvertices, out phys_nhulls))
            {
                error = "Bad physics_convex block";
                return false;
            }

            submesh_offset = -1;
            
            // only look for LOD meshs sizes

            if (map.ContainsKey("high_lod"))
            {
                tmpmap = (OSDMap)map["high_lod"];
                // see at least if there is a offset for this one
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    highlod_size = tmpmap["size"].AsInteger();
            }

            if (submesh_offset < 0 || highlod_size <= 0)
            {
                error = "Missing high_lod block";
                return false;
            }

            bool haveprev = true;

            if (map.ContainsKey("medium_lod"))
            {
                tmpmap = (OSDMap)map["medium_lod"];
                if (tmpmap.ContainsKey("size"))
                    medlod_size = tmpmap["size"].AsInteger();
                else
                    haveprev = false;
            }

            if (haveprev && map.ContainsKey("low_lod"))
            {
                tmpmap = (OSDMap)map["low_lod"];
                if (tmpmap.ContainsKey("size"))
                    lowlod_size = tmpmap["size"].AsInteger();
                else
                    haveprev = false;
            }

            if (haveprev && map.ContainsKey("lowest_lod"))
            {
                tmpmap = (OSDMap)map["lowest_lod"];
                if (tmpmap.ContainsKey("size"))
                    lowestlod_size = tmpmap["size"].AsInteger();
            }

            if (map.ContainsKey("skin"))
            {
                tmpmap = (OSDMap)map["skin"];
                if (tmpmap.ContainsKey("size"))
                    skin_size = tmpmap["size"].AsInteger();
            }

            cost.highLODSize = highlod_size;
            cost.medLODSize = medlod_size;
            cost.lowLODSize = lowlod_size;
            cost.lowestLODSize = lowestlod_size;

            submesh_offset = -1;

            tmpmap = null;
            if(map.ContainsKey("physics_mesh"))
                tmpmap = (OSDMap)map["physics_mesh"];
            else if (map.ContainsKey("physics_shape")) // old naming
                tmpmap = (OSDMap)map["physics_shape"];

            if(tmpmap != null)
            {
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    physmesh_size = tmpmap["size"].AsInteger();

                if (submesh_offset >= 0 || physmesh_size > 0)
                {

                    if (!submesh(data, submesh_offset, physmesh_size, out phys_ntriangles))
                    {
                        error = "Model data parsing error";
                        return false;
                    }
                }
            }

            // upload is done in convex shape type so only one hull
            phys_hullsvertices++;
            cost.physicsCost = 0.04f * phys_hullsvertices;

            float sfee;
            
            sfee = data.Length; // start with total compressed data size

            // penalize lod meshs that should be more builder optimized
            sfee += medSizeWth * medlod_size;
            sfee += lowSizeWth * lowlod_size;
            sfee += lowestSizeWth * lowlod_size;

            // physics
            // favor potencial optimized meshs versus automatic decomposition
            if (physmesh_size != 0)
                sfee += physMeshSizeWth * (physmesh_size + hulls_size / 4); // reduce cost of mandatory convex hull
            else
                sfee += physHullSizeWth * hulls_size;

            // bytes to money
            sfee *= bytecost;
           
            cost.costFee = sfee;
            return true;
        }

        // parses a LOD or physics mesh component
        private bool submesh(byte[] data, int offset, int size, out int ntriangles)
        {
            ntriangles = 0;

            OSD decodedMeshOsd = new OSD();
            byte[] meshBytes = new byte[size];
            System.Buffer.BlockCopy(data, offset, meshBytes, 0, size);
            try
            {
                using (MemoryStream inMs = new MemoryStream(meshBytes))
                {
                    using (MemoryStream outMs = new MemoryStream())
                    {
                        using (ZOutputStream zOut = new ZOutputStream(outMs))
                        {
                            byte[] readBuffer = new byte[4096];
                            int readLen = 0;
                            while ((readLen = inMs.Read(readBuffer, 0, readBuffer.Length)) > 0)
                            {
                                zOut.Write(readBuffer, 0, readLen);
                            }
                            zOut.Flush();
                            outMs.Seek(0, SeekOrigin.Begin);

                            byte[] decompressedBuf = outMs.GetBuffer();
                            decodedMeshOsd = OSDParser.DeserializeLLSDBinary(decompressedBuf);
                        }
                    }
                }
            }
            catch (Exception e)
            {
                return false;
            }

            OSDArray decodedMeshOsdArray = null;
            if ((!decodedMeshOsd is OSDArray))
                return false;

            byte[] dummy;

            decodedMeshOsdArray = (OSDArray)decodedMeshOsd;
            foreach (OSD subMeshOsd in decodedMeshOsdArray)
            {
                if (subMeshOsd is OSDMap)
                {
                    OSDMap subtmpmap = (OSDMap)subMeshOsd;
                    if (subtmpmap.ContainsKey("NoGeometry") && ((OSDBoolean)subtmpmap["NoGeometry"]))
                        continue;

                    if (!subtmpmap.ContainsKey("Position"))
                        return false;

                    if (subtmpmap.ContainsKey("TriangleList"))
                    {
                        dummy = subtmpmap["TriangleList"].AsBinary();
                        ntriangles += dummy.Length / bytesPerCoord;
                    }
                    else
                        return false;
                }
            }

            return true;
        }

        // parses convex hulls component
        private bool hulls(byte[] data, int offset, int size, out int nvertices, out int nhulls)
        {
            nvertices = 0;
            nhulls = 1;

            OSD decodedMeshOsd = new OSD();
            byte[] meshBytes = new byte[size];
            System.Buffer.BlockCopy(data, offset, meshBytes, 0, size);
            try
            {
                using (MemoryStream inMs = new MemoryStream(meshBytes))
                {
                    using (MemoryStream outMs = new MemoryStream())
                    {
                        using (ZOutputStream zOut = new ZOutputStream(outMs))
                        {
                            byte[] readBuffer = new byte[4096];
                            int readLen = 0;
                            while ((readLen = inMs.Read(readBuffer, 0, readBuffer.Length)) > 0)
                            {
                                zOut.Write(readBuffer, 0, readLen);
                            }
                            zOut.Flush();
                            outMs.Seek(0, SeekOrigin.Begin);

                            byte[] decompressedBuf = outMs.GetBuffer();
                            decodedMeshOsd = OSDParser.DeserializeLLSDBinary(decompressedBuf);
                        }
                    }
                }
            }
            catch (Exception e)
            {
                return false;
            }

            OSDMap cmap = (OSDMap)decodedMeshOsd;
            if (cmap == null)
                return false;

            byte[] dummy;

            // must have one of this
            if (cmap.ContainsKey("BoundingVerts"))
            {
                dummy = cmap["BoundingVerts"].AsBinary();
                nvertices = dummy.Length / bytesPerCoord;
            }
            else
                return false;

/* upload is done with convex shape type
            if (cmap.ContainsKey("HullList"))
            {
                dummy = cmap["HullList"].AsBinary();
                nhulls += dummy.Length;
            }


            if (cmap.ContainsKey("Positions"))
            {
                dummy = cmap["Positions"].AsBinary();
                nvertices = dummy.Length / bytesPerCoord;
            }
 */

            return true;
        }

        // returns streaming cost from on mesh LODs sizes in curCost and square of prim size length 
        private float streamingCost(ameshCostParam curCost, float sqdiam)
        {
            // compute efective areas
            float ma = 262144f;

            float mh = sqdiam * highLodFactor;
            if (mh > ma)
                mh = ma;
            float mm = sqdiam * midLodFactor;
            if (mm > ma)
                mm = ma;

            float ml = sqdiam * lowLodFactor;
            if (ml > ma)
                ml = ma;

            float mlst = ma;

            mlst -= ml;
            ml -= mm;
            mm -= mh;

            if (mlst < 1.0f)
                mlst = 1.0f;
            if (ml < 1.0f)
                ml = 1.0f;
            if (mm < 1.0f)
                mm = 1.0f;
            if (mh < 1.0f)
                mh = 1.0f;

            ma = mlst + ml + mm + mh;

            // get LODs compressed sizes
            // giving 384 bytes bonus
            int lst = curCost.lowestLODSize - 384;
            int l = curCost.lowLODSize - 384;
            int m = curCost.medLODSize - 384;
            int h = curCost.highLODSize - 384;

            // use previus higher LOD size on missing ones
            if (m <= 0)
                m = h;
            if (l <= 0)
                l = m;
            if (lst <= 0)
                lst = l;

            // force minumum sizes
            if (lst < 16)
                lst = 16;
            if (l < 16)
                l = 16;
            if (m < 16)
                m = 16;
            if (h < 16)
                h = 16;

            // compute cost weighted by relative effective areas
            float cost = (float)lst * mlst + (float)l * ml + (float)m * mm + (float)h * mh;
            cost /= ma;

            cost *= 0.004f; // overall tunning parameter

            return cost;
        }
    }
}