CommonConvert.cpp

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/* Copyright (C) 2011 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "CommonConvert.h"

#include "StdSkeletons.h"
#include "XMLFix.h"

#include "FCollada.h"
#include "FCDocument/FCDSceneNode.h"
#include "FCDocument/FCDSkinController.h"
#include "FUtils/FUDaeSyntax.h"
#include "FUtils/FUFileManager.h"

#include <cassert>
#include <algorithm>

void require_(int line, bool value, const char* type, const char* message)
{
    if (value) return;
    char linestr[16];
    sprintf(linestr, "%d", line);
    throw ColladaException(std::string(type) + " (line " + linestr + "): " + message);
}

/** Error handler for libxml2 */
void errorHandler(void* ctx, const char* msg, ...)
{
    char buffer[1024];
    va_list ap;
    va_start(ap, msg);
    vsnprintf(buffer, sizeof(buffer), msg, ap);
    buffer[sizeof(buffer)-1] = '\0';
    va_end(ap);

    *((std::string*)ctx) += buffer;
}

FColladaErrorHandler::FColladaErrorHandler(std::string& xmlErrors_)
: xmlErrors(xmlErrors_)
{
    // Grab all the error output from libxml2, for useful error reporting
    xmlSetGenericErrorFunc(&xmlErrors, &errorHandler);

    FUError::AddErrorCallback(FUError::DEBUG_LEVEL, this, &FColladaErrorHandler::OnError);
    FUError::AddErrorCallback(FUError::WARNING_LEVEL, this, &FColladaErrorHandler::OnError);
    FUError::AddErrorCallback(FUError::ERROR_LEVEL, this, &FColladaErrorHandler::OnError);
}

FColladaErrorHandler::~FColladaErrorHandler()
{
    xmlSetGenericErrorFunc(NULL, NULL);

    FUError::RemoveErrorCallback(FUError::DEBUG_LEVEL, this, &FColladaErrorHandler::OnError);
    FUError::RemoveErrorCallback(FUError::WARNING_LEVEL, this, &FColladaErrorHandler::OnError);
    FUError::RemoveErrorCallback(FUError::ERROR_LEVEL, this, &FColladaErrorHandler::OnError);
}

void FColladaErrorHandler::OnError(FUError::Level errorLevel, uint32 errorCode, uint32 UNUSED(lineNumber))
{
    // Ignore warnings about missing materials, since we ignore materials entirely anyway
    if (errorCode == FUError::WARNING_INVALID_POLYGON_MAT_SYMBOL)
        return;

    const char* errorString = FUError::GetErrorString((FUError::Code) errorCode);
    if (! errorString)
        errorString = "Unknown error code";

    if (errorLevel == FUError::DEBUG_LEVEL)
        Log(LOG_INFO, "FCollada %d: %s", errorCode, errorString);
    else if (errorLevel == FUError::WARNING_LEVEL)
        Log(LOG_WARNING, "FCollada %d: %s", errorCode, errorString);
    else
        throw ColladaException(errorString);
}


//////////////////////////////////////////////////////////////////////////

void FColladaDocument::LoadFromText(const char *text)
{
    document.reset(FCollada::NewTopDocument());

    const char* newText = NULL;
    size_t newTextSize = 0;
    FixBrokenXML(text, &newText, &newTextSize);

    // Log(LOG_INFO, "%s", newText);
    bool status = FCollada::LoadDocumentFromMemory("unknown.dae", document.get(), (void*)newText, newTextSize);

    if (newText != text)
        xmlFree((void*)newText);

    REQUIRE_SUCCESS(status);
}

void FColladaDocument::ReadExtras(xmlNode* UNUSED(colladaNode))
{
    // TODO: This was needed to recognise and load XSI models.
    // XSI support should be reintroduced some time, but this function
    // may not be necessary since FCollada might now provide access to the
    // 'extra' data via a proper API.

    /*
    if (! IsEquivalent(colladaNode->name, DAE_COLLADA_ELEMENT))
        return;

    extra.reset(new FCDExtra(document.get()));

    xmlNodeList extraNodes;
    FUXmlParser::FindChildrenByType(colladaNode, DAE_EXTRA_ELEMENT, extraNodes);
    for (xmlNodeList::iterator it = extraNodes.begin(); it != extraNodes.end(); ++it)
    {
        xmlNode* extraNode = (*it);
        extra->LoadFromXML(extraNode);
    }
    */
}

//////////////////////////////////////////////////////////////////////////

CommonConvert::CommonConvert(const char* text, std::string& xmlErrors)
: m_Err(xmlErrors)
{
    m_Doc.LoadFromText(text);
    FCDSceneNode* root = m_Doc.GetDocument()->GetVisualSceneRoot();
    REQUIRE(root != NULL, "has root object");

    // Find the instance to convert
    if (! FindSingleInstance(root, m_Instance, m_EntityTransform))
        throw ColladaException("Couldn't find object to convert");

    assert(m_Instance);
    Log(LOG_INFO, "Converting '%s'", m_Instance->GetEntity()->GetName().c_str());

    m_IsXSI = false;
    FCDAsset* asset = m_Doc.GetDocument()->GetAsset();
    if (asset && asset->GetContributorCount() >= 1)
    {
        std::string tool (asset->GetContributor(0)->GetAuthoringTool());
        if (tool.find("XSI") != tool.npos)
            m_IsXSI = true;
    }

    FMVector3 upAxis = m_Doc.GetDocument()->GetAsset()->GetUpAxis();
    m_YUp = (upAxis.y != 0); // assume either Y_UP or Z_UP (TODO: does anyone ever do X_UP?)
}

CommonConvert::~CommonConvert()
{
}

//////////////////////////////////////////////////////////////////////////

// HACK: The originals don't get exported properly from FCollada (3.02, DLL), so define
// them here instead of fixing it correctly.
const FMVector3 FMVector3_XAxis(1.0f, 0.0f, 0.0f);
static float identity[] = { 1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1 };
FMMatrix44 FMMatrix44_Identity(identity);

struct FoundInstance
{
    FCDEntityInstance* instance;
    FMMatrix44 transform;
};

static bool IsVisible_XSI(FCDSceneNode* node, bool& visible)
{
    // Look for <extra><technique profile="XSI"><SI_Visibility><xsi_param sid="visibility">

    FCDExtra* extra = node->GetExtra();
    if (! extra) return false;

    FCDEType* type = extra->GetDefaultType();
    if (! type) return false;

    FCDETechnique* technique = type->FindTechnique("XSI");
    if (! technique) return false;

    FCDENode* visibility1 = technique->FindChildNode("SI_Visibility");
    if (! visibility1) return false;

    FCDENode* visibility2 = visibility1->FindChildNode("xsi_param");
    if (! visibility2) return false;

    if (IsEquivalent(visibility2->GetContent(), "TRUE"))
        visible = true;
    else if (IsEquivalent(visibility2->GetContent(), "FALSE"))
        visible = false;
    return true;
}

static bool IsVisible(FCDSceneNode* node)
{
    bool visible = false;

    // Try the XSI visibility property
    if (IsVisible_XSI(node, visible))
        return visible;

    // Else fall back to the FCollada-specific setting
    visible = (node->GetVisibility() != 0.0);
    return visible;
}

/**
 * Recursively finds all entities under the current node. If onlyMarked is
 * set, only matches entities where the user-defined property was set to
 * "export" in the modelling program.
 *
 * @param node root of subtree to search
 * @param instances output - appends matching entities
 * @param transform transform matrix of current subtree
 * @param onlyMarked only match entities with "export" property
 */
static void FindInstances(FCDSceneNode* node, std::vector<FoundInstance>& instances, const FMMatrix44& transform, bool onlyMarked)
{
    for (size_t i = 0; i < node->GetChildrenCount(); ++i)
    {
        FCDSceneNode* child = node->GetChild(i);
        FindInstances(child, instances, transform * node->ToMatrix(), onlyMarked);
    }

    for (size_t i = 0; i < node->GetInstanceCount(); ++i)
    {
        if (onlyMarked)
        {
            if (node->GetNote() != "export")
                continue;
        }

        // Only accept instances of appropriate types, and not e.g. lights
        FCDEntity::Type type = node->GetInstance(i)->GetEntityType();
        if (! (type == FCDEntity::GEOMETRY || type == FCDEntity::CONTROLLER))
            continue;

        // Ignore invisible objects, because presumably nobody wanted to export them
        if (! IsVisible(node))
            continue;

        FoundInstance f;
        f.transform = transform * node->ToMatrix();
        f.instance = node->GetInstance(i);
        instances.push_back(f);
        Log(LOG_INFO, "Found convertible object '%s'", node->GetName().c_str());
    }
}

bool FindSingleInstance(FCDSceneNode* node, FCDEntityInstance*& instance, FMMatrix44& transform)
{
    std::vector<FoundInstance> instances;

    FindInstances(node, instances, FMMatrix44_Identity, true);
    if (instances.size() > 1)
    {
        Log(LOG_ERROR, "Found too many export-marked objects");
        return false;
    }
    if (instances.empty())
    {
        FindInstances(node, instances, FMMatrix44_Identity, false);
        if (instances.size() > 1)
        {
            Log(LOG_ERROR, "Found too many possible objects to convert - try adding the 'export' property to disambiguate one");
            return false;
        }
        if (instances.empty())
        {
            Log(LOG_ERROR, "Didn't find any objects in the scene");
            return false;
        }
    }

    assert(instances.size() == 1); // if we got this far
    instance = instances[0].instance;
    transform = instances[0].transform;
    return true;
}

//////////////////////////////////////////////////////////////////////////

static bool ReverseSortWeight(const FCDJointWeightPair& a, const FCDJointWeightPair& b)
{
    return (a.weight > b.weight);
}

void SkinReduceInfluences(FCDSkinController* skin, size_t maxInfluenceCount, float minimumWeight)
{
    // Approximately equivalent to:
    //    skin->ReduceInfluences(maxInfluenceCount, minimumWeight);
    // except this version merges multiple weights for the same joint

    for (size_t i = 0; i < skin->GetInfluenceCount(); ++i)
    {
        FCDSkinControllerVertex& influence = *skin->GetVertexInfluence(i);

        std::vector<FCDJointWeightPair> newWeights;
        for (size_t i = 0; i < influence.GetPairCount(); ++i)
        {
            FCDJointWeightPair* weight = influence.GetPair(i);

            for (size_t j = 0; j < newWeights.size(); ++j)
            {
                FCDJointWeightPair& newWeight = newWeights[j];
                if (weight->jointIndex == newWeight.jointIndex)
                {
                    newWeight.weight += weight->weight;
                    goto MERGED_WEIGHTS;
                }
            }

            newWeights.push_back(*weight);
MERGED_WEIGHTS: ;
        }

        // Put highest-weighted influences at the front of the list
        std::sort(newWeights.begin(), newWeights.end(), ReverseSortWeight);

        // Limit the maximum number of influences
        if (newWeights.size() > maxInfluenceCount)
            newWeights.resize(maxInfluenceCount);

        // Enforce the minimum weight per influence
        // (This is done here rather than in the earlier loop, because several
        // small weights for the same bone might add up to a value above the
        // threshold)
        while (!newWeights.empty() && newWeights.back().weight < minimumWeight)
            newWeights.pop_back();

        // Renormalise, so sum(weights)=1
        float totalWeight = 0;
        for (std::vector<FCDJointWeightPair>::iterator itNW = newWeights.begin(); itNW != newWeights.end(); ++itNW)
            totalWeight += itNW->weight;
        for (std::vector<FCDJointWeightPair>::iterator itNW = newWeights.begin(); itNW != newWeights.end(); ++itNW)
            itNW->weight /= totalWeight;

        // Copy new weights into the skin
        influence.SetPairCount(0);
        for (std::vector<FCDJointWeightPair>::iterator itNW = newWeights.begin(); itNW != newWeights.end(); ++itNW)
            influence.AddPair(itNW->jointIndex, itNW->weight);
    }

    skin->SetDirtyFlag();
}


void FixSkeletonRoots(FCDControllerInstance& UNUSED(controllerInstance))
{
    // TODO: Need to reintroduce XSI support at some point
#if 0
    // HACK: The XSI exporter doesn't do a <skeleton> and FCollada doesn't
    // seem to know where else to look, so just guess that it's somewhere
    // under Scene_Root
    if (controllerInstance.GetSkeletonRoots().empty())
    {
        // HACK (evil): SetSkeletonRoot is declared but not defined, and there's
        // no other proper way to modify the skeleton-roots list, so cheat horribly
        FUUriList& uriList = const_cast<FUUriList&>(controllerInstance.GetSkeletonRoots());
        uriList.push_back(FUUri("Scene_Root"));
        controllerInstance.LinkImport();
    }
#endif
}

const Skeleton& FindSkeleton(const FCDControllerInstance& controllerInstance)
{
    // I can't see any proper way to determine the real root of the skeleton,
    // so just choose an arbitrary bone and search upwards until we find a
    // recognised ancestor (or until we fall off the top of the tree)

    const Skeleton* skeleton = NULL;
    const FCDSceneNode* joint = controllerInstance.GetJoint(0);
    while (joint && (skeleton = Skeleton::FindSkeleton(joint->GetName().c_str())) == NULL)
    {
        joint = joint->GetParent();
    }
    REQUIRE(skeleton != NULL, "recognised skeleton structure");
    return *skeleton;
}

void TransformBones(std::vector<BoneTransform>& bones, const FMMatrix44& scaleTransform, bool yUp)
{
    for (size_t i = 0; i < bones.size(); ++i)
    {
        // Apply the desired transformation to the bone coordinates
        FMVector3 trans(bones[i].translation, 0);
        trans = scaleTransform.TransformCoordinate(trans);
        bones[i].translation[0] = trans.x;
        bones[i].translation[1] = trans.y;
        bones[i].translation[2] = trans.z;

        // DON'T apply the transformation to orientation, because I can't get
        // that kind of thing to work in practice (interacting nicely between
        // the models and animations), so this function assumes the transform
        // just does scaling, so there's no need to rotate anything. (But I think
        // this code would work for rotation, though not very efficiently.)
        /*
        FMMatrix44 m = FMQuaternion(bones[i].orientation[0], bones[i].orientation[1], bones[i].orientation[2], bones[i].orientation[3]).ToMatrix();
        m *= scaleTransform;
        HMatrix matrix;
        memcpy(matrix, m.Transposed().m, sizeof(matrix));
        AffineParts parts;
        decomp_affine(matrix, &parts);

        bones[i].orientation[0] = parts.q.x;
        bones[i].orientation[1] = parts.q.y;
        bones[i].orientation[2] = parts.q.z;
        bones[i].orientation[3] = parts.q.w;
        */

        if (yUp)
        {
            // TODO: this is all just guesses which seem to work for data
            // exported from XSI, rather than having been properly thought
            // through
            bones[i].translation[2] = -bones[i].translation[2];
            bones[i].orientation[2] = -bones[i].orientation[2];
            bones[i].orientation[3] = -bones[i].orientation[3];
        }
        else
        {
            // Convert bone translations from xyz into xzy axes:
            std::swap(bones[i].translation[1], bones[i].translation[2]);

            // To convert the quaternions: imagine you're using the axis/angle
            // representation, then swap the y,z basis vectors and change the
            // direction of rotation by negating the angle ( => negating sin(angle)
            // => negating x,y,z => changing (x,y,z,w) to (-x,-z,-y,w)
            // but then (-x,-z,-y,w) == (x,z,y,-w) so do that instead)
            std::swap(bones[i].orientation[1], bones[i].orientation[2]);
            bones[i].orientation[3] = -bones[i].orientation[3];
        }
    }
}