CWE-ou-minkata/Sources/Plasma/CoreLib/plViewTransform.cpp

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*==LICENSE==*/

#include "HeadSpin.h"
#pragma hdrstop

#include "hsBounds.h"
#include "hsStream.h"
#include "plViewTransform.h"

const float plViewTransform::kMinHither = 0.25f;

plViewTransform::plViewTransform()
:   fFlags(kViewPortRelative),
    fWidth(0),
    fHeight(0)
{
    fCameraToWorld.Reset();
    fWorldToCamera.Reset();

    fViewPortX.Set(0,1.f,1.f);
    fViewPortY.Set(0,1.f,1.f);

    fMapMin.Set(0.f, 0.f, 0.f);
    fMapMax.Set(1.f, 1.f, 1.f);
}

void plViewTransform::Reset()
{
    fFlags = kViewPortRelative;
    fCameraToWorld.Reset();
    fWorldToCamera.Reset();

    fViewPortX.Set(0,1.f,1.f);
    fViewPortY.Set(0,1.f,1.f);
}

void plViewTransform::ISetCameraToNDC() const
{
    fCameraToNDC.Reset();
    fCameraToNDC.NotIdentity();

    if( GetOrthogonal() )
    {
        hsPoint3    worldSizeInv;

        worldSizeInv.fX = hsInvert( fMax.fX - fMin.fX ) * 2.f;
        worldSizeInv.fY = hsInvert( fMax.fY - fMin.fY ) * 2.f;
        worldSizeInv.fZ = hsInvert( fMax.fZ - fMin.fZ );

        fCameraToNDC.fMap[0][0] = worldSizeInv.fX;
        fCameraToNDC.fMap[0][3] = -fMin.fX * worldSizeInv.fX - 1.f;

        fCameraToNDC.fMap[1][1] = worldSizeInv.fY;
        fCameraToNDC.fMap[1][3] = -fMin.fY * worldSizeInv.fY - 1.f;

        // Map Screen Z to range 0 (at hither) to 1 (at yon)
        fCameraToNDC.fMap[2][2] = worldSizeInv.fZ;
        fCameraToNDC.fMap[2][3] = -fMin.fZ * worldSizeInv.fZ;
    }
    else
    {

        fCameraToNDC.fMap[0][0] = 2.f / (fMax.fX - fMin.fX);
        fCameraToNDC.fMap[0][2] = (fMax.fX + fMin.fX) / (fMax.fX - fMin.fX);

        fCameraToNDC.fMap[1][1] = 2.f / (fMax.fY - fMin.fY);
        fCameraToNDC.fMap[1][2] = (fMax.fY + fMin.fY) / (fMax.fY - fMin.fY);

        fCameraToNDC.fMap[2][2] = fMax.fZ / (fMax.fZ - fMin.fZ);
        fCameraToNDC.fMap[2][3] = -fMax.fZ * fMin.fZ / (fMax.fZ - fMin.fZ);

        fCameraToNDC.fMap[3][2] = 1.f;
        fCameraToNDC.fMap[3][3] = 0.f;

    }
    ISetFlag(kCameraToNDCSet);
}

void plViewTransform::SetViewPort(const hsPoint2& mins, const hsPoint2& maxs, bool relative)
{ 
    fViewPortX.Set(mins.fX, maxs.fX, 1.f / (maxs.fX - mins.fX)); 
    fViewPortY.Set(mins.fY, maxs.fY, 1.f / (maxs.fY - mins.fY)); 
    ISetFlag(kViewPortRelative, relative);
}

hsScalarTriple plViewTransform::ScreenToNDC(const hsScalarTriple& scrP) const
{
    hsPoint2 vpMin, vpMax;
    GetViewPort(vpMin, vpMax);
    hsPoint3 ndc;

    ndc.fX = (scrP.fX - vpMin.fX) / (vpMax.fX - vpMin.fX) * 2.f - 1.f;

    ndc.fY = (vpMax.fY - scrP.fY) / (vpMax.fY - vpMin.fY) * 2.f - 1.f;

    ndc.fZ = scrP.fZ;
    
    return ndc;
}

hsScalarTriple plViewTransform::NDCToScreen(const hsScalarTriple& ndc) const
{
    hsPoint2 vpMin, vpMax;
    GetViewPort(vpMin, vpMax);

    hsPoint3 scrP;
    scrP.fX = (ndc.fX + 1.f) * 0.5f * (vpMax.fX - vpMin.fX) + vpMin.fX;
    scrP.fY = (-ndc.fY + 1.f) * 0.5f * (vpMax.fY - vpMin.fY) + vpMin.fY;
    scrP.fZ = ndc.fZ;

    return scrP;
}

hsScalarTriple plViewTransform::NDCToCamera(const hsScalarTriple& ndc) const
{
    hsPoint3 camP;
    float w = ndc.fZ;

    const hsMatrix44& c2NDC = GetCameraToNDC();

    camP.fX = (ndc.fX - c2NDC.fMap[0][2]) * w / c2NDC.fMap[0][0];

    camP.fY = (ndc.fY - c2NDC.fMap[1][2]) * w / c2NDC.fMap[1][1];

    camP.fZ = ndc.fZ;

    return camP;
}

hsScalarTriple plViewTransform::CameraToNDC(const hsScalarTriple& camP) const
{
    const hsMatrix44& c2NDC = GetCameraToNDC();
    
#ifdef MF_FLIP_SPARSE
    // We count on the fact that we set up CameratToNDC, so we know where the
    // zeros are. Also, note that the proper "* camP.fZ"'s are missing off the
    // c2NDC.fMap[i][2] terms, because they just get cancelled out by the invW.

    hsPoint3 ndc;
    if( GetOrthogonal() )
    {
        ndc.fX = c2NDC.fMap[0][0] * camP.fX 
            + c2NDC.fMap[0][2];

        ndc.fY = c2NDC.fMap[1][1] * camP.fY 
            + c2NDC.fMap[1][2];

        ndc.fZ = c2NDC.fMap[2][2] * camP.fZ 
            + c2NDC.fMap[2][3];
    }
    else
    {
        float invW = 1.f / camP.fZ;
        ndc.fX = c2NDC.fMap[0][0] * camP.fX * invW
            + c2NDC.fMap[0][2];

        ndc.fY = c2NDC.fMap[1][1] * camP.fY * invW
            + c2NDC.fMap[1][2];

        ndc.fZ = c2NDC.fMap[2][2] * camP.fZ 
            + c2NDC.fMap[2][3];
        ndc.fZ *= invW;
    }
#else // MF_FLIP_SPARSE
    hsPoint3 ndc = c2NDC * hsPoint3(camP);
    if( !GetOrthogonal() )
    {
        float invW = 1.f / camP.fZ;
        ndc *= invW;
    }
#endif // MF_FLIP_SPARSE

    return ndc;
}

hsScalarTriple plViewTransform::NDCToMap(const hsScalarTriple& ndcP) const
{
    hsPoint3 map;
    map.fX = fMapMin.fX + (ndcP.fX + 1.f) * 0.5f * (fMapMax.fX - fMapMin.fX);
    map.fY = fMapMin.fY + (ndcP.fY + 1.f) * 0.5f * (fMapMax.fY - fMapMin.fY);
    map.fZ = fMapMin.fZ + (ndcP.fZ + 1.f) * 0.5f * (fMapMax.fZ - fMapMin.fZ);

    return map;
}

bool plViewTransform::SetProjection(const hsBounds3& bnd)
{
    hsPoint3 maxs;
    hsPoint3 mins;
    if( IGetMaxMinsFromBnd(bnd, mins, maxs) )
    {
        SetView(mins, maxs);
        return true;
    }
    return false;
}

bool plViewTransform::SetProjectionWorld(const hsBounds3& wBnd)
{
    hsBounds3Ext cBnd = wBnd;
    cBnd.Transform(&GetWorldToCamera());
    return SetProjection(cBnd);
}

bool plViewTransform::IGetMaxMinsFromBnd(const hsBounds3& bnd, hsPoint3& mins, hsPoint3& maxs) const
{
    if( bnd.GetMaxs().fZ <= kMinHither )
        return false;

    hsPoint3 minBnd = bnd.GetMins();
    hsPoint3 maxBnd = bnd.GetMaxs();
    // If the box intersects the hither plane, we'll need to chop it
    // off.
    if( minBnd.fZ < kMinHither )
    {
        minBnd.fZ = kMinHither;     
    }
    mins.Set(minBnd.fX / minBnd.fZ, minBnd.fY / minBnd.fZ, minBnd.fZ);
    maxs.Set(maxBnd.fX / minBnd.fZ, maxBnd.fY / minBnd.fZ, maxBnd.fZ);

    return true;
}

bool plViewTransform::Intersect(const plViewTransform& view)
{
    hsPoint3 mins;
    hsPoint3 maxs;

    bool retVal = true;
    int i;
    for( i = 0; i < 3; i++ )
    {
        mins[i] = std::max(fMin[i], view.fMin[i]);

        maxs[i] = std::min(fMax[i], view.fMax[i]);

        if( mins[i] >= maxs[i] )
        {
            mins[i] = maxs[i] = (mins[i] + maxs[i]) * 0.5f;
            retVal = false;
        }
    }
    SetView(mins, maxs);
    return retVal;
}

bool plViewTransform::Union(const plViewTransform& view)
{
    hsPoint3 mins;
    hsPoint3 maxs;

    int i;
    for( i = 0; i < 3; i++ )
    {
        mins[i] = std::min(fMin[i], view.fMin[i]);

        maxs[i] = std::max(fMax[i], view.fMax[i]);

    }
    SetView(mins, maxs);
    return true;
}

float plViewTransform::GetFovX() const
{
    float minAng = atan2(fMin.fX, 1.f);
    float maxAng = atan2(fMax.fX, 1.f);

    return maxAng - minAng;
}

float plViewTransform::GetFovY() const
{
    float minAng = atan2(fMin.fY, 1.f);
    float maxAng = atan2(fMax.fY, 1.f);

    return maxAng - minAng;
}

void plViewTransform::GetViewPort(hsPoint2& mins, hsPoint2& maxs) const 
{ 
    if( GetViewPortRelative() )
    {
        mins.Set(fViewPortX.fX * fWidth, fViewPortY.fX * fHeight); 
        maxs.Set(fViewPortX.fY * fWidth, fViewPortY.fY * fHeight); 
    }
    else
    {
        mins.Set(fViewPortX.fX, fViewPortY.fX); 
        maxs.Set(fViewPortX.fY, fViewPortY.fY); 
    }
}

void plViewTransform::GetViewPort(int& loX, int& loY, int& hiX, int& hiY) const 
{ 
    if( GetViewPortRelative() )
    {
        loX = int(fViewPortX.fX * fWidth); 
        loY = int(fViewPortY.fX * fHeight); 
        hiX = int(fViewPortX.fY * fHeight); 
        hiY = int(fViewPortY.fY * fWidth); 
    }
    else
    {
        loX = int(fViewPortX.fX); 
        loY = int(fViewPortY.fX); 
        hiX = int(fViewPortX.fY); 
        hiY = int(fViewPortY.fY); 
    }
}

void plViewTransform::Read(hsStream* s)
{
    fFlags = s->ReadLE32();
    fFlags &= ~kSetMask;

    fCameraToWorld.Read(s);
    fWorldToCamera.Read(s);

    fMin.Read(s);
    fMax.Read(s);

    fWidth = s->ReadLE16();
    fHeight = s->ReadLE16();

    fViewPortX.Read(s);
    fViewPortY.Read(s);

    fMapMin.Read(s);
    fMapMin.Read(s);
}

void plViewTransform::Write(hsStream* s)
{
    s->WriteLE32(fFlags & ~kSetMask);

    fCameraToWorld.Write(s);
    fWorldToCamera.Write(s);

    fMin.Write(s);
    fMax.Write(s);

    s->WriteLE16(fWidth);
    s->WriteLE16(fHeight);

    fViewPortX.Write(s);
    fViewPortY.Write(s);

    fMapMin.Write(s);
    fMapMin.Write(s);
}