RixIES.h

Go to the documentation of this file.

/*
# ------------------------------------------------------------------------------
#
# Copyright (c) 1986-2019 Pixar. All rights reserved.
#
# The information in this file (the "Software") is provided for the exclusive
# use of the software licensees of Pixar ("Licensees").  Licensees have the
# right to incorporate the Software into other products for use by other
# authorized software licensees of Pixar, without fee. Except as expressly
# permitted herein, the Software may not be disclosed to third parties, copied
# or duplicated in any form, in whole or in part, without the prior written
# permission of Pixar.
#
# The copyright notices in the Software and this entire statement, including the
# above license grant, this restriction and the following disclaimer, must be
# included in all copies of the Software, in whole or in part, and all permitted
# derivative works of the Software, unless such copies or derivative works are
# solely in the form of machine-executable object code generated by a source
# language processor.
#
# PIXAR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL PIXAR BE
# LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
# OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  IN NO CASE WILL
# PIXAR'S TOTAL LIABILITY FOR ALL DAMAGES ARISING OUT OF OR IN CONNECTION WITH
# THE USE OR PERFORMANCE OF THIS SOFTWARE EXCEED $50.
#
# Pixar
# 1200 Park Ave
# Emeryville CA 94608
#
# ------------------------------------------------------------------------------
*/


#ifndef RixIES_h
#define RixIES_h

#include <cstddef>                      // for NULL
#include <string>                       // for string
#include "RixInterfaces.h"              // for RixInterface, etc
#include "prmanapi.h"                   // for PRMAN_INLINE
#include "ri.h"                         // for RtConstString

/*
 * RixIES interface -- Rix Light Emission Profile interface
 *
 * Each RixLight optionally has an emission profile
 * accessable via "RixIES* profile = light->GetRixIES();".
 *
 * profile->EvaluateIESProfile, profile->EvaluateConeAngle()
 * are methods to evaluate emission.
 *
 * profile->ReadIESProfile reads all the params/settings of a IES profile.
 *
 */

class RixIES : public RixInterface
{
public:
    struct IESProfile
    {
        IESProfile()
            : mapName(US_NULL),
              profile(NULL),
              nu(0),
              nv(0),
              isColor(false),
              isExr(false),
              profileScale(1.0f)
        {
        }

        ~IESProfile() { clearProfile(); }

        void clearProfile()
        {
            delete[] profile;
            profile = NULL;
        }
        void clear()
        {
            clearProfile();
            mapName = US_NULL;
            nu      = 0;
            nv      = 0;
            isExr   = false;
            isColor = false;
        }

        RtUString mapName;
        float* profile;
        // RtMatrix    profileSpace;
        int nu, nv;
        bool isColor;
        bool isExr;
        float profileScale;
    };

    RixIES()
        : RixInterface(1),
          m_coneAngle(-1.0f),
          m_coneOffset(0.0f),
          m_hasNegativeDeterminant(false),
          m_normalizationFactor(1.0f)
    {
        // FIXME: do we need to support a profileSpace?
        // MxIdentity(m_profileSpace);
    }

    PRMAN_INLINE void EvaluateIESProfile(
        RtFloat3 const& P,
        RtColorRGB* emission) const;

    PRMAN_INLINE bool ReadIESProfile(
        RixContext const& rixCtx,
        RtUString const iesProfile);

    PRMAN_INLINE float EvaluateConeAngle(RtFloat3 const& P) const;

    PRMAN_INLINE float EvaluateConeAngle(RtPoint3 const& lightP, RtVector3& lightN,
                                         RtPoint3 const& offsetP, RtVector3 const& segmentDir,
                                         float& minT, float& maxT) const;

    // clang-format off
    // get/set funcs
    IESProfile& GetIESProfile()                   { return m_iesProfile; }

    float GetConeAngle() const                    { return m_coneAngle; }
    float GetConeOffset() const                   { return m_coneOffset; }
    bool GetHasNegativeDeterminant() const        { return m_hasNegativeDeterminant; }
    float GetNormalizationFactor() const          { return m_normalizationFactor; }

    void SetConeAngle(float v)                    { m_coneAngle = v; m_cosConeAngle = cosf(m_coneAngle); }
    void SetConeOffset(float v)                   { m_coneOffset = v; }
    void SetHasNegativeDeterminant(float v)       { m_hasNegativeDeterminant = v; }
    // clang-format on

private:
    // Utility routines
    PRMAN_INLINE float calcLongitude(float x, float y, bool isExr) const;

    PRMAN_INLINE void calcLatLongParam(
        int n,               // number of points in BOP
        float* dir,          // array of reflection directions
        bool openEXR,        // Is this an EXR latlong?
        float* s,           // output s array pointer
        float* t) const;    // output t array pointer

private:
    IESProfile m_iesProfile; // only the read func accesses its members

    float m_coneAngle;
    float m_cosConeAngle;
    float m_coneOffset;

    bool m_hasNegativeDeterminant;

    // The factor that scales the profile data to sum to unit intensity over the
    // entire sphere.
    float m_normalizationFactor;
};

#include "RixIESInline.h" // IWYU pragma: export

#endif