TLinearGradientTexture.ipp

Go to the documentation of this file.

#pragma once
 
#include "Core/Texture/TLinearGradientTexture.h"
#include "Core/Texture/SampleLocation.h"
 
#include <Common/assertion.h>
 
namespace ph
{
 
template<typename OutputType>
inline TLinearGradientTexture<OutputType>::TLinearGradientTexture(
    const real                                   beginU,
    const std::shared_ptr<TTexture<OutputType>>& beginTexture,
    const real                                   endU,
    const std::shared_ptr<TTexture<OutputType>>& endTexture) :
 
    TLinearGradientTexture(
        {beginU, 0, 0},
        beginTexture, 
        {endU, 0, 0},
        endTexture)
{}
 
template<typename OutputType>
inline TLinearGradientTexture<OutputType>::TLinearGradientTexture(
    const math::Vector2R&                        beginUV,
    const std::shared_ptr<TTexture<OutputType>>& beginTexture,
    const math::Vector2R&                        endUV,
    const std::shared_ptr<TTexture<OutputType>>& endTexture) :
 
    TLinearGradientTexture(
        {beginUV.x, beginUV.y, 0},
        beginTexture, 
        {endUV.x, endUV.y, 0},
        endTexture)
{}
 
template<typename OutputType>
inline TLinearGradientTexture<OutputType>::TLinearGradientTexture(
    const math::Vector3R&                        beginUVW,
    const std::shared_ptr<TTexture<OutputType>>& beginTexture,
    const math::Vector3R&                        endUVW,
    const std::shared_ptr<TTexture<OutputType>>& endTexture) :
 
    TTexture<OutputType>(),
 
    m_beginUVW    (beginUVW),
    m_beginTexture(beginTexture),
    m_endUVW      (endUVW),
    m_endTexture  (endTexture)
{
    PH_ASSERT(!beginUVW.isEqual(endUVW));
    PH_ASSERT(beginTexture);
    PH_ASSERT(endTexture);
}
 
template<typename OutputType>
inline void TLinearGradientTexture<OutputType>::sample(const SampleLocation& sampleLocation, OutputType* const out_value) const
{
    PH_ASSERT(out_value);
    PH_ASSERT(m_beginTexture);
    PH_ASSERT(m_beginTexture.get() != this);
    PH_ASSERT(m_endTexture);
    PH_ASSERT(m_endTexture.get() != this);
 
    const auto baseVec       = m_endUVW - m_beginUVW;
    const real baseLength    = baseVec.length();
    const real rcpBaseLength = 1.0_r / baseLength;
    const auto baseAxis      = baseVec * rcpBaseLength;
    const auto sampleVec     = sampleLocation.uvw() - m_beginUVW;
    const real sampleLength  = sampleVec.dot(baseAxis);
 
    // Lerp between endpoints
 
    const real beginRatio = (baseLength - sampleLength) * rcpBaseLength;
    const real endRatio   = sampleLength * rcpBaseLength;
 
    OutputType beginValue, endValue;
    m_beginTexture->sample(sampleLocation, &beginValue);
    m_endTexture->sample(sampleLocation, &endValue);
 
    *out_value = beginValue * beginRatio + endValue * endRatio;
}
 
}// end namespace ph