directional_light_uniforms.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2026                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * Mozilla Public License Version 2.0                                        *
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#ifndef VCL_BGFX_DRAWABLE_UNIFORMS_DIRECTIONAL_LIGHT_UNIFORMS_H
#define VCL_BGFX_DRAWABLE_UNIFORMS_DIRECTIONAL_LIGHT_UNIFORMS_H
 
#include <vclib/bgfx/uniform.h>
#include <vclib/render/viewer/lights/directional_light.h>
 
#include <bgfx/bgfx.h>
 
namespace vcl {
 
class DirectionalLightUniforms
{
    // just first 3 components are used
    inline static std::array<float, 4> sDir = {0.0, 0.0, 1.0, 0.0};
 
    // just first 3 components are used
    inline static std::array<float, 4> sCol = {1.0, 1.0, 1.0, 1.0};
 
    inline static Uniform sLightDirUniform;
    inline static Uniform sLightColorUniform;
 
public:
    DirectionalLightUniforms() = delete;
 
    template<typename S>
    static void setLight(const vcl::DirectionalLight<S>& light)
    {
        sDir[0] = light.direction().x();
        sDir[1] = light.direction().y();
        sDir[2] = light.direction().z();
 
        sCol[0] = light.color().redF();
        sCol[1] = light.color().greenF();
        sCol[2] = light.color().blueF();
        // light color alpha is not used
    }
 
    static void bind()
    {
        // lazy initialization
        // to avoid creating uniforms before bgfx is initialized
        if (!sLightDirUniform.isValid())
            sLightDirUniform =
                Uniform("u_lightDirPack", bgfx::UniformType::Vec4);
        if (!sLightColorUniform.isValid())
            sLightColorUniform =
                Uniform("u_lightColorPack", bgfx::UniformType::Vec4);
        sLightDirUniform.bind(sDir.data());
        sLightColorUniform.bind(sCol.data());
    }
};
 
} // namespace vcl
 
#endif // VCL_BGFX_DRAWABLE_UNIFORMS_DIRECTIONAL_LIGHT_UNIFORMS_H