drawable_mesh_uniforms.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2026                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * it under the terms of the Mozilla Public License Version 2.0 as published *
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 * This program 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              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_BGFX_DRAWABLE_UNIFORMS_DRAWABLE_MESH_UNIFORMS_H
#define VCL_BGFX_DRAWABLE_UNIFORMS_DRAWABLE_MESH_UNIFORMS_H
 
#include <vclib/bgfx/uniform.h>
#include <vclib/mesh.h>
 
namespace vcl {
 
class DrawableMeshUniforms
{
    inline static std::array<float, 4> sMeshColor = {0.5, 0.5, 0.5, 1.0};
 
    // sMeshData[0] -> as uint, mesh id
    // sMeshData[1] -> as uint, first chunk primitive id drawn
    inline static std::array<float, 4> sMeshData = {0.0, 0.0, 0.0, 0.0};
 
    inline static Uniform sMeshColorUniform;
    inline static Uniform sMeshDataUniform;
 
public:
    DrawableMeshUniforms() = delete;
 
    template<MeshConcept MeshType>
    static void setColor(const MeshType& m)
    {
        if constexpr (HasColor<MeshType>) {
            sMeshColor[0] = m.color().redF();
            sMeshColor[1] = m.color().greenF();
            sMeshColor[2] = m.color().blueF();
            sMeshColor[3] = m.color().alphaF();
        }
    }
 
    static void setMeshId(uint meshId)
    {
        sMeshData[0] = std::bit_cast<float>(meshId);
    }
 
    static void setFirstChunkIndex(uint firstChunkIndex)
    {
        sMeshData[1] = std::bit_cast<float>(firstChunkIndex);
    }
 
    static void bind()
    {
        // lazy initialization
        // to avoid creating uniforms before bgfx is initialized
        if (!sMeshColorUniform.isValid())
            sMeshColorUniform = Uniform("u_meshColor", bgfx::UniformType::Vec4);
        if (!sMeshDataUniform.isValid())
            sMeshDataUniform = Uniform("u_meshData", bgfx::UniformType::Vec4);
        sMeshColorUniform.bind(sMeshColor.data());
        sMeshDataUniform.bind(sMeshData.data());
    }
};
 
} // namespace vcl
 
#endif // VCL_BGFX_DRAWABLE_UNIFORMS_DRAWABLE_MESH_UNIFORMS_H