texture.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
 *                                                                           *
 * All rights reserved.                                                      *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the Mozilla Public License Version 2.0 as published *
 * by the Mozilla Foundation; either version 2 of the License, or            *
 * (at your option) any later version.                                       *
 *                                                                           *
 * 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_TEXTURE_H
#define VCL_BGFX_TEXTURE_H
 
#include <vclib/base.h>
#include <vclib/space/core.h>
 
#include <bgfx/bgfx.h>
#include <bimg/bimg.h>
 
namespace vcl {
 
class Texture
{
    bgfx::TextureHandle mTextureHandle = BGFX_INVALID_HANDLE;
 
public:
    Texture() = default;
 
    Texture(const Texture& other) = delete;
 
    Texture(Texture&& other) noexcept { swap(other); }
 
    ~Texture()
    {
        if (bgfx::isValid(mTextureHandle))
            bgfx::destroy(mTextureHandle);
    }
 
    Texture& operator=(const Texture& other) = delete;
 
    Texture& operator=(Texture&& other) noexcept
    {
        swap(other);
        return *this;
    }
 
    void swap(Texture& other)
    {
        using std::swap;
        swap(mTextureHandle, other.mTextureHandle);
    }
 
    friend void swap(Texture& a, Texture& b) { a.swap(b); }
 
    bool isValid() const { return bgfx::isValid(mTextureHandle); }
 
    void set(
        const void*         data,
        const vcl::Point2i& size,
        bool                hasMips   = false,
        uint64_t            flags     = BGFX_TEXTURE_NONE | BGFX_SAMPLER_NONE,
        bgfx::ReleaseFn     releaseFn = nullptr)
    {
        uint32_t sz = bimg::imageGetSize(
            nullptr,
            size.x(),
            size.y(),
            1,
            false,
            hasMips,
            1,
            bimg::TextureFormat::RGBA8);
        set(bgfx::makeRef(data, sz, releaseFn),
            size,
            hasMips,
            1,
            bgfx::TextureFormat::RGBA8,
            flags);
    }
 
    void set(
        const bgfx::Memory*       texture,
        const vcl::Point2i&       size,
        bool                      hasMips,
        uint                      nLayers,
        bgfx::TextureFormat::Enum format = bgfx::TextureFormat::RGBA8,
        uint64_t                  flags = BGFX_TEXTURE_NONE | BGFX_SAMPLER_NONE)
    {
        if (bgfx::isValid(mTextureHandle))
            bgfx::destroy(mTextureHandle);
 
        mTextureHandle = bgfx::createTexture2D(
            size.x(), size.y(), hasMips, nLayers, format, flags, texture);
    }
 
    void bind(
        uint                stage,
        bgfx::UniformHandle samplerHandle,
        uint                samplerFlags = UINT32_MAX) const
    {
        if (bgfx::isValid(mTextureHandle) && bgfx::isValid(samplerHandle)) {
            bgfx::setTexture(
                stage, samplerHandle, mTextureHandle, samplerFlags);
        }
    }
 
    static uint samplerFlagsFromTexture(const TextureDescriptor& tex)
    {
        using enum TextureDescriptor::MinificationFilter;
        using enum TextureDescriptor::WrapMode;
 
        uint flags = BGFX_SAMPLER_NONE;
 
        // set minification filter - bgfx default is linear
        if (tex.minFilter() == NEAREST ||
            tex.minFilter() == NEAREST_MIPMAP_LINEAR ||
            tex.minFilter() == NEAREST_MIPMAP_NEAREST)
            flags |= BGFX_SAMPLER_MIN_POINT;
 
        // set mipmap filter - bgfx default is linear
        if (tex.minFilter() == NEAREST_MIPMAP_NEAREST ||
            tex.minFilter() == LINEAR_MIPMAP_NEAREST)
            flags |= BGFX_SAMPLER_MIP_POINT;
 
        // set magnification filter - bgfx default is linear
        if (tex.magFilter() == TextureDescriptor::MagnificationFilter::NEAREST)
            flags |= BGFX_SAMPLER_MAG_POINT;
 
        // set wrap modes - bgfx default is repeat
        if (tex.wrapU() == CLAMP_TO_EDGE)
            flags |= BGFX_SAMPLER_U_CLAMP;
        else if (tex.wrapU() == MIRRORED_REPEAT)
            flags |= BGFX_SAMPLER_U_MIRROR;
 
        if (tex.wrapV() == CLAMP_TO_EDGE)
            flags |= BGFX_SAMPLER_V_CLAMP;
        else if (tex.wrapV() == MIRRORED_REPEAT)
            flags |= BGFX_SAMPLER_V_MIRROR;
 
        return flags;
    }
};
 
} // namespace vcl
 
#endif // VCL_BGFX_TEXTURE_H