MSW/GteWICFileIO.h

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// David Eberly, Geometric Tools, Redmond WA 98052
// Copyright (c) 1998-2017
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
// File Version: 3.0.0 (2016/06/19)

#pragma once

#include <Graphics/GteTexture2.h>
#include <guiddef.h>
#include <memory>

namespace gte
{

class GTE_IMPEXP WICFileIO
{
public:
    // Support for loading from BMP, GIF, ICON, JPEG, PNG, and TIFF.
    // The returned texture has a format that matches as close as possible
    // the format on disk.  If the load is not successful, the function
    // returns a null object.
    static std::shared_ptr<Texture2> Load(std::string const& filename,
        bool wantMipmaps);

    // Support for saving to PNG format.  Currently, the only formats
    // supported are R8G8B8A8 and R16.
    static bool SaveToPNG(std::string const& filename,
        std::shared_ptr<Texture2> const& texture);

    // Support for saving to JPEG format.  Currently, the only formats
    // supported are R8G8B8A8 and R16.  The image quality is in [0,1], where
    // a value of 0 indicates lowest quality (largest amount of compression)
    // and a value of 1 indicates highest quality (smallest amount of
    // compression).
    static bool SaveToJPEG(std::string const& filename,
        std::shared_ptr<Texture2> const& texture, float imageQuality);

private:
    class ComInitializer
    {
    public:
        ~ComInitializer();
        ComInitializer();
        bool IsInitialized() const;
    private:
        bool mInitialized;
    };

    template <typename T>
    class ComObject
    {
    public:
        ComObject();
        ComObject(T* inObject);
        ~ComObject();
        operator T*() const;
        T& operator*() const;
        T** operator&();
        T* operator->() const;
    private:
        T* object;
    };

    struct LoadFormatMap
    {
        DFType gtFormat;
        GUID const* wicInputGUID;
        GUID const* wicConvertGUID;
    };
    enum { NUM_LOAD_FORMATS = 14 };
    static LoadFormatMap const msLoadFormatMap[NUM_LOAD_FORMATS];

    struct SaveFormatMap
    {
        DFType gtFormat;
        GUID const* wicOutputGUID;
    };
    enum { NUM_SAVE_FORMATS = 11 };
    static SaveFormatMap const msSaveFormatMap[NUM_SAVE_FORMATS];

    // Helper function to share code between saving PNG and JPEG.  Set
    // imageQuality to -1.0f for PNG.  Set it to a number in [0,1] for
    // JPEG.
    static bool SaveTo(std::string const& filename,
        std::shared_ptr<Texture2> const& texture, float imageQuality);
};

}