gvplugin_gdiplus.cpp

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
#include <guiddef.h>
#include <gvc/gvplugin.h>
 
#include "gvplugin_gdiplus.h"
 
extern gvplugin_installed_t gvrender_gdiplus_types[];
extern gvplugin_installed_t gvtextlayout_gdiplus_types[];
extern gvplugin_installed_t gvloadimage_gdiplus_types[];
extern gvplugin_installed_t gvdevice_gdiplus_types[];
extern gvplugin_installed_t gvdevice_gdiplus_types_for_cairo[];
 
using namespace std;
using namespace Gdiplus;
 
/* class id corresponding to each format_type */
static GUID format_id [] = {
        GUID_NULL,
        GUID_NULL,
        ImageFormatBMP,
        ImageFormatEMF,
        ImageFormatEMF,
        ImageFormatGIF,
        ImageFormatJPEG,
        ImageFormatPNG,
        ImageFormatTIFF
};
 
static ULONG_PTR _gdiplusToken = 0;
 
static void UnuseGdiplus()
{
        GdiplusShutdown(_gdiplusToken);
}
 
void UseGdiplus()
{
        /* only startup once, and ensure we get shutdown */
        if (!_gdiplusToken)
        {
                GdiplusStartupInput input;
                GdiplusStartup(&_gdiplusToken, &input, nullptr);
                atexit(&UnuseGdiplus);
        }
}
 
const Gdiplus::StringFormat* GetGenericTypographic()
{
        const Gdiplus::StringFormat* format = StringFormat::GenericTypographic();
        return format;
}
 
void SaveBitmapToStream(Bitmap &bitmap, IStream *stream, int format)
{
        /* search the encoders for one that matches our device id, then save the bitmap there */
        GdiplusStartupInput gdiplusStartupInput;
        ULONG_PTR gdiplusToken;
        GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, nullptr);
        UINT encoderNum;
        UINT encoderSize;
        GetImageEncodersSize(&encoderNum, &encoderSize);
        vector<char> codec_buffer(encoderSize);
        ImageCodecInfo *codecs = (ImageCodecInfo *)&codec_buffer.front();
        GetImageEncoders(encoderNum, encoderSize, codecs);
        for (UINT i = 0; i < encoderNum; ++i)
                if (IsEqualGUID(format_id[format], codecs[i].FormatID)) {
                        bitmap.Save(stream, &codecs[i].Clsid, nullptr);
                        break;
                }
}
 
static gvplugin_api_t apis[] = {
    {API_render, gvrender_gdiplus_types},
        {API_textlayout, gvtextlayout_gdiplus_types},
        {API_loadimage, gvloadimage_gdiplus_types},
    {API_device, gvdevice_gdiplus_types},
        {API_device, gvdevice_gdiplus_types_for_cairo},
    {(api_t)0, 0},
};
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifdef GVDLL
#define GVPLUGIN_GDIPLUS_API __declspec(dllexport)
#else
#define GVPLUGIN_GDIPLUS_API
#endif
 
GVPLUGIN_GDIPLUS_API gvplugin_library_t gvplugin_gdiplus_LTX_library = {
  const_cast<char*>("gdiplus"), apis
};
 
#ifdef __cplusplus
}
#endif