gvloadimage_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 "config.h"
 
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
 
#include <gvc/gvplugin_loadimage.h>
#include "gvplugin_gdiplus.h"
#include <stringapiset.h>
#include <windows.h>
#include <gdiplus.h>
#include <vector>
 
using namespace Gdiplus;
 
static void gdiplus_freeimage(usershape_t *us) {
  delete reinterpret_cast<Image*>(us->data);
}
 
// convert a UTF-8 string to UTF-16
static std::vector<wchar_t> utf8_to_utf16(const char *s) {
 
  // how much space do we need for the UTF-16 string?
  const int wide_count = MultiByteToWideChar(CP_UTF8, 0, s, -1, nullptr, 0);
 
  // translate it
  std::vector<wchar_t> utf16(wide_count);
  if (wide_count > 0) {
    (void)MultiByteToWideChar(CP_UTF8, 0, s, -1, utf16.data(), wide_count);
  } else {
    utf16.push_back(0);
  }
 
  return utf16;
}
 
static Image* gdiplus_loadimage(GVJ_t * job, usershape_t *us)
{
    assert(job);
    (void)job;
    assert(us);
    assert(us->name);
 
    if (us->data && us->datafree != gdiplus_freeimage) {
             us->datafree(us);        /* free incompatible cache data */
             us->data = nullptr;
             us->datafree = nullptr;
        }
    
    if (!us->data) { /* read file into cache */
                if (!gvusershape_file_access(us))
                        return nullptr;
 
                /* create image from the usershape file */
                const std::vector<wchar_t> filename = utf8_to_utf16(us->name);
                us->data = Image::FromFile(filename.data());
                
                /* clean up */
                if (us->data)
                        us->datafree = gdiplus_freeimage;
                        
                gvusershape_file_release(us);
    }
    return reinterpret_cast<Image*>(us->data);
}
 
static void gdiplus_loadimage_gdiplus(GVJ_t * job, usershape_t *us, boxf b, bool)
{
        /* get the image from usershape details, then blit it to the context */
        if (Image *image = gdiplus_loadimage(job, us)) {
                auto g = reinterpret_cast<Graphics*>(job->context);
                g->DrawImage(image, RectF(b.LL.x, b.LL.y, b.UR.x - b.LL.x, b.UR.y - b.LL.y));
        }
}
 
static gvloadimage_engine_t engine = {
    gdiplus_loadimage_gdiplus
};
 
gvplugin_installed_t gvloadimage_gdiplus_types[] = {
        {FORMAT_BMP, "bmp:gdiplus", 8, &engine, nullptr},
        {FORMAT_GIF, "gif:gdiplus", 8, &engine, nullptr},
        {FORMAT_JPEG, "jpe:gdiplus", 8, &engine, nullptr},
        {FORMAT_JPEG, "jpeg:gdiplus", 8, &engine, nullptr},
        {FORMAT_JPEG, "jpg:gdiplus", 8, &engine, nullptr},
        {FORMAT_PNG, "png:gdiplus", 8, &engine, nullptr},
        {0, nullptr, 0, nullptr, nullptr}
};