fltk/src/Fl_SVG_Image.cxx

//
// "$Id: Fl_SVG_Image.cxx 12239 2017-05-17 11:54:18Z manolo $"
//
// SVG image code for the Fast Light Tool Kit (FLTK).
//
// Copyright 2017 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//

#include <config.h>

#if defined(FLTK_USE_NANOSVG) || defined(FL_DOXYGEN)

#include <FL/Fl_SVG_Image.H>
#include <stdio.h>

#define NANOSVG_ALL_COLOR_KEYWORDS	// Include full list of color keywords.
#define NANOSVG_IMPLEMENTATION		// Expands implementation
#include "../nanosvg/nanosvg.h"

#define NANOSVGRAST_IMPLEMENTATION	// Expands implementation
#include "../nanosvg/altsvgrast.h"


/** The constructor loads the SVG image from the given .svg filename or in-memory data.
 \param filename A full path and name pointing to an SVG file.
 \param filedata A pointer to the memory location of the SVG image data.
 This parameter allows to load an SVG image from in-memory data, and requires that \p filename is NULL.
 \note In-memory SVG data is modified by the object constructor and is no longer used after construction.
 */
Fl_SVG_Image::Fl_SVG_Image(const char *filename, char *filedata) : Fl_RGB_Image(NULL, 0, 0, 4) {
  init_(filename, filedata, NULL);
}


// private constructor
Fl_SVG_Image::Fl_SVG_Image(Fl_SVG_Image *source) : Fl_RGB_Image(NULL, 0, 0, 4) {
  init_(NULL, NULL, source);
}


/** The destructor frees all memory and server resources that are used by the SVG image. */
Fl_SVG_Image::~Fl_SVG_Image() {
  if ( --counted_svg_image_->ref_count <= 0) {
    nsvgDelete(counted_svg_image_->svg_image);
    delete counted_svg_image_;
  }
}


float Fl_SVG_Image::svg_scaling_(int W, int H) {
  float f1 = float(W) / int(counted_svg_image_->svg_image->width+0.5);
  float f2 = float(H) / int(counted_svg_image_->svg_image->height+0.5);
  return (f1 < f2) ? f1 : f2;
}


void Fl_SVG_Image::init_(const char *filename, char *filedata, Fl_SVG_Image *copy_source) {
  if (copy_source) {
    filename = filedata = NULL;
    counted_svg_image_ = copy_source->counted_svg_image_;
    counted_svg_image_->ref_count++;
  } else {
    counted_svg_image_ = new counted_NSVGimage;
    counted_svg_image_->svg_image = NULL;
    counted_svg_image_->ref_count = 1;
  }
  to_desaturate_ = false;
  average_weight_ = 1;
  proportional = true;
  if (filename) {
    filedata = NULL;
    FILE *fp = fopen(filename, "rb");
    if (fp) {
      fseek(fp, 0, SEEK_END);
      size_t size = ftell(fp);
      fseek(fp, 0, SEEK_SET);
      filedata = (char*)malloc(size+1);
      if (filedata) {
        if (fread(filedata, 1, size, fp) == size) filedata[size] = '\0';
        else {
          free(filedata);
          filedata = NULL;
        }
      }
      fclose(fp);
    } else ld(ERR_FILE_ACCESS);
  }
  if (filedata) {
    counted_svg_image_->svg_image = nsvgParse(filedata, "px", 96);
    if (filename) free(filedata);
    if (counted_svg_image_->svg_image->width == 0 || counted_svg_image_->svg_image->height == 0) {
      d(-1);
      ld(ERR_FORMAT);
    } else {
      w(counted_svg_image_->svg_image->width + 0.5);
      h(counted_svg_image_->svg_image->height + 0.5);
    }
  } else if (copy_source) {
    w(copy_source->w());
    h(copy_source->h());
  }
  rasterized_ = false;
}


void Fl_SVG_Image::rasterize_(int W, int H) {
  static NSVGrasterizer *rasterizer = nsvgCreateRasterizer();
  double fx, fy;
  if (proportional) {
    fx = svg_scaling_(W, H);
    fy = fx;
  } else {
    fx = (double)W / counted_svg_image_->svg_image->width;
    fy = (double)H / counted_svg_image_->svg_image->height;
  }
  array = new uchar[W*H*4];
  nsvgAltRasterize(rasterizer, counted_svg_image_->svg_image, 0, 0, fx, fy, (uchar* )array, W, H, W*4);
  alloc_array = 1;
  data((const char * const *)&array, 1);
  d(4);
  if (to_desaturate_) Fl_RGB_Image::desaturate();
  if (average_weight_ < 1) Fl_RGB_Image::color_average(average_color_, average_weight_);
  rasterized_ = true;
  raster_w_ = W;
  raster_h_ = H;
}


Fl_Image *Fl_SVG_Image::copy(int W, int H) {
  Fl_SVG_Image *svg2 = new Fl_SVG_Image(this);
  svg2->to_desaturate_ = to_desaturate_;
  svg2->average_weight_ = average_weight_;
  svg2->average_color_ = average_color_;
  svg2->w(W); svg2->h(H);
  return svg2;
}


/** Have the svg data (re-)rasterized using the given width and height values.
 By default, the resulting image width and height will preserve the width/height ratio
 of the SVG data.
 If \ref proportional was set to false, the image is rasterized to the given \c width
 and \v height values.*/
void Fl_SVG_Image::resize(int width, int height) {
  if (ld() < 0) {
    return;
  }
  int w1 = width, h1 = height;
  if (proportional) {
    float f = svg_scaling_(width, height);
    w1 = int( int(counted_svg_image_->svg_image->width+0.5)*f + 0.5 );
    h1 = int( int(counted_svg_image_->svg_image->height+0.5)*f + 0.5 );
  }
  w(w1); h(h1);
  if (rasterized_ && w1 == raster_w_ && h1 == raster_h_) return;
  if (array) {
    delete[] array;
    array = NULL;
  }
  uncache();
  rasterize_(w1, h1);
}


void Fl_SVG_Image::draw(int X, int Y, int W, int H, int cx, int cy) {
  resize(w(), h());
  Fl_RGB_Image::draw(X, Y, W, H, cx, cy);
}


void Fl_SVG_Image::desaturate() {
  to_desaturate_ = true;
  Fl_RGB_Image::desaturate();
}


void Fl_SVG_Image::color_average(Fl_Color c, float i) {
  average_color_ = c;
  average_weight_ = i;
  Fl_RGB_Image::color_average(c, i);
}


int Fl_SVG_Image::draw_scaled_(int X, int Y, int W, int H) {
  w(W);
  h(H);
  draw(X, Y, W, H, 0, 0);
  return 1;
}

#endif // FLTK_USE_NANOSVG


//
// End of "$Id: Fl_SVG_Image.cxx 12239 2017-05-17 11:54:18Z manolo $".
//