maplegend.c

/******************************************************************************
 *
 * Project:  MapServer
 * Purpose:  Legend generation.
 * Author:   Steve Lime and the MapServer team.
 *
 ******************************************************************************
 * Copyright (c) 1996-2005 Regents of the University of Minnesota.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in 
 * all copies of this Software or works derived from this Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * $Log$
 * Revision 1.57.2.2  2006/03/27 05:50:52  sdlime
 * Fixed symbol initialization error with embedded scalebars and legends. (bug 1725)
 *
 * Revision 1.57.2.1  2006/01/16 20:41:22  sdlime
 * Fixed error with image legends (shifted text) introduced by the 1449 bug fix. (bug 1607)
 *
 * Revision 1.57  2005/11/17 05:56:30  sdlime
 * Updated msDrawLegend to respect class min/max scale values. (bug 1524)
 *
 * Revision 1.56  2005/10/31 06:03:26  sdlime
 * Updated msDrawLegend() to consider layer order. (bug 1484)
 *
 * Revision 1.55  2005/09/14 00:11:35  frank
 * fixed leak of imageObj when embedding legends
 *
 * Revision 1.54  2005/06/14 16:03:33  dan
 * Updated copyright date to 2005
 *
 * Revision 1.53  2005/02/18 18:57:26  sean
 * turn on GD alpha blending for legend icon images if specified by the target layer (bugs 490, 1250)
 *
 * Revision 1.52  2005/02/18 03:06:46  dan
 * Turned all C++ (//) comments into C comments (bug 1238)
 *
 * Revision 1.51  2005/01/11 00:24:07  frank
 * added labelObj arg to msAddLabel()
 *
 * Revision 1.50  2004/11/22 03:43:54  sdlime
 * Added tests to mimimize the threat of recursion problems when evaluating LAYER REQUIRES or LABELREQUIRES expressions. Note that via MapScript it is possible to circumvent that test by defining layers with problems after running prepareImage. Other things crop up in that case too (symbol scaling dies) so it should be considered bad programming practice.
 *
 * Revision 1.49  2004/11/05 19:19:05  frank
 * avoid casting warning i msDrawLegendIcon call
 *
 * Revision 1.48  2004/11/04 21:33:08  frank
 * Removed unused variable.
 *
 * Revision 1.47  2004/10/28 18:16:17  dan
 * Fixed WMS GetLegendGraphic which was returning an exception (GD error)
 * when requested layer was out of scale (bug 1006)
 *
 * Revision 1.46  2004/10/21 04:30:55  frank
 * Added standardized headers.  Added MS_CVSID().
 *
 */

#include "map.h"

MS_CVSID("$Id$")

#define PSF .8
#define VMARGIN 5 /* margin at top and bottom of legend graphic */
#define HMARGIN 5 /* margin at left and right of legend graphic */

int msDrawLegendIcon(mapObj *map, layerObj *lp, classObj *class, int width, int height, gdImagePtr img, int dstX, int dstY)
{
  int i, type;
  shapeObj box, zigzag;
  pointObj marker;
  char szPath[MS_MAXPATHLEN];
  imageObj *image = NULL;
  styleObj outline_style;

  /* if drawing an outline (below) we need to set clipping to keep symbols withing the outline */
  if(MS_VALID_COLOR(map->legend.outlinecolor))
    gdImageSetClip(img, dstX, dstY, dstX + width - 1, dstY + height - 1);

  /* initialize the box used for polygons and for outlines */
  box.line = (lineObj *)malloc(sizeof(lineObj));
  box.numlines = 1;
  box.line[0].point = (pointObj *)malloc(sizeof(pointObj)*5);
  box.line[0].numpoints = 5;

  box.line[0].point[0].x = dstX;
  box.line[0].point[0].y = dstY;
  box.line[0].point[1].x = dstX + width - 1;
  box.line[0].point[1].y = dstY;
  box.line[0].point[2].x = dstX + width - 1;
  box.line[0].point[2].y = dstY + height - 1;
  box.line[0].point[3].x = dstX;
  box.line[0].point[3].y = dstY + height - 1;
  box.line[0].point[4].x = box.line[0].point[0].x;
  box.line[0].point[4].y = box.line[0].point[0].y;
  box.line[0].numpoints = 5;
    
  /* if the class has a keyimage then load it, scale it and we're done */
  if(class->keyimage != NULL) {
    image = msImageLoadGD(msBuildPath(szPath, map->mappath, class->keyimage));
    if(!image) return(MS_FAILURE);

    /* TO DO: we may want to handle this differently depending on the relative size of the keyimage */
    gdImageCopyResampled(img, image->img.gd, dstX, dstY, 0, 0, width, height, image->img.gd->sx, image->img.gd->sy);
  } else {        
    /* some polygon layers may be better drawn using zigzag if there is no fill */
    type = lp->type;
    if(type == MS_LAYER_POLYGON) {
      type = MS_LAYER_LINE;
      for(i=0; i<class->numstyles; i++) {
        if(MS_VALID_COLOR(class->styles[i].color)) { /* there is a fill */
	  type = MS_LAYER_POLYGON;
	  break;
        }
      }
    }

    /* 
    ** now draw the appropriate color/symbol/size combination 
    */     

    /* Bug 490 - switch alpha blending on for a layer that requires it */
    if (lp->transparency == MS_GD_ALPHA) {
        gdImageAlphaBlending(img, 1);
    }

    switch(type) {
    case MS_LAYER_ANNOTATION:
    case MS_LAYER_POINT:
      marker.x = dstX + MS_NINT(width / 2.0);
      marker.y = dstY + MS_NINT(height / 2.0);

      for(i=0; i<class->numstyles; i++)
        msDrawMarkerSymbolGD(&map->symbolset, img, &marker, &(class->styles[i]), 1.0);          
      break;
    case MS_LAYER_LINE:
      zigzag.line = (lineObj *)malloc(sizeof(lineObj));
      zigzag.numlines = 1;
      zigzag.line[0].point = (pointObj *)malloc(sizeof(pointObj)*4);
      zigzag.line[0].numpoints = 4;

      zigzag.line[0].point[0].x = dstX;
      zigzag.line[0].point[0].y = dstY + height - 1;
      zigzag.line[0].point[1].x = dstX + MS_NINT(width / 3.0) - 1;
      zigzag.line[0].point[1].y = dstY;
      zigzag.line[0].point[2].x = dstX + MS_NINT(2.0 * width / 3.0) - 1;
      zigzag.line[0].point[2].y = dstY + height - 1;
      zigzag.line[0].point[3].x = dstX + width - 1;
      zigzag.line[0].point[3].y = dstY;
      zigzag.line[0].numpoints = 4;

      for(i=0; i<class->numstyles; i++)
        msDrawLineSymbolGD(&map->symbolset, img, &zigzag, &(class->styles[i]), 1.0); 

      free(zigzag.line[0].point);
      free(zigzag.line);	
      break;
    case MS_LAYER_CIRCLE:
    case MS_LAYER_RASTER:
    case MS_LAYER_POLYGON:
      for(i=0; i<class->numstyles; i++)     
        msDrawShadeSymbolGD(&map->symbolset, img, &box, &(class->styles[i]), 1.0);
      break;
    default:
      return MS_FAILURE;
      break;
    } /* end symbol drawing */
  }   

  /* handle an outline if necessary */
  if(MS_VALID_COLOR(map->legend.outlinecolor)) {
    initStyle(&outline_style);
    outline_style.color = map->legend.outlinecolor;
    msDrawLineSymbolGD(&map->symbolset, img, &box, &outline_style, 1.0);    
    gdImageSetClip(img, 0, 0, img->sx - 1, img->sy - 1); /* undo any clipping settings */
  }

  free(box.line[0].point);
  free(box.line);
  
  return MS_SUCCESS;
}

imageObj *msCreateLegendIcon(mapObj* map, layerObj* lp, classObj* class, int width, int height)
{
  imageObj *image;
  outputFormatObj *format = NULL;
  int i = 0;

  if(!map->outputformat || !MS_RENDERER_GD(map->outputformat) ) 
  {
      msSetError(MS_GDERR, 
                 "Map outputformat must be set to a GD format!", 
                 "msCreateLegendIcon()");
      return(NULL);
  }

  /* ensure we have an image format representing the options for the legend */
  msApplyOutputFormat(&format, map->outputformat, map->legend.transparent, map->legend.interlace, MS_NOOVERRIDE);

  /* create image */
  image = msImageCreateGD(width, height, map->outputformat, map->web.imagepath, map->web.imageurl);

  /* drop this reference to output format */
  msApplyOutputFormat( &format, NULL, MS_NOOVERRIDE, MS_NOOVERRIDE, MS_NOOVERRIDE );

  if(image == NULL) {
    msSetError(MS_GDERR, "Unable to initialize image.","msCreateLegendIcon()");
    return(NULL);
  }

  /* allocate the background color */
  msImageInitGD( image, &(map->legend.imagecolor));

  /* Call drawLegendIcon with destination (0, 0) */
  /* Return an empty image if lp==NULL || class=NULL  */
  /* (If class is NULL draw the legend for all classes. Modifications done */
  /* Fev 2004 by AY) */
  if (lp) {
    msClearLayerPenValues(lp); /* just in case the mapfile has already been processed */
    if (class) {
      msDrawLegendIcon(map, lp, class, width, height, image->img.gd, 0, 0);
    }
    else {
      for (i=0; i<lp->numclasses; i++) {
        msDrawLegendIcon(map, lp, &lp->class[i], width, height, image->img.gd, 0, 0);
      }
    }
  }

  return image;
}


/*
** Creates a GD image of a legend for a specific map. msDrawLegend()
** respects the current scale, and classes without a name are not
** added to the legend.
**
** scale_independent is used for WMS GetLegendGraphic. It should be set to
** MS_FALSE in most cases. If it is set to MS_TRUE then the layers' minscale
** and maxscale are ignored and layers that are currently out of scale still
** show up in the legend.
*/
imageObj *msDrawLegend(mapObj *map, int scale_independent)
{
  int status;

  gdImagePtr img; /* image data structure */
  int i,j; /* loop counters */
  pointObj pnt;
  int size_x, size_y;
  layerObj *lp;  
  int maxwidth=0, maxheight=0, n=0;
  int *heights;
  rectObj rect;
  imageObj *image = NULL;
  outputFormatObj *format = NULL;

  if (!scale_independent) {
      map->cellsize = msAdjustExtent(&(map->extent), map->width, map->height);
      status = msCalculateScale(map->extent, map->units, map->width, map->height, map->resolution, &map->scale);
      if(status != MS_SUCCESS) return(NULL);
  }

  if(msValidateContexts(map) != MS_SUCCESS) return NULL; /* make sure there are no recursive REQUIRES or LABELREQUIRES expressions */

  /*
  ** allocate heights array
  */
  for(i=0; i<map->numlayers; i++) {
    lp = &(map->layers[map->layerorder[i]]);

    if((lp->status == MS_OFF) || (lp->type == MS_LAYER_QUERY)) /* skip it */
      continue;

    for(j=0;j<lp->numclasses;j++) {
      if(!lp->class[j].name)
	continue; /* skip it */
      n++;
    }
  }

  if((heights = (int *)malloc(sizeof(int)*n)) == NULL) {
    msSetError(MS_MEMERR, "Error allocating heights array.", "msDrawLegend()");
    return(NULL);
  }

  /*
  ** Calculate the optimal image size for the legend
  */
  n=0;
  for(i=0; i<map->numlayers; i++) { /* Need to find the longest legend label string */
    lp = &(map->layers[map->layerorder[i]]);

    if((lp->status == MS_OFF) || (lp->type == MS_LAYER_QUERY)) /* skip it */
      continue;

    if(!scale_independent && map->scale > 0) {
      if((lp->maxscale > 0) && (map->scale > lp->maxscale))
	continue;
      if((lp->minscale > 0) && (map->scale <= lp->minscale))
	continue;
    }
 
    for(j=0;j<lp->numclasses;j++) {
      if(!lp->class[j].name)
	continue; /* skip it */

      if(!scale_independent && map->scale > 0) {  /* verify class scale here */
	if((lp->class[j].maxscale > 0) && (map->scale > lp->class[j].maxscale))
	  continue;
	if((lp->class[j].minscale > 0) && (map->scale <= lp->class[j].minscale))
	  continue;
      }

      if(msGetLabelSize(lp->class[j].name, &map->legend.label, &rect, &(map->fontset), 1.0, MS_FALSE) != 0)
	return(NULL); /* something bad happened */
      maxheight = MS_MAX(maxheight, MS_NINT(rect.maxy - rect.miny));
      maxwidth = MS_MAX(maxwidth, MS_NINT(rect.maxx - rect.minx));
      heights[n] = MS_NINT(rect.maxy - rect.miny);

      n++;
    }
  }

  size_x = (2*HMARGIN)+(maxwidth)+(map->legend.keyspacingx)+(map->legend.keysizex);
  size_y = (2*VMARGIN) + ((n-1)*map->legend.keyspacingy);
  for(i=0; i<n; i++) {
    heights[i] = MS_MAX(heights[i], maxheight);
    size_y += MS_MAX(heights[i], map->legend.keysizey);
  }

  /* ensure we have an image format representing the options for the legend. */
  msApplyOutputFormat(&format, map->outputformat, map->legend.transparent, map->legend.interlace, MS_NOOVERRIDE);

  /* initialize the legend image */
  image = msImageCreateGD(size_x, size_y, format, map->web.imagepath, map->web.imageurl);

  /* drop this reference to output format */
  msApplyOutputFormat(&format, NULL, MS_NOOVERRIDE, MS_NOOVERRIDE, MS_NOOVERRIDE);

  if (image)
    img = image->img.gd;
  else {
    msSetError(MS_GDERR, "Unable to initialize image.", "msDrawLegend()");
    return(NULL);
  }
  
  /* Set background */
  if(image != NULL)
    msImageInitGD(image, &(map->legend.imagecolor));

  msClearPenValues(map); /* just in case the mapfile has already been processed */

  pnt.y = VMARGIN;
    
  /* for(i=0; i<map->numlayers; i++) { */
  for(i=map->numlayers-1; i>=0; i--) {
    lp = &(map->layers[map->layerorder[i]]); /* for brevity */

    if((lp->numclasses == 0) || (lp->status == MS_OFF) || (lp->type == MS_LAYER_QUERY))
      continue; /* skip this layer */

    if(!scale_independent && map->scale > 0) {
      if((lp->maxscale > 0) && (map->scale > lp->maxscale))
	continue;
      if((lp->minscale > 0) && (map->scale <= lp->minscale))
	continue;
    }

    for(j=0; j<lp->numclasses; j++) { /* always at least 1 class */

      if(!lp->class[j].name) continue; /* skip it */
     
      if(!scale_independent && map->scale > 0) {  /* verify class scale here */
        if((lp->class[j].maxscale > 0) && (map->scale > lp->class[j].maxscale))
          continue;
        if((lp->class[j].minscale > 0) && (map->scale <= lp->class[j].minscale))
          continue;
      }
 
      pnt.x = HMARGIN + map->legend.keysizex + map->legend.keyspacingx;
      
      /* TODO */
      if (msDrawLegendIcon(map, lp, &(lp->class[j]),  map->legend.keysizex,  map->legend.keysizey, image->img.gd, HMARGIN, (int) pnt.y) != MS_SUCCESS)
         return NULL;

      pnt.y += MS_MAX(map->legend.keysizey, maxheight);
      /* TODO */
      msDrawLabel(image, pnt, lp->class[j].name, &(map->legend.label), &map->fontset, 1.0);

      pnt.y += map->legend.keyspacingy; /* bump y for next label */
	
    } /* next label */
  } /* next layer */

  free(heights);
  return(image);
}


/* TODO */
int msEmbedLegend(mapObj *map, gdImagePtr img)
{
  int s,l;
  pointObj point;
  imageObj *image = NULL;

  s = msGetSymbolIndex(&(map->symbolset), "legend", MS_FALSE);
  if(s == -1) {
    s = map->symbolset.numsymbols;
    map->symbolset.numsymbols++;
    initSymbol(&(map->symbolset.symbol[s]));
  } else {
    if(map->symbolset.symbol[s].img) 
      gdImageDestroy(map->symbolset.symbol[s].img);
  }
  
  /* render the legend. */
  image = msDrawLegend(map, MS_FALSE);

  /* steal the gdImage and free the rest of the imageObj */
  map->symbolset.symbol[s].img = image->img.gd; 
  image->img.gd = NULL;
  msFreeImage( image );

  if(!map->symbolset.symbol[s].img) return(-1); /* something went wrong creating scalebar */

  map->symbolset.symbol[s].type = MS_SYMBOL_PIXMAP; /* intialize a few things */
  map->symbolset.symbol[s].name = strdup("legend");  
  map->symbolset.symbol[s].sizex = map->symbolset.symbol[s].img->sx;
  map->symbolset.symbol[s].sizey = map->symbolset.symbol[s].img->sy;

  /* I'm not too sure this test is sufficient ... NFW. */
  if(map->legend.transparent == MS_ON)
    gdImageColorTransparent(map->symbolset.symbol[s].img, 0);

  switch(map->legend.position) {
  case(MS_LL):
    point.x = MS_NINT(map->symbolset.symbol[s].img->sx/2.0);
    point.y = map->height - MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  case(MS_LR):
    point.x = map->width - MS_NINT(map->symbolset.symbol[s].img->sx/2.0);
    point.y = map->height - MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  case(MS_LC):
    point.x = MS_NINT(map->width/2.0);
    point.y = map->height - MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  case(MS_UR):
    point.x = map->width - MS_NINT(map->symbolset.symbol[s].img->sx/2.0);
    point.y = MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  case(MS_UL):
    point.x = MS_NINT(map->symbolset.symbol[s].img->sx/2.0);
    point.y = MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  case(MS_UC):
    point.x = MS_NINT(map->width/2.0);
    point.y = MS_NINT(map->symbolset.symbol[s].img->sy/2.0);
    break;
  }

  l = msGetLayerIndex(map, "__embed__legend");
  if(l == -1) {
    l = map->numlayers;
    map->numlayers++;

    if(initLayer(&(map->layers[l]), map) == -1) return(-1);
    map->layers[l].name = strdup("__embed__legend");
    map->layers[l].type = MS_LAYER_ANNOTATION;

    if(initClass(&(map->layers[l].class[0])) == -1) return(-1);
    map->layers[l].numclasses = 1; /* so we make sure to free it */
        
    /* update the layer order list with the layer's index. */
    map->layerorder[l] = l;
  }

  map->layers[l].status = MS_ON;

  map->layers[l].class[0].numstyles = 1;
  map->layers[l].class[0].styles[0].symbol = s;
  map->layers[l].class[0].styles[0].color.pen = -1;
  map->layers[l].class[0].label.force = MS_TRUE;
  map->layers[l].class[0].label.size = MS_MEDIUM; /* must set a size to have a valid label definition */

  if(map->legend.postlabelcache) /* add it directly to the image */
    msDrawMarkerSymbolGD(&map->symbolset, img, &point, &(map->layers[l].class[0].styles[0]), 1.0);
  else
    msAddLabel(map, l, 0, -1, -1, &point, " ", 1.0, NULL);

  /* Mark layer as deleted so that it doesn't interfere with html legends or */
  /* with saving maps */
  map->layers[l].status = MS_DELETE;

  return(0);
}