/*
-----------------------------------------------
HDR HTML Viewer ver. 1.0
Author: Rafal Mantiuk
URL:    http://www.cs.ubc.ca/~mantiuk/hdrhtml.html
----------------------------------------------- */

            function set_opacity( obj, opacity ) {
              // for IE8
              obj.style.filter="progid:DXImageTransform.Microsoft.Alpha(Opacity=" + opacity*100 + ")";
              // for IE5-7
              obj.style.filter = "alpha(opacity=" + opacity*100 + ")";
              // for all other browsers
              obj.style.opacity = opacity;
            }
            
            function update_exp_text( hdr_image, new_exp ) {
               document.getElementById(hdr_image.base_name + "_exp_text").innerHTML = "EV: " + Math.round( (hdr_image.best_exp-new_exp)*10 )/10 + " f";
            }            
            
            function change_exp( hdr_image, exp_change ) {
            
            hdr_active_image = hdr_image;
            hdr_image.exposure = hdr_image.exposure + exp_change;
            
            if( hdr_image.exposure > hdr_image.f8_stops*8 ) {
              hdr_image.exposure = hdr_image.f8_stops*8;  
            } 
            else if( hdr_image.exposure < 0 ) {
              hdr_image.exposure = 0;
            }
            
            exp_cur = Math.floor(hdr_image.exposure / 8);
            exp_shar = exp_cur + 1;
                        
            exp_blend = Math.round((hdr_image.exposure - exp_cur*8)*hdr_image.f_step_res);
            
            var i;
            for( i = 0; i < hdr_image.basis; i++ ) {
            var img_obj = document.getElementById(hdr_image.base_name+"_"+i);
            img_obj.src = hdr_image.image_dir + hdr_image.base_name + "_"+exp_cur+"_" + (i+1) + ".jpg";
            set_opacity( img_obj, cf[exp_blend][i] );
            }
            
            for( i = 0; i < hdr_image.shared_basis; i++ ) {
            var img_obj = document.getElementById(hdr_image.base_name+"_"+(i+hdr_image.basis));  
            img_obj.src = hdr_image.image_dir + hdr_image.base_name + "_"+exp_shar+"_" + (i+1) + ".jpg";  
            set_opacity( img_obj, cf[exp_blend][i+hdr_image.basis] );
            }
            
            var hist_left = (hdr_image.exposure-hdr_image.hist_start)*hdr_image.pix_per_fstop;
            
            drw_obj = document.getElementById(hdr_image.base_name+"_dr_wind");
            drw_obj.style.left = Math.round(hist_left) + "px";
            drw_obj.style.width = hdr_image.pix_per_fstop*8 + "px";
            set_opacity( drw_obj, 0.7 );
            
            update_exp_text( hdr_image, hdr_image.exposure );
            }    
            
            function insert_hdr_image( hdr_image ) {
            
            for( i = 0; i < hdr_image.basis + hdr_image.shared_basis; i++ ) {
            document.write("<img id=\"" + hdr_image.base_name + "_" + i +
                                 "\" style=\"margin: 0px; padding: 0px; opacity: 1; width: " +
                                 hdr_image.width + "px; height: " + hdr_image.height + 
                                 "px; position: absolute; top: 0px; left: 0px\"" + 
                                 " />\n");
                                 }
            }
                                 
            function getAbsX (obj) {
              var abs_x=0;
              while(obj) {
                abs_x+= obj.offsetLeft;
                obj= obj.offsetParent;
              }
              return abs_x;
            }
                                 
            function dr_wind_clicked( event, hdr_image ) {

                var drw_obj = document.getElementById(hdr_image.base_name+"_dr_wind");
                var drw_left = drw_obj.offsetLeft;
                var drw_right = drw_obj.offsetLeft + drw_obj.offsetWidth;

                var hist_obj = document.getElementById(hdr_image.base_name + "_hist");
                var rel_x = event.clientX - getAbsX(hist_obj) - 5;

                var small_step_marg = 20;

                if( rel_x < drw_left ) {
                  change_exp( hdr_image, (drw_left-rel_x) < small_step_marg ? -1/3 : -1 );
                } else if( rel_x > drw_right ) {
                  change_exp( hdr_image, (rel_x-drw_right) < small_step_marg ? 1/3 : 1 );
                }

            }

            function dr_wind_mousedown( event, hdr_image ) {

                if(event.preventDefault) {
                  event.preventDefault();
                }
            
                var ctrl_obj = document.getElementById(hdr_image.base_name + "_dr_ctrl");
                var drw_obj = document.getElementById(hdr_image.base_name+"_dr_wind");
                set_opacity( drw_obj, 0.5 );

                hdr_mousedrag.hdr_image = hdr_image;
                hdr_mousedrag.start_mouse_x = event.clientX;
                hdr_mousedrag.start_win_x = drw_obj.offsetLeft + 2;
                ctrl_obj.onmousemove = dr_wind_move;
                ctrl_obj.onmouseup = dr_wind_mouseup;
            }

            function dr_wind_mouseup( event ) {
              event = event || window.event;

              hdr_image = hdr_mousedrag.hdr_image;

              var ctrl_obj = document.getElementById(hdr_image.base_name + "_dr_ctrl");
              var drw_obj = document.getElementById(hdr_image.base_name+"_dr_wind");
              var drw_left = drw_obj.offsetLeft;

              var new_exp = Math.round((drw_obj.offsetLeft/hdr_image.pix_per_fstop + hdr_image.hist_start)*3)/3;

              ctrl_obj.onmousemove = null;
              ctrl_obj.onmouseup = null;
              hdr_mousedrag.hdr_image = null;

              change_exp( hdr_image, new_exp - hdr_image.exposure );
            }


            function dr_wind_move(event){ 
              event = event || window.event;

              hdr_image = hdr_mousedrag.hdr_image;
              var drw_obj = document.getElementById(hdr_image.base_name+"_dr_wind");  

              var new_pos = (event.clientX-hdr_mousedrag.start_mouse_x) + hdr_mousedrag.start_win_x;
              drw_obj.style.left = new_pos + "px";

              var new_exp = Math.round((drw_obj.offsetLeft/hdr_image.pix_per_fstop + hdr_image.hist_start)*3)/3;
              update_exp_text( hdr_image, new_exp );
            }

            function hdr_show_help() {
                newwindow=window.open('','name','height=400,width=300');
                var tmp = newwindow.document;
                tmp.write('<html><head><title>HDR HTML viewer help</title>');
                tmp.write('</head><body>');
                tmp.write('<a href="http://pfstools.sourceforge.net/hdrhtml/" target="_blank">HDR HTML viewer</a> <div style="font-size: small">ver. 1.0</div>');
                tmp.write('<div style="font-size: small">(C) 2008 Rafal Mantiuk</div>');
                tmp.write('<ul style="font-size: small">');
                tmp.write('<li>Change exposure by scrolling the blue dynamic range window left and right.</li>');
                tmp.write('<li>Click on the left or right side of the dynamic range window to change exposure by either 1 or 1/3 of an f-stop depending on how far from the window you click.</li>');
                tmp.write('<li>Press "-" and "=" keys to change exposure by 1 f-stop.</li>');
                tmp.write('<li>The green plot represents image histogram. Each tick represent one f-stop. EV value is given in f-stops (log<sub>2</sub> units) relative to the inital exposure.</li>');
                tmp.write('</ul>');
                tmp.write('</body></html>');
                tmp.close();
            }

            function hdr_onkeydown(e) {              
              var hdr_image = hdr_active_image;
              var keynum;
              if( hdr_image == null )
                  return;
                
              if(window.event) { // IE
                keynum = window.event.keyCode;
                if( keynum == 189 )
                  change_exp( hdr_image, +1 );
                if( keynum == 187 )
                  change_exp( hdr_image, -1 );                                
              } else if(e.which) { // Netscape/Firefox/Opera                
                keynum = e.which;
                if( keynum == 109 )
                  change_exp( hdr_image, +1 );
                if( keynum == 61 )
                  change_exp( hdr_image, -1 );                
              }
                
            }