pcottle.learnGitBranching/arbor_src/graphics/graphics.js

//
//  graphics.js
//
//  Created by Christian Swinehart on 2010-12-07.
//  Copyright (c) 2011 Samizdat Drafting Co. All rights reserved.
//

var Graphics = function(canvas){
  var dom = $(canvas)
  var ctx = $(dom).get(0).getContext('2d')

  var _bounds = null

  var _colorMode = "rgb" // vs hsb
  var _coordMode = "origin" // vs "center"

  var _drawLibrary = {}
  var _drawStyle = {background:null, 
                    fill:null, 
                    stroke:null,
                    width:0}

  var _fontLibrary = {}
  var _fontStyle = {font:"sans-serif",
                   size:12, 
                   align:"left",
                   color:Colors.decode("black"),
                   alpha:1,
                   baseline:"ideographic"}

  var _lineBuffer = [] // calls to .lines sit here until flushed by .drawlines
  
  ///MACRO:primitives-start
  var primitives = Primitives(ctx, _drawStyle, _fontStyle)
  var _Oval = primitives._Oval
  var _Rect = primitives._Rect
  var _Color = primitives._Color
  var _Path = primitives._Path
  ///MACRO:primitives-end    


  // drawStyle({background:"color" or {r,g,b,a}, 
  //            fill:"color" or {r,g,b,a}, 
  //            stroke:"color" or {r,g,b,a}, 
  //            alpha:<number>, 
  //            weight:<number>})




  
  var that = {
    init:function(){
      if (!ctx) return null
      return that
    },

    // canvas-wide settings
    size:function(width,height){
      if (!isNaN(width) && !isNaN(height)){
        dom.attr({width:width,height:height})
        
        // if (_drawStyle.fill!==null) that.fill(_drawStyle.fill)
        // if (_drawStyle.stroke!==null) that.stroke(_drawStyle.stroke)
        // that.textStyle(_fontStyle)
        
        // trace(_drawStyle,_fontStyle)
      }
      return {width:dom.attr('width'), height:dom.attr('height')}
    },

    clear:function(x,y,w,h){
      if (arguments.length<4){
        x=0; y=0
        w=dom.attr('width')
        h=dom.attr('height')
      }
      
      ctx.clearRect(x,y,w,h)
      if (_drawStyle.background!==null){
        ctx.save()
        ctx.fillStyle = Colors.encode(_drawStyle.background)
        ctx.fillRect(x,y,w,h)
        ctx.restore()
      }
    },

    background:function(a,b,c,d){
      if (a==null){
        _drawStyle.background = null
        return null
      }
      
      var fillColor = Colors.decode(a,b,c,d)
      if (fillColor){
        _drawStyle.background = fillColor
        that.clear()
      }
    },


    // drawing to screen
    noFill:function(){
      _drawStyle.fill = null
    },
    fill:function(a,b,c,d){
      if (arguments.length==0){
        return _drawStyle.fill
      }else if (arguments.length>0){
        var fillColor = Colors.decode(a,b,c,d)
        _drawStyle.fill = fillColor
        ctx.fillStyle = Colors.encode(fillColor)
      }
    },
    
    noStroke:function(){
      _drawStyle.stroke = null
      ctx.strokeStyle = null
    },
    stroke:function(a,b,c,d){
      if (arguments.length==0 && _drawStyle.stroke!==null){
        return _drawStyle.stroke
      }else if (arguments.length>0){
        var strokeColor = Colors.decode(a,b,c,d)
        _drawStyle.stroke = strokeColor
        ctx.strokeStyle = Colors.encode(strokeColor)
      }
    },
    strokeWidth:function(ptsize){
      if (ptsize===undefined) return ctx.lineWidth
      ctx.lineWidth = _drawStyle.width = ptsize
    },
    
    
    
    Color:function(clr){
      return new _Color(clr)
    },


    // Font:function(fontName, pointSize){
    //   return new _Font(fontName, pointSize)
    // },
    // font:function(fontName, pointSize){
    //   if (fontName!==undefined) _fontStyle.font = fontName
    //   if (pointSize!==undefined) _fontStyle.size = pointSize
    //   ctx.font = nano("{size}px {font}", _fontStyle)
    // },


    drawStyle:function(style){
      // without arguments, show the current state
      if (arguments.length==0) return objcopy(_drawStyle)
      
      // if this is a ("stylename", {style}) invocation, don't change the current
      // state but add it to the library
      if (arguments.length==2){
        var styleName = arguments[0]
        var styleDef = arguments[1]
        if (typeof styleName=='string' && typeof styleDef=='object'){
          var newStyle = {}
          if (styleDef.color!==undefined){
            var textColor = Colors.decode(styleDef.color)
            if (textColor) newStyle.color = textColor
          }
          $.each('background fill stroke width'.split(' '), function(i, param){
            if (styleDef[param]!==undefined) newStyle[param] = styleDef[param]
          })
          if (!$.isEmptyObject(newStyle)) _drawLibrary[styleName] = newStyle
        }
        return
      }
      
      // if a ("stylename") invocation, load up the selected style
      if (arguments.length==1 && _drawLibrary[arguments[0]]!==undefined){
        style = _drawLibrary[arguments[0]]
      }
            
      // for each of the properties specified, update the canvas state
      if (style.width!==undefined) _drawStyle.width = style.width
      ctx.lineWidth = _drawStyle.width
      
      $.each('background fill stroke',function(i, color){
        if (style[color]!==undefined){
          if (style[color]===null) _drawStyle[color] = null
          else{
            var useColor = Colors.decode(style[color])
            if (useColor) _drawStyle[color] = useColor
          }
        }
      })
      ctx.fillStyle = _drawStyle.fill
      ctx.strokeStyle = _drawStyle.stroke
    },

    textStyle:function(style){
      // without arguments, show the current state
      if (arguments.length==0) return objcopy(_fontStyle)
      
      // if this is a ("name", {style}) invocation, don't change the current
      // state but add it to the library
      if (arguments.length==2){
        var styleName = arguments[0]
        var styleDef = arguments[1]
        if (typeof styleName=='string' && typeof styleDef=='object'){
          var newStyle = {}
          if (styleDef.color!==undefined){
            var textColor = Colors.decode(styleDef.color)
            if (textColor) newStyle.color = textColor
          }
          $.each('font size align baseline alpha'.split(' '), function(i, param){
            if (styleDef[param]!==undefined) newStyle[param] = styleDef[param]
          })
          if (!$.isEmptyObject(newStyle)) _fontLibrary[styleName] = newStyle
        }
        return
      }
      
      if (arguments.length==1 && _fontLibrary[arguments[0]]!==undefined){
        style = _fontLibrary[arguments[0]]
      }
            
      if (style.font!==undefined) _fontStyle.font = style.font
      if (style.size!==undefined) _fontStyle.size = style.size
      ctx.font = nano("{size}px {font}", _fontStyle)

      if (style.align!==undefined){
         ctx.textAlign = _fontStyle.align = style.align
      }
      if (style.baseline!==undefined){
         ctx.textBaseline = _fontStyle.baseline = style.baseline
      }

      if (style.alpha!==undefined) _fontStyle.alpha = style.alpha
      if (style.color!==undefined){
        var textColor = Colors.decode(style.color)
        if (textColor) _fontStyle.color = textColor
      }
      if (_fontStyle.color){
        var textColor = Colors.blend(_fontStyle.color, _fontStyle.alpha)
        if (textColor) ctx.fillStyle = textColor
      }
      // trace(_fontStyle,opts)
    },

    text:function(textStr, x, y, opts){ // opts: x,y, color, font, align, baseline, width
      if (arguments.length>=3 && !isNaN(x)){
        opts = opts || {}
        opts.x = x
        opts.y = y
      }else if (arguments.length==2 && typeof(x)=='object'){
        opts = x
      }else{
        opts = opts || {}
      }

      var style = objmerge(_fontStyle, opts)
      ctx.save()
        if (style.align!==undefined) ctx.textAlign = style.align
        if (style.baseline!==undefined) ctx.textBaseline = style.baseline
        if (style.font!==undefined && !isNaN(style.size)){
          ctx.font = nano("{size}px {font}", style)
        }

        var alpha = (style.alpha!==undefined) ? style.alpha : _fontStyle.alpha
        var color = (style.color!==undefined) ? style.color : _fontStyle.color
        ctx.fillStyle = Colors.blend(color, alpha)
        
        // if (alpha>0) ctx.fillText(textStr, style.x, style.y);        
        if (alpha>0) ctx.fillText(textStr, Math.round(style.x), style.y);        
      ctx.restore()
    },

    textWidth:function(textStr, style){ // style: x,y, color, font, align, baseline, width
      style = objmerge(_fontStyle, style||{})
      ctx.save()
        ctx.font = nano("{size}px {font}", style)
        var width = ctx.measureText(textStr).width			  
      ctx.restore()
      return width
    },
    
    // hasFont:function(fontName){
    //   var testTxt = 'H h H a H m H b H u H r H g H e H r H f H o H n H s H t H i H v H'
    //   ctx.save()
    //   ctx.font = '10px sans-serif'
    //   var defaultWidth = ctx.measureText(testTxt).width
    // 
    //   ctx.font = '10px "'+fontName+'"'
    //   var putativeWidth = ctx.measureText(testTxt).width
    //   ctx.restore()
    //   
    //   // var defaultWidth = that.textWidth(testTxt, {font:"Times New Roman", size:120})
    //   // var putativeWidth = that.textWidth(testTxt, {font:fontName, size:120})
    //   trace(defaultWidth,putativeWidth,ctx.font)
    //   // return (putativeWidth!=defaultWidth || fontName=="Times New Roman")
    //   return putativeWidth!=defaultWidth
    // },
    
    
    // shape primitives.
    // classes will return an {x,y,w,h, fill(), stroke()} object without drawing
    // functions will draw the shape based on current stroke/fill state
    Rect:function(x,y,w,h,r,style){
      return new _Rect(x,y,w,h,r,style)
    },
    rect:function(x, y, w, h, r, style){
      _Rect.prototype._draw(x,y,w,h,r,style)
    },
    
    Oval:function(x, y, w, h, style) {
      return new _Oval(x,y,w,h, style)
    },
    oval:function(x, y, w, h, style) {
      style = style || {}
      _Oval.prototype._draw(x,y,w,h, style)
    },
    
    // draw a line immediately
    line:function(x1, y1, x2, y2, style){
      var p = new _Path(x1,y1,x2,y2)
      p.draw(style)
    },
    
    // queue up a line segment to be drawn in a batch by .drawLines
    lines:function(x1, y1, x2, y2){
      if (typeof y2=='number'){
        // ƒ( x1, y1, x2, y2)
        _lineBuffer.push( [ {x:x1,y:y1}, {x:x2,y:y2} ] )
      }else{
        // ƒ( {x:1, y:1}, {x:2, y:2} )
        _lineBuffer.push( [ x1,y1 ] )
      }
    },
    
    // flush the buffered .lines to screen
    drawLines:function(style){
      var p = new _Path(_lineBuffer)
      p.draw(style)
      _lineBuffer = []
    }
    

  }
  
  return that.init()    
}


// // helpers for figuring out where to draw arrows
// var intersect_line_line = function(p1, p2, p3, p4)
// {
//  var denom = ((p4.y - p3.y)*(p2.x - p1.x) - (p4.x - p3.x)*(p2.y - p1.y));
// 
//  // lines are parallel
//  if (denom === 0) {
//    return false;
//  }
// 
//  var ua = ((p4.x - p3.x)*(p1.y - p3.y) - (p4.y - p3.y)*(p1.x - p3.x)) / denom;
//  var ub = ((p2.x - p1.x)*(p1.y - p3.y) - (p2.y - p1.y)*(p1.x - p3.x)) / denom;
// 
//  if (ua < 0 || ua > 1 || ub < 0 || ub > 1) {
//    return false;
//  }
// 
//  return arbor.Point(p1.x + ua * (p2.x - p1.x), p1.y + ua * (p2.y - p1.y));
// }
// 
// var intersect_line_box = function(p1, p2, p3, w, h)
// {
//  var tl = {x: p3.x, y: p3.y};
//  var tr = {x: p3.x + w, y: p3.y};
//  var bl = {x: p3.x, y: p3.y + h};
//  var br = {x: p3.x + w, y: p3.y + h};
// 
//  var result;
//  if (result = intersect_line_line(p1, p2, tl, tr)) { return result; } // top
//  if (result = intersect_line_line(p1, p2, tr, br)) { return result; } // right
//  if (result = intersect_line_line(p1, p2, br, bl)) { return result; } // bottom
//  if (result = intersect_line_line(p1, p2, bl, tl)) { return result; } // left
// 
//  return false;
// }