michael@0: // -*- mode: js2; indent-tabs-mode: nil; -*-
michael@0: 
michael@0: // A RectArray<X,k> is a subclass of Array with 'width', 'height',
michael@0: // and 'payload' properties (where payload holds 'k').
michael@0: // properties, and 'width*height*k' elements (each an X) in the array.
michael@0: //
michael@0: // A RectTypedByteArray<k> is a subclass of ArrayBuffer with 'width'
michael@0: // and 'height' properties, and 'width*height*k' bytes in the buffer.
michael@0: //
michael@0: // The 'payload' property is initialized with the value of 'k'.
michael@0: //
michael@0: // (Felix would have used Array or ArrayView, but for the following bug: 
michael@0: //   Bug 695438 - TypedArrays don't support new named properties
michael@0: //   https://bugzilla.mozilla.org/show_bug.cgi?id=695438
michael@0: //  and so he is resorting to extending ArrayBuffer instead.)
michael@0: //
michael@0: // Both classes add a .get(x,y[,k]) method that eases access to the
michael@0: // contents, and a set(x,y[,k],value) method that eases modifying
michael@0: // their entries.
michael@0: //
michael@0: // In addition, for those who prefer functional-style,
michael@0: // RectArray.build,
michael@0: // and RectByteTypedArray.build
michael@0: 
michael@0: var RectArray, RectByteTypedArray;
michael@0: 
michael@0: // This is a variant of RectArray that supports the same interface,
michael@0: // but instead of attempting to extend Array (a practice fraught with
michael@0: // peril), it instead makes a wrapper around another array.
michael@0: 
michael@0: var WrapArray, WrapByteTypedArray;
michael@0: 
michael@0: (function (){
michael@0: 
michael@0:    function defineReadOnly(x, name, value) {
michael@0:      Object.defineProperty(x, name, {
michael@0:                              value: value,
michael@0:                              writable: false,
michael@0:                              enumerable: true,
michael@0:                              configurable: true });
michael@0:    }
michael@0: 
michael@0:    RectArray = function RectArray(w,h,k) {
michael@0:      if (k === undefined)
michael@0:        k = 1;
michael@0:      this.length = w*h*k;
michael@0:      defineReadOnly(this, "width", w);
michael@0:      defineReadOnly(this, "height", h);
michael@0:      defineReadOnly(this, "payload", k);
michael@0:    };
michael@0: 
michael@0:    RectByteTypedArray = function RectByteTypedArray(w,h,k) {
michael@0:      if (k === undefined)
michael@0:        k = 1;
michael@0:      ArrayBuffer.call(this, w*h*k);
michael@0:      defineReadOnly(this, "width", w);
michael@0:      defineReadOnly(this, "height", h);
michael@0:      defineReadOnly(this, "payload", k);
michael@0:    };
michael@0: 
michael@0:    WrapArray = function WrapArray(w,h,k) {
michael@0:      if (k === undefined)
michael@0:        k = 1;
michael@0:      this.backingArray = new Array(w*h*k);
michael@0:      defineReadOnly(this, "width", w);
michael@0:      defineReadOnly(this, "height", h);
michael@0:      defineReadOnly(this, "payload", k);
michael@0:    };
michael@0: 
michael@0:    WrapByteTypedArray = function WrapByteTypedArray(w,h,k) {
michael@0:      if (k === undefined)
michael@0:        k = 1;
michael@0:      this.backingArray = new Uint8Array(new ArrayBuffer(w*h*k));
michael@0:      defineReadOnly(this, "width", w);
michael@0:      defineReadOnly(this, "height", h);
michael@0:      defineReadOnly(this, "payload", k);
michael@0:    };
michael@0: 
michael@0:    WrapArray.prototype.slice = function(a,b) this.backingArray.slice(a,b);
michael@0:    WrapArray.prototype.join  = function(a) this.backingArray.join(a);
michael@0: 
michael@0:    RectArray.prototype = new Array();
michael@0:    RectByteTypedArray.prototype = new ArrayBuffer();
michael@0: 
michael@0:    RectArray.prototype.get = function get(x,y,j) {
michael@0:      if (j === undefined) j = 0;
michael@0:      return this[(y*this.width+x)*this.payload+j];
michael@0:    };
michael@0: 
michael@0:    RectArray.prototype.set = function set(x,y,j,value) {
michael@0:      if (value === undefined) {
michael@0:        value = j;
michael@0:        j = 0;
michael@0:      }
michael@0:      this[(y*this.width+x)*this.payload+j] = value;
michael@0:    };
michael@0: 
michael@0:    RectByteTypedArray.prototype.get = function get(x,y,j) {
michael@0:      if (j === undefined) j = 0;
michael@0:      return (new Uint8Array(this))[(y*this.width+x)*this.payload+j];
michael@0:    };
michael@0: 
michael@0:    RectByteTypedArray.prototype.set = function set(x,y,j,value) {
michael@0:      if (value === undefined) {
michael@0:        value = j;
michael@0:        j = 0;
michael@0:      }
michael@0:      (new Uint8Array(this))[(y*this.width+x)*this.payload+j] = value;
michael@0:    };
michael@0: 
michael@0:    WrapArray.prototype.get = function get(x,y,j) {
michael@0:      if (j === undefined) j = 0;
michael@0:      return this.backingArray[(y*this.width+x)*this.payload+j];
michael@0:    };
michael@0: 
michael@0:    WrapArray.prototype.set = function set(x,y,j,value) {
michael@0:      if (value === undefined) {
michael@0:        value = j;
michael@0:        j = 0;
michael@0:      }
michael@0:      this.backingArray[(y*this.width+x)*this.payload+j] = value;
michael@0:    };
michael@0: 
michael@0:    WrapByteTypedArray.prototype.get = function get(x,y,j) {
michael@0:      if (j === undefined) j = 0;
michael@0:      return this.backingArray[(y*this.width+x)*this.payload+j];
michael@0:    };
michael@0: 
michael@0:    WrapByteTypedArray.prototype.set = function set(x,y,j,value) {
michael@0:      if (value === undefined) {
michael@0:        value = j;
michael@0:        j = 0;
michael@0:      }
michael@0:      this.backingArray[(y*this.width+x)*this.payload+j] = value;
michael@0:    };
michael@0: 
michael@0:    function viewToSource(view, width, height, payload) {
michael@0:      var ret = "[";
michael@0:      var i=0;
michael@0:      var matrixNeedsNewline = false;
michael@0:      for (var row=0; row < height; row++) {
michael@0:        if (matrixNeedsNewline)
michael@0:          ret += ",\n ";
michael@0:        ret += "[";
michael@0:        var rowNeedsComma = false;
michael@0:        for (var x=0; x < width; x++) {
michael@0:          if (rowNeedsComma)
michael@0:            ret += ", ";
michael@0:          if (payload == 1) {
michael@0:            if (view[i] !== undefined)
michael@0:              ret += view[i];
michael@0:            i++;
michael@0:          } else {
michael@0:            var entryNeedsComma = false;
michael@0:            ret += "(";
michael@0:            for (var k=0; k < payload; k++) {
michael@0:              // Might be inefficient (does JavaScript have
michael@0:              // StringBuffers?, or use them internally, like Tamarin?)
michael@0:              if (entryNeedsComma)
michael@0:                ret += ", ";
michael@0:              if (view[i] !== undefined)
michael@0:                ret += view[i];
michael@0:              entryNeedsComma = true;
michael@0:              i++;
michael@0:            }
michael@0:            ret += ")";
michael@0:          }
michael@0:          rowNeedsComma = true;
michael@0:        }
michael@0:        ret += "]";
michael@0:        matrixNeedsNewline = true;
michael@0:      }
michael@0:      ret += "]";
michael@0:      return ret;
michael@0:    }
michael@0: 
michael@0:    RectArray.prototype.toSource = function toSource() {
michael@0:      return viewToSource(this,
michael@0:                          this.width, this.height, this.payload);
michael@0:    };
michael@0: 
michael@0:    RectByteTypedArray.prototype.toSource = function toSource() {
michael@0:      return viewToSource(new Uint8Array(this),
michael@0:                          this.width, this.height, this.payload);
michael@0:    };
michael@0: 
michael@0:    WrapArray.prototype.toSource = function toSource() {
michael@0:      return viewToSource(this.backingArray,
michael@0:                          this.width, this.height, this.payload);
michael@0:    };
michael@0: 
michael@0:    WrapByteTypedArray.prototype.toSource = function toSource() {
michael@0:      return viewToSource(this.backingArray,
michael@0:                          this.width, this.height, this.payload);
michael@0:    };
michael@0: 
michael@0:    RectArray.prototype.map = function map(f) {
michael@0:      var ret = Array.map(this, f);
michael@0:      ret.__proto__ = RectArray.prototype;
michael@0:      defineReadOnly(ret, "width", this.width);
michael@0:      defineReadOnly(ret, "height", this.height);
michael@0:      defineReadOnly(ret, "payload", this.payload);
michael@0:      return ret;
michael@0:    };
michael@0: 
michael@0:    WrapArray.prototype.map = function map(f) {
michael@0:      var ret = new WrapArray(this.width, this.height, this.payload);
michael@0:      ret.backingArray = this.backingArray.map(f);
michael@0:      return ret;
michael@0:    };
michael@0: 
michael@0:    // (Array<X>|ArrayView<X>) Nat Nat Nat (Nat Nat Nat -> X) -> void
michael@0:    function fillArrayView(view, width, height, k, fill) {
michael@0:      var i = 0;
michael@0:      for (var y=0; y < height; y++) {
michael@0:        for (var x=0; x < width; x++) {
michael@0:          for (var j=0; j < k; j++) {
michael@0:            view[i++] = fill(x, y, j);
michael@0:          }
michael@0:        }
michael@0:      }
michael@0:    }
michael@0: 
michael@0: 
michael@0:    // Nat Nat (Nat Nat [Nat] -> X) -> RectArray<X,1>
michael@0:    RectArray.build =
michael@0:      function buildRectArray1(width, height, fill) {
michael@0:        var a = new RectArray(width, height, 1);
michael@0:        fillArrayView(a, width, height, 1, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    RectArray.buildA =
michael@0:      function buildRectArrayA(width, height, fill) {
michael@0:        var a = new Array(width*height);
michael@0:        fillArrayView(a, width, height, 1, fill);
michael@0:        a.width = width;
michael@0:        a.height = height;
michael@0:        a.payload = 1;
michael@0:        function F() { }
michael@0:        F.prototype = RectArray.prototype;
michael@0:        a.__proto__ = new F();
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    // Nat Nat (Nat Nat Nat -> X) -> RectArray<X,4>
michael@0:    RectArray.build4 =
michael@0:      function buildRectArray4(width, height, fill) {
michael@0:        var a = new RectArray(width, height, 4);
michael@0:        fillArrayView(a, width, height, 4, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    // Nat Nat (Nat Nat Nat -> X) -> RectArray<X,1>
michael@0:    RectArray.buildN =
michael@0:      function buildRectArrayN(width, height, n, fill) {
michael@0:        var a = new RectArray(width, height, n);
michael@0:        fillArrayView(a, width, height, n, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0: 
michael@0:    // Nat Nat (Nat Nat [Nat] -> Byte) -> RectTypedByteArray<4>
michael@0:    RectByteTypedArray.build =
michael@0:      function buildRectByteTypedArray1(width, height, fill) {
michael@0:        var buf = new RectByteTypedArray(width, height, 1);
michael@0:        fillArrayView(new Uint8Array(buf), width, height, 1, fill);
michael@0:        return buf;
michael@0:      };
michael@0: 
michael@0:    // Nat Nat (Nat Nat Nat -> Byte) -> RectTypedByteArray<4>
michael@0:    RectByteTypedArray.build4 =
michael@0:      function buildRectByteTypedArray4(width, height, fill) {
michael@0:        var buf = new RectByteTypedArray(width, height, 4);
michael@0:        fillArrayView(new Uint8Array(buf), width, height, 4, fill);
michael@0:        return buf;
michael@0:      };
michael@0: 
michael@0:    // Nat Nat (Nat Nat Nat -> Byte) -> RectTypedByteArray<4>
michael@0:    RectByteTypedArray.buildN =
michael@0:      function buildRectByteTypedArray4(width, height, n, fill) {
michael@0:        var buf = new RectByteTypedArray(width, height, n);
michael@0:        fillArrayView(new Uint8Array(buf), width, height, n, fill);
michael@0:        return buf;
michael@0:      };
michael@0: 
michael@0:    WrapArray.build =
michael@0:      function buildWrapArray1(width, height, fill) {
michael@0:        var a = new WrapArray(width, height, 1);
michael@0:        fillArrayView(a, width, height, 1, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    WrapArray.build =
michael@0:      function buildWrapArray1(width, height, fill) {
michael@0:        var a = new WrapArray(width, height, 1);
michael@0:        fillArrayView(a.backingArray, width, height, 1, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    WrapArray.build4 =
michael@0:      function buildWrapArray1(width, height, fill) {
michael@0:        var a = new WrapArray(width, height, 4);
michael@0:        fillArrayView(a.backingArray, width, height, 4, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:    WrapArray.buildN =
michael@0:      function buildWrapArray1(width, height, n, fill) {
michael@0:        var a = new WrapArray(width, height, n);
michael@0:        fillArrayView(a.backingArray, width, height, n, fill);
michael@0:        return a;
michael@0:      };
michael@0: 
michael@0:  })();