Merge pull request #5134 from yurydelendik/fun4

Improves speed of the functions

src/core/colorspace.js

@@ -380,23 +380,20 @@ var AlternateCS = (function AlternateCSClosure() {
     }
     this.base = base;
     this.tintFn = tintFn;
+    this.tmpBuf = new Float32Array(base.numComps);
   }
 
   AlternateCS.prototype = {
     getRgb: ColorSpace.prototype.getRgb,
     getRgbItem: function AlternateCS_getRgbItem(src, srcOffset,
                                                 dest, destOffset) {
-      var baseNumComps = this.base.numComps;
+      var tmpBuf = this.tmpBuf;
-      var input = 'subarray' in src ?
+      this.tintFn(src, srcOffset, tmpBuf, 0);
-        src.subarray(srcOffset, srcOffset + this.numComps) :
+      this.base.getRgbItem(tmpBuf, 0, dest, destOffset);
-        Array.prototype.slice.call(src, srcOffset, srcOffset + this.numComps);
-      var tinted = this.tintFn(input);
-      this.base.getRgbItem(tinted, 0, dest, destOffset);
     },
     getRgbBuffer: function AlternateCS_getRgbBuffer(src, srcOffset, count,
                                                     dest, destOffset, bits,
                                                     alpha01) {
-      var tinted;
       var tintFn = this.tintFn;
       var base = this.base;
       var scale = 1 / ((1 << bits) - 1);
@@ -409,13 +406,14 @@ var AlternateCS = (function AlternateCSClosure() {
       var numComps = this.numComps;
 
       var scaled = new Float32Array(numComps);
+      var tinted = new Float32Array(baseNumComps);
       var i, j;
       if (usesZeroToOneRange) {
         for (i = 0; i < count; i++) {
           for (j = 0; j < numComps; j++) {
             scaled[j] = src[srcOffset++] * scale;
           }
-          tinted = tintFn(scaled);
+          tintFn(scaled, 0, tinted, 0);
           for (j = 0; j < baseNumComps; j++) {
             baseBuf[pos++] = tinted[j] * 255;
           }
@@ -425,7 +423,7 @@ var AlternateCS = (function AlternateCSClosure() {
           for (j = 0; j < numComps; j++) {
             scaled[j] = src[srcOffset++] * scale;
           }
-          tinted = tintFn(scaled);
+          tintFn(scaled, 0, tinted, 0);
           base.getRgbItem(tinted, 0, baseBuf, pos);
           pos += baseNumComps;
         }

src/core/function.js

@@ -97,6 +97,24 @@ var PDFFunction = (function PDFFunctionClosure() {
       return this.fromIR(IR);
     },
 
+    parseArray: function PDFFunction_parseArray(xref, fnObj) {
+      if (!isArray(fnObj)) {
+        // not an array -- parsing as regular function
+        return this.parse(xref, fnObj);
+      }
+
+      var fnArray = [];
+      for (var j = 0, jj = fnObj.length; j < jj; j++) {
+        var obj = xref.fetchIfRef(fnObj[j]);
+        fnArray.push(PDFFunction.parse(xref, obj));
+      }
+      return function (src, srcOffset, dest, destOffset) {
+        for (var i = 0, ii = fnArray.length; i < ii; i++) {
+          fnArray[i](src, srcOffset, dest, destOffset + i);
+        }
+      };
+    },
+
     constructSampled: function PDFFunction_constructSampled(str, dict) {
       function toMultiArray(arr) {
         var inputLength = arr.length;
@@ -161,7 +179,8 @@ var PDFFunction = (function PDFFunctionClosure() {
         return ymin + ((x - xmin) * ((ymax - ymin) / (xmax - xmin)));
       }
 
-      return function constructSampledFromIRResult(args) {
+      return function constructSampledFromIRResult(src, srcOffset,
+                                                   dest, destOffset) {
         // See chapter 3, page 110 of the PDF reference.
         var m = IR[1];
         var domain = IR[2];
@@ -173,13 +192,6 @@ var PDFFunction = (function PDFFunctionClosure() {
         //var mask = IR[8];
         var range = IR[9];
 
-        if (m !== args.length) {
-          error('Incorrect number of arguments: ' + m + ' != ' +
-                args.length);
-        }
-
-        var x = args;
-
         // Building the cube vertices: its part and sample index
         // http://rjwagner49.com/Mathematics/Interpolation.pdf
         var cubeVertices = 1 << m;
@@ -196,7 +208,8 @@ var PDFFunction = (function PDFFunctionClosure() {
           // x_i' = min(max(x_i, Domain_2i), Domain_2i+1)
           var domain_2i = domain[i][0];
           var domain_2i_1 = domain[i][1];
-          var xi = Math.min(Math.max(x[i], domain_2i), domain_2i_1);
+          var xi = Math.min(Math.max(src[srcOffset +i], domain_2i),
+                            domain_2i_1);
 
           // e_i = Interpolate(x_i', Domain_2i, Domain_2i+1,
           //                   Encode_2i, Encode_2i+1)
@@ -227,7 +240,6 @@ var PDFFunction = (function PDFFunctionClosure() {
           pos <<= 1;
         }
 
-        var y = new Float64Array(n);
         for (j = 0; j < n; ++j) {
           // Sum all cube vertices' samples portions
           var rj = 0;
@@ -240,10 +252,9 @@ var PDFFunction = (function PDFFunctionClosure() {
           rj = interpolate(rj, 0, 1, decode[j][0], decode[j][1]);
 
           // y_j = min(max(r_j, range_2j), range_2j+1)
-          y[j] = Math.min(Math.max(rj, range[j][0]), range[j][1]);
+          dest[destOffset + j] = Math.min(Math.max(rj, range[j][0]),
+                                          range[j][1]);
         }
-
-        return y;
       };
     },
 
@@ -274,16 +285,13 @@ var PDFFunction = (function PDFFunctionClosure() {
 
       var length = diff.length;
 
-      return function constructInterpolatedFromIRResult(args) {
+      return function constructInterpolatedFromIRResult(src, srcOffset,
-        var x = (n === 1 ? args[0] : Math.pow(args[0], n));
+                                                        dest, destOffset) {
+        var x = n === 1 ? src[srcOffset] : Math.pow(src[srcOffset], n);
 
-        var out = [];
         for (var j = 0; j < length; ++j) {
-          out.push(c0[j] + (x * diff[j]));
+          dest[destOffset + j] = c0[j] + (x * diff[j]);
         }
-
-        return out;
-
       };
     },
 
@@ -317,12 +325,14 @@ var PDFFunction = (function PDFFunctionClosure() {
       var encode = IR[3];
       var fnsIR = IR[4];
       var fns = [];
+      var tmpBuf = new Float32Array(1);
 
       for (var i = 0, ii = fnsIR.length; i < ii; i++) {
         fns.push(PDFFunction.fromIR(fnsIR[i]));
       }
 
-      return function constructStichedFromIRResult(args) {
+      return function constructStichedFromIRResult(src, srcOffset,
+                                                   dest, destOffset) {
         var clip = function constructStichedFromIRClip(v, min, max) {
           if (v > max) {
             v = max;
@@ -333,7 +343,7 @@ var PDFFunction = (function PDFFunctionClosure() {
         };
 
         // clip to domain
-        var v = clip(args[0], domain[0], domain[1]);
+        var v = clip(src[srcOffset], domain[0], domain[1]);
         // calulate which bound the value is in
         for (var i = 0, ii = bounds.length; i < ii; ++i) {
           if (v < bounds[i]) {
@@ -354,10 +364,10 @@ var PDFFunction = (function PDFFunctionClosure() {
         var rmin = encode[2 * i];
         var rmax = encode[2 * i + 1];
 
-        var v2 = rmin + (v - dmin) * (rmax - rmin) / (dmax - dmin);
+        tmpBuf[0] = rmin + (v - dmin) * (rmax - rmin) / (dmax - dmin);
 
         // call the appropriate function
-        return fns[i]([v2]);
+        fns[i](tmpBuf, 0, dest, destOffset);
       };
     },
 
@@ -386,6 +396,18 @@ var PDFFunction = (function PDFFunctionClosure() {
       var domain = IR[1];
       var range = IR[2];
       var code = IR[3];
+
+      var compiled = (new PostScriptCompiler()).compile(code, domain, range);
+      if (compiled) {
+        // Compiled function consists of simple expressions such as addition,
+        // subtraction, Math.max, and also contains 'var' and 'return'
+        // statements. See the generation in the PostScriptCompiler below.
+        /*jshint -W054 */
+        return new Function('src', 'srcOffset', 'dest', 'destOffset', compiled);
+      }
+
+      info('Unable to compile PS function');
+
       var numOutputs = range.length >> 1;
       var numInputs = domain.length >> 1;
       var evaluator = new PostScriptEvaluator(code);
@@ -396,22 +418,26 @@ var PDFFunction = (function PDFFunctionClosure() {
       // seen in our tests.
       var MAX_CACHE_SIZE = 2048 * 4;
       var cache_available = MAX_CACHE_SIZE;
-      return function constructPostScriptFromIRResult(args) {
+      var tmpBuf = new Float32Array(numInputs);
+
+      return function constructPostScriptFromIRResult(src, srcOffset,
+                                                      dest, destOffset) {
         var i, value;
         var key = '';
-        var input = new Array(numInputs);
+        var input = tmpBuf;
         for (i = 0; i < numInputs; i++) {
-          value = args[i];
+          value = src[srcOffset + i];
           input[i] = value;
           key += value + '_';
         }
 
         var cachedValue = cache[key];
         if (cachedValue !== undefined) {
-          return cachedValue;
+          cachedValue.set(dest, destOffset);
+          return;
         }
 
-        var output = new Array(numOutputs);
+        var output = new Float32Array(numOutputs);
         var stack = evaluator.execute(input);
         var stackIndex = stack.length - numOutputs;
         for (i = 0; i < numOutputs; i++) {
@@ -431,7 +457,7 @@ var PDFFunction = (function PDFFunctionClosure() {
           cache_available--;
           cache[key] = output;
         }
-        return output;
+        output.set(dest, destOffset);
       };
     }
   };
@@ -454,7 +480,8 @@ function isPDFFunction(v) {
 var PostScriptStack = (function PostScriptStackClosure() {
   var MAX_STACK_SIZE = 100;
   function PostScriptStack(initialStack) {
-    this.stack = initialStack || [];
+    this.stack = !initialStack ? [] :
+                 Array.prototype.slice.call(initialStack, 0);
   }
 
   PostScriptStack.prototype = {
@@ -736,3 +763,370 @@ var PostScriptEvaluator = (function PostScriptEvaluatorClosure() {
   };
   return PostScriptEvaluator;
 })();
+
+// Most of the PDFs functions consist of simple operations such as:
+//   roll, exch, sub, cvr, pop, index, dup, mul, if, gt, add.
+//
+// We can compile most of such programs, and at the same moment, we can
+// optimize some expressions using basic math properties. Keeping track of
+// min/max values will allow us to avoid extra Math.min/Math.max calls.
+var PostScriptCompiler = (function PostScriptCompilerClosure() {
+  function AstNode(type) {
+    this.type = type;
+  }
+  AstNode.prototype.visit = function (visitor) {
+    throw new Error('abstract method');
+  };
+
+  function AstArgument(index, min, max) {
+    AstNode.call(this, 'args');
+    this.index = index;
+    this.min = min;
+    this.max = max;
+  }
+  AstArgument.prototype = Object.create(AstNode.prototype);
+  AstArgument.prototype.visit = function (visitor) {
+    visitor.visitArgument(this);
+  };
+
+  function AstLiteral(number) {
+    AstNode.call(this, 'literal');
+    this.number = number;
+    this.min = number;
+    this.max = number;
+  }
+  AstLiteral.prototype = Object.create(AstNode.prototype);
+  AstLiteral.prototype.visit = function (visitor) {
+    visitor.visitLiteral(this);
+  };
+
+  function AstBinaryOperation(op, arg1, arg2, min, max) {
+    AstNode.call(this, 'binary');
+    this.op = op;
+    this.arg1 = arg1;
+    this.arg2 = arg2;
+    this.min = min;
+    this.max = max;
+  }
+  AstBinaryOperation.prototype = Object.create(AstNode.prototype);
+  AstBinaryOperation.prototype.visit = function (visitor) {
+    visitor.visitBinaryOperation(this);
+  };
+
+  function AstMin(arg, max) {
+    AstNode.call(this, 'max');
+    this.arg = arg;
+    this.min = arg.min;
+    this.max = max;
+  }
+  AstMin.prototype = Object.create(AstNode.prototype);
+  AstMin.prototype.visit = function (visitor) {
+    visitor.visitMin(this);
+  };
+
+  function AstVariable(index, min, max) {
+    AstNode.call(this, 'var');
+    this.index = index;
+    this.min = min;
+    this.max = max;
+  }
+  AstVariable.prototype = Object.create(AstNode.prototype);
+  AstVariable.prototype.visit = function (visitor) {
+    visitor.visitVariable(this);
+  };
+
+  function AstVariableDefinition(variable, arg) {
+    AstNode.call(this, 'definition');
+    this.variable = variable;
+    this.arg = arg;
+  }
+  AstVariableDefinition.prototype = Object.create(AstNode.prototype);
+  AstVariableDefinition.prototype.visit = function (visitor) {
+    visitor.visitVariableDefinition(this);
+  };
+
+  function ExpressionBuilderVisitor() {
+    this.parts = [];
+  }
+  ExpressionBuilderVisitor.prototype = {
+    visitArgument: function (arg) {
+      this.parts.push('Math.max(', arg.min, ', Math.min(',
+                      arg.max, ', src[srcOffset + ', arg.index, ']))');
+    },
+    visitVariable: function (variable) {
+      this.parts.push('v', variable.index);
+    },
+    visitLiteral: function (literal) {
+      this.parts.push(literal.number);
+    },
+    visitBinaryOperation: function (operation) {
+      this.parts.push('(');
+      operation.arg1.visit(this);
+      this.parts.push(' ', operation.op, ' ');
+      operation.arg2.visit(this);
+      this.parts.push(')');
+    },
+    visitVariableDefinition: function (definition) {
+      this.parts.push('var ');
+      definition.variable.visit(this);
+      this.parts.push(' = ');
+      definition.arg.visit(this);
+      this.parts.push(';');
+    },
+    visitMin: function (max) {
+      this.parts.push('Math.min(');
+      max.arg.visit(this);
+      this.parts.push(', ', max.max, ')');
+    },
+    toString: function () {
+      return this.parts.join('');
+    }
+  };
+
+  function buildAddOperation(num1, num2) {
+    if (num2.type === 'literal' && num2.number === 0) {
+      // optimization: second operand is 0
+      return num1;
+    }
+    if (num1.type === 'literal' && num1.number === 0) {
+      // optimization: first operand is 0
+      return num2;
+    }
+    if (num2.type === 'literal' && num1.type === 'literal') {
+      // optimization: operands operand are literals
+      return new AstLiteral(num1.number + num2.number);
+    }
+    return new AstBinaryOperation('+', num1, num2,
+                                  num1.min + num2.min, num1.max + num2.max);
+  }
+
+  function buildMulOperation(num1, num2) {
+    if (num2.type === 'literal') {
+      // optimization: second operands is a literal...
+      if (num2.number === 0) {
+        return new AstLiteral(0); // and it's 0
+      } else if (num2.number === 1) {
+        return num1; // and it's 1
+      } else if (num1.type === 'literal') {
+        // ... and first operands is a literal too
+        return new AstLiteral(num1.number * num2.number);
+      }
+    }
+    if (num1.type === 'literal') {
+      // optimization: first operands is a literal...
+      if (num1.number === 0) {
+        return new AstLiteral(0); // and it's 0
+      } else if (num1.number === 1) {
+        return num2; // and it's 1
+      }
+    }
+    var min = Math.min(num1.min * num2.min, num1.min * num2.max,
+                       num1.max * num2.min, num1.max * num2.max);
+    var max = Math.max(num1.min * num2.min, num1.min * num2.max,
+                       num1.max * num2.min, num1.max * num2.max);
+    return new AstBinaryOperation('*', num1, num2, min, max);
+  }
+
+  function buildSubOperation(num1, num2) {
+    if (num2.type === 'literal') {
+      // optimization: second operands is a literal...
+      if (num2.number === 0) {
+        return num1; // ... and it's 0
+      } else if (num1.type === 'literal') {
+        // ... and first operands is a literal too
+        return new AstLiteral(num1.number - num2.number);
+      }
+    }
+    if (num2.type === 'binary' && num2.op === '-' &&
+      num1.type === 'literal' && num1.number === 1 &&
+      num2.arg1.type === 'literal' && num2.arg1.number === 1) {
+      // optimization for case: 1 - (1 - x)
+      return num2.arg2;
+    }
+    return new AstBinaryOperation('-', num1, num2,
+                                  num1.min - num2.max, num1.max - num2.min);
+  }
+
+  function buildMinOperation(num1, max) {
+    if (num1.min >= max) {
+      // optimization: num1 min value is not less than required max
+      return new AstLiteral(max); // just returning max
+    } else if (num1.max <= max) {
+      // optimization: num1 max value is not greater than required max
+      return num1; // just returning an argument
+    }
+    return new AstMin(num1, max);
+  }
+
+  function PostScriptCompiler() {}
+  PostScriptCompiler.prototype = {
+    compile: function PostScriptCompiler_compile(code, domain, range) {
+      var stack = [];
+      var i, ii;
+      var instructions = [];
+      var inputSize = domain.length >> 1, outputSize = range.length >> 1;
+      var lastRegister = 0;
+      var n, j, min, max;
+      var num1, num2, ast1, ast2, tmpVar, item;
+      for (i = 0; i < inputSize; i++) {
+        stack.push(new AstArgument(i, domain[i * 2], domain[i * 2 + 1]));
+      }
+
+      for (i = 0, ii = code.length; i < ii; i++) {
+        item = code[i];
+        if (typeof item === 'number') {
+          stack.push(new AstLiteral(item));
+          continue;
+        }
+
+        switch (item) {
+          case 'add':
+            if (stack.length < 2) {
+              return null;
+            }
+            num2 = stack.pop();
+            num1 = stack.pop();
+            stack.push(buildAddOperation(num1, num2));
+            break;
+          case 'cvr':
+            if (stack.length < 1) {
+              return null;
+            }
+            break;
+          case 'mul':
+            if (stack.length < 2) {
+              return null;
+            }
+            num2 = stack.pop();
+            num1 = stack.pop();
+            stack.push(buildMulOperation(num1, num2));
+            break;
+          case 'sub':
+            if (stack.length < 2) {
+              return null;
+            }
+            num2 = stack.pop();
+            num1 = stack.pop();
+            stack.push(buildSubOperation(num1, num2));
+            break;
+          case 'exch':
+            if (stack.length < 2) {
+              return null;
+            }
+            ast1 = stack.pop(); ast2 = stack.pop();
+            stack.push(ast1, ast2);
+            break;
+          case 'pop':
+            if (stack.length < 1) {
+              return null;
+            }
+            stack.pop();
+            break;
+          case 'index':
+            if (stack.length < 1) {
+              return null;
+            }
+            num1 = stack.pop();
+            if (num1.type !== 'literal') {
+              return null;
+            }
+            n = num1.number;
+            if (n < 0 || (n|0) !== n || stack.length < n) {
+              return null;
+            }
+            ast1 = stack[stack.length - n - 1];
+            if (ast1.type === 'literal' || ast1.type === 'var') {
+              stack.push(ast1);
+              break;
+            }
+            tmpVar = new AstVariable(lastRegister++, ast1.min, ast1.max);
+            stack[stack.length - n - 1] = tmpVar;
+            stack.push(tmpVar);
+            instructions.push(new AstVariableDefinition(tmpVar, ast1));
+            break;
+          case 'dup':
+            if (stack.length < 1) {
+              return null;
+            }
+            if (typeof code[i + 1] === 'number' && code[i + 2] === 'gt' &&
+                code[i + 3] === i + 7 && code[i + 4] === 'jz' &&
+                code[i + 5] === 'pop' && code[i + 6] === code[i + 1]) {
+              // special case of the commands sequence for the min operation
+              num1 = stack.pop();
+              stack.push(buildMinOperation(num1, code[i + 1]));
+              i += 6;
+              break;
+            }
+            ast1 = stack[stack.length - 1];
+            if (ast1.type === 'literal' || ast1.type === 'var') {
+              // we don't have to save into intermediate variable a literal or
+              // variable.
+              stack.push(ast1);
+              break;
+            }
+            tmpVar = new AstVariable(lastRegister++, ast1.min, ast1.max);
+            stack[stack.length - 1] = tmpVar;
+            stack.push(tmpVar);
+            instructions.push(new AstVariableDefinition(tmpVar, ast1));
+            break;
+          case 'roll':
+            if (stack.length < 2) {
+              return null;
+            }
+            num2 = stack.pop();
+            num1 = stack.pop();
+            if (num2.type !== 'literal' || num1.type !== 'literal') {
+              // both roll operands must be numbers
+              return null;
+            }
+            j = num2.number;
+            n = num1.number;
+            if (n <= 0 || (n|0) !== n || (j|0) !== j || stack.length < n) {
+              // ... and integers
+              return null;
+            }
+            j = ((j % n) + n) % n;
+            if (j === 0) {
+              break; // just skipping -- there are nothing to rotate
+            }
+            Array.prototype.push.apply(stack,
+                                       stack.splice(stack.length - n, n - j));
+            break;
+          default:
+            return null; // unsupported operator
+        }
+      }
+
+      if (stack.length !== outputSize) {
+        return null;
+      }
+
+      var result = [];
+      instructions.forEach(function (instruction) {
+        var statementBuilder = new ExpressionBuilderVisitor();
+        instruction.visit(statementBuilder);
+        result.push(statementBuilder.toString());
+      });
+      stack.forEach(function (expr, i) {
+        var statementBuilder = new ExpressionBuilderVisitor();
+        expr.visit(statementBuilder);
+        var min = range[i * 2], max = range[i * 2 + 1];
+        var out = [statementBuilder.toString()];
+        if (min > expr.min) {
+          out.unshift('Math.max(', min, ', ');
+          out.push(')');
+        }
+        if (max < expr.max) {
+          out.unshift('Math.min(', max, ', ');
+          out.push(')');
+        }
+        out.unshift('dest[destOffset + ', i, '] = ');
+        out.push(';');
+        result.push(out.join(''));
+      });
+      return result.join('\n');
+    }
+  };
+
+  return PostScriptCompiler;
+})();

src/core/pattern.js

@@ -122,29 +122,7 @@ Shadings.RadialAxial = (function RadialAxialClosure() {
     this.extendEnd = extendEnd;
 
     var fnObj = dict.get('Function');
-    var fn;
+    var fn = PDFFunction.parseArray(xref, fnObj);
-    if (isArray(fnObj)) {
-      var fnArray = [];
-      for (var j = 0, jj = fnObj.length; j < jj; j++) {
-        var obj = xref.fetchIfRef(fnObj[j]);
-        if (!isPDFFunction(obj)) {
-          error('Invalid function');
-        }
-        fnArray.push(PDFFunction.parse(xref, obj));
-      }
-      fn = function radialAxialColorFunction(arg) {
-        var out = [];
-        for (var i = 0, ii = fnArray.length; i < ii; i++) {
-          out.push(fnArray[i](arg)[0]);
-        }
-        return out;
-      };
-    } else {
-      if (!isPDFFunction(fnObj)) {
-        error('Invalid function');
-      }
-      fn = PDFFunction.parse(xref, fnObj);
-    }
 
     // 10 samples seems good enough for now, but probably won't work
     // if there are sharp color changes. Ideally, we would implement
@@ -162,9 +140,12 @@ Shadings.RadialAxial = (function RadialAxialClosure() {
       return;
     }
 
+    var color = new Float32Array(cs.numComps), ratio = new Float32Array(1);
     var rgbColor;
     for (var i = t0; i <= t1; i += step) {
-      rgbColor = cs.getRgb(fn([i]), 0);
+      ratio[0] = i;
+      fn(ratio, 0, color, 0);
+      rgbColor = cs.getRgb(color, 0);
       var cssColor = Util.makeCssRgb(rgbColor);
       colorStops.push([(i - t0) / diff, cssColor]);
     }
@@ -232,6 +213,12 @@ Shadings.Mesh = (function MeshClosure() {
     this.context = context;
     this.buffer = 0;
     this.bufferLength = 0;
+
+    var numComps = context.numComps;
+    this.tmpCompsBuf = new Float32Array(numComps);
+    var csNumComps = context.colorSpace;
+    this.tmpCsCompsBuf = context.colorFn ? new Float32Array(csNumComps) :
+                                           this.tmpCompsBuf;
   }
   MeshStreamReader.prototype = {
     get hasData() {
@@ -302,15 +289,16 @@ Shadings.Mesh = (function MeshClosure() {
       var scale = bitsPerComponent < 32 ? 1 / ((1 << bitsPerComponent) - 1) :
         2.3283064365386963e-10; // 2 ^ -32
       var decode = this.context.decode;
-      var components = [];
+      var components = this.tmpCompsBuf;
       for (var i = 0, j = 4; i < numComps; i++, j += 2) {
         var ci = this.readBits(bitsPerComponent);
-        components.push(ci * scale * (decode[j + 1] - decode[j]) + decode[j]);
+        components[i] = ci * scale * (decode[j + 1] - decode[j]) + decode[j];
       }
+      var color = this.tmpCsCompsBuf;
       if (this.context.colorFn) {
-        components = this.context.colorFn(components);
+        this.context.colorFn(components, 0, color, 0);
       }
-      return this.context.colorSpace.getRgb(components, 0);
+      return this.context.colorSpace.getRgb(color, 0);
     }
   };
 
@@ -716,31 +704,7 @@ Shadings.Mesh = (function MeshClosure() {
       cs.getRgb(dict.get('Background'), 0) : null;
 
     var fnObj = dict.get('Function');
-    var fn;
+    var fn = fnObj ? PDFFunction.parseArray(xref, fnObj) : null;
-    if (!fnObj) {
-      fn = null;
-    } else if (isArray(fnObj)) {
-      var fnArray = [];
-      for (var j = 0, jj = fnObj.length; j < jj; j++) {
-        var obj = xref.fetchIfRef(fnObj[j]);
-        if (!isPDFFunction(obj)) {
-          error('Invalid function');
-        }
-        fnArray.push(PDFFunction.parse(xref, obj));
-      }
-      fn = function radialAxialColorFunction(arg) {
-        var out = [];
-        for (var i = 0, ii = fnArray.length; i < ii; i++) {
-          out.push(fnArray[i](arg)[0]);
-        }
-        return out;
-      };
-    } else {
-      if (!isPDFFunction(fnObj)) {
-        error('Invalid function');
-      }
-      fn = PDFFunction.parse(xref, fnObj);
-    }
 
     this.coords = [];
     this.colors = [];

test/unit/function_spec.js

@@ -1,7 +1,8 @@
 /* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
 /* globals expect, it, describe, beforeEach, isArray, StringStream,
-           PostScriptParser, PostScriptLexer, PostScriptEvaluator */
+           PostScriptParser, PostScriptLexer, PostScriptEvaluator,
+           PostScriptCompiler*/
 
 'use strict';
 
@@ -413,5 +414,110 @@ describe('function', function() {
       expect(stack).toMatchArray(expectedStack);
     });
   });
+
+
+  describe('PostScriptCompiler', function() {
+    function check(code, domain, range, samples) {
+      var compiler = new PostScriptCompiler();
+      var compiledCode = compiler.compile(code, domain, range);
+      if (samples === null) {
+        expect(compiledCode).toBeNull();
+      } else {
+        expect(compiledCode).not.toBeNull();
+        /*jshint -W054 */
+        var fn = new Function('src', 'srcOffset', 'dest', 'destOffset',
+                              compiledCode);
+        for (var i = 0; i < samples.length; i++) {
+          var out = new Float32Array(samples[i].output.length);
+          fn(samples[i].input, 0, out, 0);
+          expect(Array.prototype.slice.call(out, 0)).
+            toMatchArray(samples[i].output);
+        }
+      }
+    }
+
+    it('check compiled add', function() {
+      check([0.25, 0.5, 'add'], [], [0, 1], [{input: [], output: [0.75]}]);
+      check([0, 'add'], [0, 1], [0, 1], [{input: [0.25], output: [0.25]}]);
+      check([0.5, 'add'], [0, 1], [0, 1], [{input: [0.25], output: [0.75]}]);
+      check([0, 'exch', 'add'], [0, 1], [0, 1],
+            [{input: [0.25], output: [0.25]}]);
+      check([0.5, 'exch', 'add'], [0, 1], [0, 1],
+            [{input: [0.25], output: [0.75]}]);
+      check(['add'], [0, 1, 0, 1], [0, 1],
+            [{input: [0.25, 0.5], output: [0.75]}]);
+      check(['add'], [0, 1], [0, 1], null);
+    });
+    it('check compiled sub', function() {
+      check([0.5, 0.25, 'sub'], [], [0, 1], [{input: [], output: [0.25]}]);
+      check([0, 'sub'], [0, 1], [0, 1], [{input: [0.25], output: [0.25]}]);
+      check([0.5, 'sub'], [0, 1], [0, 1], [{input: [0.75], output: [0.25]}]);
+      check([0, 'exch', 'sub'], [0, 1], [-1, 1],
+            [{input: [0.25], output: [-0.25]}]);
+      check([0.75, 'exch', 'sub'], [0, 1], [-1, 1],
+            [{input: [0.25], output: [0.5]}]);
+      check(['sub'], [0, 1, 0, 1], [-1, 1],
+            [{input: [0.25, 0.5], output: [-0.25]}]);
+      check(['sub'], [0, 1], [0, 1], null);
+
+      check([1, 'dup', 3, 2, 'roll', 'sub', 'sub'], [0, 1], [0, 1],
+            [{input: [0.75], output: [0.75]}]);
+    });
+    it('check compiled mul', function() {
+      check([0.25, 0.5, 'mul'], [], [0, 1], [{input: [], output: [0.125]}]);
+      check([0, 'mul'], [0, 1], [0, 1], [{input: [0.25], output: [0]}]);
+      check([0.5, 'mul'], [0, 1], [0, 1], [{input: [0.25], output: [0.125]}]);
+      check([1, 'mul'], [0, 1], [0, 1], [{input: [0.25], output: [0.25]}]);
+      check([0, 'exch', 'mul'], [0, 1], [0, 1], [{input: [0.25], output: [0]}]);
+      check([0.5, 'exch', 'mul'], [0, 1], [0, 1],
+            [{input: [0.25], output: [0.125]}]);
+      check([1, 'exch', 'mul'], [0, 1], [0, 1],
+            [{input: [0.25], output: [0.25]}]);
+      check(['mul'], [0, 1, 0, 1], [0, 1],
+            [{input: [0.25, 0.5], output: [0.125]}]);
+      check(['mul'], [0, 1], [0, 1], null);
+    });
+    it('check compiled max', function() {
+      check(['dup', 0.75, 'gt', 7, 'jz', 'pop', 0.75], [0, 1], [0, 1],
+            [{input: [0.5], output: [0.5]}]);
+      check(['dup', 0.75, 'gt', 7, 'jz', 'pop', 0.75], [0, 1], [0, 1],
+            [{input: [1], output: [0.75]}]);
+      check(['dup', 0.75, 'gt', 5, 'jz', 'pop', 0.75], [0, 1], [0, 1], null);
+    });
+    it('check pop/roll/index', function() {
+      check([1, 'pop'], [0, 1], [0, 1], [{input: [0.5], output: [0.5]}]);
+      check([1, 3, -1, 'roll'], [0, 1, 0, 1], [0, 1, 0, 1, 0, 1],
+            [{input: [0.25, 0.5], output: [0.5, 1, 0.25]}]);
+      check([1, 3, 1, 'roll'], [0, 1, 0, 1], [0, 1, 0, 1, 0, 1],
+            [{input: [0.25, 0.5], output: [1, 0.25, 0.5]}]);
+      check([1, 3, 1.5, 'roll'], [0, 1, 0, 1], [0, 1, 0, 1, 0, 1], null);
+      check([1, 1, 'index'], [0, 1], [0, 1, 0, 1, 0, 1],
+            [{input: [0.5], output: [0.5, 1, 0.5]}]);
+      check([1, 3, 'index', 'pop'], [0, 1], [0, 1], null);
+      check([1, 0.5, 'index', 'pop'], [0, 1], [0, 1], null);
+    });
+    it('check input boundaries', function () {
+      check([], [0, 0.5], [0, 1], [{input: [1], output: [0.5]}]);
+      check([], [0.5, 1], [0, 1], [{input: [0], output: [0.5]}]);
+      check(['dup'], [0.5, 0.75], [0, 1, 0, 1],
+            [{input: [0], output: [0.5, 0.5]}]);
+      check([], [100, 1001], [0, 10000], [{input: [1000], output: [1000]}]);
+    });
+    it('check output boundaries', function () {
+      check([], [0, 1], [0, 0.5], [{input: [1], output: [0.5]}]);
+      check([], [0, 1], [0.5, 1], [{input: [0], output: [0.5]}]);
+      check(['dup'], [0, 1], [0.5, 1, 0.75, 1],
+            [{input: [0], output: [0.5, 0.75]}]);
+      check([], [0, 10000], [100, 1001], [{input: [1000], output: [1000]}]);
+    });
+    it('compile optimized', function () {
+      var compiler = new PostScriptCompiler();
+      var code = [0, 'add', 1, 1, 3, -1, 'roll', 'sub', 'sub', 1, 'mul'];
+      var compiledCode = compiler.compile(code, [0, 1], [0, 1]);
+      expect(compiledCode).toEqual(
+        'dest[destOffset + 0] = Math.max(0, Math.min(1, src[srcOffset + 0]));');
+
+    });
+  });
 });