Adding type4 postscript function support.

This commit is contained in:
Brendan Dahl 2011-12-23 19:41:12 -08:00
parent f7f7269253
commit 1089c30b56
3 changed files with 751 additions and 6 deletions

View File

@ -336,16 +336,519 @@ var PDFFunction = (function PDFFunctionClosure() {
};
},
constructPostScript: function pdfFunctionConstructPostScript() {
return [CONSTRUCT_POSTSCRIPT];
constructPostScript: function pdfFunctionConstructPostScript(fn, dict, xref) {
var domain = dict.get('Domain');
var range = dict.get('Range');
if (!domain)
error('No domain.');
if(!range)
error('No range.')
var lexer = new PostScriptLexer(fn);
var parser = new PostScriptParser(lexer);
var code = parser.parse();
return [CONSTRUCT_POSTSCRIPT, domain, range, code];
},
constructPostScriptFromIR: function pdfFunctionConstructPostScriptFromIR() {
TODO('unhandled type of function');
return function constructPostScriptFromIRResult() {
return [255, 105, 180];
constructPostScriptFromIR:
function pdfFunctionConstructPostScriptFromIR(IR) {
var domain = IR[1];
var range = IR[2];
var code = IR[3];
var numOutputs = range.length / 2;
var evaluator = new PostScriptEvaluator(code);
// Cache the values for a big speed up, the cache size is limited though
// since the number of possible values can be huge from a PS function.
var cache = new FunctionCache();
return function constructPostScriptFromIRResult(args) {
var initialStack = [];
for (var i = 0, ii = (domain.length / 2); i < ii; ++i) {
initialStack.push(args[i]);
}
var key = initialStack.join('_');
if (cache.has(key))
return cache.get(key);
var stack = evaluator.execute(initialStack);
var transformed = new Array(numOutputs);
for (i = numOutputs - 1; i >= 0; --i) {
var out = stack.pop();
var rangeIndex = 2 * i;
if (out < range[rangeIndex])
out = range[rangeIndex];
else if (out > range[rangeIndex + 1])
out = range[rangeIndex + 1];
transformed[i] = out;
}
cache.set(key, transformed);
return transformed;
};
}
};
})();
var FunctionCache = (function FunctionCache() {
var MAX_CACHE_SIZE = 1024;
function FunctionCache() {
this.cache = {};
this.total = 0;
}
FunctionCache.prototype = {
has: function(key) {
return key in this.cache
},
get: function(key) {
return this.cache[key];
},
set: function(key, value) {
if (this.total < MAX_CACHE_SIZE) {
this.cache[key] = value;
this.total++;
}
}
};
return FunctionCache;
})();
var PostScriptStack = (function PostScriptStack() {
var MAX_STACK_SIZE = 100;
function PostScriptStack(initialStack) {
this.stack = initialStack || [];
}
PostScriptStack.prototype = {
push: function push(value) {
if (this.stack.length >= MAX_STACK_SIZE)
error('PostScript function stack overflow.');
this.stack.push(value);
},
pop: function pop() {
if (this.stack.length <= 0)
error('PostScript function stack underflow.');
return this.stack.pop();
},
copy: function copy(n) {
if (this.stack.length + n >= MAX_STACK_SIZE)
error('PostScript function stack overflow.');
var part = this.stack.slice(this.stack.length - n);
this.stack = this.stack.concat(part);
},
index: function index(n) {
this.push(this.stack[this.stack.length - n - 1]);
},
roll: function roll(n, p) {
// rotate the last n stack elements p times
var a = this.stack.splice(this.stack.length - n, n);
// algorithm from http://jsfromhell.com/array/rotate
var l = a.length, p = (Math.abs(p) >= l && (p %= l),
p < 0 && (p += l), p), i, x;
for(; p; p = (Math.ceil(l / p) - 1) * p - l + (l = p))
for(i = l; i > p; x = a[--i], a[i] = a[i - p], a[i - p] = x);
this.stack = this.stack.concat(a);
}
};
return PostScriptStack;
})();
var PostScriptEvaluator = (function PostScriptEvaluator() {
function PostScriptEvaluator(code) {
this.code = code;
console.log(code);
}
PostScriptEvaluator.prototype = {
execute: function(initialStack) {
var stack = new PostScriptStack(initialStack);
var counter = 0;
var code = this.code;
var a, b;
while (counter < this.code.length) {
var instruction = this.code[counter++];
var operator = instruction[0];
switch (operator) {
// non standard ps operators
case 'push':
stack.push(instruction[1]);
break;
case 'jz': // jump if false
a = stack.pop();
if (!a)
counter = instruction[1];
break;
case 'j': // jump
counter = instruction[1];
break;
// all ps operators in alphabetical order (excluding if/ifelse)
case 'abs':
a = stack.pop();
stack.push(Math.abs(a));
break;
case 'add':
b = stack.pop();
a = stack.pop();
stack.push(a + b);
break;
case 'and':
b = stack.pop();
a = stack.pop();
if (isBool(a) && isBool(b))
stack.push(a && b);
else
stack.push(a & b);
break;
case 'atan':
a = stack.pop();
stack.push(Math.atan(a));
break;
case 'bitshift':
b = stack.pop();
a = stack.pop();
if (a > 0)
stack.push(a << b);
else
stack.push(a >> b);
break;
case 'ceiling':
a = stack.pop();
stack.push(Math.ceil(a));
break;
case 'copy':
a = stack.pop();
stack.copy(a);
break;
case 'cos':
a = stack.pop();
stack.push(Math.cos(a));
break;
case 'cvi':
a = stack.pop();
if (a >= 0)
stack.push(Math.floor(a));
else
stack.push(Math.ceil(a));
break;
case 'cvr':
// noop
break;
case 'div':
b = stack.pop();
a = stack.pop();
stack.push(a / b);
break;
case 'dup':
stack.copy(1);
break;
case 'eq':
b = stack.pop();
a = stack.pop();
stack.push(a == b);
break;
case 'exch':
stack.roll(2, 1);
break;
case 'exp':
b = stack.pop();
a = stack.pop();
stack.push(Math.pow(a, b));
break;
case 'false':
stack.push(false);
break;
case 'floor':
a = stack.pop();
stack.push(Math.floor(a));
break;
case 'ge':
b = stack.pop();
a = stack.pop();
stack.push(a >= b);
break;
case 'gt':
b = stack.pop();
a = stack.pop();
stack.push(a > b);
break;
case 'idiv':
b = stack.pop();
a = stack.pop();
stack.push(Math.floor(a / b));
break;
case 'index':
a = stack.pop();
stack.index(a);
break;
case 'le':
b = stack.pop();
a = stack.pop();
stack.push(a <= b);
break;
case 'ln':
a = stack.pop();
stack.push(Math.log(a));
break;
case 'log':
a = stack.pop();
stack.push(Math.log(a) / Math.LN10);
break;
case 'lt':
b = stack.pop();
a = stack.pop();
stack.push(a < b);
break;
case 'mod':
b = stack.pop();
a = stack.pop();
stack.push(a % b);
break;
case 'mul':
b = stack.pop();
a = stack.pop();
stack.push(a * b);
break;
case 'ne':
b = stack.pop();
a = stack.pop();
stack.push(a != b);
break;
case 'neg':
a = stack.pop();
stack.push(-1 * b);
break;
case 'not':
a = stack.pop();
if (isBool(a) && isBool(b))
stack.push(a && b);
else
stack.push(a & b);
break;
case 'or':
b = stack.pop();
a = stack.pop();
if (isBool(a) && isBool(b))
stack.push(a || b);
else
stack.push(a | b);
break;
case 'pop':
stack.pop();
break;
case 'roll':
b = stack.pop();
a = stack.pop();
stack.roll(a, b);
break;
case 'round':
a = stack.pop();
stack.push(Math.round(a));
break;
case 'sin':
a = stack.pop();
stack.push(Math.sin(a));
break;
case 'sqrt':
a = stack.pop();
stack.push(Math.sqrt(a));
break;
case 'sub':
b = stack.pop();
a = stack.pop();
stack.push(a - b);
break;
case 'true':
stack.push(true);
break;
case 'truncate':
a = stack.pop();
if (a >= 0)
stack.push(Math.floor(a));
else
stack.push(Math.ceil(a));
break;
case 'xor':
b = stack.pop();
a = stack.pop();
if (isBool(a) && isBool(b))
stack.push((a ^ b) ? true : false);
else
stack.push(a ^ b);
break;
default:
error('Unknown operator ' + operator);
break
}
}
return stack.stack;
}
}
return PostScriptEvaluator;
})();
var PostScriptParser = (function PostScriptParser() {
function PostScriptParser(lexer) {
this.lexer = lexer;
this.code = [];
this.token;
this.prev;
}
PostScriptParser.prototype = {
nextToken: function nextToken() {
this.prev = this.token;
this.token = this.lexer.getToken();
},
accept: function accept(type) {
if (this.token.type == type) {
this.nextToken();
return true;
}
return false;
},
expect: function expect(type) {
if (this.accept(type))
return true;
error('Unexpected symbol: found ' + this.token.type + ' expected ' +
type + '.');
},
parse: function parse() {
this.nextToken();
this.expect(PostScriptTokenTypes.LBRACE);
this.parseBlock();
this.expect(PostScriptTokenTypes.RBRACE);
return this.code;
},
parseBlock: function parseBlock() {
while (true) {
if (this.accept(PostScriptTokenTypes.NUMBER)) {
this.code.push(['push', this.prev.value]);
} else if (this.accept(PostScriptTokenTypes.OPERATOR)) {
this.code.push([this.prev.value]);
} else if (this.accept(PostScriptTokenTypes.LBRACE)) {
this.parseCondition();
} else {
return;
}
}
},
parseCondition: function parseCondition() {
var counter = this.code.length - 1;
var condition = [];
this.code.push(condition);
this.parseBlock();
this.expect(PostScriptTokenTypes.RBRACE);
if (this.accept(PostScriptTokenTypes.IF)) {
// The true block is right after the 'if' so it just falls through on
// true else it jumps and skips the true block.
condition.push('jz', this.code.length);
} else if(this.accept(PostScriptTokenTypes.LBRACE)) {
var jump = [];
this.code.push(jump);
var endOfTrue = this.code.length;
this.parseBlock();
this.expect(PostScriptTokenTypes.RBRACE);
this.expect(PostScriptTokenTypes.IFELSE);
// The jump is added at the end of the true block to skip the false
// block.
jump.push('j', this.code.length);
condition.push('jz', endOfTrue);
} else {
error('PS Function: error parsing conditional.');
}
}
};
return PostScriptParser;
})();
var PostScriptTokenTypes = {
LBRACE: 0,
RBRACE: 1,
NUMBER: 2,
OPERATOR: 3,
IF: 4,
IFELSE: 5
};
var PostScriptToken = (function PostScriptToken() {
function PostScriptToken(type, value) {
this.type = type;
this.value = value;
}
return PostScriptToken;
})();
var PostScriptLexer = (function PostScriptLexer() {
function PostScriptLexer(stream) {
this.stream = stream;
}
PostScriptLexer.prototype = {
getToken: function getToken() {
var s = '';
var ch;
var comment = false;
var stream = this.stream;
// skip comments
while (true) {
if (!(ch = stream.getChar()))
return EOF;
if (comment) {
if (ch == '\x0a' || ch == '\x0d')
comment = false;
} else if (ch == '%') {
comment = true;
} else if (!Lexer.isSpace(ch)) {
break;
}
}
switch (ch) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '+': case '-': case '.':
return new PostScriptToken(PostScriptTokenTypes.NUMBER,
this.getNumber(ch));
case '{':
return new PostScriptToken(PostScriptTokenTypes.LBRACE, '{');
case '}':
return new PostScriptToken(PostScriptTokenTypes.RBRACE, '}');
}
// operator
var str = ch.toLowerCase();
while (true) {
ch = stream.lookChar().toLowerCase();
if (ch >= 'a' && ch <= 'z')
str += ch;
else
break;
stream.skip();
}
switch (str) {
case 'if':
return new PostScriptToken(PostScriptTokenTypes.IF, str);
case 'ifelse':
return new PostScriptToken(PostScriptTokenTypes.IFELSE, str);
default:
return new PostScriptToken(PostScriptTokenTypes.OPERATOR, str);
}
},
getNumber: function getNumber(ch) {
var str = ch;
var stream = this.stream;
while (true) {
ch = stream.lookChar();
if ((ch >= '0' && ch <= '9') || ch == '-' || ch == '.')
str += ch;
else
break;
stream.skip();
}
var value = parseFloat(str);
if (isNaN(value))
error('Invalid floating point number: ' + value);
return value;
}
};
return PostScriptLexer;
})();

223
test/unit/function_spec.js Normal file
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@ -0,0 +1,223 @@
/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
'use strict';
describe('function', function() {
beforeEach(function () {
this.addMatchers({
toMatchArray: function(expected) {
var actual = this.actual;
if (actual.length != expected.length)
return false;
for (var i = 0; i < expected.length; i++) {
var a = actual[i], b = expected[i];
if (isArray(b)) {
if (a.length != b.length)
return false;
for (var j = 0; j < a.length; j++) {
var suba = a[j], subb = b[j];
if (suba !== subb)
return false
}
} else {
if (a !== b)
return false;
}
}
return true;
}
});
});
describe('PostScriptParser', function() {
function parse(program) {
var stream = new StringStream(program);
var parser = new PostScriptParser(new PostScriptLexer(stream));
return parser.parse();
}
it('parses empty programs', function() {
var output = parse('{}');
expect(output.length).toEqual(0);
});
it('parses positive numbers', function() {
var number = 999;
var program = parse('{ ' + number + ' }');
var expectedProgram = [
['push', number]
];
expect(program).toMatchArray(expectedProgram);
});
it('parses negative numbers', function() {
var number = -999;
var program = parse('{ ' + number + ' }');
var expectedProgram = [
['push', number]
];
expect(program).toMatchArray(expectedProgram);
});
it('parses negative floats', function() {
var number = 3.3;
var program = parse('{ ' + number + ' }');
var expectedProgram = [
['push', number]
];
expect(program).toMatchArray(expectedProgram);
});
it('parses operators', function() {
var program = parse('{ sub }');
var expectedProgram = [
['sub']
];
expect(program).toMatchArray(expectedProgram);
});
it('parses if statements', function() {
var program = parse('{ { 99 } if }');
var expectedProgram = [
['jz', 2],
['push', 99]
];
expect(program).toMatchArray(expectedProgram);
});
it('parses ifelse statements', function() {
var program = parse('{ { 99 } { 44 } ifelse }');
var expectedProgram = [
['jz', 3],
['push', 99],
['j', 4],
['push', 44],
];
expect(program).toMatchArray(expectedProgram);
});
it('handles missing brackets', function() {
expect(function() { parse('{'); }).toThrow(
new Error('Unexpected symbol: found undefined expected 1.'));
});
});
describe('PostScriptEvaluator', function() {
function evaluate(program) {
var stream = new StringStream(program);
var parser = new PostScriptParser(new PostScriptLexer(stream));
var code = parser.parse();
var evaluator = new PostScriptEvaluator(code);
var output = evaluator.execute();
console.log(output);
return output;
}
it('pushes stack', function() {
var stack = evaluate('{ 99 }');
var expectedStack = [99];
expect(stack).toMatchArray(expectedStack);
});
it('handles if with true', function() {
var stack = evaluate('{ 1 {99} if }');
var expectedStack = [99];
expect(stack).toMatchArray(expectedStack);
});
it('handles if with false', function() {
var stack = evaluate('{ 0 {99} if }');
var expectedStack = [];
expect(stack).toMatchArray(expectedStack);
});
it('handles ifelse with true', function() {
var stack = evaluate('{ 1 {99} {77} ifelse }');
var expectedStack = [99];
expect(stack).toMatchArray(expectedStack);
});
it('handles ifelse with false', function() {
var stack = evaluate('{ 0 {99} {77} ifelse }');
var expectedStack = [77];
expect(stack).toMatchArray(expectedStack);
});
it('handles nested if', function() {
var stack = evaluate('{ 1 {1 {77} if} if }');
var expectedStack = [77];
expect(stack).toMatchArray(expectedStack);
});
it('abs', function() {
var stack = evaluate('{ -2 abs }');
var expectedStack = [2];
expect(stack).toMatchArray(expectedStack);
});
it('adds', function() {
var stack = evaluate('{ 1 2 add }');
var expectedStack = [3];
expect(stack).toMatchArray(expectedStack);
});
it('boolean ands', function() {
var stack = evaluate('{ true false and }');
var expectedStack = [false];
expect(stack).toMatchArray(expectedStack);
});
it('bitwise ands', function() {
var stack = evaluate('{ 254 1 and }');
var expectedStack = [254 & 1];
expect(stack).toMatchArray(expectedStack);
});
// TODO atan
// TODO bitshift
// TODO ceiling
// TODO copy
// TODO cos
// TODO cvi
// TODO cvr
// TODO div
it('duplicates', function() {
var stack = evaluate('{ 99 dup }');
var expectedStack = [99, 99];
expect(stack).toMatchArray(expectedStack);
});
// TODO eq
it('exchanges', function() {
var stack = evaluate('{ 44 99 exch }');
var expectedStack = [99, 44];
expect(stack).toMatchArray(expectedStack);
});
// TODO exp
// TODO false
// TODO floor
// TODO ge
// TODO gt
// TODO idiv
it('duplicates index', function() {
var stack = evaluate('{ 4 3 2 1 2 index }');
var expectedStack = [4, 3, 2, 1, 3];
expect(stack).toMatchArray(expectedStack);
});
// TODO le
// TODO ln
// TODO log
// TODO lt
// TODO mod
// TODO mul
// TODO ne
// TODO neg
// TODO not
// TODO or
it('pops stack', function() {
var stack = evaluate('{ 1 2 pop }');
var expectedStack = [1];
expect(stack).toMatchArray(expectedStack);
});
it('rolls stack right', function() {
var stack = evaluate('{ 1 3 2 2 4 1 roll }');
var expectedStack = [2, 1, 3, 2];
expect(stack).toMatchArray(expectedStack);
});
it('rolls stack left', function() {
var stack = evaluate('{ 1 3 2 2 4 -1 roll }');
var expectedStack = [3, 2, 2, 1];
expect(stack).toMatchArray(expectedStack);
});
// TODO round
// TODO sin
// TODO sqrt
// TODO sub
// TODO true
// TODO truncate
// TODO xor
});
});

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@ -11,9 +11,28 @@
<!-- include spec files here... -->
<script type="text/javascript" src="obj_spec.js"></script>
<script type="text/javascript" src="function_spec.js"></script>
<!-- include source files here... -->
<script type="text/javascript" src="../../src/core.js"></script>
<script type="text/javascript" src="../../src/util.js"></script>
<script type="text/javascript" src="../../src/canvas.js"></script>
<script type="text/javascript" src="../../src/obj.js"></script>
<script type="text/javascript" src="../../src/function.js"></script>
<script type="text/javascript" src="../../src/charsets.js"></script>
<script type="text/javascript" src="../../src/cidmaps.js"></script>
<script type="text/javascript" src="../../src/colorspace.js"></script>
<script type="text/javascript" src="../../src/crypto.js"></script>
<script type="text/javascript" src="../../src/evaluator.js"></script>
<script type="text/javascript" src="../../src/fonts.js"></script>
<script type="text/javascript" src="../../src/glyphlist.js"></script>
<script type="text/javascript" src="../../src/image.js"></script>
<script type="text/javascript" src="../../src/metrics.js"></script>
<script type="text/javascript" src="../../src/parser.js"></script>
<script type="text/javascript" src="../../src/pattern.js"></script>
<script type="text/javascript" src="../../src/stream.js"></script>
<script type="text/javascript" src="../../src/worker.js"></script>
<script type="text/javascript" src="../../external/jpgjs/jpg.js"></script>
<script type="text/javascript">
'use strict';