gecko-dev/dom/canvas/WebGLValidateStrings.h

252 строки
7.8 KiB
C++

/*
* Copyright (C) 2011 Apple Inc. All rights reserved.
* Copyright (C) 2011 Mozilla Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef WEBGLVALIDATESTRINGS_H_
#define WEBGLVALIDATESTRINGS_H_
#include "WebGLContext.h"
namespace mozilla {
// The following code was taken from the WebKit WebGL implementation,
// which can be found here:
// http://trac.webkit.org/browser/trunk/Source/WebCore/html/canvas/WebGLRenderingContext.cpp?rev=93625#L121
// Note that some modifications were done to adapt it to Mozilla.
/****** BEGIN CODE TAKEN FROM WEBKIT ******/
bool WebGLContext::ValidateGLSLCharacter(char16_t c)
{
// Printing characters are valid except " $ ` @ \ ' DEL.
if (c >= 32 && c <= 126 &&
c != '"' && c != '$' && c != '`' && c != '@' && c != '\\' && c != '\'')
{
return true;
}
// Horizontal tab, line feed, vertical tab, form feed, carriage return are also valid.
if (c >= 9 && c <= 13) {
return true;
}
return false;
}
// Strips comments from shader text. This allows non-ASCII characters
// to be used in comments without potentially breaking OpenGL
// implementations not expecting characters outside the GLSL ES set.
class StripComments {
public:
explicit StripComments(const nsAString& aStr)
: m_parseState(BeginningOfLine)
, m_end(aStr.EndReading())
, m_current(aStr.BeginReading())
, m_position(0)
{
m_result.SetLength(aStr.Length());
parse();
}
const nsTArray<char16_t>& result()
{
return m_result;
}
size_t length()
{
return m_position;
}
private:
bool hasMoreCharacters()
{
return (m_current < m_end);
}
void parse()
{
while (hasMoreCharacters()) {
process(current());
// process() might advance the position.
if (hasMoreCharacters())
advance();
}
}
void process(char16_t);
bool peek(char16_t& character)
{
if (m_current + 1 >= m_end)
return false;
character = *(m_current + 1);
return true;
}
char16_t current()
{
//ASSERT(m_position < m_length);
return *m_current;
}
void advance()
{
++m_current;
}
bool isNewline(char16_t character)
{
// Don't attempt to canonicalize newline related characters.
return (character == '\n' || character == '\r');
}
void emit(char16_t character)
{
m_result[m_position++] = character;
}
enum ParseState {
// Have not seen an ASCII non-whitespace character yet on
// this line. Possible that we might see a preprocessor
// directive.
BeginningOfLine,
// Have seen at least one ASCII non-whitespace character
// on this line.
MiddleOfLine,
// Handling a preprocessor directive. Passes through all
// characters up to the end of the line. Disables comment
// processing.
InPreprocessorDirective,
// Handling a single-line comment. The comment text is
// replaced with a single space.
InSingleLineComment,
// Handling a multi-line comment. Newlines are passed
// through to preserve line numbers.
InMultiLineComment
};
ParseState m_parseState;
const char16_t* m_end;
const char16_t* m_current;
size_t m_position;
nsTArray<char16_t> m_result;
};
void StripComments::process(char16_t c)
{
if (isNewline(c)) {
// No matter what state we are in, pass through newlines
// so we preserve line numbers.
emit(c);
if (m_parseState != InMultiLineComment)
m_parseState = BeginningOfLine;
return;
}
char16_t temp = 0;
switch (m_parseState) {
case BeginningOfLine:
// If it's an ASCII space.
if (c <= ' ' && (c == ' ' || (c <= 0xD && c >= 0x9))) {
emit(c);
break;
}
if (c == '#') {
m_parseState = InPreprocessorDirective;
emit(c);
break;
}
// Transition to normal state and re-handle character.
m_parseState = MiddleOfLine;
process(c);
break;
case MiddleOfLine:
if (c == '/' && peek(temp)) {
if (temp == '/') {
m_parseState = InSingleLineComment;
emit(' ');
advance();
break;
}
if (temp == '*') {
m_parseState = InMultiLineComment;
// Emit the comment start in case the user has
// an unclosed comment and we want to later
// signal an error.
emit('/');
emit('*');
advance();
break;
}
}
emit(c);
break;
case InPreprocessorDirective:
// No matter what the character is, just pass it
// through. Do not parse comments in this state. This
// might not be the right thing to do long term, but it
// should handle the #error preprocessor directive.
emit(c);
break;
case InSingleLineComment:
// The newline code at the top of this function takes care
// of resetting our state when we get out of the
// single-line comment. Swallow all other characters.
break;
case InMultiLineComment:
if (c == '*' && peek(temp) && temp == '/') {
emit('*');
emit('/');
m_parseState = MiddleOfLine;
advance();
break;
}
// Swallow all other characters. Unclear whether we may
// want or need to just emit a space per character to try
// to preserve column numbers for debugging purposes.
break;
}
}
/****** END CODE TAKEN FROM WEBKIT ******/
} // end namespace mozilla
#endif // WEBGLVALIDATESTRINGS_H_