/**************************************************************************/
/* shader_expression.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#include "shader_expression.h"
Error ShaderExpression::_get_token(Token &r_token) {
while (true) {
#define GET_CHAR() (str_ofs >= expression.length() ? 0 : expression[str_ofs++])
char32_t cchar = GET_CHAR();
bool invalid_character = false;
switch (cchar) {
case 0: {
r_token.type = TK_EOF;
return OK;
}
case '{': {
invalid_character = true;
break;
}
case '}': {
invalid_character = true;
break;
}
case '[': {
invalid_character = true;
break;
}
case ']': {
invalid_character = true;
break;
}
case '(': {
r_token.type = TK_PARENTHESIS_OPEN;
return OK;
}
case ')': {
r_token.type = TK_PARENTHESIS_CLOSE;
return OK;
}
case ',': {
invalid_character = true;
break;
}
case ':': {
invalid_character = true;
break;
}
case '$': {
invalid_character = true;
break;
}
case '=': {
cchar = GET_CHAR();
if (cchar == '=') {
r_token.type = TK_OP_EQUAL;
} else {
_set_error("Expected '='.");
r_token.type = TK_ERROR;
return ERR_PARSE_ERROR;
}
return OK;
}
case '!': {
if (expression[str_ofs] == '=') {
r_token.type = TK_OP_NOT_EQUAL;
str_ofs++;
} else {
r_token.type = TK_OP_NOT;
}
return OK;
}
case '>': {
if (expression[str_ofs] == '=') {
r_token.type = TK_OP_GREATER_EQUAL;
str_ofs++;
} else if (expression[str_ofs] == '>') {
r_token.type = TK_OP_SHIFT_RIGHT;
str_ofs++;
} else {
r_token.type = TK_OP_GREATER;
}
return OK;
}
case '<': {
if (expression[str_ofs] == '=') {
r_token.type = TK_OP_LESS_EQUAL;
str_ofs++;
} else if (expression[str_ofs] == '<') {
r_token.type = TK_OP_SHIFT_LEFT;
str_ofs++;
} else {
r_token.type = TK_OP_LESS;
}
return OK;
}
case '+': {
r_token.type = TK_OP_ADD;
return OK;
}
case '-': {
r_token.type = TK_OP_SUB;
return OK;
}
case '/': {
r_token.type = TK_OP_DIV;
return OK;
}
case '*': {
r_token.type = TK_OP_MUL;
return OK;
}
case '%': {
r_token.type = TK_OP_MOD;
return OK;
}
case '&': {
if (expression[str_ofs] == '&') {
r_token.type = TK_OP_AND;
str_ofs++;
} else {
r_token.type = TK_OP_BIT_AND;
}
return OK;
}
case '|': {
if (expression[str_ofs] == '|') {
r_token.type = TK_OP_OR;
str_ofs++;
} else {
r_token.type = TK_OP_BIT_OR;
}
return OK;
}
case '^': {
r_token.type = TK_OP_BIT_XOR;
break;
}
case '~': {
r_token.type = TK_OP_BIT_INVERT;
break;
}
case '\'': {
invalid_character = true;
break;
}
case '"': {
invalid_character = true;
break;
}
default: {
if (cchar <= 32) {
break;
}
char32_t next_char = (str_ofs >= expression.length()) ? 0 : expression[str_ofs];
if (is_digit(cchar)) {
//a number
String num;
#define READING_SIGN 0
#define READING_INT 1
#define READING_HEX 2
#define READING_BIN 3
#define READING_DEC 4
#define READING_EXP 5
#define READING_DONE 6
int reading = READING_INT;
char32_t c = cchar;
bool exp_sign = false;
bool exp_beg = false;
bool bin_beg = false;
bool hex_beg = false;
bool is_float = false;
bool is_first_char = true;
while (true) {
switch (reading) {
case READING_INT: {
if (is_digit(c)) {
if (is_first_char && c == '0') {
if (next_char == 'b' || next_char == 'B') {
reading = READING_BIN;
} else if (next_char == 'x' || next_char == 'X') {
reading = READING_HEX;
}
}
} else if (c == '.') {
reading = READING_DEC;
is_float = true;
} else if (c == 'e' || c == 'E') {
reading = READING_EXP;
is_float = true;
} else {
reading = READING_DONE;
}
if (is_float) {
_set_error("Floating-point number operations are not supported by the shader preprocessor.");
r_token.type = TK_ERROR;
return ERR_PARSE_ERROR;
}
} break;
case READING_BIN: {
if (bin_beg && !is_binary_digit(c)) {
reading = READING_DONE;
} else if (c == 'b' || c == 'B') {
bin_beg = true;
}
} break;
case READING_HEX: {
if (hex_beg && !is_hex_digit(c)) {
reading = READING_DONE;
} else if (c == 'x' || c == 'X') {
hex_beg = true;
}
} break;
case READING_DEC: {
if (is_digit(c)) {
} else if (c == 'e' || c == 'E') {
reading = READING_EXP;
} else {
reading = READING_DONE;
}
} break;
case READING_EXP: {
if (is_digit(c)) {
exp_beg = true;
} else if ((c == '-' || c == '+') && !exp_sign && !exp_beg) {
exp_sign = true;
} else {
reading = READING_DONE;
}
} break;
}
if (reading == READING_DONE) {
break;
}
num += c;
c = GET_CHAR();
is_first_char = false;
}
if (c != 0) {
str_ofs--;
}
r_token.type = TK_CONSTANT;
if (is_float) {
r_token.value = num.to_float();
} else if (bin_beg) {
r_token.value = num.bin_to_int();
} else if (hex_beg) {
r_token.value = num.hex_to_int();
} else {
r_token.value = num.to_int();
}
return OK;
} else if (is_unicode_identifier_start(cchar)) {
String id = String::chr(cchar);
cchar = GET_CHAR();
while (is_unicode_identifier_continue(cchar)) {
id += cchar;
cchar = GET_CHAR();
}
str_ofs--; //go back one
if (id == "true") {
r_token.type = TK_CONSTANT;
r_token.value = true;
} else if (id == "false") {
r_token.type = TK_CONSTANT;
r_token.value = false;
} else {
r_token.type = TK_IDENTIFIER;
r_token.value = id;
}
return OK;
} else {
invalid_character = true;
}
}
}
if (invalid_character) {
_set_error("Unexpected character.");
r_token.type = TK_ERROR;
return ERR_PARSE_ERROR;
}
#undef GET_CHAR
}
r_token.type = TK_ERROR;
return ERR_PARSE_ERROR;
}