//19. <关系表达式>—> <表达式> <关系> <表达式>
TFexit relationexpression(){
Val v1 = expression();
int re = relation();
Val v2 = expression();
quadruples.push_back(Quadruple(sno++, re, v1, v2));
quadruples.push_back(Quadruple(sno++,0,Val(),Val()));//无条件跳转op=0
return TFexit(sno - 2, sno - 1);
}
unsigned
TopographyFile::GetSkipSteps(fixed map_scale) const
{
if (Quadruple(map_scale) > scale_threshold * 3)
return 4;
if (Double(map_scale) > scale_threshold)
return 3;
if (Quadruple(map_scale) > scale_threshold)
return 2;
return 1;
}
//16.<项>—> <因子> [ *|/ <因子> ]
Val Item(){
Val v1 = Factor();
while (lookahead == mutiply || lookahead == div){
int op = lookahead;
if (op == mutiply) match(mutiply);
else match(div);
Val v2 = Factor();
quadruples.push_back(Quadruple(sno++, op == mutiply ? mutiply : div, v1, v2, temp));
//生成四元式
/*printf("%3d （%c，", sno++, op == mutiply ? '*' : '/');
if (v1.type == 1) printf("%s", GetNameByID(v1.value1));
else if (v1.type == 0) printf("%d", v1.value1);
else if (v1.type == 2) printf("%lf", v1.value2);
else printf("t%d", v1.value1);
printf("，");
if (v2.type == 1) printf("%s", GetNameByID(v2.value1));
else if (v2.type == 0) printf("%d", v2.value1);
else if (v2.type == 2) printf("%lf", v2.value2);
else printf("t%d", v2.value1);
printf("，t%d）\n", temp);*/
v1.type = -1;
v1.value1 = temp++;
}
return v1;
}
//15.<表达式>—> <项> [ +|－ <项> ]
Val expression(){
Val v1 = Item();
while (lookahead == plus || lookahead == minus){
int op = lookahead;
if (lookahead == plus) match(plus);
else match(minus);
Val v2 = Item();
quadruples.push_back(Quadruple(sno++, op == plus ? plus : minus, v1,v2,temp));
//生成四元式
/*printf("%3d （%c，", sno++, op == plus ? '+' : '-');
if (v1.type == 1) printf("%s", GetNameByID(v1.value1));
else if (v1.type == 0) printf("%d", v1.value1);
else if (v1.type == 2) printf("%lf", v1.value2);
else printf("t%d", v1.value1);
printf("，");
if (v2.type == 1) printf("%s", GetNameByID(v2.value1));
else if (v2.type == 0) printf("%d", v2.value1);
else if (v2.type == 2) printf("%lf", v2.value2);
else printf("t%d", v2.value1);
printf("，t%d）\n", temp);*/
v1.type = -1;
v1.value1 = temp++;
}
return v1;
}
//13.<分支语句>—> if <布尔表达式> then <语句>
//| if <布尔表达式> then <语句> else <语句>
void switchStatement(){
if (lookahead == IF){
match(IF);
TFexit tf = booleaexpression();//真假出口
match(THEN);
//填真出口
BackPatch(tf.TC, sno);
statementlists();
if (lookahead == ELSE){
// 1 无条件跳转
int j = sno;
quadruples.push_back(Quadruple(sno++, 0,Val(),Val()));
match(ELSE);
//回填假出口
BackPatch(tf.FC, sno);
statementlists();
//回填 1 无条件跳转
BackPatch(j, sno);
}
else {
// 回填假出口
BackPatch(tf.FC, sno);
}
}
else{
error(24);
}
}
//10.<赋值语句>—> id = <表达式> ；
void assignment(){
char varname[MAXIDLEN];
strcpy(varname, token);
Val v2 = Val(1, GetIdByName(varname));
match(id);
if (!isexist(varname)){
strcpy(token, varname);
error(46);
}
match(equl);
Val v = expression();
match(semicolon);
quadruples.push_back(Quadruple(sno++, equl, v, v2));
//生成四元式
/*printf("%3d （=，", sno++);
if (v.type == 1) printf("%s", GetNameByID(v.value1));
else if (v.type == 0) printf("%d", v.value1);
else if (v.type == 2) printf("%lf", v.value2);
else printf("t%d", v.value1);
printf("，%s）\n", varname);*/
}
void
WindArrowRenderer::Draw(Canvas &canvas, const Angle screen_angle,
const SpeedVector wind, const PixelPoint pos,
const PixelRect rc, WindArrowStyle arrow_style)
{
// Draw arrow (and tail)
const unsigned length = uround(Quadruple(wind.norm));
DrawArrow(canvas, pos, wind.bearing - screen_angle, length, arrow_style);
// Draw wind speed label
StaticString<12> buffer;
buffer.Format(_T("%i"), iround(Units::ToUserWindSpeed(wind.norm)));
canvas.SetTextColor(COLOR_BLACK);
canvas.Select(*look.font);
const unsigned offset = uround(M_SQRT2 * wind.norm);
BulkPixelPoint label[] = {
{ 18, -26 - int(offset) },
};
PolygonRotateShift(label, ARRAY_SIZE(label),
pos, wind.bearing - screen_angle);
TextInBoxMode style;
style.align = TextInBoxMode::Alignment::CENTER;
style.vertical_position = TextInBoxMode::VerticalPosition::CENTERED;
style.shape = LabelShape::OUTLINED;
TextInBox(canvas, buffer, label[0].x, label[0].y, style, rc);
}
void
InfoBoxContentWindArrow::OnCustomPaint(Canvas &canvas, const PixelRect &rc)
{
const auto &info = CommonInterface::Calculated();
const RasterPoint pt = rc.GetCenter();
UPixelScalar padding = Layout::FastScale(10);
UPixelScalar size = std::min(rc.right - rc.left, rc.bottom - rc.top);
if (size > padding)
size -= padding;
// Normalize the size because the Layout::Scale is applied
// by the DrawArrow() function again
size = size * 100 / Layout::Scale(100);
auto angle = info.wind.bearing - CommonInterface::Basic().attitude.heading;
PixelScalar length =
std::min(size, (UPixelScalar)std::max(10, iround(Quadruple(info.wind.norm))));
PixelScalar offset = -length / 2;
auto style = CommonInterface::GetMapSettings().wind_arrow_style;
WindArrowRenderer renderer(UIGlobals::GetLook().wind_arrow_info_box);
renderer.DrawArrow(canvas, pt, angle, length, style, offset);
}
fixed
IGCWriter::GetEPE(const GPSState &gps)
{
/*
* EPE (Estimated Position Error in meters)
* based on Parkinson, Bradford W. Global Positioning System Theory and Applications Volume 1.
* URE (User Range Error) is an estimate of "Signals in Space" errors, i.e., ephemeris data,
* satellite clocks, ionospheric delay and tropospheric delay. These errors can be greatly
* reduced by differential and multiple frequency techniques. Differential correction sources
* include user provided reference stations, community base stations, governmental beacon
* transmissions, FM sub-carrier transmissions and geosynchronous satellite transmissions.
* UEE (User Equipment Errors) includes receiver noise, multipath, antenna orientation,
* EMI/RFI. Receiver and antenna design can greatly reduce UEE error sources--usually at
* substantial cost.
*
* Typical Error components of an autonomous (non Differential) GPS signal are:
* Error Error in meters (autonomous) DGPS Type error
* Ephemeris data 2.1 0 URE
* Satellite clock 2.1 0 URE
* Ionosphere 4 0.4 URE
* Troposphere 0.7 0.2 URE
* Multipath 1.4 1.4 UEE
* Receiver measurement 0.5 0.5 UEE
*
* Autonomous:
* EPE 2-sigma = EPE (2drms) = 2* HDOP * SQRT [URE^2 + UEE^2] = HDOP * 18.2
*
* Differential:
* EPE 2-sigma = EPE (2drms) = 2* HDOP * SQRT [URE^2 + UEE^2] = HDOP * 4.0
* Assumptions: XCSoar does not know any details about the hardware of the receiver,
* so we assume the table above is a valid estimation.
*
* The WAAS function in the US does not set the DGPS flag
* fix_quality
* 1 = GPS fix (SPS)
* 2 = DGPS fix
* 3 = PPS fix
* 4 = Real Time Kinematic
* 5 = Float RTK
* 6 = estimated (dead reckoning) (2.3 feature)
* 7 = Manual input mode
* 8 = Simulation mode
*/
switch (gps.fix_quality) {
case FixQuality::GPS:
return gps.hdop * fixed(18.2);
case FixQuality::DGPS:
return Quadruple(gps.hdop);
default:
return fixed(0);
}
}
unsigned
TopographyFile::GetThinningLevel(fixed map_scale) const
{
if (Double(map_scale) > scale_threshold)
return 3;
if (map_scale * 3 > scale_threshold)
return 2;
if (Quadruple(map_scale) > scale_threshold)
return 1;
return 0;
}
unsigned
TopographyFile::GetMinimumPointDistance(unsigned level) const
{
switch (level) {
case 1:
return (unsigned)(Quadruple(scale_threshold) / 30);
case 2:
return (unsigned)(6 * scale_threshold / 30);
case 3:
return (unsigned)(9 * scale_threshold / 30);
}
return 1;
}
//14.<循环语句>—> while <布尔表达式> do <语句>
void loopStatement(){
match(WHILE);
//int boolId = 序号全局变量
int boolId = sno;
TFexit tf = booleaexpression();//真假出口
match(DO);
//回填真出口
BackPatch(tf.TC, sno);
statementlists();
//(j boolId)
quadruples.push_back(Quadruple(sno++, 0, Val(), Val(), boolId));
//回填假出口
BackPatch(tf.FC, sno);
}
void Code::generate(CodeOp op, SymbolTableEntry* arg1, SymbolTableEntry* arg2, SymbolTableEntry* result)
{
m_qList.push_back(Quadruple(op,arg1,arg2,result));
}