How to Rotate a BlockReferenceEntity by code

[kamimail]

Hi ,there
I am a newbie to QCAD programming.
I want to rotate lines with some degree for learning how to code with QCAD.
So I have given a try to write a simple GUIACTION test programming, but it does not works as expect in QCAD UI ( rotating a line with 90 degree)
hope someone can help me find problems in the code beblow ,thanks so much.

static RTransaction addObjOp(RDocumentInterface* di, const QSharedPointer<RObject>& obj) {
RAddObjectOperation* op = new RAddObjectOperation;
op->addObject(obj);
return di->applyOperation(op);
}

void demo_rotation(RDocumentInterface* di,RDocument& doc)
{
//1.block
QString blkName = "TestBlk";
QSharedPointer<RBlock> blk(new RBlock(&doc, blkName, RVector(0,0)));
addObjOp(di, blk);
RBlock::Id blkId = doc.getBlockId(blkName);


// 2. a horiztonal line starting from (0,0) to (10,0)
QSharedPointer<RLineEntity> lineInBlock(new RLineEntity( &doc, RLineData(RVector(0,0), RVector(10,0))));
lineInBlock->setBlockId(blkId);
addObj(di, lineInBlock);
REntity::Id childLineId = lineInBlock->getId();


// 3) switch to model space, one blockref for rotation,one without rotation
doc.setCurrentBlock(doc.getModelSpaceBlockId());

// 3.1) one without rotation,horizontal line
{
RBlockReferenceData brd(blkId,
/*position*/ RVector(0,0),
/*scale*/ RVector(1,1,1),
/*rotation*/ 0.0);
QSharedPointer<RBlockReferenceEntity> br(new RBlockReferenceEntity(&doc, brd));
br->setBlockId(doc.getCurrentBlockId());
addObjOp(di, br);

}


// 3.2) rotation 90 degree
{
RBlockReferenceData brd(blkId,
/*position*/ RVector(0,0),
/*scale*/ RVector(1,1,1),
/*rotation*/ M_PI/2);
QSharedPointer<RBlockReferenceEntity> br(new RBlockReferenceEntity(&doc, brd));
br->setBlockId(doc.getCurrentBlockId());
addObjOp(di, br);
}


di->regenerateScenes();
di->repaintViews();
}

2025-09-19 190234.png (198.09 KiB) Viewed 5446 times

[CVH]

Hi, and welcome to the QCAD forum.

First:
Please include code on the forum in a code panel.
Edit your topic, select the textual code and hit the [</>] button above the text area.
Same for creating a new post or replying to one.

Second:
How do you intend to run this code?
I presume that it is written in C++ and then your sole option would be as a plugin
Perhaps as an RCC Plugin, see tutorial: Creating an RCC Plugin

The other options are a Script Add-on, a simple script to execute (with GE or XC) or a Command Line script.
Scripts are written in ECMAScript.
Also see the tutorial: Script Programming


Not a specialist on the C++ level myself.

If your code creates a Block definition with a line in it and inserts a Block Reference angled at zero rads ...
But doesn't for a different angle ...
Are you sure that M_PI is defined without including something?

Regards,
CVH