Rotating after scaling results in border offset

@br0mid wrote:

I have a border that gets drawn using the translation, rotation and scale transformations of an image. The border and the image match up perfectly when I rotate without any scale. However, once I scale the image and begin rotating an offset begins to grow between the image and the border and gets more severe as the angle increases. After a full rotation, the image and border match up again. Can’t think of what I’m doing wrong here.

 ofPushMatrix();
ofSetColor(255,255,255);
ofTranslate(pic->imageCenter.x, pic->imageCenter.y);
ofScale((pic->width/pic->image.getWidth()), (pic->height/pic->image.getHeight()), 0);
ofRotateZRad(pic->angle);
pic->image.draw(-1*pic->image.getWidth()/2, -1*pic->image.getHeight()/2);
ofPopMatrix();

ofPushMatrix();
ofTranslate(pic->imageCenter.x, pic->imageCenter.y);
ofRotateZRad(pic->angle);
ofSetColor(0,0,255);
ofNoFill();
ofSetLineWidth(3);
ofDrawRectangle(-1*pic->width/2, -1*pic->height/2, pic->width, pic->height);
ofPopMatrix();

Screen Shot 2019-03-12 at 10.58.15 AM.jpg1854×1498 158 KB

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