rotate Canvas

[leon.fuchs]

Hello all,
I have a question about the WidgetCanvas Class I have drawn a triangle, which should rotate in a circle. However, when rotating it, it is only visible in a certain area. Maybe someone could tell me how to make it visible everywhere.
With kind regards
Leon

 

init()
{
	obj_Gui = checked_ptr_cast<ObjectGui>(World::getNodeById(568410087));
	obj_Gui->setBackground(1);
	auto gui1 = obj_Gui->getGui();
	
	canvas = WidgetCanvas::create(gui1);
	
  	int SouthTriangle = canvas->addPolygon(8);
	for (int i = 0; i <= 3; i++)
	{
		float s = sin(360 / 3 * UNIGINE_DEG2RAD * i) * 20 + 0;
		float c = cos(360 / 3 * UNIGINE_DEG2RAD * i) * 20 +100;
		canvas->addPolygonPoint(SouthTriangle, vec3(s, c, 0.0f));
	}
	canvas->setPolygonColor(SouthTriangle, vec4(0.0f, 0.0f, 1.0f, 1.0f));
  	gui1->addChild(canvas, Gui::ALIGN_OVERLAP | Gui::ALIGN_CENTER);
}

update()
{
	i = i + 0.5;
	canvas->setPolygonTransform(SouthTriangle, (mat4(rotateZ(i))));
}

 

2021-12-06 14-52-29.mkv

 

[karpych11]

Hello,

The position of the widget is determined by the upper left corner, i.e. for the canvas, it is located in the center of the GUI. With the current transformation change, the polygon extends outside the canvas. For correct display, the polygon must be rotated and moved to the center of the widget. You can try to change the code like in the example below:

int canvas_width = 400;
int canvas_height = 400;

init()
{
	//...
	// create canvas
	//...

	canvas->setWidth(canvas_width);
	canvas->setHeight(canvas_height);
	canvas->setPosition((obj_Gui->getScreenWidth() - canvas_width) / 2, (obj_Gui->getScreenHeight() - canvas_height) / 2);
  	gui1->addChild(canvas, Gui::ALIGN_OVERLAP);
}

update()
{
	i = i + 0.5;
	canvas->setPolygonTransform(SouthTriangle, translate(vec3(canvas_width / 2, canvas_height / 2, 0.0f)) * rotateZ(i));
}

 

[Ugly1-1]

Question. What if you wanted to "stencil", or clip the polygon or text to the canvas as well?

Edited December 8, 2021 by Ugly1-1

[karpych11]

This feature is currently not supported for canvas.