setMousePosition method
**** SET MOUSE POS Set the iMouse uniform Shows how to use the mouse input (only left button supported):
mouse.xy = mouse position during last button down
abs(mouse.zw) = mouse position during last button click sign(mouze.z) = button is down sign(mouze.w) = button is clicked
This is automatically processed by OpenGLTexture widget
For reference: https://www.shadertoy.com/view/llySRh https://www.shadertoy.com/view/Mss3zH
Implementation
void setMousePosition(
Offset startingPos,
Offset pos,
PointerEventType eventType,
Size twSize,
) {
return _setMousePosition(
pos.dx,
pos.dy,
eventType == PointerEventType.onPointerDown ||
eventType == PointerEventType.onPointerMove
? startingPos.dx
: -startingPos.dx,
-startingPos.dy,
twSize.width,
twSize.height,
);
}