Irrlicht Engine

Code: Select all

if(selector == NULL){
						selector = new Selector(mysmgr->getRootSceneNode(), mysmgr, 100000);
					}
					// where the mouse is from the camers (forms line)
					core::line3d< f32 > lol = mysmgr->getSceneCollisionManager()->
						getRayFromScreenCoordinates(from, camera);
					
					// plane, first position, second normal
					core::plane3d< f32 > ground(core::vector3d<f32>(0, 0, 0), core::vector3d<f32>(0, 10, 0));

					// where the line hits the ground
					core::vector3d< f32 >intersection(0,2,0);

					// if it intersects, it will return true and store intersetion where the line meets
					if(ground.getIntersectionWithLimitedLine(lol.start,lol.end,intersection)){
						intersection.Y += 2; // so it sticks above the ground
					}
                    selector->setPosition (intersection);

Code: Select all

// User over units
void DragFrom(scene::ICameraSceneNode* camera, 
	core::position2d<s32> from){
	
	if(selector == NULL){
		selector = new Selector(mysmgr->getRootSceneNode(), mysmgr, 100000);
	}
	// line from the camera to the mouse (technically its a ray)
	core::line3d< f32 > lol = mysmgr->getSceneCollisionManager()->
		getRayFromScreenCoordinates(from, camera);
	
	// plane, first position, second normal
	core::plane3d< f32 > ground(core::vector3d<f32>(0, 0, 0), core::vector3d<f32>(0, 1, 0));

	// where the line hits the ground
	core::vector3d< f32 >intersection(0,2,0);

	// if it intersects, it will return true and store intersetion where the line meets
	if(ground.getIntersectionWithLine(lol.start,lol.end,intersection)){
		intersection.Y += 2; // so it sticks above the ground
	}
    selector->setPosition (intersection);
}

Code: Select all

				// Calculates where the line intersects the ground plane
				core::vector3d< f32 > IntersectPlane(core::line3d< f32 > myLine){
					core::vector3d< f32 >intersection(0, 0, 0);

				   // plane, first position, second normal. 
				   // You can of course replace it with your own plane
				   core::plane3d< f32 > ground(
					   core::vector3d<f32>(0, 0, 0), 
					   core::vector3d<f32>(0, 1, 0)); 

					// calculates the intersection
					ground.getIntersectionWithLine(myLine.start,myLine.end,intersection);

					return intersection; // so it sticks above the ground
				}

				// User drags from X to Y
				void DragFrom(scene::ICameraSceneNode* camera, 
					core::position2d<s32> from, core::position2d<s32> to){

					// create new selector class 
					// (extends ISceneNode with custom function strechPosition) 
					if(selector == NULL){
						selector = new Selector(mysmgr->getRootSceneNode(), mysmgr, 100000);
					}

					// line from the camera to the mouse (technically its a ray)
					core::line3d< f32 > cameraRay = mysmgr->getSceneCollisionManager()->
						getRayFromScreenCoordinates(to, camera);
					
					// where the line hits the ground
					core::vector3d< f32 > intersection = IntersectPlane(cameraRay);

					// line from the camera to the mouse (technically its a ray)
					core::line3d< f32 > cameraRayTo = mysmgr->getSceneCollisionManager()->
						getRayFromScreenCoordinates(from, camera);
					
					// where the line hits the ground
					core::vector3d< f32 >intersectionTo = IntersectPlane(cameraRayTo);

					// Strech the selector unit
					selector->strechPosition(intersection,intersectionTo);
				}

				// deletes the draginging thing
				void removeDrag(){
					if(selector != NULL){
						selector->remove();
						selector->drop();
						selector= NULL;
					}
				}