3D Game Programming

document.addEventListener('keydown',function(event) {

varcode = event.keyCode;

if(code == 37) { // left

marker.position.x = marker.position.x-5;

is_moving_left = true;

}

if(code == 38) { // up

marker.position.z = marker.position.z-5;

is_moving_forward = true;

}

if(code == 39) { // right

marker.position.x = marker.position.x+5;

is_moving_right = true;

}

if(code == 40) { // down

marker.position.z = marker.position.z+5;

is_moving_back = true;

}

if(code == 67) is_cartwheeling = !is_cartwheeling;// C

if(code == 70) is_flipping = !is_flipping; // F

if(detectCollisions()) {

if(is_moving_left) marker.position.x = marker.position.x+5;

if(is_moving_right) marker.position.x = marker.position.x-5;

if(is_moving_forward) marker.position.z = marker.position.z+5;

if(is_moving_back) marker.position.z = marker.position.z-5;

}

});

document.addEventListener('keyup',function(event) {

varcode = event.keyCode;

if(code == 37) is_moving_left = false;

if(code == 38) is_moving_forward = false;

if(code == 39) is_moving_right = false;

if(code == 40) is_moving_back = false;

});

functiondetectCollisions() {

varvector =newTHREE.Vector3(0, -1, 0);

varray =newTHREE.Ray(marker.position, vector);

varintersects = ray.intersectObjects(not_allowed);

if(intersects.length > 0)returntrue;

returnfalse;

}

</script>

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Code: Collisions • 233

Prepared exclusively for Michael Powell