/**
* This function determines whether entity A will, and has crossed paths with entity B. We make
* use of the following formulas:
*
* <pre>
* A = a1 - b1
* B = (a2 - a1) - (b2 - b1)
* d^2 = A^2 - ((A · B)^2 / B^2)
* t = (-(A·B) - Sqr((A·B)^2 - B^2 (A^2 - (r(a) + r(b))^2))) / B^2
* </pre>
*
* if B^2 = 0, then either both a and b are: stationary or moving in the same direction at the
* same speed, and can thus not collide.
*
* <p>if d^2 > (r(a) + r(b))^2 - the sum of the entities radii squared. then the entities can
* never collide on there current trajectories.
*
* <p>if t is greater or equal to 0, and smaller than 1. Then entities a and b intersect in the
* current time step.
*
* @param a
* @param b
* @return
*/
protected boolean intersectionTesting(State a, State b) {
Vec3 B = (a.pos.subtract(a.prevPos)).subtract(b.pos.subtract(b.prevPos));
double bSqr = B.getLengthSquared();
if (Double.compare(bSqr, 0.0f) == 0) {
return false;
}
Vec3 A = a.prevPos.subtract(b.prevPos);
double aSqr = A.getLengthSquared();
double rrSqr = ((a.scale.add(b.scale)).getLengthSquared()) / 2;
double aDotb = (A.dot(B));
double aDotbSqr = aDotb * aDotb;
double d2 = aSqr - (aDotbSqr / bSqr);
if (Double.compare(d2, rrSqr) > 0) {
return false;
}
// find fastInv double implimentation
double t =
(-(aDotb) - FastMath.sqrtFast((float) ((aDotbSqr) - bSqr * (aSqr - (rrSqr))))) / bSqr;
if (Double.compare(t, 0) < 0 || Double.compare(t, 1) >= 0) {
return false;
}
return true;
}
@Override
public void update(Engine engine, double time, double dt) {
Window window = engine.getGlobal(Window.class);
window.closing = Display.isCloseRequested();
if (Display.wasResized()) {
window.width = Display.getWidth();
window.height = Display.getHeight();
}
KeyboardComponent keyboard = engine.getGlobal(KeyboardComponent.class);
Keyboard.poll();
for (int i = 0; i < keyboard.down.length; i++) {
keyboard.pressed[i] = false;
keyboard.released[i] = false;
keyboard.down[i] = Keyboard.isKeyDown(i);
}
while (Keyboard.next()) {
int key = Keyboard.getEventKey();
keyboard.pressed[key] = Keyboard.getEventKeyState();
keyboard.released[key] = !keyboard.pressed[key];
}
MouseComponent mouse = engine.getGlobal(MouseComponent.class);
Mouse.poll();
for (int i = 0; i < Mouse.getButtonCount(); i++) {
mouse.pressed[i] = false;
mouse.pressed[i] = false;
mouse.down[i] = Mouse.isButtonDown(i);
mouse.dx = 0;
mouse.dy = 0;
}
while (Mouse.next()) {
int btn = Mouse.getEventButton();
if (btn != -1) {
mouse.pressed[btn] = Mouse.getEventButtonState();
mouse.released[btn] = !mouse.pressed[btn];
} else {
mouse.dx += Mouse.getEventDX();
mouse.dy += Mouse.getEventDY();
}
mouse.x = Mouse.getEventX();
mouse.y = Mouse.getEventY();
}
mouse.nx = ((float) mouse.x / (float) window.width) * 2.0f - 1.0f;
mouse.ny = ((float) mouse.y / (float) window.height) * 2.0f - 1.0f;
Vec3[] mp = MouseUtils.mouseToWorld(window, engine.getGlobal(Camera.class), mouse);
mouse.near = mp[0];
mouse.far = mp[1];
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
for (Map m : objects.values()) {
m.clear();
}
// calculate the world matrix of each renderable,
// and add them to their respective "shader buckets"
for (RenderNode node : engine.getNodeList(RenderNode.class)) {
ID<Entity> id = node.getEntity().getId();
worlds.put(id, StateUtils.getMatrix(node.state));
Program program = resourceManager.getProgram(node.renderable.shader);
Map<ID<Entity>, RenderNode> renderables = objects.get(program);
if (renderables == null) {
renderables = new HashMap<>();
objects.put(program, renderables);
}
renderables.put(id, node);
}
for (ViewportNode vpnode : engine.getNodeList(ViewportNode.class)) {
Camera camera = vpnode.camera;
glViewport(
(int) (window.width * vpnode.viewport.x),
(int) (window.height * vpnode.viewport.y),
(int) (window.width * vpnode.viewport.width),
(int) (window.height * vpnode.viewport.height));
// for each shader, draw each object that uses that shader
for (Map.Entry<Program, Map<ID<Entity>, RenderNode>> e : objects.entrySet()) {
Program program = e.getKey();
program.use();
program.setView(camera.viewMatrix);
program.setProjection(camera.projection);
program.setSun(engine.getGlobal(Sun.class).location);
program.setEye(camera.eye);
for (Map.Entry<ID<Entity>, RenderNode> e2 : e.getValue().entrySet()) {
RenderNode node = e2.getValue();
program.setWorld(worlds.get(e2.getKey()));
program.setColour(node.renderable.colour);
program.setOpacity(node.renderable.opacity);
Mesh mesh = resourceManager.getMesh(node.mesh);
mesh.draw();
}
}
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glDisable(GL_CULL_FACE);
Program program = resourceManager.getProgram("passthrough");
program.use();
program.setView(camera.viewMatrix);
program.setProjection(camera.projection);
for (BBoxNode node : engine.getNodeList(BBoxNode.class)) {
program.setWorld(node.bbox.getMatrix());
Vec3 e = node.bbox.getExtents();
glBegin(GL_QUADS);
{
glColor3f(1, 0, 1);
glVertex3f(e.getX(), e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), -e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), -e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), -e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), -e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), -e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), -e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(e.getX(), e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), -e.getY(), e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), -e.getY(), -e.getZ());
glColor3f(1, 0, 1);
glVertex3f(-e.getX(), e.getY(), -e.getZ());
}
glEnd();
}
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glEnable(GL_CULL_FACE);
}
Display.update();
}
