From 6401a6a3d387423ac096ede27f942137d960572d Mon Sep 17 00:00:00 2001
From: Rtch90 <ritchie.cunningham@protonmail.com>
Date: Sun, 8 Apr 2018 18:59:33 +0100
Subject: [PATCH] [Add] Linear collision response between dynamic bodies.
---
src/main.cpp | 26 ++++++++++++++------------
src/space.cpp | 33 +++++++++++++++++++++++++++------
2 files changed, 41 insertions(+), 18 deletions(-)
diff --git a/src/main.cpp b/src/main.cpp
index 4e5a609..3d0ae2a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -166,18 +166,20 @@ void L3D::HandleEvents(void) {
if(event.key.keysym.sym == SDLK_i) L3D::showDebugInfo = !L3D::showDebugInfo;
#ifdef DEBUG
if(event.key.keysym.sym == SDLK_F12) {
- /* Add test object. */
- /*Ship* body = new Ship(ShipType::LADYBIRD);
- body->SetLabel("A friend");
- body->SetFrame(L3D::player->GetFrame());
- body->SetPosition(L3D::player->GetPosition()+vector3d(0,0,-1000));
- Space::AddBody(body);*/
- SpaceStation* station = new SpaceStation(SpaceStation::JJHOOP);
- station->SetLabel("Poemi-chan's Folly");
- station->SetFrame(L3D::player->GetFrame());
- station->SetRotMatrix(matrix4x4d::RotateZMatrix(M_PI));
- station->SetPosition(L3D::player->GetPosition() + vector3d(0, 0, -5000));
- Space::AddBody(station);
+ if(KeyState(SDLK_LSHIFT)) {
+ SpaceStation* station = new SpaceStation(SpaceStation::JJHOOP);
+ station->SetLabel("Poemi-chan's Folly");
+ station->SetFrame(L3D::player->GetFrame());
+ station->SetRotMatrix(matrix4x4d::RotateZMatrix(M_PI));
+ station->SetPosition(L3D::player->GetPosition()+vector3d(0,0,-5000));
+ Space::AddBody(station);
+ } else {
+ Ship* body = new Ship(ShipType::LADYBIRD);
+ body->SetLabel("A Friend");
+ body->SetFrame(L3D::player->GetFrame());
+ body->SetPosition(L3D::player->GetPosition()+vector3d(0,0,-1000));
+ Space::AddBody(body);
+ }
}
#endif
if(event.key.keysym.sym == SDLK_F11) SDL_WM_ToggleFullScreen(L3D::scrSurface);
diff --git a/src/space.cpp b/src/space.cpp
index 8d479b4..a0991c9 100644
--- a/src/space.cpp
+++ b/src/space.cpp
@@ -327,7 +327,7 @@ static bool _OnCollision2(Object* o1, Object* o2, CollisionContact* c) {
}
static void hitCallback(CollisionContact* c) {
- printf("AUCH!! %x (depth %f)\n", SDL_GetTicks(), c->depth);
+ //printf("AUCH!! %x (depth %f)\n", SDL_GetTicks(), c->depth);
Object* po1 = static_cast<Object*>(c->userData1);
Object* po2 = static_cast<Object*>(c->userData2);
@@ -340,17 +340,38 @@ static void hitCallback(CollisionContact* c) {
assert(po1_isDynBody || po2_isDynBody);
if(po1_isDynBody && po2_isDynBody) {
+ DynamicBody* b1 = static_cast<DynamicBody*>(po1);
+ DynamicBody* b2 = static_cast<DynamicBody*>(po2);
+ vector3d vel1 = b1->GetVelocity();
+ vector3d vel2 = b2->GetVelocity();
+ const vector3d relVel = vel2 - vel1;
+ const double invMass1 = 1.0 / b1->GetMass();
+ const double invMass2 = 1.0 / b2->GetMass();
+ const double coeff_rest = 0.8;
+ const double j = (-(1+coeff_rest) * (vector3d::Dot(relVel, c->normal))) /
+ (vector3d::Dot(c->normal, c->normal) *
+ (invMass1 + invMass2));
+
+ /* Step back. */
+ b1->TimeStepUpdate(-L3D::GetTimeStep());
+ b2->TimeStepUpdate(-L3D::GetTimeStep());
+ /* Apply impulse. */
+ b1->SetVelocity(vel1 - (j*c->normal)*invMass1);
+ b2->SetVelocity(vel2 + (j*c->normal)*invMass2);
} else {
/* One body is static. */
vector3d hitNormal;
- if(po2_isDynBody) hitNormal = -c->normal;
- else hitNormal = c->normal;
- printf("Hi! %f,%f,%f\n", hitNormal.x, hitNormal.y, hitNormal.z);
DynamicBody* mover;
- if(po1_isDynBody) mover = static_cast<DynamicBody*>(po1);
- else mover = static_cast<DynamicBody*>(po2);
+
+ if(po1_isDynBody) {
+ mover = static_cast<DynamicBody*>(po1);
+ hitNormal = c->normal;
+ } else {
+ mover = static_cast<DynamicBody*>(po2);
+ hitNormal = c->normal;
+ }
const vector3d vel = mover->GetVelocity();
vector3d reflect = vel - (hitNormal * vector3d::Dot(vel, hitNormal) * 2.0f);