FT collision part4: ball to ball collision.

TBall uses multiple inheritance, interesting.

SpaceCadetPinball/TBall.cpp

@@ -11,7 +11,8 @@
 #include "TPinballTable.h"
 #include "TTableLayer.h"
 
-TBall::TBall(TPinballTable* table) : TPinballComponent(table, -1, false)
+TBall::TBall(TPinballTable* table, int groupIndex) : TCollisionComponent(table, groupIndex, false),
+                                                     TEdgeSegment(this, &ActiveFlag, 0)
 {
 	visualStruct visual{};
 	char ballGroupName[10]{"ball"};
@@ -22,19 +23,29 @@ TBall::TBall(TPinballTable* table) : TPinballComponent(table, -1, false)
 	CollisionComp = nullptr;
 	EdgeCollisionCount = 0;
 	TimeDelta = 0.0;
-	CollisionMask = 1;
 	CollisionFlag = 0;
 	Speed = 0.0;
 	Direction.Y = 0.0;
 	Direction.X = 0.0;
-	Position.X = 0.0;
-	Position.Y = 0.0;
-	HasGroupFlag = false;
-
 	ListBitmap = new std::vector<SpriteData>();
 
+	if (groupIndex == -1)
+	{
+		HasGroupFlag = false;
+		Position = {0, 0, 0};
+		CollisionMask = 1;
+	}
+	else
+	{
+		HasGroupFlag = true;
+		loader::query_visual(groupIndex, 0, &visual);
+		CollisionMask = visual.CollisionGroup;
+		auto floatArr = loader::query_float_attribute(groupIndex, 0, 408);
+		Position = {floatArr[0], floatArr[1], floatArr[3]};
+	}
+
 	/*Full tilt: ball is ballN, where N[0,2] resolution*/
-	auto groupIndex = loader::query_handle(ballGroupName);
+	groupIndex = loader::query_handle(ballGroupName);
 	if (groupIndex < 0)
 	{
 		ballGroupName[4] = '0' + fullscrn::GetResolution();
@@ -112,7 +123,7 @@ int TBall::Message(MessageCode code, float value)
 {
 	if (code == MessageCode::Reset)
 	{
-		SpriteSetBall(-1, { 0,0 }, 0.0f);
+		SpriteSetBall(-1, {0, 0}, 0.0f);
 		Position.X = 0.0;
 		CollisionComp = nullptr;
 		Position.Y = 0.0;
@@ -139,6 +150,47 @@ void TBall::throw_ball(vector3* direction, float angleMult, float speedMult1, fl
 	Speed = (1.0f - (rnd + rnd)) * (speedMult1 * speedMult2) + speedMult1;
 }
 
+void TBall::EdgeCollision(TBall* ball, float distance)
+{
+	ball->AsEdgeCollisionFlag = true;
+	vector2 nextPos{
+		        ball->Position.X + ball->Direction.X * distance,
+		        ball->Position.Y + ball->Direction.Y * distance
+	        },
+	        collDir{nextPos.X - Position.X, nextPos.Y - Position.Y};
+	maths::normalize_2d(collDir);
+	vector2 invCollDir{ -collDir.X, -collDir.Y };
+
+	ball->Position.X = nextPos.X;
+	ball->Position.Y = nextPos.Y;
+	ball->Direction.X *= ball->Speed;
+	ball->Direction.Y *= ball->Speed;
+	Direction.X *= Speed;
+	Direction.Y *= Speed;
+
+	auto coef = -maths::DotProduct(ball->Direction, collDir);
+	vector2 v44{collDir.X * coef, collDir.Y * coef};
+	vector2 v13{ball->Direction.X + v44.X, ball->Direction.Y + v44.Y};
+	
+	coef = -maths::DotProduct(Direction, invCollDir);
+	vector2 v11{invCollDir.X * coef, invCollDir.Y * coef};
+	vector2 v10{Direction.X + v11.X, Direction.Y + v11.Y};
+
+	ball->Direction.X = -v11.X + v13.X;
+	ball->Direction.Y = -v11.Y + v13.Y;
+	ball->Speed = maths::normalize_2d(ball->Direction);
+	Direction.X = -v44.X + v10.X;
+	Direction.Y = -v44.Y + v10.Y;
+	Speed = maths::normalize_2d(Direction);
+}
+
+float TBall::FindCollisionDistance(const ray_type& ray)
+{
+	// Original inherits TCircle and aliases position.
+	const circle_type ballCircle{{Position.X, Position.Y}, Radius * Radius * 4.0f};
+	return maths::ray_intersect_circle(ray, ballCircle);
+}
+
 vector2 TBall::get_coordinates()
 {
 	return TTableLayer::edge_manager->NormalizeBox(Position);

SpaceCadetPinball/TBall.h

@@ -1,14 +1,12 @@
 #pragma once
 #include "maths.h"
-#include "TPinballComponent.h"
+#include "TCollisionComponent.h"
+#include "TEdgeSegment.h"
 
-class TCollisionComponent;
+class TBall : public TCollisionComponent, public TEdgeSegment
-class TEdgeSegment;
-
-class TBall : public TPinballComponent
 {
 public :
-	TBall(TPinballTable* table);
+	TBall(TPinballTable* table, int groupIndex);
 	void Repaint();
 	void not_again(TEdgeSegment* edge);
 	bool already_hit(TEdgeSegment* edge);
@@ -16,6 +14,9 @@ public :
 	vector2 get_coordinates() override;
 	void Disable();
 	void throw_ball(vector3* direction, float angleMult, float speedMult1, float speedMult2);
+	void place_in_grid(RectF* aabb) override {}
+	void EdgeCollision(TBall* ball, float distance) override;
+	float FindCollisionDistance(const ray_type& ray) override;
 
 	vector3 Position{};
 	vector3 PrevPosition{};

SpaceCadetPinball/TCircle.cpp

@@ -12,9 +12,9 @@ TCircle::TCircle(TCollisionComponent* collComp, char* activeFlag, unsigned colli
 	Circle.Center = *center;
 }
 
-float TCircle::FindCollisionDistance(ray_type* ray)
+float TCircle::FindCollisionDistance(const ray_type& ray)
 {
-	return maths::ray_intersect_circle(*ray, Circle);
+	return maths::ray_intersect_circle(ray, Circle);
 }
 
 void TCircle::EdgeCollision(TBall* ball, float distance)

SpaceCadetPinball/TCircle.h

@@ -10,7 +10,7 @@ public:
 
 	TCircle(TCollisionComponent* collComp, char* activeFlag, unsigned int collisionGroup, vector2* center,
 	        float radius);
-	float FindCollisionDistance(ray_type* ray) override;
+	float FindCollisionDistance(const ray_type& ray) override;
 	void EdgeCollision(TBall* ball, float distance) override;
 	void place_in_grid(RectF* aabb) override;
 };

SpaceCadetPinball/TEdgeManager.cpp

@@ -76,7 +76,7 @@ int TEdgeManager::TestGridBox(int x, int y, float* distPtr, TEdgeSegment** edgeD
 		for (auto it = edgeBox->EdgeList.rbegin(); it != edgeBox->EdgeList.rend(); ++it)
 		{
 			auto edge = *it;
-			if (!edge->ProcessedFlag && *edge->ActiveFlag && (edge->CollisionGroup & ray->CollisionMask))
+			if (!edge->ProcessedFlag && *edge->ActiveFlagPtr && (edge->CollisionGroup & ray->CollisionMask))
 			{
 				if (!ball->already_hit(edge))
 				{
@@ -84,7 +84,7 @@ int TEdgeManager::TestGridBox(int x, int y, float* distPtr, TEdgeSegment** edgeD
 					*edgePtr = edge;
 					++edgePtr;
 					edge->ProcessedFlag = 1;
-					auto dist = edge->FindCollisionDistance(ray);
+					auto dist = edge->FindCollisionDistance(*ray);
 					if (dist < *distPtr)
 					{
 						*distPtr = dist;

SpaceCadetPinball/TEdgeSegment.cpp

@@ -8,7 +8,7 @@
 TEdgeSegment::TEdgeSegment(TCollisionComponent* collComp, char* activeFlag, unsigned collisionGroup)
 {
 	CollisionComponent = collComp;
-	ActiveFlag = activeFlag;
+	ActiveFlagPtr = activeFlag;
 	CollisionGroup = collisionGroup;
 	ProcessedFlag = 0;
 }

SpaceCadetPinball/TEdgeSegment.h

@@ -15,7 +15,7 @@ class TEdgeSegment
 {
 public:
 	TCollisionComponent* CollisionComponent;
-	char* ActiveFlag;
+	char* ActiveFlagPtr;
 	char ProcessedFlag;
 	void* WallValue{};
 	unsigned int CollisionGroup;
@@ -26,7 +26,7 @@ public:
 	virtual void EdgeCollision(TBall* ball, float distance) = 0;
 	virtual void port_draw();
 	virtual void place_in_grid(RectF* aabb) = 0;
-	virtual float FindCollisionDistance(ray_type* ray) = 0;
+	virtual float FindCollisionDistance(const ray_type& ray) = 0;
 
 	static TEdgeSegment* install_wall(float* floatArr, TCollisionComponent* collComp, char* activeFlagPtr,
 	                                  unsigned int collisionGroup, float offset, size_t wallValue);

SpaceCadetPinball/TFlipperEdge.cpp

@@ -104,12 +104,12 @@ void TFlipperEdge::port_draw()
 	set_control_points(CurrentAngle);
 }
 
-float TFlipperEdge::FindCollisionDistance(ray_type* ray)
+float TFlipperEdge::FindCollisionDistance(const ray_type& ray)
 {
 	ray_type dstRay{};
 	if (ControlPointDirtyFlag)
 		set_control_points(CurrentAngle);
-	auto distance = maths::distance_to_flipper(this, *ray, dstRay);
+	auto distance = maths::distance_to_flipper(this, ray, dstRay);
 	if (distance >= 1e9f)
 		return 1e9f;
 

SpaceCadetPinball/TFlipperEdge.h

@@ -12,7 +12,7 @@ public:
 	             vector3* origin, vector3* vecT1, vector3* vecT2, float extendSpeed, float retractSpeed, float collMult,
 	             float elasticity, float smoothness);
 	void port_draw() override;
-	float FindCollisionDistance(ray_type* ray) override;
+	float FindCollisionDistance(const ray_type& ray) override;
 	void EdgeCollision(TBall* ball, float distance) override;
 	void place_in_grid(RectF* aabb) override;
 	void set_control_points(float angle);

SpaceCadetPinball/TLine.cpp

@@ -36,9 +36,9 @@ void TLine::Offset(float offset)
 	maths::line_init(Line, X0, Y0, X1, Y1);
 }
 
-float TLine::FindCollisionDistance(ray_type* ray)
+float TLine::FindCollisionDistance(const ray_type& ray)
 {
-	return maths::ray_intersect_line(*ray, Line);
+	return maths::ray_intersect_line(ray, Line);
 }
 
 void TLine::EdgeCollision(TBall* ball, float distance)

SpaceCadetPinball/TLine.h

@@ -11,7 +11,7 @@ public:
 	TLine(TCollisionComponent* collCmp, char* activeFlag, unsigned int collisionGroup, float x0, float y0, float x1, float y1);
 	TLine(TCollisionComponent* collCmp, char* activeFlag, unsigned int collisionGroup, const vector2& start, const vector2& end);
 	void Offset(float offset);
-	float FindCollisionDistance(ray_type* ray) override;
+	float FindCollisionDistance(const ray_type& ray) override;
 	void EdgeCollision(TBall* ball, float distance) override;
 	void place_in_grid(RectF* aabb) override;
 };

SpaceCadetPinball/TPinballTable.cpp

@@ -625,7 +625,7 @@ TBall* TPinballTable::AddBall(float x, float y)
 	{
 		if (BallList.size() >= 20)
 			return nullptr;
-		ball = new TBall(this);
+		ball = new TBall(this, -1);
 		BallList.push_back(ball);
 	}
 
@@ -655,6 +655,16 @@ int TPinballTable::BallCountInRect(const RectF& rect)
 	return count;
 }
 
+int TPinballTable::BallCountInRect(const vector2& pos, float margin)
+{
+	RectF rect{};
+	rect.XMin = pos.X - margin;
+	rect.XMax = pos.X + margin;
+	rect.YMin = pos.Y - margin;
+	rect.YMax = pos.Y + margin;
+	return BallCountInRect(rect);
+}
+
 void TPinballTable::EndGame_timeout(int timerId, void* caller)
 {
 	auto table = static_cast<TPinballTable*>(caller);

SpaceCadetPinball/TPinballTable.h

@@ -37,6 +37,7 @@ public:
 	int Message(MessageCode code, float value) override;
 	TBall* AddBall(float x, float y);
 	int BallCountInRect(const RectF& rect);
+	int BallCountInRect(const vector2& pos, float margin);
 
 	static void EndGame_timeout(int timerId, void* caller);
 	static void LightShow_timeout(int timerId, void* caller);

SpaceCadetPinball/pb.cpp

@@ -33,7 +33,7 @@ DatFile* pb::record_table = nullptr;
 int pb::time_ticks = 0;
 GameModes pb::game_mode = GameModes::GameOver;
 float pb::time_now = 0, pb::time_next = 0, pb::time_ticks_remainder = 0;
-float pb::BallMaxSpeed, pb::BallHalfRadius, pb::ball_collision_dist;
+float pb::BallMaxSpeed, pb::BallHalfRadius, pb::BallToBallCollisionDistance;
 bool pb::FullTiltMode = false, pb::FullTiltDemoMode = false, pb::cheat_mode = false, pb::demo_mode = false;
 std::string pb::DatFileName, pb::BasePath;
 ImU32 pb::TextBoxColor;
@@ -106,7 +106,7 @@ int pb::init()
 	auto ball = MainTable->BallList.at(0);
 	BallMaxSpeed = ball->Radius * 200.0f;
 	BallHalfRadius = ball->Radius * 0.5f;
-	ball_collision_dist = (ball->Radius + BallHalfRadius) * 2.0f;
+	BallToBallCollisionDistance = (ball->Radius + BallHalfRadius) * 2.0f;
 
 	int red = 255, green = 255, blue = 255;
 	auto fontColor = get_rc_string(Msg::TextBoxColor);
@@ -424,8 +424,7 @@ void pb::timed_frame(float timeNow, float timeDelta, bool drawBalls)
 					auto distance = TTableLayer::edge_manager->FindCollisionDistance(&ray, ball, &edge);
 					if (distance > 0.0f)
 					{
-						// Todo: ball to ball collision
+						distance = BallToBallCollision(ray, *ball, &edge, distance);
-						//distance = ball_to_ball_collision();
 					}
 					if (ball->EdgeCollisionResetFlag)
 					{
@@ -605,9 +604,13 @@ void pb::InputDown(GameInput input)
 		switch (input.Value)
 		{
 		case 'b':
-			if (MainTable->AddBall(6.0f, 7.0f))
+			{
-				MainTable->MultiballCount++;
+				vector2 pos{6.0f, 7.0f};
-			break;
+				if (!MainTable->BallCountInRect(pos, MainTable->CollisionCompOffset * 1.2f) && MainTable->AddBall(
+					pos.X, pos.Y))
+					MainTable->MultiballCount++;
+				break;
+			}
 		case 'h':
 			{
 				high_score_struct entry{{0}, 1000000000};
@@ -754,3 +757,27 @@ void pb::ShowMessageBox(Uint32 flags, LPCSTR title, LPCSTR message)
 	fprintf(flags == SDL_MESSAGEBOX_ERROR ? stderr : stdout, "BL error: %s\n%s\n", title, message);
 	SDL_ShowSimpleMessageBox(flags, title, message, winmain::MainWindow);
 }
+
+float pb::BallToBallCollision(const ray_type& ray, const TBall& ball, TEdgeSegment** edge, float collisionDistance)
+{
+	for (auto curBall : MainTable->BallList)
+	{
+		if (curBall->ActiveFlagPtr && curBall != &ball && (curBall->CollisionMask & ball.CollisionMask) != 0 &&
+			std::abs(curBall->Position.X - ball.Position.X) < BallToBallCollisionDistance &&
+			std::abs(curBall->Position.Y - ball.Position.Y) < BallToBallCollisionDistance)
+		{
+			auto distance = curBall->FindCollisionDistance(ray);
+			if (distance < 1e9f)
+			{
+				distance = std::max(0.0f, distance - 0.002f);
+				if (collisionDistance > distance)
+				{
+					collisionDistance = distance;
+					*edge = curBall;
+				}
+			}
+		}
+	}
+
+	return collisionDistance;
+}

SpaceCadetPinball/pb.h

@@ -1,6 +1,8 @@
 #pragma once
 #include "high_score.h"
 
+class TEdgeSegment;
+struct ray_type;
 struct GameInput;
 class TPinballTable;
 class DatFile;
@@ -43,7 +45,7 @@ class pb
 public:
 	static int time_ticks;
 	static float time_now, time_next, time_ticks_remainder;
-	static float BallMaxSpeed, BallHalfRadius, ball_collision_dist;
+	static float BallMaxSpeed, BallHalfRadius, BallToBallCollisionDistance;
 	static GameModes game_mode;
 	static bool cheat_mode;
 	static DatFile* record_table;
@@ -81,4 +83,5 @@ public:
 	static void ShowMessageBox(Uint32 flags, LPCSTR title, LPCSTR message);
 private:
 	static bool demo_mode;
+	static float BallToBallCollision(const ray_type& ray, const TBall& ball, TEdgeSegment** edge, float collisionDistance);
 };