Working Catmull-Rom Splines for loopping trajectories of enemies

CMakeLists.txt

@@ -43,7 +43,7 @@ set(ASSETS_cg
 
   assets-cg/Sprites/Enemies/mainship2.png
   assets-cg/Sprites/Enemies/Enemy_Blue_Lvl1.png
-  
+  assets-cg/Sprites/Enemies/Enemy_Red_Lvl1.png  
   
   # ...
 )

src/collections.cpp

@@ -59,6 +59,32 @@ void Create_Ennemies( void )
     Enemy* e4 = new Enemy( 348, 112, 1);
     e4->Set_Speed_Vector( 1, 3, 3 );
     MyEnemies.push_back( e4 );
+
+
+
+
+    Point2D *A = new Point2D( 348, 112 );
+    Point2D *B = new Point2D( 371, 199 );
+    Point2D *C = new Point2D( 198, 149 );
+    Point2D *D = new Point2D( 25, 199 );
+    Point2D *E = new Point2D( 25, 25 );
+    Point2D *F = new Point2D( 198, 75 );
+    Point2D *G = new Point2D( 371, 25 );
+
+
+    Trajectory *MyTrajectory= new Trajectory();
+    MyTrajectory->AddPoint( A );
+    MyTrajectory->AddPoint( B );
+    MyTrajectory->AddPoint( C );
+    MyTrajectory->AddPoint( D );
+    MyTrajectory->AddPoint( E );
+    MyTrajectory->AddPoint( F );
+    MyTrajectory->AddPoint( G );
+
+    Enemy* e5 = new Enemy( 348, 112, 2);
+    e5->hasTrajectory = true;
+    e5->pathToFollow = MyTrajectory;
+    MyEnemies.push_back( e5 );
 }
 
 

src/collections.h

@@ -9,6 +9,7 @@
 #include "enemy.h"
 #include "MyAzurShaders.h"
 #include "impact.h"
+#include "trajectory.h"
 
 
 void Create_Player_Shoot( uint8_t id );

src/enemy.cpp

@@ -5,6 +5,7 @@
 
 extern bopti_image_t img_mainship2;
 extern bopti_image_t img_Enemy_Blue_Lvl1;
+extern bopti_image_t img_Enemy_Red_Lvl1;
 
 Enemy::Enemy( int16_t _x, int16_t _y, uint8_t _id )
 {
@@ -28,6 +29,12 @@ Enemy::Enemy( int16_t _x, int16_t _y, uint8_t _id )
         height = img_Enemy_Blue_Lvl1.height/2;
         speed = 2;
     }
+    else if (ID==2)
+    {
+        width = img_Enemy_Red_Lvl1.width/2;
+        height = img_Enemy_Red_Lvl1.height/2;
+        speed = 2;
+    }
 
     xmin = (int) x - width;
     xmax = (int) x + width;
@@ -38,22 +45,33 @@ Enemy::Enemy( int16_t _x, int16_t _y, uint8_t _id )
 
     if (ID==0) life = 400;
     else if (ID==1) life = 200;
+    else if (ID==2) life = 100;
 }
 
 Enemy::~Enemy()
 {
-
-
+    if (hasTrajectory)
+        delete(pathToFollow);
 }
 
 void Enemy::Update( float dt )
 {
-    libnum::num a = libnum::num( dt / 60000.0f );
-    x += a * libnum::num( dirx * speed );
-    y += a * libnum::num( diry * speed );
+    if (!hasTrajectory)
+    {
+        libnum::num a = libnum::num( dt / 60000.0f );
+        x += a * libnum::num( dirx * speed );
+        y += a * libnum::num( diry * speed );
 
-    if (x<width || x>azrp_width-width) dirx=-1*dirx;
-    if (y<height || y>azrp_height-height) diry=-1*diry;
+        if (x<width || x>azrp_width-width) dirx=-1*dirx;
+        if (y<height || y>azrp_height-height) diry=-1*diry;
+    }
+    else
+    {
+        int tempX, tempY;
+        pathToFollow->CalculatePosition( dt, speed, true, &tempX, &tempY );
+        x = libnum::num( tempX );
+        y = libnum::num( tempY );
+    }
 
     xmin = (int) x - width;
     xmax = (int) x + width;
@@ -65,8 +83,9 @@ void Enemy::Update( float dt )
 
 void Enemy::Render( void )
 {
-    if (ID==0) azrp_image_p8_effect(xmin, ymin, &img_mainship2, IMAGE_VFLIP);
+    if (ID==0) azrp_image_p8_effect(xmin, ymin, &img_mainship2, DIMAGE_NONE);
     if (ID==1) azrp_image_p8_effect(xmin, ymin, &img_Enemy_Blue_Lvl1, DIMAGE_NONE);
+    if (ID==2) azrp_image_p8_effect(xmin, ymin, &img_Enemy_Red_Lvl1, DIMAGE_NONE);
 }
 
 

src/enemy.h

@@ -9,6 +9,7 @@
 
 #include <num/num.h>
 #include "bullet.h"
+#include "trajectory.h"
 
 
 class Enemy
@@ -31,6 +32,8 @@ class Enemy
         uint8_t speed;                   // speed of this ennemy
         bool toberemoved;
 
+        bool hasTrajectory = false;
+        Trajectory *pathToFollow;
 
     private:
         int8_t dirx, diry;                  // vector of the current direction of the ennemy (TODO : to implement more complex displacement pattern)

src/main.cpp

@@ -1,4 +1,4 @@
-#define DEBUG_MODE  1
+#define DEBUG_MODE  0
 
 #include <azur/azur.h>
 #include <azur/gint/render.h>
@@ -253,12 +253,13 @@ static void get_inputs( float dt  )
         if(keydown(KEY_8) && usb_is_open())    {record = true; };
         if(keydown(KEY_9) && usb_is_open())    {record = false; };
         if(keydown(KEY_DEL) && usb_is_open())    {textoutput = true;};
+    #endif     
         
         if(keydown(KEY_SHIFT) && keydown(KEY_F1))   {texttodraw=0;}
         if(keydown(KEY_SHIFT) && keydown(KEY_F2))   {texttodraw=1;}
         if(keydown(KEY_SHIFT) && keydown(KEY_F3))   {texttodraw=2;}
         if(keydown(KEY_SHIFT) && keydown(KEY_F4))   {texttodraw=3;}
-    #endif
+   
 
 
     if(keydown(KEY_LEFT))
@@ -344,6 +345,8 @@ void FreeMoreRAM( void )
 }
 
 
+extern bopti_image_t img_Enemy_Red_Lvl1;
+
 
 int main(void)
 {

src/trajectory.cpp

@@ -2,12 +2,60 @@
 
 Trajectory::Trajectory( )
 {
-
+    accumulatedTime = 0.0f;
 }
 
 
 Trajectory::~Trajectory( )
 {
-
+    for( auto& p : ControlPoints )
+        delete( p );
     
+    ControlPoints.clear();
+}
+
+
+void Trajectory::AddPoint( Point2D *p )
+{
+    ControlPoints.push_back( p );
+}
+
+
+void Trajectory::CalculatePosition( float time, uint16_t speed, bool looped, int *xreturn, int *yreturn )
+{
+    accumulatedTime += speed * time / 2000000.0f;
+	if (accumulatedTime>ControlPoints.size()) accumulatedTime-=ControlPoints.size();
+
+    libnum::num t = libnum::num( accumulatedTime - (int) accumulatedTime );    
+
+	int p0, p1, p2, p3;
+
+	if (!looped)
+	{
+		p1 = (int) accumulatedTime + 1;
+		p2 = p1 + 1;
+		p3 = p2 + 1;
+		p0 = p1 - 1;
+	}
+	else
+	{
+		p1 = (int) accumulatedTime;
+		p2 = (p1 + 1) % ControlPoints.size();
+		p3 = (p2 + 1) % ControlPoints.size();
+		p0 = p1 >= 1 ? p1 - 1 : ControlPoints.size() - 1;
+	}
+
+	libnum::num tt = t * t;
+	libnum::num ttt = tt * t;
+
+	libnum::num q1 = -ttt + 2*tt - t;
+	libnum::num q2 = 3*ttt - 5*tt + libnum::num( 2 );
+	libnum::num q3 = -3*ttt + 4*tt + t;
+	libnum::num q4 = ttt - tt;
+
+	libnum::num tx = libnum::num( 0.5f ) * (ControlPoints[p0]->x * q1 + ControlPoints[p1]->x * q2 + ControlPoints[p2]->x * q3 + ControlPoints[p3]->x * q4);
+	libnum::num ty = libnum::num( 0.5f ) * (ControlPoints[p0]->y * q1 + ControlPoints[p1]->y * q2 + ControlPoints[p2]->y * q3 + ControlPoints[p3]->y * q4);
+
+	*xreturn = (int) tx;
+    *yreturn = (int) ty;
 }

src/trajectory.h

@@ -15,9 +15,12 @@ class Trajectory
         Trajectory( );
         ~Trajectory( );
 
+        void AddPoint( Point2D *p );
+        void CalculatePosition( float time, uint16_t speed, bool looped, int *xreturn, int *yreturn );
 
         std::vector<Point2D*> ControlPoints;
         bool isLoop;
+        float accumulatedTime;
 };