fishB and fishA orientation

fishA.cpp

@@ -18,9 +18,9 @@ fishA::fishA() {
 	tailAngleInc = 1.0f;
 
         // Fish Speed
-        xInc = 0.1;
-        yInc = 0;
-        zInc = 0.05;
+        xInc = 0.0;
+        yInc = -0.1;
+        zInc = 0.0;
 }
 
 void fishA::draw(void) {
@@ -38,6 +38,9 @@ void fishA::draw(void) {
 
     glPushMatrix();
     glTranslatef(x,y,z);
+    getCrossProduct(xInc,yInc,zInc,1,0,0);        // get cross product
+    std::cout << "getangle: " << getAngle(xInc,yInc,zInc,0,0,1) << std::endl;   // debug
+    glRotatef(getAngle(1,0,0,xInc,yInc,zInc), xcp, ycp, zcp);    // rotate to look to where it is moving
 
     // set up the material properties (only front needs to be set)
     glMaterialfv(GL_FRONT, GL_AMBIENT, material);
@@ -116,6 +119,23 @@ void fishA::printXYZ(void) {
     std::cout << std::endl;
 }
 
+float fishA::vectorDistance(float x, float y, float z) {
+    return (float)sqrt((x*x)+(y*y)+(z*z));
+}
+
+float fishA::getAngle(float x, float y, float z, float a, float b, float c) {
+    float dot_product = (x*a) + (y*b) + (z*c);
+    float div = vectorDistance(x,y,z)*vectorDistance(a,b,c);
+    float arc = (float) acos(dot_product/div);
+    return arc* 180.0 / PI;
+}
+
+void fishA::getCrossProduct(float x, float y, float z, float a, float b, float c) {
+    xcp = (y*c)-(z*b);
+    ycp = (z*a)-(x*c);
+    zcp = (x*b)-(y*a);
+}
+
 GLfloat fishA::vertex[] ={
     // 2				|					|					|
     0.0f, 0.0f, 0.0f, 0.5f, -0.5f, 0.0f, 0.5f, 0.0f, 0.45f,

fishA.h

@@ -5,6 +5,7 @@
 #include <iostream>
 #include <stdio.h>
 #define FISH_TEXTURE 2
+#define PI 3.14159
 
 class fishA : public Renderable {
 public:
@@ -16,6 +17,8 @@ class fishA : public Renderable {
     GLfloat rx,ry, rz; // rotation angle of object
     GLfloat sx,sy,sz; // scale of object
     GLfloat xInc, yInc, zInc;   // speed of object
+    float xcp, ycp, zcp;        // Variables for cross-product
+
 
     static unsigned int textures[2]; /// texture id array
     static GLUquadricObj *quadric; /// quadric object for all renderables
@@ -32,6 +35,9 @@ class fishA : public Renderable {
     static GLfloat shininess;
 
     void drawSide();
+    float vectorDistance(float x, float y, float z);
+    float getAngle(float x, float y, float z, float a, float b, float c);
+    void getCrossProduct(float x, float y, float z, float a, float b, float c);
 
 };
 

fishB.cpp

@@ -4,20 +4,19 @@
 #include <GLUT/glut.h>
 #endif
 
-#define FOV_RADIUS 3           // Radius of field of view
-#define FOV_ANGLE 110          // Radius of field of view angle
 
 #include "fishB.h"
 #include "math.h"
+#include <iostream>
 
 fishB::fishB() {
     x = 1;
     y = 1;
     z = 1;
 
-    xInc = 0;
-    yInc = -0.1;
-    zInc = 0;
+    xInc = 0.1;
+    yInc = 0.1;
+    zInc = 0.0;
 
     angle = 40;
     Autorun = 0;
@@ -39,8 +38,10 @@ void fishB::draw(void) {
     z += zInc;
   glPushMatrix();
 
-  glTranslatef(x,y,z);
-  glRotatef(90, 1,0,0);     // correction
+  glTranslatef(x,y,z);                          // move to where it is right now
+  getCrossProduct(xInc,yInc,zInc,0,0,-1);        // get cross product
+  //    std::cout << "getangle: " << getAngle(xInc,yInc,zInc,0,0,1) << std::endl;   // debug
+  glRotatef(getAngle(xInc,yInc,zInc,0,0,-1), xcp, ycp, zcp);    // rotate to look to where it is moving
 
   glEnable(GL_LIGHTING);
 
@@ -81,13 +82,13 @@ void fishB::draw(void) {
   glDisable(GL_LIGHTING);
 
   // Radius of influence
-  if ( true ) {
+  if ( false ) {
     glColor3f( 0.2, 0.2, 0.2 );
     glutWireSphere(FOV_RADIUS, 10, 3 );
   }
 
   // Draw Axis
-  if ( true ) {
+  if ( false ) {
     glColor3f( 1, 0, 0 );	
     glBegin( GL_LINES );
     glVertex3f(0,0,0);
@@ -108,7 +109,7 @@ void fishB::draw(void) {
   }
 
   // Draw Blind Cone
-  if ( true ) {
+  if ( false ) {
     glPushMatrix();
     glTranslatef( 0, 0, -FOV_RADIUS );
     glutWireCone( FOV_RADIUS * tan( ( 180 - FOV_ANGLE )* PI / 180.0 ), FOV_RADIUS, 4, 1 );
@@ -124,3 +125,20 @@ void fishB::printXYZ(void) {
     std::cout << "z " << z << std::endl;
     std::cout << std::endl;
 }
+
+float fishB::vectorDistance(float x, float y, float z) {
+    return (float)sqrt((x*x)+(y*y)+(z*z));
+}
+
+float fishB::getAngle(float x, float y, float z, float a, float b, float c) {
+    float dot_product = (x*a) + (y*b) + (z*c);
+    float div = vectorDistance(x,y,z)*vectorDistance(a,b,c);
+    float arc = (float) acos(dot_product/div);
+    return arc* 180.0 / PI;
+}
+
+void fishB::getCrossProduct(float x, float y, float z, float a, float b, float c) {
+    xcp = (y*c)-(z*b);
+    ycp = (z*a)-(x*c);
+    zcp = (x*b)-(y*a);
+}

fishB.h

@@ -5,21 +5,27 @@
 #include <iostream>
 #include <stdio.h>
 #define PI 3.14159
+#define FOV_RADIUS 3           // Radius of field of view
+#define FOV_ANGLE 110          // Radius of field of view angle
 
 class fishB : public Renderable {
 public:
     fishB();
     virtual void draw();
     void printXYZ(void);
 
-    GLfloat x,y,z;            // For Movement
-    GLfloat xInc, yInc, zInc;   // speed of object
+    float x,y,z;            // For Movement
+    float xInc, yInc, zInc;   // speed of object
     float colour[4];
+    float xcp, ycp, zcp;        // Variables for cross-product
 
 private:             	
     float angle;  			// For Function animation
     float Autorun;			// For Movement Autorun
-
+
+    float vectorDistance(float x, float y, float z);
+    float getAngle(float x, float y, float z, float a, float b, float c);
+    void getCrossProduct(float x, float y, float z, float a, float b, float c);
 };
 
 #endif

main.cpp

@@ -27,8 +27,21 @@ int main(int argc, char** argv) {
     fish2.y=5;
     fish2.z=0;
 
+    fishB fish3;
+    fishB fish4;
+
+    fish3.x=0;
+    fish3.y=0;
+    fish3.z=0;
+
+    fish4.x=0;
+    fish4.y=-1;
+    fish4.z=0;
+
     viewer.addRenderable(&fish);
     viewer.addRenderable(&fish2);
+    viewer.addRenderable(&fish3);
+    viewer.addRenderable(&fish4);
 
    //fish.printXYZ();