windows-xp/Source/XPSP1/NT/multimedia/opengl/test/demos/atlantis/swim.c

#include <windows.h>
#include <stdlib.h>
#include <math.h>
#include <GL/gl.h>
#include "atlantis.h"


void FishTransform(fishRec *fish)
{

    glTranslatef(fish->y, fish->z, -fish->x);
    glRotatef(-fish->psi, 0.0, 1.0, 0.0);
    glRotatef(fish->theta, 1.0, 0.0, 0.0); 
    glRotatef(-fish->phi, 0.0, 0.0, 1.0);
}

void WhalePilot(fishRec *fish)
{

    fish->phi = -20.0;
    fish->theta = 0.0;
    fish->psi -= 0.5;

    fish->x += WHALESPEED * fish->v * cos(fish->psi/RAD) * cos(fish->theta/RAD);
    fish->y += WHALESPEED * fish->v * sin(fish->psi/RAD) * cos(fish->theta/RAD);
    fish->z += WHALESPEED * fish->v * sin(fish->theta/RAD);
}

void SharkPilot(fishRec *fish)
{
    static int sign = 1;
    float X, Y, Z, tpsi, ttheta, thetal;

    fish->xt = 60000.0;
    fish->yt = 0.0;
    fish->zt = 0.0;

    X = fish->xt - fish->x;
    Y = fish->yt - fish->y;
    Z = fish->zt - fish->z;

    thetal = fish->theta;

    ttheta = RAD * atan(Z/(sqrt(X*X+Y*Y)));

    if (ttheta > fish->theta+0.25) {
        fish->theta += 0.5;
    } else if (ttheta < fish->theta-0.25) {
        fish->theta -= 0.5;
    }

    if (fish->theta > 90.0) {
	fish->theta =  90.0;
    }
    if (fish->theta < -90.0) {
	fish->theta = -90.0;
    }

    fish->dtheta = fish->theta - thetal;

    tpsi =  RAD * atan2(Y, X);
        
    fish->attack = 0;

    if (fabs(tpsi-fish->psi) < 10.0) {
        fish->attack = 1;
    } else if (fabs(tpsi-fish->psi) < 45.0) {
        if (fish->psi > tpsi) {
            fish->psi -= 0.5;
            if (fish->psi < -180.0) {
		fish->psi += 360.0;
	    }
        } else if (fish->psi < tpsi) {
            fish->psi += 0.5;
            if (fish->psi >  180.0) {
		fish->psi -= 360.0;
	    }
        }
    } else {
        if (rand()%100 > 98) {
	    sign = 1 - sign;
	}
        fish->psi += sign;
        if (fish->psi > 180.0) {
	    fish->psi -= 360.0;
	}
        if (fish->psi < -180.0) {
	    fish->psi += 360.0;
	}
    }

    if (fish->attack) {
        if (fish->v < 1.1) {
	    fish->spurt = 1;
	}
        if (fish->spurt) {
	    fish->v += 0.2;
	}
        if (fish->v > 5.0) {
	    fish->spurt = 0;
	}
        if ((fish->v > 1.0) && (!fish->spurt)) {
	    fish->v -= 0.2;
	}
    } else {
        if (!(rand()%400) && (!fish->spurt)) {
	    fish->spurt = 1;
	}
        if (fish->spurt) {
	    fish->v += 0.05;
	}
        if (fish->v > 3.0) {
	    fish->spurt = 0;
	}
        if ((fish->v > 1.0) && (!fish->spurt)) {
	    fish->v -= 0.05;
	}
    }

    fish->x += SHARKSPEED * fish->v * cos(fish->psi/RAD) * cos(fish->theta/RAD);
    fish->y += SHARKSPEED * fish->v * sin(fish->psi/RAD) * cos(fish->theta/RAD);
    fish->z += SHARKSPEED * fish->v * sin(fish->theta/RAD);
}

void SharkMiss(int i)
{
    int j;
    float avoid, thetal;
    float X, Y, Z, R;

    for (j = 0; j < NUM_SHARKS; j++) {
        if (j != i) { 
            X = sharks[j].x - sharks[i].x;
            Y = sharks[j].y - sharks[i].y;
            Z = sharks[j].z - sharks[i].z;

            R = sqrt(X*X+Y*Y+Z*Z);

            avoid = 1.0;
            thetal = sharks[i].theta;

            if (R < SHARKSIZE) {
                if (Z > 0.0) {
                    sharks[i].theta -= avoid;
                } else {
                    sharks[i].theta += avoid;
                }
            }

            sharks[i].dtheta += (sharks[i].theta - thetal);
        }
    }
}