TileStorm.cpp

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//
// Das Tank - Copyright (C) 2006, 2007 Windsor Schmidt <windsor@windsorworld.net>
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program; if not, write to the Free Software Foundation, Inc., 59 Temple
// Place, Suite 330, Boston, MA 02111-1307 USA
//


#ifndef STDAFX
#include "stdafx.h"
#endif

TileStorm::TileStorm(void)
{
       int i;
       vPosition.x = 0;
       vPosition.y = 0;
       vPosition.z = 0;

       vForce.x = 0;
       vForce.y = 0;
       vForce.z = 0;

       fSpreadAngle = PI/2; // 90 degrees
       fFriction = 1;
       iNumParticles = 1;

       iTexture = TEXID_NULL;

       pParticles = (Particle *) malloc(sizeof(Particle) * iNumParticles);

       for(i=0; i<iNumParticles; i++) // init particles
       {
              pParticles[i].fPosX = 0;
              pParticles[i].fPosY = 0;
              pParticles[i].fVelX = 0;
              pParticles[i].fVelY = 0;
              pParticles[i].fRotVel = 0;
              pParticles[i].fSize = .01;
              pParticles[i].bAlive = true;
              pParticles[i].fAngle = 0;
              pParticles[i].fEnergy = 1;
       }

       fRandomness = 0;
       fDecayRate = 0;
}


TileStorm::TileStorm(Vector vPos, Vector vFce, float fSAngle, float fFric, float fRand, int iParticles, int tex)
{
       int i;
       Vector vTemp;
       float angle1, angle2;

       vPosition = vPos;
       vForce = vFce;

       fSpreadAngle = fSAngle;
       fFriction = fFric;
       iNumParticles = iParticles;

       iTexture = tex;

       angle1 = -(fSAngle/2);

       if(iNumParticles > MAX_PARTICLES) { iNumParticles = MAX_PARTICLES; } // limit particles

       pParticles = (Particle *) malloc(sizeof(Particle) * iNumParticles); // reserve memory

       for(i=0; i<iNumParticles; i++) // init particles
       {
              fRandomness = fRand;
              fDecayRate = .001;

              vTemp = vForce;
              vTemp *= 1 + ((float)(rand()%100) -50) / 100 * fRandomness;
              angle2 = angle1 + ((float) i/ (float) iNumParticles) * fSpreadAngle;
              vTemp = VRotate2D(angle2 + ((float)(rand()%100) -50) / 100 * fRandomness, vTemp);

              pParticles[i].fPosX = vPos.x;
              pParticles[i].fPosY = vPos.y;
              pParticles[i].fVelX = vTemp.x;
              pParticles[i].fVelY = vTemp.y;
              pParticles[i].fSize = .1 + ((float)(rand()%100) - 50) / 100 * 6.0;
              pParticles[i].bAlive = true;
              pParticles[i].fAngle = 0;
              pParticles[i].fEnergy = 1;
              pParticles[i].fDecayRate = fDecayRate + (((float)(rand()%100)) / 100) * .0001;

              pParticles[i].fRotVel = ((float)(rand()%100) -50) / 100 * 1.0;
       }
}


TileStorm::~TileStorm(void)
{
       free(pParticles); // free memory reserved for particles
}


bool TileStorm::Step(float timeStep)
{
       int i;
       bool someAlive = false; // still some particles with energy

       for(i=0; i<iNumParticles; i++)
       {
              if(pParticles[i].fEnergy <= 0)
              {
                     pParticles[i].bAlive = false;
                     continue; // done with this particle
              }

              pParticles[i].fVelX *= 1 / fFriction;
              pParticles[i].fVelY *= 1 / fFriction;

              pParticles[i].fPosX += (pParticles[i].fVelX * timeStep);
              pParticles[i].fPosY += (pParticles[i].fVelY * timeStep);

              pParticles[i].fAngle += pParticles[i].fRotVel;

              pParticles[i].fEnergy -= fDecayRate;

              someAlive = true; // at least this particle is still alive
       }

       if(someAlive == false) // no particles left alive
       {
              return true; // expired
       }
       else
       {
              return false; // not expired yet
       }
}

void TileStorm::Draw(void)
{
       int i;

       glEnable (GL_BLEND);
       glEnable(GL_TEXTURE_2D);
       glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
       glBindTexture( GL_TEXTURE_2D, GetTexture(iTexture));
       glColor4f(1, 1, 1, 1);

       glPushMatrix();

       for(i=0; i<iNumParticles; i++)
       {
              glPushMatrix();
              glTranslatef(pParticles[i].fPosX, pParticles[i].fPosY,.5);
              glRotatef(pParticles[i].fAngle,0,0,1);

              glBegin(GL_QUADS);                        // start drawing a polygon (4 sided)
              glTexCoord2d(0.0,1.0); glVertex3f(-1, 1, 0.1f);         // top left
              glTexCoord2d(1.0,1.0); glVertex3f(1, 1, 0.1f);          // top right
              glTexCoord2d(1.0,0.0); glVertex3f(1, -1, 0.1f);  // bottom right
              glTexCoord2d(0.0,0.0); glVertex3f(-1, -1, 0.1f); // bottom left       
              glEnd(); // done with the polygon

              glPopMatrix();
       }
       glPopMatrix();
}

 

Copyright Windsor Schmidt 2006 - All rights reserved.