OpenGL Alpha Channel Problem - Printable Version

Code:
void UpdateRain(void)

{

    for (int i = 0; i < MAX_PARTICLES; i++)

    {

        int iRandX = ((rand()%500) - 250);

        float dRandX = float(iRandX)/9;



        int iRandZ = (rand()%500) - 250;

        float dRandZ = (float)iRandZ/9;



        int iRandLife = rand()%100;

        float dRandLife = (float)iRandLife/100;



        int iRandDeath = (rand()%10);

        float dRandDeath = (float)iRandDeath/1000;



        // Draw the particles using our RGB values

        glColor4f(Rain[i].r,Rain[i].g,Rain[i].b,Rain[i].life);



        Rain[i].xPos += Rain[i].xDir; //move on the x axis by x speed

        Rain[i].yPos += Rain[i].yDir; //move on the y axis by y speed

        Rain[i].zPos += Rain[i].zDir; //move on the z axis by z speed



        Rain[i].life -= Rain[i].death; //reduce life by value of death



        if (Rain[i].life < Rain[i].death)

        {

            Rain[i].xPos = dRandX;

            Rain[i].yPos = 20;

            Rain[i].zPos = dRandZ;

            Rain[i].xDir = 0.01f;

            Rain[i].yDir = -0.5f;

            Rain[i].zDir = 0;

            Rain[i].r = 0.90f;

            Rain[i].g = 0.90f;

            Rain[i].b = 1.0f;

            Rain[i].life = dRandLife;

            Rain[i].death = 0.01f;

            Rain[i].speed = (float)(rand()%360);

            Rain[i].angle = 160;

        }        

    }

}



void DrawRain(void)

{    

    

    for (int i = 0; i < MAX_PARTICLES; i++)

    {

    

        glPushMatrix();



        glTranslatef (Rain[i].xPos, Rain[i].yPos, Rain[i].zPos);

   

        glDisable (GL_DEPTH_TEST);

        glEnable (GL_BLEND);

        

        glBlendFunc (GL_DST_COLOR, GL_ZERO);

        glBindTexture (GL_TEXTURE_2D, myTexture[0]);



        //glvertex3f determines particle size

        glBegin (GL_QUADS);

        glTexCoord2d (0, 0); //bottom left

        glVertex3f (.05f, 0, 0.05f);

        glTexCoord2d (1, 0); //bottom right

        glVertex3f (.1f, 0, .1f);

        glTexCoord2d (1, 1); //top right

        glVertex3f (0.05f, .55f, 0.05f);

        glTexCoord2d (0, 1); //top left

        glVertex3f (0.05f, .5f, 0.05f);

        glEnd();



        glBlendFunc (GL_ONE, GL_ONE);

        glBindTexture (GL_TEXTURE_2D, myTexture[1]);

    

        glBegin (GL_QUADS);

        glTexCoord2d (0, 0); //bottom left

        glVertex3f (.05f, 0, 0.05f);

        glTexCoord2d (1, 0); //bottom right

        glVertex3f (.1f, 0, .1f);

        glTexCoord2d (1, 1); //top right

        glVertex3f (0.05f, .55f, 0.05f);

        glTexCoord2d (0, 1); //top left

        glVertex3f (0.05f, .5f, 0.05f);

        glEnd();

       

        glEnable(GL_DEPTH_TEST);



        glPopMatrix();

    }

}