OpenGL (SDL,C++) - ray tracing - third.cpp

//http://www.youtube.com/user/thecplusplusguy
//watch the video for explonation
//ray-sphere and ray-plane collision detection.
//if you find a bug, let me know
#include "functions.h"
#include "objloader.h"

float angle=0.0;

int cube;
objloader obj;
bool mousein=false;
coordinate spherecenter(0.0,0.0,0.0);
coordinate raystart(0.0,0.0,0.0);
void init()
{
    glClearColor(0.5,0.5,0.5,1.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45,640.0/480.0,1.0,500.0);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_DEPTH_TEST);
    cube=obj.load("test10.obj");
//  cube=loadObject("test.obj");
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    float col[]={1.0,1.0,1.0,1.0};
    glLightfv(GL_LIGHT0,GL_DIFFUSE,col);
    initskybox();
}

coordinate p1(-5.0,5.0,-5.0);
coordinate p2(5.0,5.0,-5.0);
coordinate p3(5.0,-5.0,-5.0);
coordinate p4(-5.0,-5.0,-5.0);
/*

*/

void display()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    Control(0.2,0.2,mousein);
    drawSkybox(50.0);
    UpdateCamera();
    float pos[]={-1.0,1.0,-2.0,1.0};
    glLightfv(GL_LIGHT0,GL_POSITION,pos);
//  glTranslatef(0.0,0.0,-4.0);
//  glRotatef(angle,1,1,1);
    glDisable(GL_LIGHTING);
//  if(raysphere(spherecenter.x,spherecenter.y,spherecenter.z,0.0,0.0,1.0,raystart.x, raystart.y,raystart.z,1.0))
    if(rayplane(0.0,0.0,1.0,raystart.x,raystart.y,raystart.z,0.0,0.0,-1.0,p1,p2,p3,p4))
        glColor3f(1.0,0.0,0.0);
    else
        glColor3f(1.0,1.0,1.0);
    //xs+t*xd
    glBegin(GL_LINES);
        glVertex3f(raystart.x,raystart.y,raystart.z);
        glVertex3f(raystart.x+100*0,raystart.y+100*0,raystart.z+100*-1);
    glEnd();
    glBegin(GL_QUADS);
        glVertex3f(-5.0,5.0,-5.0);
        glVertex3f(5.0,5.0,-5.0);
        glVertex3f(5.0,-5.0,-5.0);
        glVertex3f(-5.0,-5.0,-5.0);
    glEnd();
    glEnable(GL_LIGHTING);
    glCallList(cube);
    glColor3f(1.0,1.0,1.0);
}


int main()
{
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_Surface* screen=SDL_SetVideoMode(640,480,32,SDL_SWSURFACE|SDL_OPENGL);
    bool running=true;
    Uint32 start;
    SDL_Event event;
    init();
    bool b[4]={0,0,0,0};
    while(running)
    {
        start=SDL_GetTicks();
        while(SDL_PollEvent(&event))
        {
            switch(event.type)
            {
                case SDL_QUIT:
                    running=false;
                    break;
                case SDL_MOUSEBUTTONDOWN:
                    mousein=true;
                    SDL_ShowCursor(SDL_DISABLE);
                    break;
                case SDL_KEYDOWN:
                    if(event.key.keysym.sym==SDLK_p)
                    {
                        mousein=false;
                        SDL_ShowCursor(SDL_ENABLE);
                        break;
                    }
                    if(event.key.keysym.sym==SDLK_ESCAPE)
                    {
                        running=false;
                        break;
                    }
                    switch(event.key.keysym.sym)
                    {
                        case SDLK_UP:
                            b[0]=1;
                            break;

                        case SDLK_LEFT:
                            b[1]=1;
                            break;

                        case SDLK_DOWN:
                            b[2]=1;
                            break;

                        case SDLK_RIGHT:
                            b[3]=1;
                            break;
                    }
                    break;
                case SDL_KEYUP:
                    switch(event.key.keysym.sym)
                    {
                        case SDLK_UP:
                            b[0]=0;
                            break;

                        case SDLK_LEFT:
                            b[1]=0;
                            break;

                        case SDLK_DOWN:
                            b[2]=0;
                            break;

                        case SDLK_RIGHT:
                            b[3]=0;
                            break;
                    }
                    break;
            }
        }
        if(b[0])
            raystart.y+=0.3;
        if(b[1])
            raystart.x-=0.3;
        if(b[2])
            raystart.y-=0.3;
        if(b[3])
            raystart.x+=0.3;
        display();
        SDL_GL_SwapBuffers();
        angle+=0.5;
        if(angle>360)
            angle-=360;
        if(1000/30>(SDL_GetTicks()-start))
            SDL_Delay(1000/30-(SDL_GetTicks()-start));
    }
    SDL_Quit();
    killskybox();
    return 0;
}