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| #include <iostream>
#include <SDL/SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>
const int WIN_X = 800;
const int WIN_Y = 600;
const int BUFSIZE = 1024;
int sTime;
int cTime;
int eTime;
bool go = true;
int mx = 0;
int my = 0;
bool click;
SDL_Surface *screen;
SDL_Event event;
void initGL()
{
SDL_Init(SDL_INIT_VIDEO);
SDL_WM_SetCaption("OpenGL Rox", NULL);
screen = SDL_SetVideoMode(WIN_X, WIN_Y, 32, SDL_OPENGL);
glEnable(GL_DEPTH_TEST);
SDL_WarpMouse(screen->w / 2, screen->h / 2);
}
void taketime(bool cas)
{
if (!cas)
sTime = SDL_GetTicks();
else
{
cTime = SDL_GetTicks();
eTime = cTime - sTime;
if (eTime < 10)
SDL_Delay(10 - eTime);
}
}
void drawsquare(bool cas)
{
if (cas)
glLoadName(1);
glColor3ub(255, 255, 255);
glBegin(GL_QUADS);
glVertex3d(0, 0, 0);
glVertex3d(0, 10, 0);
glVertex3d(10, 10, 0);
glVertex3d(10, 0, 0);
glEnd();
if (cas)
glLoadName(2);
glColor3ub(255, 0, 0);
glBegin(GL_QUADS);
glVertex3d(3, 3, 0.2);
glVertex3d(3, 7, 0.2);
glVertex3d(7, 7, 0.2);
glVertex3d(7, 3, 0.2);
glEnd();
}
void processHits(GLint hits, GLuint *buffer)
{
unsigned int i;
unsigned int j;
GLuint names;
GLuint *ptr;
std::cout << "hits = " << hits << std::endl;
ptr = (GLuint *)buffer;
for (i = 0; i < hits; i++)
{
names = *ptr;
std::cout << " number of names for this hit = " << names << std::endl;
ptr++;
std::cout << " z1 is " << (float) *ptr / 0x7fffffff;
ptr++;
std::cout << " z2 is " << (float) *ptr / 0x7fffffff << std::endl;
ptr++;
std::cout << " NAMES ";
for (j = 0; j < names; j++)
{
std::cout << *ptr << std::endl;
ptr++;
}
std::cout << std::endl;
}
std::cout << "\n-----------------------------------------\n" << std::endl;;
}
void picking()
{
glPushAttrib(GL_ALL_ATTRIB_BITS);
GLuint selectBuf[BUFSIZE];
GLint hits = 0;
GLint viewport[4];
glGetIntegerv(GL_VIEWPORT, viewport);
glSelectBuffer(BUFSIZE, selectBuf);
(void) glRenderMode(GL_SELECT);
glInitNames();
glPushName(0);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
gluPickMatrix((GLdouble) mx, (GLdouble) (viewport[3] - my), 2.0, 2.0, viewport);
gluPerspective(70, float(WIN_X / WIN_Y), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
drawsquare(true);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix ();
hits = glRenderMode(GL_RENDER);
processHits(hits, selectBuf);
glPopAttrib();
}
void draw()
{
glViewport(0, 0, WIN_X, WIN_Y);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(70, float(WIN_X / WIN_Y), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
gluLookAt(-10, -10, 10, 0, 0, 0, 0, 0, 1);
drawsquare(false);
if (click)
picking();
glFlush();
SDL_GL_SwapBuffers();
}
void checkevents()
{
if (event.type == SDL_QUIT)
go = false;
else if (event.type == SDL_KEYDOWN)
if (event.key.keysym.sym == SDLK_ESCAPE || event.key.keysym.sym == SDLK_DELETE)
go = false;
if (event.type == SDL_MOUSEMOTION)
{
mx = event.motion.x;
my = event.motion.y;
}
//MOUSE
if (event.type == SDL_MOUSEBUTTONDOWN)
{
if (event.button.button == SDL_BUTTON_LEFT)
click = true;
}
else if (event.type == SDL_MOUSEBUTTONUP)
{
if (event.button.button == SDL_BUTTON_LEFT)
click = false;
}
if (click)
{
std::cout << "x : " << mx << std::endl;
std::cout << "y : " << my << std::endl << std::endl;
}
}
int main(int argc, char **argv)
{
#ifdef WIN32
freopen("CON","w", stderr);
freopen("CON","w", stdout);
#endif
initGL();
while (go)
{
taketime(false);
while (SDL_PollEvent(&event))
checkevents();
draw();
taketime(true);
}
SDL_Quit();
return (0);
} |
