Hi guys!
Im new to Allegro5 and OpenGL. I was really exicted when i got my first 3D cube to be drawn. but yesterday I got really depressed when I got this problem… I’ve googled it like 3000000 times but it seems nobody else has this horrible problem.
Im uploading a screenshot:
opengl forums won’t let me post the picture…
As u can see it must be related with the way I configure the DEPTH BUFFER… but I really dont know what I’m doing wrong.
I’m using Code::Blocks 12.11 C++ with MINGW 4.7 and the I’m not sure what openGL version im using but it’s the one provided with MINGW 4.7
And here is my whole code:
#include <stdio.h>
#include <allegro5/allegro.h>
#include <gl/glu.h>
#include <math.h>
void DrawCube(void);
int main(int argc, char **argv){
bool finish=false, draw= true;
const float FPS = 60.0;
int resX=1280,resY=720;
double Angle=90, Ratio=float(resX)/float(resY),ClippingBorder1=0,ClippingBorder2=100;
float x=0,z=0, y=0,rotX=0,incl=0,moveSpeed = 0.1;
ALLEGRO_DISPLAY *display = NULL;
if(!al_init()) {
fprintf(stderr, "failed to initialize allegro!
");
return -1;
}
al_set_new_display_flags( ALLEGRO_OPENGL );
al_set_new_display_option( ALLEGRO_COLOR_SIZE, 32, ALLEGRO_REQUIRE);
al_set_new_display_option( ALLEGRO_DEPTH_SIZE, 24, ALLEGRO_REQUIRE);
al_set_new_display_option( ALLEGRO_STENCIL_SIZE, 8, ALLEGRO_REQUIRE);
al_set_new_display_option( ALLEGRO_AUX_BUFFERS, 0, ALLEGRO_REQUIRE);
al_set_new_display_option( ALLEGRO_SAMPLE_BUFFERS, 1, ALLEGRO_SUGGEST);
al_set_new_display_option( ALLEGRO_SAMPLES, 4, ALLEGRO_SUGGEST);
display = al_create_display(resX, resY);
if(!display){
fprintf(stderr, "failed to create display!
");
return -1;
}
al_clear_to_color(al_map_rgb(0,0,0));
al_hide_mouse_cursor(display);
al_install_keyboard();
al_install_mouse();
ALLEGRO_KEYBOARD_STATE keyState;
ALLEGRO_MOUSE_STATE mouseState;
ALLEGRO_TIMER *timer = al_create_timer(1.0 / FPS);
ALLEGRO_EVENT_QUEUE *event_queue = al_create_event_queue();
al_register_event_source(event_queue, al_get_keyboard_event_source());
al_register_event_source(event_queue, al_get_mouse_event_source());
al_register_event_source(event_queue, al_get_timer_event_source(timer));
al_start_timer(timer);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
//glDepthMask(GL_TRUE);
glDepthFunc(GL_LEQUAL);
//glDepthRange(0.0f, 1.0f);
glShadeModel(GL_FLAT);
while(!finish){
ALLEGRO_EVENT events;
al_wait_for_event(event_queue, &events);
if(events.type == ALLEGRO_EVENT_KEY_UP)
{
switch(events.keyboard.keycode)
{
case ALLEGRO_KEY_ESCAPE:
finish = true;
}
}
if(events.type == ALLEGRO_EVENT_TIMER)
{
al_get_keyboard_state(&keyState);
al_get_mouse_state(&mouseState);
rotX+=(mouseState.x-resX/2)/100.0;
if(incl>-1.45 && incl<1.45)
incl-=float(mouseState.y-resY/2)/200.0;
else{
if(incl<-1.45)incl=-1.44;
if(incl>1.45)incl=1.44;
}
if(al_key_down(&keyState, ALLEGRO_KEY_RIGHT))
rotX += 0.1;
if(al_key_down(&keyState, ALLEGRO_KEY_LEFT))
rotX -= 0.1;
if(al_key_down(&keyState, ALLEGRO_KEY_UP)){
if(incl<1.45)incl += 0.1;//limitamos el angulo max de inclinación a PI/2
}
if(al_key_down(&keyState, ALLEGRO_KEY_DOWN)){
if(incl>-1.45)incl -= 0.1;//limitamos el angulo min de inclinación a -PI/2
}
if(al_key_down(&keyState, ALLEGRO_KEY_A)){
x-=moveSpeed*cos(rotX+1.57);
z-=moveSpeed*sin(rotX+1.57);
}
if(al_key_down(&keyState, ALLEGRO_KEY_D)){
x+=moveSpeed*cos(rotX+1.57);
z+=moveSpeed*sin(rotX+1.57);
}
if(al_key_down(&keyState, ALLEGRO_KEY_W)){
x+=moveSpeed*cos(rotX);
z+=moveSpeed*sin(rotX);
}
if(al_key_down(&keyState, ALLEGRO_KEY_S)){
x-=moveSpeed*cos(rotX);
z-=moveSpeed*sin(rotX);
}
if(al_key_down(&keyState, ALLEGRO_KEY_Z))
Angle++;
if(al_key_down(&keyState, ALLEGRO_KEY_X))
Angle--;
al_set_mouse_xy(display, resX/2, resY/2);
draw = true;
}
if(draw)
{
draw = false;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT| GL_STENCIL_BUFFER_BIT);
glMatrixMode(GL_PROJECTION); //Open the projection matrix as current
glLoadIdentity(); //clear its contents to an identity matrix (which doesn't change anything when applied)
gluPerspective( Angle, Ratio, ClippingBorder1, ClippingBorder2);
glMatrixMode(GL_MODELVIEW); //select the matrix
glLoadIdentity(); //clear ...
gluLookAt (x,y,z,x+cos(incl)*cos(rotX),y+sin(incl),z+cos(incl)*sin(rotX),0,1,0);//CameraX , CameraY, CameraZ, SceneX, SceneY, SceneZ, UpVectorApexX, UpVectorApexY, UpVectorApexZ );
DrawCube(); //Draw CUBE
glBegin(GL_QUADS); // Draw SINLGE FACE behing CUBE
glColor3f(0.0f,1.0f,0.0f); // Color Red
glVertex3f( 1.0f, 1.0f, -3.0f); // Top Right Of The Quad (Front)
glVertex3f(-1.0f, 1.0f, -3.0f); // Top Left Of The Quad (Front)
glVertex3f(-1.0f,-1.0f, -3.0f); // Bottom Left Of The Quad (Front)
glVertex3f( 1.0f,-1.0f, -3.0f); // Bottom Right Of The Quad (Front)
glEnd();
glFlush();
al_wait_for_vsync();
al_flip_display();
al_clear_to_color(al_map_rgb(0, 0, 0));
}
}
printf("Finalizado por el usuario.");
al_rest(1.0);
al_destroy_display(display);
al_destroy_timer(timer);
al_destroy_event_queue(event_queue);
return 0;
}
void DrawCube(void)
{
// Draw The Cube Using quads
glColor3f(0.0f,1.0f,0.0f); // Color Blue
glBegin(GL_QUADS);
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Top)
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Top)
glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Quad (Top)
glVertex3f( 1.0f, 1.0f, 1.0f); // Bottom Right Of The Quad (Top)
glEnd();
glColor3f(1.0f,0.5f,0.0f); // Color Orange
glBegin(GL_QUADS);
glVertex3f( 1.0f,-1.0f, 1.0f); // Top Right Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f, 1.0f); // Top Left Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Bottom)
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Bottom)
glEnd();
glColor3f(1.0f,0.0f,0.0f); // Color Red
glBegin(GL_QUADS);
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Front)
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Front)
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Front)
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Front)
glEnd();
glColor3f(1.0f,1.0f,0.0f); // Color Yellow
glBegin(GL_QUADS);
glVertex3f( 1.0f,-1.0f,-1.0f); // Top Right Of The Quad (Back)
glVertex3f(-1.0f,-1.0f,-1.0f); // Top Left Of The Quad (Back)
glVertex3f(-1.0f, 1.0f,-1.0f); // Bottom Left Of The Quad (Back)
glVertex3f( 1.0f, 1.0f,-1.0f); // Bottom Right Of The Quad (Back)
glEnd();
glColor3f(0.0f,0.0f,1.0f); // Color Blue
glBegin(GL_QUADS);
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Left)
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Left)
glEnd();
glColor3f(1.0f,0.0f,1.0f); // Color Violet
glBegin(GL_QUADS);
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Right)
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Right)
glEnd(); // End Drawing The Cube
}
THANKYOU so much in advance!! Id be so pleased if you can solve this…