Hello. I’m making a simple 3D shooting game. The problem is that I want to shoot the bullet whenever the “x” button is pressed, but I can’t even make it to appear on screen. I’m using this code as a structure. Here is the code:
#include <glut.h>
#include <math.h>
// angle of rotation for the camera direction
float angle = 0.0f;
// actual vector representing the camera's direction
float lx=0.0f,lz=-1.0f;
// XZ position of the camera
float x=0.0f, z=5.0f;
// the key states. These variables will be zero
//when no key is being presses
float deltaAngle = 0.0f;
float deltaMove = 0;
void changeSize(int w, int h) {
// Prevent a divide by zero, when window is too short
// (you cant make a window of zero width).
if (h == 0)
h = 1;
float ratio = w * 1.0 / h;
// Use the Projection Matrix
glMatrixMode(GL_PROJECTION);
// Reset Matrix
glLoadIdentity();
// Set the viewport to be the entire window
glViewport(0, 0, w, h);
// Set the correct perspective.
gluPerspective(45.0f, ratio, 0.1f, 100.0f);
// Get Back to the Modelview
glMatrixMode(GL_MODELVIEW);
}
void drawBullet(){
glPushMatrix();
glColor3f(0.0f,1.0f,0.4f);
glTranslatef(0,1,1);
glutSolidSphere(0.05f,10,10);
glPopMatrix();
}
void drawSnowMan() {
// Draw Body
glPushMatrix();
glColor3f(0.6f, 0.6f, 0.6f);
glScalef(1, 1.3, 1);
glTranslatef(0.0f ,0.75f, 0.0f);
glutSolidCube(0.8);
glPopMatrix();
// Draw Head
glPushMatrix();
glColor3f(1.0f, 1.0f, 0.1f);
glTranslatef(0.0f, 1.75f, 0.0f);
glutSolidSphere(0.4,25,25);
glPopMatrix();
}
void computePos(float deltaMove) {
x += deltaMove * lx * 0.1f;
z += deltaMove * lz * 0.1f;
}
void computeDir(float deltaAngle) {
angle += deltaAngle;
lx = sin(angle);
lz = -cos(angle);
}
void renderScene(void) {
if (deltaMove)
computePos(deltaMove);
if (deltaAngle)
computeDir(deltaAngle);
// Clear Color and Depth Buffers
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Reset transformations
glLoadIdentity();
// Set the camera
gluLookAt( x, 1.0f, z,
x+lx, 1.0f, z+lz,
0.0f, 1.0f, 0.0f);
// Draw ground
glColor3f(0.9f, 0.9f, 0.9f);
glBegin(GL_QUADS);
glVertex3f(-100.0f, 0.0f, -100.0f);
glVertex3f(-100.0f, 0.0f, 100.0f);
glVertex3f( 100.0f, 0.0f, 100.0f);
glVertex3f( 100.0f, 0.0f, -100.0f);
glEnd();
// Draw 36 SnowMen
for(int i = -3; i < 3; i++)
for(int j=-3; j < 3; j++) {
glPushMatrix();
glTranslatef(i*10.0,0,j * 10.0);
drawSnowMan();
glPopMatrix();
}
glutSwapBuffers();
}
void pressKey(int key, int xx, int yy) {
switch (key) {
case GLUT_KEY_LEFT : deltaAngle = -0.01f; break;
case GLUT_KEY_RIGHT : deltaAngle = 0.01f; break;
case GLUT_KEY_UP : deltaMove = 0.5f; break;
case GLUT_KEY_DOWN : deltaMove = -0.5f; break;
}
}
void shoot(unsigned char key, int xmouse, int ymouse){
if(key=='x'){
drawBullet();
}
glutPostRedisplay();
}
void releaseKey(int key, int x, int y) {
switch (key) {
case GLUT_KEY_LEFT :
case GLUT_KEY_RIGHT : deltaAngle = 0.0f;break;
case GLUT_KEY_UP :
case GLUT_KEY_DOWN : deltaMove = 0;break;
}
}
int main(int argc, char **argv) {
// init GLUT and create window
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(100,100);
glutInitWindowSize(320,320);
glutCreateWindow("Bullet");
// register callbacks
glutDisplayFunc(renderScene);
glutReshapeFunc(changeSize);
glutIdleFunc(renderScene);
glutSpecialFunc(pressKey);
glutKeyboardFunc(shoot);
// here are the new entries
glutIgnoreKeyRepeat(1);
glutSpecialUpFunc(releaseKey);
// OpenGL init
glEnable(GL_DEPTH_TEST);
// enter GLUT event processing cycle
glutMainLoop();
return 1;
}
Thanks in advance.