Object doesn't seems to collide using AABB collision method - c++

Question

I am new to opengl. I am doing a simple 2D shooting game and using AABB collision to do collision between objects and bullet. I do the collision for my plane and the square but it doesn't seems to work. Can help me check what's my problem?
#include <iostream>
#include <time.h>
#include <windows.h>
#include <string.h>
#include <math.h>
#include <GL/glut.h>
using namespace std;
#define SPACEBAR 32
class Plane {
public:
GLfloat x = 0.05f;
GLfloat y = 0.95f;
GLfloat width = 0.05f;
GLfloat height = 0.10f;
GLfloat moveX = 0.0f;
GLfloat moveY = 0.0f;
void drawPlane(GLfloat, GLfloat, GLfloat, GLfloat);
};
class Enemy {
public:
GLfloat x, y;
GLfloat width, height;
GLfloat sqrMoveX, sqrMoveY;
void drawEnemySqr(GLfloat, GLfloat, GLfloat, GLfloat);
};
Plane plane;
Enemy enemy;
GLfloat XMax, XMin, YMax, YMin;
GLdouble clipAreaXLeft, clipAreaXRight, clipAreaYBottom, clipAreaYTop;
int refreshMills = 30;
float RandomNumberX() {
float Min = -1.0f;
float Max = 1.0f;
return ((float(rand()) / float(RAND_MAX)) * (Max - Min)) + Min;
}
float RandomNumberY() {
float Min = 0.7f;
float Max = 1.0f;
return ((float(rand()) / float(RAND_MAX)) * (Max - Min)) + Min;
}
void Timer(int value) {
glutPostRedisplay();
glutTimerFunc(refreshMills, Timer, 0);
}
bool collision(GLfloat x1, GLfloat y1, GLfloat w1, GLfloat h1,
GLfloat x2, GLfloat y2, GLfloat w2, GLfloat h2) {
if ((x1 < (x2 + w2)) &&
((x1 + w1) > x2) &&
(y1 < (y2 + h2)) &&
((h1 + y1) > y2)) {
return true;
}
else {
return false;
}
}
void initGL() {
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
}
void Plane :: drawPlane(GLfloat planeX, GLfloat planeY, GLfloat planeWidth, GLfloat planeHeight) {
glTranslatef(moveX, moveY, 0.0f);
glBegin(GL_POLYGON);
glColor3f(1.0f, 0.0f, 0.0f);
glVertex2f(-(planeX), -(planeY));
glVertex2f(planeX, -(planeY));
glVertex2f(planeX + planeWidth, -(planeY - planeHeight));
glVertex2f(planeX - (planeWidth), -(planeY - (planeHeight + 0.20f)));
glVertex2f(-(planeX + planeWidth), -(planeY - planeHeight));
glEnd();
if (moveX > XMax) {
moveX = XMax;
}
else if (moveX < XMin) {
moveX = XMin;
}
if (moveY > YMax) {
moveY = YMax;
}
else if (moveY < YMin) {
moveY = YMin;
}
}
void Enemy :: drawEnemySqr(GLfloat enemyX, GLfloat enemyY, GLfloat enemyWidth, GLfloat enemyHeight) {
glTranslatef(sqrMoveX, sqrMoveY, 0.0f);
glBegin(GL_QUADS);
glColor3f(1.0f, 0.0f, 1.0f);
glVertex2f(enemyX, enemyY);
glVertex2f(enemyX + enemyWidth, enemyY);
glVertex2f(enemyX + enemyWidth, enemyY + enemyHeight);
glVertex2f(enemyX, enemyWidth + enemyY);
glEnd();
sqrMoveY -= 0.0005f;
if (sqrMoveY < -1.8f) {
sqrMoveX = RandomNumberX();
sqrMoveY = RandomNumberY();
}
glutPostRedisplay();
}
void display() {
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_TEXTURE_2D);
glPushMatrix();
plane.drawPlane(plane.x, plane.y, plane.width, plane.height);
glPopMatrix();
glPushMatrix();
enemy.drawEnemySqr(0.0f, 0.0f, 0.3f, 0.3f);
glPopMatrix();
if (collision(plane.moveX, plane.moveY, plane.width, plane.height,
enemy.sqrMoveX, enemy.sqrMoveY, enemy.width, enemy.height) == true) {
enemy.sqrMoveY = -2.0f;
}
glutSwapBuffers();
}
void keyButton(int key, int x, int y) {
switch (key) {
case GLUT_KEY_RIGHT:
plane.moveX += 0.05f;
break;
case GLUT_KEY_LEFT:
plane.moveX += -0.05f;
break;
case GLUT_KEY_UP:
plane.moveY += 0.05f;
break;
case GLUT_KEY_DOWN:
plane.moveY += -0.05f;
break;
default:
break;
}
glutPostRedisplay();
}
int main(int argc, char** argv) {
srand(time(NULL));
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(480, 640);
glutInitWindowPosition(50, 50);
glutCreateWindow("Plane Shooting Game");
glutDisplayFunc(display);
glutIdleFunc(idle);
glutReshapeFunc(reshape);
glutTimerFunc(25, Timer, 0);
glutSpecialFunc(keyButton);
initGL();
glutMainLoop();
return 0;
}

Answer 1

You have a problem in this line:
if (collision(plane.moveX, plane.moveY, plane.width, plane.height,
enemy.sqrMoveX, enemy.sqrMoveY, enemy.width, enemy.height) == true)
You must pass plane.x, plane.y, enemy.x, enemy.y to collision function instead of plane.moveX, plane.moveY, enemy.sqrMoveX, enemy.sqrMoveY.