code.delx.au - pong/blob - pong.c

   1 #if defined(WIN32)
   2 #pragma comment(linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"")
   3 #include "glut.h"
   4 #elif defined(__APPLE__) || defined(MACOSX)
   5 #include <GLUT/glut.h>
   6 #else
   7 #include <GL/glut.h>
   8 #endif
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12
  13 #define SPEEDINC    1.15
  14 #define PADDLESPEED 2.5
  15 #define FRAME       40
  16 #define PADDLESIZE  10
  17 #define HEIGHT      100
  18
  19 static int p1move = 0;
  20 static int p2move = 0;
  21 static int score1 = 0;
  22 static int score2 = 0;
  23 static GLdouble paddle1 = 0.0;
  24 static GLdouble paddle2 = 0.0;
  25 static GLdouble ballX = 0.0;
  26 static GLdouble ballY = 0.0;
  27 static GLdouble ballVecX = 0.0;
  28 static GLdouble ballVecY = 0.0;
  29
  30
  31 static void initball(void) {
  32         ballX = 0.0;
  33         ballY = 0.0;
  34         if(ballVecX < 0)
  35                 ballVecX = -1.2;
  36         else
  37                 ballVecX = 1.2;
  38         ballVecY = 0.7;
  39 }
  40
  41 static void run(void) {
  42         // Move the paddles
  43         paddle1 += p1move * PADDLESPEED;
  44         paddle2 += p2move * PADDLESPEED;
  45
  46         // Check for collisions with paddles
  47         if(ballVecX < 0 && ballX <= -HEIGHT + -ballVecX * 1.5) {
  48                 if(ballY >= paddle1 - PADDLESIZE && ballY <= paddle1 + PADDLESIZE) {
  49                         ballVecX *= -SPEEDINC;
  50                         ballVecY *= SPEEDINC;
  51                 }
  52         }
  53         if(ballVecX > 0 && ballX >=  HEIGHT - ballVecX * 1.5) {
  54                 if(ballY >= paddle2 - PADDLESIZE && ballY <= paddle2 + PADDLESIZE) {
  55                         ballVecX *= -SPEEDINC;
  56                         ballVecY *= SPEEDINC;
  57                 }
  58         }
  59
  60         // Check if it's past the top or bottom of the screen
  61         if(ballY >= HEIGHT || ballY <= -HEIGHT) {
  62                 ballVecY = -ballVecY;
  63         }
  64
  65         // Check if it's past the sides of the screen
  66         if(ballX >= HEIGHT) {
  67                 ++score1;
  68                 initball();
  69                 return;
  70         }
  71         if(ballX <= -HEIGHT) {
  72                 ++score2;
  73                 initball();
  74                 return;
  75         }
  76
  77         // Move the ball
  78         ballX += ballVecX;
  79         ballY += ballVecY;
  80 }
  81
  82 static void display(void) {
  83         glClear(GL_COLOR_BUFFER_BIT);
  84         glColor3d(0.0, 0.0, 0.0);
  85
  86         // Draw the paddles
  87         glLineWidth(2.0);
  88         glBegin(GL_LINES);
  89         glVertex2d(-HEIGHT + 1, paddle1 - PADDLESIZE);
  90         glVertex2d(-HEIGHT + 1, paddle1 + PADDLESIZE);
  91         glVertex2d( HEIGHT - 1, paddle2 + PADDLESIZE);
  92         glVertex2d( HEIGHT - 1, paddle2 - PADDLESIZE);
  93         glEnd();
  94
  95         // Draw the ball
  96         glPointSize(5.0);
  97         glBegin(GL_POINTS);
  98         glVertex2d(ballX, ballY);
  99         glEnd();
 100
 101         // Write the score
 102         glRasterPos2d(-5.0, HEIGHT - 10.0);
 103         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score1);
 104         glRasterPos2d( 5.0, HEIGHT - 10.0);
 105         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score2);
 106
 107         glutSwapBuffers();
 108 }
 109
 110 static void resize(int w, int h) {
 111         glViewport(0, 0, w, h);
 112         glLoadIdentity();
 113         glOrtho(-HEIGHT, HEIGHT, -HEIGHT, HEIGHT, -1.0, 1.0);
 114 }
 115
 116 static void keyboard(unsigned char key, int x, int y) {
 117         (void)x;(void)y;
 118
 119         switch(key) {
 120                 case 'q':
 121                 case 'Q':
 122                 case '\033':
 123                         exit(0);
 124
 125                 case 'w':
 126                         p1move = 1;
 127                         break;
 128                 case 's':
 129                         p1move = -1;
 130                         break;
 131
 132                 case 'i':
 133                         p2move = 1;
 134                         break;
 135                 case 'k':
 136                         p2move = -1;
 137                         break;
 138
 139                 default:
 140                         return;
 141         }
 142         glutPostRedisplay();
 143 }
 144
 145 static void keyboardUp(unsigned char key, int x, int y) {
 146         (void)x;(void)y;
 147
 148         switch(key) {
 149                 case 'w':
 150                 case 's':
 151                         p1move = 0;
 152                         break;
 153
 154                 case 'i':
 155                 case 'k':
 156                         p2move = 0;
 157                         p2move = 0;
 158                         break;
 159         }
 160 }
 161
 162 static void timer(int lastTime) {
 163         int curTime = glutGet(GLUT_ELAPSED_TIME);
 164         do {
 165                 lastTime += FRAME;
 166                 run();
 167         } while(lastTime + FRAME < curTime);
 168         glutPostRedisplay();
 169         glutTimerFunc(FRAME - (curTime - lastTime), timer, curTime);
 170 }
 171
 172 static void init(void) {
 173         glClearColor(1.0, 1.0, 1.0, 0.0);
 174         initball();
 175 }
 176
 177 int main(int argc, char *argv[]) {
 178         glutInitWindowPosition(100, 100);
 179         glutInitWindowSize(640, 480);
 180         glutInit(&argc, argv);
 181         glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
 182         glutCreateWindow(argv[0]);
 183         glutDisplayFunc(display);
 184         glutReshapeFunc(resize);
 185         glutKeyboardFunc(keyboard);
 186         glutKeyboardUpFunc(keyboardUp);
 187         glutTimerFunc(FRAME, timer, glutGet(GLUT_ELAPSED_TIME));
 188         init();
 189         glutMainLoop();
 190         return 0;
 191 }
 192