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 #include <math.h>
  13
  14 // Amount to increase speed by on x, y axis, and when bouncing
  15 #define SPEEDXINC   1.1
  16 #define SPEEDYINC   1.1
  17 #define SPEEDBINC   0.2
  18 #define PADDLESPEED 3.0
  19 #define FRAME       40
  20 #define PADDLESIZE  10
  21 #define HEIGHT      100
  22
  23 static int AI = 0;
  24 static int p1move = 0;
  25 static int p2move = 0;
  26 static int score1 = 0;
  27 static int score2 = 0;
  28 static GLdouble paddle1 = 0.0;
  29 static GLdouble paddle2 = 0.0;
  30 static GLdouble ballX = 0.0;
  31 static GLdouble ballY = 0.0;
  32 static GLdouble ballVecX = 0.0;
  33 static GLdouble ballVecY = 0.0;
  34
  35
  36 static void initball(void) {
  37         ballX = 0.0;
  38         ballY = 0.0;
  39         if(ballVecX < 0)
  40                 ballVecX = -1.2;
  41         else
  42                 ballVecX = 1.2;
  43         ballVecY = 0.7;
  44 }
  45
  46 static void run(void) {
  47         // AI
  48         if(AI) {
  49                 if(ballY < paddle2 - PADDLESIZE)
  50                         p2move = -1;
  51                 else if(ballY > paddle2 + PADDLESIZE)
  52                         p2move = 1;
  53                 else
  54                         p2move = 0;
  55         }
  56
  57         // Move the paddles
  58         paddle1 += p1move * PADDLESPEED;
  59         paddle2 += p2move * PADDLESPEED;
  60         if(paddle1 < -HEIGHT)
  61                 paddle1 = -HEIGHT;
  62         if(paddle1 > HEIGHT)
  63                 paddle1 = HEIGHT;
  64         if(paddle2 < -HEIGHT)
  65                 paddle2 = -HEIGHT;
  66         if(paddle2 > HEIGHT)
  67                 paddle2 = HEIGHT;
  68
  69         // Check for collisions with paddles
  70         if(ballVecX < 0 && ballX <= -HEIGHT + -ballVecX * 1.5) {
  71                 if(ballY >= paddle1 - PADDLESIZE && ballY <= paddle1 + PADDLESIZE) {
  72                         GLdouble speedChange = fmax(1.0, fabs(paddle1 - ballY) * SPEEDBINC);
  73                         ballVecX *= -speedChange * SPEEDXINC;
  74                         ballVecY *= speedChange * SPEEDYINC;
  75                 }
  76         }
  77         if(ballVecX > 0 && ballX >=  HEIGHT - ballVecX * 1.5) {
  78                 if(ballY >= paddle2 - PADDLESIZE && ballY <= paddle2 + PADDLESIZE) {
  79                         GLdouble speedChange = fmax(1.0, fabs(paddle2 - ballY) * SPEEDBINC);
  80                         ballVecX *= -speedChange * SPEEDXINC;
  81                         ballVecY *= speedChange * SPEEDYINC;
  82                 }
  83         }
  84
  85         // Check if it's past the top or bottom of the screen
  86         if(ballY >= HEIGHT || ballY <= -HEIGHT) {
  87                 ballVecY = -ballVecY;
  88         }
  89
  90         // Check if it's past the sides of the screen
  91         if(ballX >= HEIGHT) {
  92                 ++score1;
  93                 initball();
  94         }
  95         if(ballX <= -HEIGHT) {
  96                 ++score2;
  97                 initball();
  98         }
  99
 100         // Move the ball
 101         ballX += ballVecX;
 102         ballY += ballVecY;
 103
 104         // Check scores for winners..
 105         if(score1 == 9) {
 106                 // Player 1 wins
 107                 score1 = score2 = 0;
 108         }
 109         if(score2 == 9) {
 110                 // Player 2 wins
 111                 score1 = score2 = 0;
 112         }
 113 }
 114
 115 static void display(void) {
 116         glClear(GL_COLOR_BUFFER_BIT);
 117         glColor3d(0.0, 0.0, 0.0);
 118
 119         // Draw the paddles
 120         glLineWidth(2.0);
 121         glBegin(GL_LINES);
 122         glVertex2d(-HEIGHT + 1, paddle1 - PADDLESIZE);
 123         glVertex2d(-HEIGHT + 1, paddle1 + PADDLESIZE);
 124         glVertex2d( HEIGHT - 1, paddle2 + PADDLESIZE);
 125         glVertex2d( HEIGHT - 1, paddle2 - PADDLESIZE);
 126         glEnd();
 127
 128         // Draw the ball
 129         glPointSize(5.0);
 130         glBegin(GL_POINTS);
 131         glVertex2d(ballX, ballY);
 132         glEnd();
 133
 134         // Write the score
 135         glRasterPos2d(-5.0, HEIGHT - 10.0);
 136         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score1);
 137         glRasterPos2d( 5.0, HEIGHT - 10.0);
 138         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score2);
 139
 140         glutSwapBuffers();
 141 }
 142
 143 static void resize(int w, int h) {
 144         glViewport(0, 0, w, h);
 145         glLoadIdentity();
 146         glOrtho(-HEIGHT, HEIGHT, -HEIGHT, HEIGHT, -1.0, 1.0);
 147 }
 148
 149 static void keyboard(unsigned char key, int x, int y) {
 150         (void)x;(void)y;
 151
 152         switch(key) {
 153                 case 'q':
 154                 case 'Q':
 155                 case '\033':
 156                         exit(0);
 157
 158                 case 'w':
 159                         p1move = 1;
 160                         break;
 161                 case 's':
 162                         p1move = -1;
 163                         break;
 164
 165                 case 'i':
 166                         p2move = 1;
 167                         break;
 168                 case 'k':
 169                         p2move = -1;
 170                         break;
 171
 172                 default:
 173                         return;
 174         }
 175         glutPostRedisplay();
 176 }
 177
 178 static void keyboardUp(unsigned char key, int x, int y) {
 179         (void)x;(void)y;
 180
 181         switch(key) {
 182                 case 'w':
 183                 case 's':
 184                         p1move = 0;
 185                         break;
 186
 187                 case 'i':
 188                 case 'k':
 189                         p2move = 0;
 190                         p2move = 0;
 191                         break;
 192         }
 193 }
 194
 195 static void timer(int lastTime) {
 196         int curTime = glutGet(GLUT_ELAPSED_TIME);
 197         do {
 198                 lastTime += FRAME;
 199                 run();
 200         } while(lastTime + FRAME < curTime);
 201         glutPostRedisplay();
 202         glutTimerFunc(FRAME - (curTime - lastTime), timer, curTime);
 203 }
 204
 205 static void init(void) {
 206         glClearColor(1.0, 1.0, 1.0, 0.0);
 207         initball();
 208 }
 209
 210 int main(int argc, char *argv[]) {
 211         if(argc == 2 && *argv[1] == '1') {
 212                 AI = 1;
 213         }
 214
 215         glutInitWindowPosition(100, 100);
 216         glutInitWindowSize(640, 480);
 217         glutInit(&argc, argv);
 218         glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
 219         glutCreateWindow(argv[0]);
 220         glutDisplayFunc(display);
 221         glutReshapeFunc(resize);
 222         glutKeyboardFunc(keyboard);
 223         glutKeyboardUpFunc(keyboardUp);
 224         glutTimerFunc(FRAME, timer, glutGet(GLUT_ELAPSED_TIME));
 225         init();
 226         glutMainLoop();
 227         return 0;
 228 }
 229