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   0.15
  18 #define PADDLESPEED 3.0
  19 #define FRAME       40
  20 #define PADDLESIZE  10
  21 #define HEIGHT      100
  22
  23 #define STATE_UI 0
  24 #define STATE_1P 1
  25 #define STATE_2P 2
  26
  27 static char* menu = "";
  28 static int state  = 0;
  29 static int p1move = 0;
  30 static int p2move = 0;
  31 static int score1 = 0;
  32 static int score2 = 0;
  33 static GLdouble paddle1 = 0.0;
  34 static GLdouble paddle2 = 0.0;
  35 static GLdouble ballX = 0.0;
  36 static GLdouble ballY = 0.0;
  37 static GLdouble ballVecX = 0.0;
  38 static GLdouble ballVecY = 0.0;
  39
  40
  41 static void initBall(void) {
  42         ballX = 0.0;
  43         ballY = 0.0;
  44         if(ballVecX < 0)
  45                 ballVecX = -1.2;
  46         else
  47                 ballVecX = 1.2;
  48         ballVecY = 0.7;
  49 }
  50
  51 static void run(void) {
  52         // AI is on
  53         if(state == STATE_1P) {
  54                 if(ballY < paddle2 - PADDLESIZE)
  55                         p2move = -1;
  56                 else if(ballY > paddle2 + PADDLESIZE)
  57                         p2move = 1;
  58                 else
  59                         p2move = 0;
  60         }
  61
  62         // Move the paddles
  63         paddle1 += p1move * PADDLESPEED;
  64         paddle2 += p2move * PADDLESPEED;
  65         if(paddle1 < -HEIGHT)
  66                 paddle1 = -HEIGHT;
  67         if(paddle1 > HEIGHT)
  68                 paddle1 = HEIGHT;
  69         if(paddle2 < -HEIGHT)
  70                 paddle2 = -HEIGHT;
  71         if(paddle2 > HEIGHT)
  72                 paddle2 = HEIGHT;
  73
  74         // Check for collisions with paddles
  75         if(ballVecX < 0 && ballX <= -HEIGHT + -ballVecX * 1.5) {
  76                 if(ballY >= paddle1 - PADDLESIZE && ballY <= paddle1 + PADDLESIZE) {
  77                         GLdouble speedChange = fmax(1.0, fabs(paddle1 - ballY) * SPEEDBINC);
  78                         ballVecX *= -speedChange * SPEEDXINC;
  79                         ballVecY *= speedChange * SPEEDYINC;
  80                 }
  81         }
  82         if(ballVecX > 0 && ballX >=  HEIGHT - ballVecX * 1.5) {
  83                 if(ballY >= paddle2 - PADDLESIZE && ballY <= paddle2 + PADDLESIZE) {
  84                         GLdouble speedChange = fmax(1.0, fabs(paddle2 - ballY) * SPEEDBINC);
  85                         ballVecX *= -speedChange * SPEEDXINC;
  86                         ballVecY *= speedChange * SPEEDYINC;
  87                 }
  88         }
  89
  90         // Check if it's past the top or bottom of the screen
  91         if(ballY >= HEIGHT || ballY <= -HEIGHT) {
  92                 ballVecY = -ballVecY;
  93         }
  94
  95         // Check if it's past the sides of the screen
  96         if(ballX >= HEIGHT) {
  97                 ++score1;
  98                 initBall();
  99         }
 100         if(ballX <= -HEIGHT) {
 101                 ++score2;
 102                 initBall();
 103         }
 104
 105         // Move the ball
 106         ballX += ballVecX;
 107         ballY += ballVecY;
 108
 109         // Check scores for winners..
 110         if(score1 == 9) {
 111                 menu = "Player 1 wins!";
 112                 state = STATE_UI;
 113                 score1 = score2 = 0;
 114         }
 115         if(score2 == 9) {
 116                 menu = "Player 2 wins!";
 117                 state = STATE_UI;
 118                 score1 = score2 = 0;
 119         }
 120 }
 121
 122 static void timer(int lastTime) {
 123         if(state == STATE_UI) {
 124                 return;
 125         }
 126
 127         int curTime = glutGet(GLUT_ELAPSED_TIME);
 128         do {
 129                 lastTime += FRAME;
 130                 run();
 131         } while(lastTime + FRAME < curTime);
 132         glutPostRedisplay();
 133         glutTimerFunc(FRAME - (curTime - lastTime), timer, curTime);
 134 }
 135
 136 static void startGame(void) {
 137         glutTimerFunc(FRAME, timer, glutGet(GLUT_ELAPSED_TIME));
 138         initBall();
 139 }
 140
 141 static void drawText(double x, double y, char* str) {
 142         glRasterPos2d(x, y);
 143         while(*str) {
 144                 glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, *str);
 145                 ++str;
 146         }
 147 }
 148
 149 static void menuDisplay(void) {
 150         drawText(-20, 50, "Awesome PONG!");
 151         drawText(-50, -50, "Press 1 for a single player game.");
 152         drawText(-50, -60, "Press 2 for a multi player game.");
 153         drawText(-50, -70, "Keys: w/s and i/k");
 154         drawText(-20, 0, menu);
 155 }
 156
 157 static void gameDisplay(void) {
 158         // Draw the paddles
 159         glLineWidth(2.0);
 160         glBegin(GL_LINES);
 161         glVertex2d(-HEIGHT + 1, paddle1 - PADDLESIZE);
 162         glVertex2d(-HEIGHT + 1, paddle1 + PADDLESIZE);
 163         glVertex2d( HEIGHT - 1, paddle2 + PADDLESIZE);
 164         glVertex2d( HEIGHT - 1, paddle2 - PADDLESIZE);
 165         glEnd();
 166
 167         // Draw the ball
 168         glBegin(GL_LINES);
 169         glVertex2d(ballX, ballY);
 170         glVertex2d(ballX - ballVecX, ballY - ballVecY);
 171         glEnd();
 172
 173         // Write the score
 174         glRasterPos2d(-5.0, HEIGHT - 10.0);
 175         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score1);
 176         glRasterPos2d( 5.0, HEIGHT - 10.0);
 177         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score2);
 178 }
 179
 180 static void display(void) {
 181         glClear(GL_COLOR_BUFFER_BIT);
 182         glColor3d(0.0, 0.0, 0.0);
 183
 184         if(state == STATE_UI) {
 185                 menuDisplay();
 186         } else {
 187                 gameDisplay();
 188         }
 189
 190         glutSwapBuffers();
 191 }
 192
 193 static void resize(int w, int h) {
 194         glViewport(0, 0, w, h);
 195         glLoadIdentity();
 196         glOrtho(-HEIGHT, HEIGHT, -HEIGHT, HEIGHT, -1.0, 1.0);
 197 }
 198
 199 static void menuKeyboard(unsigned char key) {
 200         switch(key) {
 201                 case '1':
 202                         state = STATE_1P;
 203                         break;
 204
 205                 case '2':
 206                         state = STATE_2P;
 207                         break;
 208
 209                 default:
 210                         return;
 211         }
 212         startGame();
 213 }
 214
 215 static void gameKeyboard(unsigned char key) {
 216         switch(key) {
 217                 case 'w':
 218                         p1move = 1;
 219                         break;
 220                 case 's':
 221                         p1move = -1;
 222                         break;
 223
 224                 case 'i':
 225                         p2move = 1;
 226                         break;
 227                 case 'k':
 228                         p2move = -1;
 229                         break;
 230
 231                 default:
 232                         return;
 233         }
 234         glutPostRedisplay();
 235 }
 236
 237 static void keyboard(unsigned char key, int x, int y) {
 238         (void)x;(void)y;
 239
 240         switch(key) {
 241                 case 'q':
 242                 case 'Q':
 243                 case '\033':
 244                         exit(0);
 245         }
 246
 247
 248         if(state == STATE_UI) {
 249                 menuKeyboard(key);
 250         } else {
 251                 gameKeyboard(key);
 252         }
 253 }
 254
 255 static void keyboardUp(unsigned char key, int x, int y) {
 256         (void)x;(void)y;
 257
 258         switch(key) {
 259                 case 'w':
 260                 case 's':
 261                         p1move = 0;
 262                         break;
 263
 264                 case 'i':
 265                 case 'k':
 266                         p2move = 0;
 267                         p2move = 0;
 268                         break;
 269         }
 270 }
 271
 272 int main(int argc, char *argv[]) {
 273         glutInitWindowPosition(100, 100);
 274         glutInitWindowSize(640, 480);
 275         glutInit(&argc, argv);
 276         glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
 277         glutCreateWindow(argv[0]);
 278         glutDisplayFunc(display);
 279         glutReshapeFunc(resize);
 280         glutKeyboardFunc(keyboard);
 281         glutKeyboardUpFunc(keyboardUp);
 282         glClearColor(1.0, 1.0, 1.0, 0.0);
 283         glutMainLoop();
 284         return 0;
 285 }
 286