Pong is cool

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644 (file)
index 0000000..6961497
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,10 @@
+PROJECT(Pong)
+ADD_DEFINITIONS( -Wall -W )
+FIND_PACKAGE(OpenGL)
+FIND_PACKAGE(GLU)
+FIND_PACKAGE(GLUT)
+SET(GL_ALL ${OPENGL_LIBRARIES} ${GLU_LIBRARIES} ${GLUT_LIBRARIES})
+
+ADD_EXECUTABLE(pong pong.c)
+TARGET_LINK_LIBRARIES(pong ${GL_ALL})
+

diff --git a/pong.c b/pong.c
new file mode 100644 (file)
index 0000000..5f5ccf7
--- /dev/null
+++ b/pong.c
@@ -0,0 +1,172 @@
+#if defined(WIN32)
+#pragma comment(linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"")
+#include "glut.h"
+#elif defined(__APPLE__) || defined(MACOSX)
+#include <GLUT/glut.h>
+#else
+#include <GL/glut.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+enum {
+       FRAME=40,
+       HEIGHT=100,
+       PADDLESIZE=10
+};
+
+static int score1;
+static int score2;
+static GLdouble paddle1;
+static GLdouble paddle2;
+static GLdouble ballX;
+static GLdouble ballY;
+static GLdouble ballVecX;
+static GLdouble ballVecY;
+
+
+static void initball(void) {
+       ballX = 0.0;
+       ballY = 0.0;
+       if(ballVecX < 0)
+               ballVecX = -1.0;
+       else
+               ballVecX = 1.0;
+       ballVecY = 1.0;
+}
+
+static void run(void) {
+       // Check for collisions with paddles
+       if(ballVecX < 0 && ballX <= -HEIGHT + -ballVecX * 1.5) {
+               if(ballY >= paddle1 - PADDLESIZE && ballY <= paddle1 + PADDLESIZE) {
+                       ballVecX *= -1.15;
+                       ballVecY *= 1.15;
+               }
+       }
+       if(ballVecX > 0 && ballX >=  HEIGHT - ballVecX * 1.5) {
+               if(ballY >= paddle2 - PADDLESIZE && ballY <= paddle2 + PADDLESIZE) {
+                       ballVecX *= -1.15;
+                       ballVecY *= 1.15;
+               }
+       }
+
+       // Check if it's past the top or bottom of the screen
+       if(ballY >= HEIGHT || ballY <= -HEIGHT) {
+               ballVecY *= -1;
+       }
+
+       // Check if it's past the sides of the screen
+       if(ballX >= HEIGHT) {
+               ++score1;
+               initball();
+               return;
+       }
+       if(ballX <= -HEIGHT) {
+               ++score2;
+               initball();
+               return;
+       }
+
+       // Move the ball
+       ballX += ballVecX;
+       ballY += ballVecY;
+}
+
+static void display(void) {
+       glClear(GL_COLOR_BUFFER_BIT);
+       glColor3d(0.0, 0.0, 0.0);
+
+       // Draw the paddles
+       glLineWidth(2.0);
+       glBegin(GL_LINES);
+       glVertex2d(-HEIGHT + 1, paddle1 - PADDLESIZE);
+       glVertex2d(-HEIGHT + 1, paddle1 + PADDLESIZE);
+       glVertex2d( HEIGHT - 1, paddle2 + PADDLESIZE);
+       glVertex2d( HEIGHT - 1, paddle2 - PADDLESIZE);
+       glEnd();
+
+       // Draw the ball
+       glPointSize(5.0);
+       glBegin(GL_POINTS);
+       glVertex2d(ballX, ballY);
+       glEnd();
+
+       // Write the score
+       glRasterPos2d(-5.0, HEIGHT - 10.0);
+       glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score1);
+       glRasterPos2d( 5.0, HEIGHT - 10.0);
+       glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, '0' + score2);
+
+       glutSwapBuffers();
+}
+
+static void resize(int w, int h) {
+       glViewport(0, 0, w, h);
+       glLoadIdentity();
+       glOrtho(-HEIGHT, HEIGHT, -HEIGHT, HEIGHT, -1.0, 1.0);
+}
+
+static void keyboard(unsigned char key, int x, int y) {
+       (void)x;(void)y;
+
+       switch(key) {
+               case 'q':
+               case 'Q':
+               case '\033':
+                       exit(0);
+
+               case 'w':
+                       if(paddle1 + PADDLESIZE < HEIGHT)
+                               paddle1 += PADDLESIZE;
+                       break;
+               case 's':
+                       if(paddle1 - PADDLESIZE > -HEIGHT)
+                               paddle1 -= PADDLESIZE;
+                       break;
+
+               case 'i':
+                       if(paddle2 + PADDLESIZE < HEIGHT)
+                               paddle2 += PADDLESIZE;
+                       break;
+               case 'k':
+                       if(paddle2 - PADDLESIZE > -HEIGHT)
+                               paddle2 -= PADDLESIZE;
+                       break;
+
+               default:
+                       return;
+       }
+       glutPostRedisplay();
+}
+
+static void timer(int lastTime) {
+       int curTime = glutGet(GLUT_ELAPSED_TIME);
+       do {
+               lastTime += FRAME;
+               run();
+       } while(lastTime + FRAME < curTime);
+       glutPostRedisplay();
+       glutTimerFunc(FRAME - (curTime - lastTime), timer, curTime);
+}
+
+static void init(void) {
+       glClearColor(1.0, 1.0, 1.0, 0.0);
+       initball();
+}
+
+int main(int argc, char *argv[]) {
+       glutInitWindowPosition(100, 100);
+       glutInitWindowSize(640, 480);
+       glutInit(&argc, argv);
+       glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
+       glutCreateWindow(argv[0]);
+       glutDisplayFunc(display);
+       glutReshapeFunc(resize);
+       glutKeyboardFunc(keyboard);
+       glutTimerFunc(FRAME, timer, glutGet(GLUT_ELAPSED_TIME));
+       init();
+       glutMainLoop();
+       return 0;
+}
+