• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.


This topic is now archived and is closed to further replies.


Need help in drawing moving and bouncing ball

2 posts in this topic

I was currently given an assignment. Since I just started learning OpenGL (and worse, most of them are theories), thus I have no idea on how to program it. Below is the question: ================================================================ Implement a C/C++ interactive graphics program that "moving and bouncing (no gravity applied) a ball in a window" A Ball is drawn (as circle) with in multiple color to make it''s rotation clear. Implement keyboard call back function that: 1. enlarge the ball radius when press ''R'' 2. reduce the ball radius while press ''r'' 3. increase the ball velocity while press ''V'' 4. reduce the ball velocity while press ''v'' 5. increase ball direction angle (anti-clockwise) while press ''T'' 6. reduce the ball direction angle (anti-clockwise) while press ''t'' 7. increase the ball spinning speed (anti-clockwise) while press ''A'' 8. decrease the ball spinning speed (anti-clockwise) while press ''a'' Implement mouse call back function that: 1. Start / continue animation of the ball while left mouse button is pressed. 2. Pause animation while right mouse button is press ================================================================ Any help will be appreciated. Thanks.

Share this post

Link to post
Share on other sites
You should first try to do it yourself before asking. The NeHe tutorials is probably covering everything you need to know.

Share this post

Link to post
Share on other sites
So far I just managed to draw a filled circle. The problem now is how to make it move and rotate after I left-click the mouse. From what I know there are functions called:
glTranslate{fd}( dx, dy, dz );
glRotate{fd}( angleInDegrees, axisXvalue, axisYvalue, axisZvalue);

Just wondering how to implement it on my source file... I tried once but the window goes blank when I left click on it..
Below is my souce code so far (the transformation function is called rollCircle()):


void drawCircle()
float originY=100;
float originX=100;
float radius=20;
float vectorX;
float vectorY;
float vectorY1;
float vectorX1;
float angle;
for(int i=0; i<=360;i++)
if(i>120 && i<=240)


void rollCircle()
//need help on this


void myMouse(int button, int state, int x, int y)
if ( button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
glutIdleFunc(rollCircle); // starts animation

else if ( button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN)
glutIdleFunc(NULL); // stops animation


void myDisplay()

void myInit(void)

void main(int argc, char **argv)
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);

Thanks for any help.

Edited by - cwchan on October 21, 2001 6:12:18 AM

Share this post

Link to post
Share on other sites