• 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.
Sign in to follow this  
Followers 0

Trouble getting back buffer with glCopyTexImage2D

1 post in this topic

I'm attempting to capture the back buffer on a texture, and then in an attempt to make sure its working, simply redraw the texture on the screen. I've copied the appropriate sections of code line for line from a tutorial example. The example compiles and works, mine doesn't. I can't for the life of me understand why.


Here the is initialization code that creates the empty texture:


glClearColor( 0.0f, 0.0f, 0.0f, 1.0f);  // set clear color to black

unsigned int *empty = new unsigned int[((glutGet(GLUT_WINDOW_WIDTH) * glutGet(GLUT_WINDOW_HEIGHT))* 4 * sizeof(unsigned int))];

glEnable( GL_TEXTURE_2D );
glGenTextures( 1, &texture_buffer );
glBindTexture( GL_TEXTURE_2D, texture_buffer);

glBindTexture(GL_TEXTURE_2D, 0);

glBindTexture( GL_TEXTURE_2D, 0);
delete [] empty;


Here is the code that draws the scene, grabs it off the back buffer, then for testing, attempts to draw the texture to the screen:


glClear( GL_COLOR_BUFFER_BIT );   

glBindTexture(GL_TEXTURE_2D, texture_buffer);
glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, glutGet(GLUT_WINDOW_WIDTH), glutGet(GLUT_WINDOW_HEIGHT), 0);
glBegin( GL_QUADS );
    glTexCoord2f(0,1); glVertex2f(WORLD_LEFT, WORLD_TOP);     
    glTexCoord2f(1,1); glVertex2f(WORLD_RIGHT, WORLD_TOP);    
    glTexCoord2f(1,0); glVertex2f(WORLD_RIGHT, WORLD_BOTTOM); 
    glTexCoord2f(0,0); glVertex2f(WORLD_LEFT, WORLD_BOTTOM);  
glBindTexture(GL_TEXTURE_2D, 0);


Anything seem out of place?



Share this post

Link to post
Share on other sites

Some general comment...

  1. You don't need to allocate an empty buffer to create an empty texture. You can just pass a null pointer to glTexImage to just allocate the texture memory.
  2. You should use glCopyTexSubImage to update an existing texture. glCopyTexImage creates an entirely new texture from scratch which is not what you want to do in this case.
  3. You don't need to enable texturing just to bind and create your texture. The texture enable state is only used for applying texturing when drawing, but not for managing the texture object.

... and a possible cause of your error.

  1. You should clear the depth buffer also. What you draw to the frame buffer is cleared after copying to the texture and before drawing the quad, but the depth buffer is not cleared and what remains in there from rendering the texture-image bay prevent the quad from being drawn.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0