Window not updating correctly?
Author
In the quest for making a Tetris clone, I have run into yet another problem. For some reason, when I'm dropping my block, it doesn't clear the part above where the block was, leaving a streak effect like this:
Picture
Why doesn't it clean up after itself?
(source code removed; see below for updated code)
[Edited by - adam_o on May 5, 2007 7:18:17 PM]
Author
Do I need to clear it and re-draw the entire scene every time I update something? Isn't that a little excessive? Or am I just not understanding this correctly? Thank you for the help!
Edit: where did that post go?
Edit: where did that post go?
void GameApp::GameLoop(){ srand(time(NULL)); glClear(GL_COLOR_BUFFER_BIT); gameinprogress = 1; RenderFrame(); }I see you are clearing the pixel buffer each frame, but have you
set a background color? ie glClearColor()? I dont see it in
your code.
Also, you should seed the random number generator only once when your
program terminates. Try this:
void GameApp::GameLoop(){ // srand(time(NULL)); // Put in init routine glClearColor (0.0f,0.0f,0.0f,0.5f); glClear(GL_COLOR_BUFFER_BIT); gameinprogress = 1; RenderFrame(); }Quote:
Do I need to clear it and re-draw the entire scene every time I update something? Isn't that a little excessive? Or am I just not understanding this correctly? Thank you for the help!
No--One only needs to clear the screen/backbuffer. One should also
clear the Z buffer each frame, if it is being used.
Quote:
Edit: where did that post go?
I deleted it when I seen the link for your code. I wanted to provide
more help[smile] Also, I didnt know you were mixing SDL/OpenGL.
Author
Hmm... I had the glClearColor function in the header file (background_data() function) so I moved it to GameLoop() as you suggested... but it still doesn't work... I have a feeling that I didn't declare enough somewhere... am I supposed to clear something else after I clear the color?
New code
New code
Author
Quote:Quote:
Do I need to clear it and re-draw the entire scene every time I update something? Isn't that a little excessive? Or am I just not understanding this correctly? Thank you for the help!
No--One only needs to clear the screen/backbuffer. One should also
clear the Z buffer each frame, if it is being used.Quote:
Edit: where did that post go?
I deleted it when I seen the link for your code. I wanted to provide
more help[smile] Also, I didnt know you were mixing SDL/OpenGL.
Ok, I didn't quite understand that whole clearing thing, (I'm better at understanding by looking at the code itself [smile]) so what do I need to add to my code, and where? (i.e. "add glClearColor() into the RenderFrame() function)
I notice you are flushing using OpenGL's buffers first, then rendering
over it. What exactally is being flushed?
Try this:
I use OpenGL (Not SDL), but this might be the problem.
What I mean is clearing both the color and z buffer:
over it. What exactally is being flushed?
void GameApp::RenderFrame(){//etc.. glFlush(); //flush buffers--we are flushing //previous frame contents translate(); // render frame cornery--; }}Try this:
void GameApp::RenderFrame(){//etc.. // no glFlush() translate(); // render frame cornery--; }}void translate(){//etc... show_tile(); background_data(); glFlush (); SDL_GL_SwapBuffers();}I use OpenGL (Not SDL), but this might be the problem.
Quote:
Ok, I didn't quite understand that whole clearing thing,
What I mean is clearing both the color and z buffer:
glClear (GL_COLOR_BUFFER|GL_DEPTH_BUFFER);
Author
Quote:Original post by Crypter
I notice you are flushing using OpenGL's buffers first, then rendering
over it. What exactally is being flushed?void GameApp::RenderFrame(){//etc.. glFlush(); //flush buffers--we are flushing //previous frame contents translate(); // render frame cornery--; }}
Try this:
*** Source Snippet Removed ***
I use OpenGL (Not SDL), but this might be the problem.Quote:
Ok, I didn't quite understand that whole clearing thing,
What I mean is clearing both the color and z buffer:glClear (GL_COLOR_BUFFER|GL_DEPTH_BUFFER);
Thank you for clearing that up. Since I'm using gluOrtho2D(), I don't need to deal with the z buffer, though... but thank you for the update on the location of glFlush().
Unfortunately, it still does not work. [sad]
I just set up SDL, but am having some difficaulties setting the
project properties correctly (As stated before, I never used SDL :) )
(The problem Im having is that SDL routines are executing, but all routines
fail)
If you can upload your project file, Ill see if I can debug it.
project properties correctly (As stated before, I never used SDL :) )
(The problem Im having is that SDL routines are executing, but all routines
fail)
If you can upload your project file, Ill see if I can debug it.
Author
Quote:Original post by Crypter
I just set up SDL, but am having some difficaulties setting the
project properties correctly (As stated before, I never used SDL :) )
(The problem Im having is that SDL routines are executing, but all routines
fail)
If you can upload your project file, Ill see if I can debug it.
Do you use a Mac? Because otherwise, it won't work...
Quote:
Do you use a Mac? Because otherwise, it won't work...
Sorry-nope. (I use MSVC++ 8 on WinXP SP2)
Coinsidering OpenGL/SDL are portable, Can you tell me the
project configuations?
This topic is closed to new replies.
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