LWJGL Forum

I'm using this code in conjunction with an AWTGLCanvas:


public static boolean drawTo(int target, int width, int height) // target = texture ID.
{
if(renderToTextureCapable())
{
IntBuffer buffer = ByteBuffer.allocateDirect(4).order(
ByteOrder.nativeOrder()).asIntBuffer();

EXTFramebufferObject.glGenFramebuffersEXT(buffer);

int fbo =  buffer.get();

EXTFramebufferObject.glBindFramebufferEXT(
EXTFramebufferObject.GL_FRAMEBUFFER_EXT,
fbo);

EXTFramebufferObject.glFramebufferTexture2DEXT(
EXTFramebufferObject.GL_FRAMEBUFFER_EXT,
EXTFramebufferObject.GL_COLOR_ATTACHMENT0_EXT,
GL11.GL_TEXTURE_2D,
target,
0);

checkFBO(fbo);

GL11.glPushAttrib(GL11.GL_COLOR_BUFFER_BIT);
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
GL11.glColor4f(1f, 1f, 1f, 1f);

GL11.glPushAttrib(GL11.GL_VIEWPORT_BIT);
GL11.glViewport(0, 0, width, height);

GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPushMatrix();
GL11.glLoadIdentity();
GL11.glOrtho(0, width, 0, height, -1, 1);

GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glPushMatrix();
GL11.glLoadIdentity();

return true;
}
return false;
}

public static boolean finishDrawing()
{
if(renderToTextureCapable() && renderingToTexture())
{
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPopMatrix();

GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glPopMatrix();

GL11.glPopAttrib();
GL11.glPopAttrib();

EXTFramebufferObject.glBindFramebufferEXT(
EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0);
return true;
}
return false;
}

public static void checkFBO(int FBOID)
{
int status = EXTFramebufferObject.glCheckFramebufferStatusEXT(
EXTFramebufferObject.GL_FRAMEBUFFER_EXT);

switch(status)
{
case EXTFramebufferObject.GL_FRAMEBUFFER_COMPLETE_EXT:
break;
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID + ", " +
"has caused a GL_FRAMEBUFFER_INCOMPLETE_ATTACHMEN" +
"T_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_MISSI" +
"NG_ATTACHMENT_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DIMEN" +
"SIONS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DRAW_" +
"BUFFER_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_FORMA" +
"TS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
throw new RuntimeException( "FrameBuffer: " + FBOID
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_READ_" +
"BUFFER_EXT exception" );
default:
throw new RuntimeException( "Unexpected reply from glCheckFr" +
"amebufferStatusEXT: " + status );
}
}


On the AWTGLCanvas, I have an image that I render to and then display on the canvas. I render-to-texture every frame.

This causes a memory leak, where for some reason more and more page file memory starts being used. The rate of increase is significant - it's taken about 200 megs in 20-30 seconds.

Has anyone had this happen before?

It looks like you're creating a new FBO every frame. That would explain it.

How should I delete the FBO?

Quote from: CodeBunny on June 01, 2011, 20:38:23
How should I delete the FBO?

I would think it would be better and faster to just re-use the FBO you create.

Good point.

Thanks, this was kind of a dumb bug of mine but the advice helped a lot.