Question

My program renders large jpegs as textures one at a time and allows the user to switch between them by re-using the “same” texture.

I call glGenTextures(1, &texture); once at the start.

Then each time I want to swap the image I use:

FreeTexture( texture );
ROI_img = fetch_image(temp, sortVector[tPiece]);

loadTexture_Ipl( ROI_img , &texture );

here are the two functions being called:

int loadTexture_Ipl(IplImage *image, GLuint *text)
{
    if (image==NULL) return -1;
    glBindTexture( GL_TEXTURE_2D, *text );

    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, ROI_WIDTH, ROI_HEIGHT,0, GL_BGR, GL_UNSIGNED_BYTE, image->imageData);
    return 0;
}

void FreeTexture(GLuint texture)
{
    glDeleteTextures( 1, &texture);
}

My problem is that after a couple of images they stop rendering (texture is all black). If I keep trying to switch I get this error message:

test(55248,0xacdf22c0) malloc: *** mmap(size=744001536) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
Mar 19 11:57:51 Ants-MacBook-Pro.local test[55248] <Error>: CGSImageDataLock: Cannot allocate memory

I thought that glDeleteTextures would free the memory each time??

Any ideas on how to better implement this?

p.s. here is a screen of the memory leaks being encountered (https://p.twimg.com/AoWVy8FCMAEK8q7.png:large)

Answer 1

Since you want to reuse your texture, you shouldn’t delete it with glDeleteTextures. If you do that, you need to create a new texture using glGenTextures, and I don’t see you are doing it in the loadTexture_Ipl function.