Text blitting is flashing

SDL Development
1

I’ve got a pretty simple drawing going on. I fill a rectangle the size of the display surface, then a smaller rectangle centered in that, then I blit two different strings’ pre-rendered surfaces on top of that.

The second of these two strings flashes on every call to SDL_Flip(); doesn’t matter which one I do first. That is, the two rectangles and first bit of text always look solid. The second piece of text flashes each time.

I’ve tried adding the SDL_DOUBLEBUF to my SetVideo call, makes no difference.

This is SDL 1.2/SDL_TTF 2.0 on OS X.

Any ideas what I might be doing wrong?–
Rick

2

post your codes

JetForMe wrote:> I’ve got a pretty simple drawing going on. I fill a rectangle the size of the display surface, then a smaller rectangle centered in that, then I blit two different strings’ pre-rendered surfaces on top of that.

The second of these two strings flashes on every call to SDL_Flip(); doesn’t matter which one I do first. That is, the two rectangles and first bit of text always look solid. The second piece of text flashes each time.

I’ve tried adding the SDL_DOUBLEBUF to my SetVideo call, makes no difference.

This is SDL 1.2/SDL_TTF 2.0 on OS X.

Any ideas what I might be doing wrong?

–
Rick

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http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

3

That’s going to be challenging. It’s a tiny view system, spanning half a dozen classes. Do you really want me to post it all?On Jun 23, 2014, at 00:36 , AlexRou wrote:

post your codes

JetForMe wrote:
I’ve got a pretty simple drawing going on. I fill a rectangle the size of the display surface, then a smaller rectangle centered in that, then I blit two different strings’ pre-rendered surfaces on top of that.

The second of these two strings flashes on every call to SDL_Flip(); doesn’t matter which one I do first. That is, the two rectangles and first bit of text always look solid. The second piece of text flashes each time.

I’ve tried adding the SDL_DOUBLEBUF to my SetVideo call, makes no difference.

This is SDL 1.2/SDL_TTF 2.0 on OS X.

Any ideas what I might be doing wrong?

–
Rick

SDL mailing list

http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

–
Rick

4

Ok then recreate this issue in a simple main function, if you cannot then you might want to check your classes and how you’re handling things

JetForMe wrote:> That’s going to be challenging. It’s a tiny view system, spanning half a dozen classes. Do you really want me to post it all?

On Jun 23, 2014, at 00:36 , AlexRou <@AlexRou> wrote:

post your codes

JetForMe wrote:
I’ve got a pretty simple drawing going on. I fill a rectangle the size of the display surface, then a smaller rectangle centered in that, then I blit two different strings’ pre-rendered surfaces on top of that.

The second of these two strings flashes on every call to SDL_Flip(); doesn’t matter which one I do first. That is, the two rectangles and first bit of text always look solid. The second piece of text flashes each time.

I’ve tried adding the SDL_DOUBLEBUF to my SetVideo call, makes no difference.

This is SDL 1.2/SDL_TTF 2.0 on OS X.

Any ideas what I might be doing wrong?

–
Rick

SDL mailing list

http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

–
Rick

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

5

Thanks much! In making the sample, I found that I was calling SDL_Flip() twice in a row. Strange that the results turned out the way they did, but I’m glad it’s fixed.On Jun 23, 2014, at 01:00 , AlexRou wrote:

Ok then recreate this issue in a simple main function, if you cannot then you might want to check your classes and how you’re handling things

JetForMe wrote:
That’s going to be challenging. It’s a tiny view system, spanning half a dozen classes. Do you really want me to post it all?

On Jun 23, 2014, at 00:36 , AlexRou <> wrote:

Quote:
post your codes

JetForMe wrote:
I’ve got a pretty simple drawing going on. I fill a rectangle the size of the display surface, then a smaller rectangle centered in that, then I blit two different strings’ pre-rendered surfaces on top of that.

The second of these two strings flashes on every call to SDL_Flip(); doesn’t matter which one I do first. That is, the two rectangles and first bit of text always look solid. The second piece of text flashes each time.

I’ve tried adding the SDL_DOUBLEBUF to my SetVideo call, makes no difference.

This is SDL 1.2/SDL_TTF 2.0 on OS X.

Any ideas what I might be doing wrong?

–
Rick

SDL mailing list

http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list

http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

–
Rick

SDL mailing list

http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

–
Rick