SDL2 texture repeat / wrapping property

Question

I want to use texture repeat with SDL2 (SDL_RenderCopy), and couldn't find how. by texture repeat I mean to give texture coords twice the size of the texture and have it tiled twice over the surface. like this: http://www.felixgers.de/teaching/jogl/textureClamp.html

anyone knows how to do it in SDL? do I need to access openGL functions myself?

thanks,

Zammalad Zammalad · Accepted Answer · 2014-07-30T15:11:47

It's not an ideal solution but if you don't want to go down the route of using OpenGL functions:

glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, DEFAULT_TEXTURE_WRAP );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, DEFAULT_TEXTURE_WRAP );

Then you could calculate the source and destination rects on the fly as you draw. For example lets imagine you have a texture that is 100x100 and a screen drawing area 150x150. Starting at the top left you would see you can fit the full texture in on the first call

SDL_Rect dest = {0,0,100,100}
SDL_RenderCopy(renderer, texture, NULL, &dest);

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|    |  |
|    |  |
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|       |
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So now you can see that you have to draw only 50 pixels width of the texture but still the full height and starting at the point 100,0

SDL_Rect src = {0,0,50,100}
SDL_Rect dest = {100,0,50,100}
SDL_RenderCopy(renderer, texture, &src, &dest);

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|    |  |
|    |  |
--------|
|       |
---------

You could work that in to a bit of an iteration and tidy up the calculation to get it to work for you. As I say it isn't ideal but it is an alternative.

SDL2 texture repeat / wrapping property

1 Answers