SDL_RenderTextureTiled in Emscripten

[brccabral]

Hi,
SDL_RenderTextureTiled works fine in executables, but not in Emscripten.

    SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
    SDL_RenderClear(renderer);
    SDL_RenderTextureTiled(renderer, texture,  NULL, 1, NULL);
    SDL_RenderPresent(renderer);

[icculus]

Confirmed broken here. It works with a src_rect and dst_rect specified, but doesn't appear to draw anything if you pass NULL and NULL (to fill the whole screen with the bitmap, tiled). Checking why...

[icculus]

It's not the opengles2 renderer in general, that is also working on desktop here.

[icculus]

I'm bouncing over to an urgent SDL2 issue for now, but this works on Emscripten if you force SDL_RenderTextureTiled() to take the SDL_RenderTextureTiled_Iterate() approach instead of the SDL_RenderTextureTiled_Wrap() path, but I haven't looked closer as to why, yet.

[icculus]

Oh, here you go, written in the Firefox console:

WebGL warning: drawArraysInstanced: TEXTURE_2D at unit 0 is incomplete: Non-power-of-two textures must have a wrap mode of CLAMP_TO_EDGE.

SDL_RenderTextureTiled_Wrap() tries to draw with a wrap mode of GL_REPEAT, so that's why that is failing here.

To fix, we should be checking for the GL_ARB_texture_non_power_of_two extension in OpenGL ES 2, and using SDL_RenderTextureTiled_Iterate() if the extension isn't there and the texture is NPOT. OpenGL ES 3 has this functionality in the Core profile, so this is strictly a GLES2 issue (and, I suppose, a pre-OpenGL2 thing too, as GL2 has it in Core as well).

This might take a little reworking to do this. I'll take a look and see if it's reasonable to do so. If not, I'll slap an #ifdef on the thing and call it good enough for now.

[slouken]

Not supporting GL_REPEAT is potentially a showstopper for the new wrap modes in SDL 3.4...

[icculus]

potentially a showstopper for the new wrap modes in SDL 3.4

I just pushed a fix for this issue's specific problem, but I have to look at the 3.4 wrap mode stuff, then. I'll open a new issue.