Sokol: State corruption issue with sokol_imgui.h + sokol_gl.h

[floooh]

In some situations, sokol_imgui.h doesn't seem to properly bind its font texture when sgl_draw() is called before simgui_render(). Need to investigate.

"it seems to me that simgui_render binds its pipeline properly, so I'm guessing there's leaked state from sgl_draw that I might need to restore? As a test, I'm calling only drawTriangle from sgl-sapp.c, which works. If I don't call drawTriangle (but do invoke sgl_draw()) then simgui_render works."

...this might also be a hole in the sokol-gfx validation layer(?).

[floooh]

Potential fix: https://github.com/floooh/sokol/commit/51f4c084c6ba117e12d612c6ab625c0fb1877aeb

Waiting for feedback...

[meshula]

This fixes the issue in my test program, thanks so much!!

[meshula]

Update - it looks like it's not completely fixed - if I tweak the drawTriangle routine thus:

c static void draw_triangle(void) { sgl_defaults(); static float wut = 0.f; sgl_scale(1.f + wut, 1.f, 1.f); wut += 0.015f; sgl_begin_triangles(); sgl_v2f_c3b(0.0f, 0.5f, 255, 0, 0); sgl_v2f_c3b(-0.5f, -0.5f, 0, 0, 255); sgl_v2f_c3b(0.5f, -0.5f, 0, 255, 0); sgl_end(); }

The triangle becomes clipped as it passes the center of the window. Pretty sure it's a hidpi thing - as a hack/test I hacked the SGL_COMMAND_VIEWPORT to adjust the viewport there, and the triangle appears in the middle of the screen rather than upper left-ish.

[floooh]

...next issue might be the leaked scissor-rect from simgui_render(), when this exits, the scissor rect will be set to whatever the last one was during UI rendering, until the next begin-pass call.

I'll set the scissor-rect to "fullscreen" on exiting simgui_render(), so that there's at least a guaranteed state.

PS: reading your description of the issue it might still be some other unrelated thing... I'll try to look into this today.

[floooh]

Potential fix (set viewport and scissor to 'fullscreen' in simgui_render() entry and exit): https://github.com/floooh/sokol/commit/1dde6a20860e86c96572bb65d8145f1d0360f132

(even if it doesn't fix the specific issue it's the right thing to do IMHO)

[meshula]

I think everything is working properly now. My objects clip to the screen as expected, and are also the expected size. Thanks again!

[floooh]

Ok great :) Closing the issue again, for now ;)