opengl - Compatibility issues on GLSL fragment shaders -

opengl - Compatibility issues on GLSL fragment shaders -

i have found few times differences between gpus handling fragment shaders. 1 illustration doing pow(x) x negative. 1 gpu handled while other 1 failed.

another situation rewrote if() statements step() statement , shader worked well. blamed branching limit or something.

now in situation fragment shader works on gpus , on don't. have tried search gpu/shader limits , similar info found nothing.

the current test works everywhere tried except on gtx 780 here online(shadertoy)

i asking directions or link shader limitations , mutual issues in compatibility.

shader limitations , specification, vendor-specific, , changing along gpu architecture versions.

simply put, there's no unified way "rule them all". gpus handle branching differently, better, worse. gpus allow negative values in math functions, don't. quite depends on architecture that's been used, version of shading language , instructions allowed in compiled version of shader.

instead of reading , trying larn works on card, it's best try/test shader on specific gpu. that's reasonable decision regarding resources spent trying "fix issue".

to reply question directly, there's no (easy-to-find) resource lists entire specification of compiler used on specific architecture, follow tips'n'trick learned along way , apply suggestions , observations made others.

opengl glsl shader fragment-shader pixel-shader