Louis Régnier authored Nov 29, 2021 and Hugo Beauzée-Luyssen committed Dec 02, 2021

Without specifying the version, libplacebo might generate shaders with
a different version from the one we specified, leading to usage of
function that might not be available.

A typical failure would lead to such error messages:

    gl gl: Initialized libplacebo v3.120.3 (API v120)
    gl gl error: shader 0: 0:22(13): error: no matching function for
    call to `mix(vec3, vec3, bvec3)'; candidates are:

    0:22(13): error:    float mix(float, float, float)
    0:22(13): error:    vec2 mix(vec2, vec2, float)
    0:22(13): error:    vec3 mix(vec3, vec3, float)
    0:22(13): error:    vec4 mix(vec4, vec4, float)
    0:22(13): error:    vec2 mix(vec2, vec2, vec2)
    0:22(13): error:    vec3 mix(vec3, vec3, vec3)
    0:22(13): error:    vec4 mix(vec4, vec4, vec4)

Fixes #25324



Co-authored-by: Alexandre Janniaux <ajanni@videolabs.io>