Merge pull request #1418 from The-E/shader_normal_fix

Fix bug in normal map rendering

Author: MageKing17

code/def_files/main-f.sdr

@@ -291,7 +291,7 @@ void main()
    // Normal map - convert from DXT5nm
    vec2 normalSample;
    normal.rg = normalSample = (texture(sNormalmap, texCoord).ag * 2.0) - 1.0;
-   normal.b = sqrt(1.0 - dot(normal.rg, normal.rg));
+   normal.b = clamp(sqrt(1.0 - dot(normal.rg, normal.rg)), 0.0001, 1.0);
    normal = fragTangentMatrix * normal;
    float norm = length(normal);
    // prevent breaking of normal maps