Unity records some glsl and hlsl shader reverse code

The following content is generally based on GLSL 300

Some of the following lines of code are "pseudocode", and most of them are renderDoc reverse engineering to generate standard code.

I have zero foundation in OpenlGL, and I don't plan to learn it all over again.

Table of contents

Clip() remove function discard;

FS final color output out and final color addition equation

---

Clip() remove function discard;

    _21 = texture(_7, _14);
    //.................
    _26 = _21.w + (-_33._m4);
    _29 = _21.xyz * _33._m3.xyz;
    _24 = _26 < 0.0;
    if (_24)
    {
        discard;
    }

From the discard; command, we can know that it is usually eliminated through transparency, _26 == color.a

_21.w just corresponds to color.a

Obviously: _21 == _color; is the color of v2f

Push it up and learn that _14 == uv

FS module color output out and final color addition equation

#if FS
layout(location = 0) out vec4 _17;
//因为 —17为最终输出，所以通过逆向如下
//关键在于下面的方程式 _125 = XXXXXX + _XX;
main(){
    vec3 _125 = (_29 * vec3(_26)) + _28;
    _17 = vec4(_125.x, _125.y, _125.z, _17.w);
    _17.w = 1.0;//这行代码，不重要
}

For, this equation (find -_125 color)

vec3 _125 = (_29 * vec3(_26)) + _28;

We assume it is diffuse + ambient light (ambient)

So, _28 may be diffuse or ambient

Because the first half of the equation is multiplied by a dot product (dot direction), the first half is likely to be diffuse reflection

Therefore, _28 is inferred as ambient light, because ambient light is not needed

_26 = dot(_27, _19);
_28 = _29 * _33._m1.xyz;// _33.m1 是很奇怪的传入（binding==1）
_29 *= _33._m2.xyz;//虽然_33.m2也很奇怪

References - Extra:

Layout Qualifier (GLSL) - OpenGL Wiki (khronos.org)

opengl - GLSL Uniform layout binding and textures - Stack Overflow

Advanced GLSL - LearnOpenGL-CN

The above links include wikis, technical forum discussions, Chinese forums and other information. They are all rare first-hand information (in fact, they are quite bad. Search online and you will find a lot of them).