[DesktopGL] Pixel Shader compilation failed in runtime

[demonixis]

Hello,

I'm working on an engine called C3DE, it supports Windows and DesktopGL. Recently I've a serious issue with all my shaders for DesktopGL. The compilation from HLSL to GLSL is fine with the Pipeline tool. My code is well generated into XNB. However, when I try to use some of my shaders, it fails with a this message: An unhandled exception of type 'System.AccessViolationException' occurred in Unknown Module.

After some debugging, I found a part of the problem

The DrawIndexedPrimitives function will call many functions.

• Link(Shader vs, Shader ps) in ShaderProgramCache.cs
• GetShaderInfoLog in OpenGL.cs
• And finally GetShaderInfoLogInternal

This is the last one which causes the crash. The Vertex Program is fine, it's hashkey is normal. However almost all my pixel shader have a negative hashkey and those ones failed to compile.

This is the pixel shader generated by Pipeline

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

uniform vec4 ps_uniforms_vec4[4];
const vec4 ps_c4 = vec4(-1.0, 0.0, 1.0, 0.0);
const vec4 ps_c5 = vec4(-1.0, -2.0, -3.0, 0.0);
vec4 ps_r0;
vec4 ps_r1;
vec4 ps_r2;
vec4 ps_r3;
vec4 ps_r4;
#define ps_c0 ps_uniforms_vec4[0]
#define ps_c1 ps_uniforms_vec4[1]
#define ps_c2 ps_uniforms_vec4[2]
#define ps_c3 ps_uniforms_vec4[3]
uniform samplerCube ps_s0;
varying vec4 vTexCoord0;
#define ps_v0 vTexCoord0
#define ps_oC0 gl_FragColor

void main()
{
	ps_r0.xy = ps_c4.xy;
	ps_r0.x = ps_r0.x + ps_c3.x;
	ps_r1.xyz = normalize(ps_v0.xyz);
	ps_r1 = textureCube(ps_s0, ps_r1.xyz);
	if (-ps_r0.x != ps_r0.x) {
		ps_r2 = ps_c4.yyyy;
	} else {
		if (-ps_c1.x < ps_r0.y) {
			ps_r0.z = ps_v1.x * ps_v1.x;
			ps_r0.w = ps_c1.y * ps_c1.y;
			ps_r0.z = ps_r0.z * ps_r0.w;
			ps_r0.w = log2(ps_c0.x);
			ps_r0.z = ps_r0.w * ps_r0.z;
			ps_r0.z = exp2(ps_r0.z);
			ps_r0.z = 1.0 / ps_r0.z;
			ps_r3.x = fract(ps_c1.x);
			ps_r3.y = ((-ps_r3.x >= 0.0) ? ps_c4.y : ps_c4.z);
			ps_r0.y = ((ps_c1.x >= 0.0) ? ps_r0.y : ps_r3.y);
			ps_r3.x = -ps_r3.x + ps_c1.x;
			ps_r0.y = ps_r0.y + ps_r3.x;
			ps_r3.x = ps_c1.y * ps_v1.x;
			ps_r0.w = ps_r0.w * ps_r3.x;
			ps_r0.w = exp2(ps_r0.w);
			ps_r0.w = 1.0 / ps_r0.w;
			ps_r3.xyz = ps_r0.yyy + ps_c5.xyz;
			ps_r0.z = ((-abs(ps_r3.z) >= 0.0) ? ps_r0.z : ps_c4.z);
			ps_r0.z = ((-abs(ps_r3.y) >= 0.0) ? ps_r0.w : ps_r0.z);
			ps_r0.w = -ps_c1.z + ps_c1.w;
			ps_r0.w = 1.0 / ps_r0.w;
			ps_r3.y = ps_c1.w + -ps_v1.x;
			ps_r0.w = ps_r0.w * ps_r3.y;
			ps_r0.z = ((-abs(ps_r3.x) >= 0.0) ? ps_r0.w : ps_r0.z);
			ps_r0.w = clamp(ps_r0.z, 0.0, 1.0);
			ps_r0.y = ((-ps_r0.y >= 0.0) ? ps_r0.z : ps_r0.w);
			ps_r0.z = -ps_r0.y + ps_c4.z;
			ps_r0.yzw = (ps_r0.yyy * ps_r1.xyz) + ps_r0.zzz;
			ps_r3.xyz = ps_r0.yzw * ps_c2.xyz;
			ps_r3.w = ps_c4.z;
		} else {
			ps_r3 = ps_c4.yyyy;
		}
		ps_r4 = (ps_r1.xyzx * ps_c4.zzzy) + ps_c4.yyyz;
		ps_r2 = ((-ps_c1.x >= 0.0) ? ps_r4 : ps_r3);
	}
	ps_oC0 = ((ps_r0.x >= 0.0) ? ps_r2 : ps_r1);
}

The original HLSL shader can be found here. I tried to [change few things] and now it works (https://github.com/demonixis/C3DE/blob/develop/C3DE.Demo/Content/Shaders/SkyboxEffect.fx).

How to reproduce

• Clone the develop branch of C3DE from github
• Open the C3DE.Desktop solution
• Open C3DE.Demos/Content/Shaders/SkyboxEffect.fx and force FOG_ENABLED to True
• Start the samples and launch the VR demo (don't worry VR is disabled if you don't have a connected compatible headset).
• I recommand you to change references to use the sources of MonoGame.

Thank you.

[slick1015]

Any update on this? Encountering the same issue.

[cpt-max]

Which version of MG are you using? There's some chance that #7340 fixes this problem. The shader will probably still fail to compile, but the crash should not happen, and you should get some message why compilation failed.