JOGL - 统一int变量和for循环导致着色器链接错误

Question

我有一个混合了多个纹理的着色器。我发送纹理数作为统一的int变量。当我遍历纹理（在条件中使用此变量）时，着色器链接失败，但是当我放置确切数量的纹理时，一切正常

 //this works

if(numberOfTextures==2) { //checking if this var really contains 2 - true

    for(int i=0;i<2;i++) {
            texturesBlend += texture2D(gSamplers[i], TexCoord0.xy);
    }
    texturesBlend /= numberOfTextures;
}

//this does not work
if(numberOfTextures==2) {

    for(int i=0;i<numberOfTextures;i++) { //variable in condition - this causes linking error
            texturesBlend += texture2D(gSamplers[i], TexCoord0.xy);
    }
    texturesBlend /= numberOfTextures;
}

这个问题可能是什么原因？如果我可以检查变量的值是什么，为什么我不能在条件中使用它？

EDIT 完整着色器源

#version 150
const int MAX_TEXTURES = 6;

in vec2 TexCoord0;
in vec3 Normal0;

out vec4 FragColor;

struct DirectionalLight
{
    vec3 Color;
    float AmbientIntensity;
    float DiffuseIntensity;
    vec3 Direction;
};

uniform DirectionalLight gDirectionalLight;
uniform int numberOfTextures;
uniform sampler2D gSamplers[MAX_TEXTURES];

void main()
{
    vec4 AmbientColor = vec4(gDirectionalLight.Color, 1.0f) *
                        gDirectionalLight.AmbientIntensity;

    float DiffuseFactor = dot(normalize(Normal0), -gDirectionalLight.Direction);

    vec4 DiffuseColor;

    if (DiffuseFactor > 0) {
        DiffuseColor = vec4(gDirectionalLight.Color, 1.0f) *
                       gDirectionalLight.DiffuseIntensity *
                       DiffuseFactor;
    }
    else {
        DiffuseColor = vec4(0, 0, 0, 0);
    }

    vec4 texturesBlend = vec4(0.0, 0.0, 0.0, 0.0);

int N = 1;

if(numberOfTextures<=2) {

    for(int i=0;;i++) {
        if(i==numberOfTextures)
            break;
        texturesBlend += texture2D(gSamplers[i], TexCoord0.xy);
    }
    texturesBlend /= numberOfTextures;
}
    FragColor = texturesBlend * (AmbientColor + DiffuseColor);
};