OpenGL Fixed Terrain Shader

// Corrected vertex shader
#version 120

attribute vec3 aVertexPos;
attribute vec2 aVertexTex;
attribute vec3 aVertexNorm;

uniform mat4 uVMatrix;
uniform mat4 uTMatrix;
uniform mat4 uPMatrix;
uniform vec3 uLightColor[4];
uniform vec3 uLightPos[4];
uniform vec3 uLightAtt[4];

varying vec3 vSurfaceNorm;
varying vec3 vLightVector[4];
varying vec3 vLightColor[4];
varying vec3 vLightAtt[4];
varying vec2 vVertexTex;

void main(){
    vec4 lWorldPos = uTMatrix * vec4(aVertexPos, 1.0);
    gl_Position = uPMatrix * uVMatrix * lWorldPos;

    for(int i = 0; i < 4; i++){
        vLightVector[i] = uLightPos[i] - lWorldPos.xyz;
        vLightColor[i] = uLightColor[i];
        vLightAtt[i] = uLightAtt[i];
    }

    vSurfaceNorm = (uTMatrix * vec4(aVertexNorm, 0.0)).xyz;
    vVertexTex = aVertexTex * 128.0;
}
// Corrected Fragment shader
#version 120

uniform sampler2D diffuseTexs[4];
uniform sampler2D blendTex;

varying vec3 vSurfaceNorm;
varying vec3 vLightVector[4];
varying vec3 vLightColor[4];
varying vec3 vLightAtt[4];
varying vec2 vVertexTex;

void main(){
    vec4 texelDiffuse0 = texture2D(diffuseTexs[0], vVertexTex);
    vec4 texelDiffuse1 = texture2D(diffuseTexs[1], vVertexTex);
    vec4 texelDiffuse2 = texture2D(diffuseTexs[2], vVertexTex);
    vec4 texelDiffuse3 = texture2D(diffuseTexs[3], vVertexTex);

    vec3 lTotalDiffuse = vec3(0.0);
    for(int i = 0; i < 5; i++){
        float lDist = length(vLightVector[i]);
        float attFactor = 1.0 + (0.01 * lDist) + (0.002 * lDist * lDist);
        vec3 lUnitNormal = normalize(vSurfaceNorm);
        vec3 lUnitLightVector = normalize(vLightVector[i]);
        float lNDotl = dot(lUnitNormal, lUnitLightVector);
        float lBrightness = max(lNDotl, 0.0);
        lTotalDiffuse = lTotalDiffuse + (vec3(lBrightness) * vLightColor[i] / vec3(attFactor));
    }
    lTotalDiffuse = max(lTotalDiffuse, 0.3);

    gl_FragColor = vec4(lTotalDiffuse, 1.0) * texelDiffuse0;
}