Processing multiple light pixel Shader in GLSL - opengl

Question

i have written a fragment shader that works just fine with a single light. Now I am trying to adapt it to work with 8 lights, the implement it in Processing. Clearly I am doing something wrong in the math and I cannot see what it is... I have read other posts about this and try to adapt the answer to my problem, no luck though...
////Fragment/////
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
varying vec4 vertColor;
varying vec3 ecNormal;
varying vec3 lightDir;
void main() {
vec3 direction = normalize(lightDir);
vec3 normal = normalize(ecNormal);
float intensity = max(0.0, dot(direction, normal));
gl_FragColor = vec4(intensity, intensity, intensity, 1) * vertColor;
}
////vertex/////
#define PROCESSING_LIGHT_SHADER
uniform mat4 modelview;
uniform mat4 transform;
uniform mat3 normalMatrix;
uniform vec4 lightPosition;
uniform vec3 lightNormal;
attribute vec4 vertex;
attribute vec4 color;
attribute vec3 normal;
varying vec4 vertColor;
varying vec3 ecNormal;
varying vec3 lightDir;
void main() {
gl_Position = transform * vertex;
vec3 ecVertex = vec3(modelview * vertex);
ecNormal = normalize(normalMatrix * normal);
lightDir = normalize(lightPosition.xyz - ecVertex);
vertColor = color;
}

Answer 1

Just making it compile real quick with an online shader tool (http://shdr.bkcore.com/).
You might need to pass the attributes from the veretex shader to varyings for the fragment shader, but I'm not sure, been a while since I wrote shaders.
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
uniform mat4 modelview;
uniform mat4 normalMatrix;
uniform int lightCount;
uniform vec4 lightPosition[8];
varying vec4 vertex; //was attribute, no such thing in frag shaders
varying vec3 normal; //was attribute
varying vec4 vertColor;
void main() {
vec3 vertexCamera = vec3(modelview * vertex);
vec3 transformedNormal = normalize(normalMatrix * vec4(normal,1)).xyz; //was vec3 = normalize(mat4*vec3);
float intensity = 0.0;
for(int i = 0 ; i<8;i++){ //can't loop over a non-constant variable
if(lightCount<i)
{
vec3 direction = normalize(lightPosition[i].xyz - vertexCamera);
intensity += max(0.0, dot(direction, transformedNormal));
}
}
gl_FragColor = vec4(intensity, intensity, intensity, 1) * vertColor;
}