LightingHandler Gitch

LightingHandler Render:

public void render() {
        TextureUtil.disableTextures();
        for (Light light : lights) {
            glColorMask(false, false, false, false);
            glStencilFunc(GL_ALWAYS, 1, 1);
            glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);

            for (Mesh object : objects) {
                if(object.shaded){
                    Vector2f[] vertices = object.getVertices();
                    for (int i = 0; i < vertices.length; i++) {
                        Vector2f currentVertex = vertices[i];
                        Vector2f nextVertex = vertices[(i + 1) % vertices.length];
                        Vector2f edge = Vector2f.sub(nextVertex, currentVertex, null);
                        Vector2f normal = new Vector2f(edge.getY(), -edge.getX());
                        Vector2f lightToCurrent = Vector2f.sub(currentVertex, light.location, null);
                        if (Vector2f.dot(normal, lightToCurrent) > 0) {
                            Vector2f point1 = Vector2f.add(currentVertex, (Vector2f) Vector2f.sub(currentVertex, light.location, null).scale(800), null);
                            Vector2f point2 = Vector2f.add(nextVertex, (Vector2f) Vector2f.sub(nextVertex, light.location, null).scale(800), null);
                            glBegin(GL_QUADS); {
                                glVertex2f(currentVertex.getX(), currentVertex.getY());
                                glVertex2f(point1.getX(), point1.getY());
                                glVertex2f(point2.getX(), point2.getY());
                                glVertex2f(nextVertex.getX(), nextVertex.getY());
                            } glEnd();
                        }
                    }
                }
            }

            glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
            glStencilFunc(GL_EQUAL, 0, 1);
            glColorMask(true, true, true, true);

            glUseProgram(shaderProgram);
            glUniform2f(glGetUniformLocation(shaderProgram, "lightLocation"), light.location.getX(), Display.getHeight() - light.location.getY());
            glUniform3f(glGetUniformLocation(shaderProgram, "lightColor"), light.red, light.green, light.blue);

            glEnable(GL_BLEND);
            glBlendFunc(GL_ONE, GL_ONE);

            GL11.glColor4f(0, 0, 0, 0);

            glBegin(GL_QUADS); {
                glVertex2f(0, 0);
                glVertex2f(0, Display.getHeight());
                glVertex2f(Display.getWidth(), Display.getHeight());
                glVertex2f(Display.getWidth(), 0);
            } glEnd();

            glDisable(GL_BLEND);
            glUseProgram(0);
            glClear(GL_STENCIL_BUFFER_BIT);
        }

        for (Mesh mesh : objects) {
            glBegin(GL_QUADS); {
                for (Vector2f vertex : mesh.getVertices()) {
                    glVertex2f(vertex.getX(), vertex.getY());
                }
            } glEnd();
        }
    }


LightingHandler init:

public void init() {
        shaderProgram = glCreateProgram();
        fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        StringBuilder fragmentShaderSource = new StringBuilder();

        try {
            String line;
            BufferedReader reader = new BufferedReader(new FileReader("project-assets/shaders/shader.fs"));
            while ((line = reader.readLine()) != null) {
                fragmentShaderSource.append(line).append("\n");
            }
            reader.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        glShaderSource(fragmentShader, fragmentShaderSource);
        glCompileShader(fragmentShader);
        if (glGetShaderi(fragmentShader, GL_COMPILE_STATUS) == GL_FALSE) {
            System.err.println("Fragment shader not compiled!");
            System.err.println(GLU.gluErrorString(glGetError()));
        }

        glAttachShader(shaderProgram, fragmentShader);
        glLinkProgram(shaderProgram);
        glValidateProgram(shaderProgram);
    }

Shader.fs:

uniform vec2 lightLocation;
uniform vec3 lightColor;
uniform float screenHeight;

void main() {
    float distance = length(lightLocation - gl_FragCoord.xy);
    float attenuation = 1.0 / distance;
    vec4 color = vec4(attenuation, attenuation, attenuation, pow(attenuation, 3)) * vec4(lightColor, 1);

    gl_FragColor = color;
}