ShaderLoader.java

package com.maceswinger.utils;




import static org.lwjgl.opengl.GL11.GL_FALSE;
import static org.lwjgl.opengl.GL20.GL_COMPILE_STATUS;
import static org.lwjgl.opengl.GL20.GL_FRAGMENT_SHADER;
import static org.lwjgl.opengl.GL20.GL_LINK_STATUS;
import static org.lwjgl.opengl.GL20.GL_VERTEX_SHADER;
import static org.lwjgl.opengl.GL20.glAttachShader;
import static org.lwjgl.opengl.GL20.glCompileShader;
import static org.lwjgl.opengl.GL20.glCreateProgram;
import static org.lwjgl.opengl.GL20.glCreateShader;
import static org.lwjgl.opengl.GL20.glDeleteShader;
import static org.lwjgl.opengl.GL20.glGetProgramInfoLog;
import static org.lwjgl.opengl.GL20.glGetProgrami;
import static org.lwjgl.opengl.GL20.glGetShaderInfoLog;
import static org.lwjgl.opengl.GL20.glGetShaderi;
import static org.lwjgl.opengl.GL20.glLinkProgram;
import static org.lwjgl.opengl.GL20.glShaderSource;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;


public class ShaderLoader {
    
    public static int loadShaderPair(String vertexShaderLocation, String fragmentShaderLocation) {
        int shaderProgram = glCreateProgram();
        int vertexShader = glCreateShader(GL_VERTEX_SHADER);
        int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        StringBuilder vertexShaderSource = new StringBuilder();
        StringBuilder fragmentShaderSource = new StringBuilder();
        BufferedReader vertexShaderFileReader = null;
        try {
            vertexShaderFileReader = new BufferedReader(new FileReader(
                    vertexShaderLocation));
            String line;
            while ((line = vertexShaderFileReader.readLine()) != null) {
                vertexShaderSource.append(line).append('\n');
            }
        } catch (IOException e) {
            e.printStackTrace();
            return -1;
        } finally {
            if (vertexShaderFileReader != null) {
                try {
                    vertexShaderFileReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        BufferedReader fragmentShaderFileReader = null;
        try {
            fragmentShaderFileReader = new BufferedReader(new FileReader(
                    fragmentShaderLocation));
            String line;
            while ((line = fragmentShaderFileReader.readLine()) != null) {
                fragmentShaderSource.append(line).append('\n');
            }
        } catch (IOException e) {
            e.printStackTrace();
            return -1;
        } finally {
            if (fragmentShaderFileReader != null) {
                try {
                    fragmentShaderFileReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        glShaderSource(vertexShader, vertexShaderSource);
        glCompileShader(vertexShader);
        if (glGetShaderi(vertexShader, GL_COMPILE_STATUS) == GL_FALSE) {
            System.err
                    .println("Vertex shader wasn't able to be compiled correctly. Error log:");
            System.err.println(glGetShaderInfoLog(vertexShader, 1024));
            return -1;
        }
        glShaderSource(fragmentShader, fragmentShaderSource);
        glCompileShader(fragmentShader);
        if (glGetShaderi(fragmentShader, GL_COMPILE_STATUS) == GL_FALSE) {
            System.err
                    .println("Fragment shader wasn't able to be compiled correctly. Error log:");
            System.err.println(glGetShaderInfoLog(fragmentShader, 1024));
        }
        glAttachShader(shaderProgram, vertexShader);
        glAttachShader(shaderProgram, fragmentShader);
        glLinkProgram(shaderProgram);
        if (glGetProgrami(shaderProgram, GL_LINK_STATUS) == GL_FALSE) {
            System.err.println("Shader program wasn't linked correctly.");
            System.err.println(glGetProgramInfoLog(shaderProgram, 1024));
            return -1;
        }
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);
        return shaderProgram;
    }
}