Shader.java

/* This code is from exercise sheet written by Dr. Steve Maddock */

import gmaths.*;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.charset.Charset;

import com.jogamp.opengl.*;
import com.jogamp.opengl.util.glsl.*;

public class Shader {

    private static final boolean DISPLAY_SHADERS = false;

    private int ID;
    private String vertexShaderSource;
    private String fragmentShaderSource;

    /* The constructor */
    public Shader(GL3 gl3, String vertexPath, String fragmentPath) {
        try {
            vertexShaderSource = new String(Files.readAllBytes(Paths.get(vertexPath)), Charset.defaultCharset());
            fragmentShaderSource = new String(Files.readAllBytes(Paths.get(fragmentPath)), Charset.defaultCharset());
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (DISPLAY_SHADERS) display();
        ID = compileAndLink(gl3);
    }

    public int getID() {
        return ID;
    }

    public void use(GL3 gl3) {
        gl3.glUseProgram(ID);
    }

    public void setInt(GL3 gl3, String name, int value) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniform1i(location, value);
    }

    public void setFloat(GL3 gl3, String name, float value) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniform1f(location, value);
    }

    public void setFloat(GL3 gl3, String name, float f1, float f2) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniform2f(location, f1, f2);
    }

    public void setFloat(GL3 gl3, String name, float f1, float f2, float f3) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniform3f(location, f1, f2, f3);
    }

    public void setFloat(GL3 gl, String name, float f1, float f2, float f3, float f4) {
        int location = gl.glGetUniformLocation(ID, name);
        gl.glUniform4f(location, f1, f2, f3, f4);
    }

    public void setFloatArray(GL3 gl3, String name, float[] f) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniformMatrix4fv(location, 1, false, f, 0);
    }

    public void setVec3(GL3 gl3, String name, Vec3 v) {
        int location = gl3.glGetUniformLocation(ID, name);
        gl3.glUniform3f(location, v.x, v.y, v.z);
    }

    private void display() {
        System.out.println("***Vertex shader***");
        System.out.println(vertexShaderSource);
        System.out.println("\n***Fragment shader***");
        System.out.println(fragmentShaderSource);
    }

    private int compileAndLink(GL3 gl3) {
        String[][] sources = new String[1][1];
        sources[0] = new String[]{vertexShaderSource};
        ShaderCode vertexShaderCode = new ShaderCode(GL3.GL_VERTEX_SHADER, sources.length, sources);
        boolean compiled = vertexShaderCode.compile(gl3, System.err);
        if (!compiled)
            System.err.println("[error] Unable to compile vertex shader: " + sources[0][0]);
        sources[0] = new String[]{fragmentShaderSource};
        ShaderCode fragmentShaderCode = new ShaderCode(GL3.GL_FRAGMENT_SHADER, sources.length, sources);
        compiled = fragmentShaderCode.compile(gl3, System.err);
        if (!compiled)
            System.err.println("[error] Unable to compile fragment shader: " + sources[0][0]);
        ShaderProgram program = new ShaderProgram();
        program.init(gl3);
        program.add(vertexShaderCode);
        program.add(fragmentShaderCode);
        program.link(gl3, System.out);
        if (!program.validateProgram(gl3, System.out))
            System.err.println("[error] Unable to link program");
        return program.program();
    }

}