game.map.Shader.java Source code

Introduction

Here is the source code for game.map.Shader.java

Source

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package game.map;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import org.lwjgl.opengl.ARBFragmentShader;
import org.lwjgl.opengl.ARBShaderObjects;
import org.lwjgl.opengl.ARBVertexShader;
import org.lwjgl.opengl.GL11;

/**
 *
 * @author rplu1618
 */
public class Shader {
    public boolean useShader;
    public int program = 0;

    public Shader() {
        int vertShader = 0, fragShader = 0;

        try {
            vertShader = createShader("src/Terrain/shaders/screen.vert", ARBVertexShader.GL_VERTEX_SHADER_ARB);
            fragShader = createShader("src/Terrain/shaders/screen.frag", ARBFragmentShader.GL_FRAGMENT_SHADER_ARB);
        } catch (Exception exc) {
            exc.printStackTrace();
            return;
        } finally {
            if (vertShader == 0 || fragShader == 0)
                return;
        }

        program = ARBShaderObjects.glCreateProgramObjectARB();

        if (program == 0)
            return;

        /*
        * if the vertex and fragment shaders setup sucessfully,
        * attach them to the shader program, link the sahder program
        * (into the GL context I suppose), and validate
        */
        ARBShaderObjects.glAttachObjectARB(program, vertShader);
        ARBShaderObjects.glAttachObjectARB(program, fragShader);

        ARBShaderObjects.glLinkProgramARB(program);
        if (ARBShaderObjects.glGetObjectParameteriARB(program,
                ARBShaderObjects.GL_OBJECT_LINK_STATUS_ARB) == GL11.GL_FALSE) {
            System.err.println(getLogInfo(program));
            return;
        }

        ARBShaderObjects.glValidateProgramARB(program);
        if (ARBShaderObjects.glGetObjectParameteriARB(program,
                ARBShaderObjects.GL_OBJECT_VALIDATE_STATUS_ARB) == GL11.GL_FALSE) {
            System.err.println(getLogInfo(program));
            return;
        }

        useShader = true;
    }

    private int createShader(String filename, int shaderType) throws Exception {
        int shader = 0;
        try {
            shader = ARBShaderObjects.glCreateShaderObjectARB(shaderType);

            if (shader == 0)
                return 0;

            ARBShaderObjects.glShaderSourceARB(shader, readFileAsString(filename));
            ARBShaderObjects.glCompileShaderARB(shader);

            if (ARBShaderObjects.glGetObjectParameteriARB(shader,
                    ARBShaderObjects.GL_OBJECT_COMPILE_STATUS_ARB) == GL11.GL_FALSE)
                throw new RuntimeException("Error creating shader: " + getLogInfo(shader));

            return shader;
        } catch (Exception exc) {
            ARBShaderObjects.glDeleteObjectARB(shader);
            throw exc;
        }
    }

    private static String getLogInfo(int obj) {
        return ARBShaderObjects.glGetInfoLogARB(obj,
                ARBShaderObjects.glGetObjectParameteriARB(obj, ARBShaderObjects.GL_OBJECT_INFO_LOG_LENGTH_ARB));
    }

    private String readFileAsString(String filename) throws Exception {
        StringBuilder source = new StringBuilder();

        FileInputStream in = new FileInputStream(filename);

        Exception exception = null;

        BufferedReader reader;
        try {
            reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));

            Exception innerExc = null;
            try {
                String line;
                while ((line = reader.readLine()) != null)
                    source.append(line).append('\n');
            } catch (Exception exc) {
                exception = exc;
            } finally {
                try {
                    reader.close();
                } catch (Exception exc) {
                    if (innerExc == null)
                        innerExc = exc;
                    else
                        exc.printStackTrace();
                }
            }

            if (innerExc != null)
                throw innerExc;
        } catch (Exception exc) {
            exception = exc;
        } finally {
            try {
                in.close();
            } catch (Exception exc) {
                if (exception == null)
                    exception = exc;
                else
                    exc.printStackTrace();
            }

            if (exception != null)
                throw exception;
        }

        return source.toString();
    }
}